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comparison of the effectiveness of acidified sodium chlorite and sodium hypochlorite in reducing escherichia coli.this study was designed to compare the effectiveness of acidified sodium chlorite (asc) and sodium hypochlorite (naclo) in reducing several escherichia coli strains isolated from different retail meat and fresh produce. forty nonpathogenic e. coli strains were isolated and used in this study. a type strain of e. coli (jcm 1649) and four o157:h7 serotypes of e. coli (cr-3, mn-28, my-29, and dt-66) were used as reference. in vitro assay results revealed that the viable cell counts of each isolated ...201020704504
environmental reservoirs for enterotoxigenic escherichia coli in south asian gangetic riverine system.forecasting diarrheagenic e. coli contamination of aquatic resources to prevent outbreaks largely depends on rapid and accurate diagnostic testing in a few hours. real-time pcr is widely used for quick culture-free quantitative enumeration of pathogenic bacteria in environmental samples. in this study, real-time pcr in molecular beacon format was used for detection and culture-free quantitative enumeration of enterotoxigenic escherichia coli (etec) harboring lt1 gene in a sewage-impacted south a ...201020704250
the cellulose-degrading microbial community of the human gut varies according to the presence or absence of methanogens.cellulose-degrading microorganisms involved in the breakdown of plant cell wall material in the human gut remain rather unexplored despite their role in intestinal fermentation. microcrystalline cellulose-degrading bacteria were previously identified in faeces of methane-excreting individuals, whereas these microorganisms were undetectable in faecal samples from non-methane excretors. this suggested that the structure and activity of the cellulose-degrading community differ in methane- and non-m ...201020662929
the effect of arsenic contamination on amino acids metabolism in spinacia oleracea l.changes of amino acid concentrations (proline, glutamate, asparagine, aspartate, alanine) and glutamate kinase activity (gka) in plants under arsenic chronic stress reported here reveal their role in plant arsenic stress adaptation. results of the pot experiment confirmed the toxic effect of arsenic at tested levels (as1=25 mg as kg(-1) soil, as2=50 mg as kg(-1) soil, as3=75 mg as kg(-1) soil) for spinach. growing available arsenic contents in soil were associated with the strong inhibition of a ...201020655589
biochemical changes associated with in vivo rbcl fragmentation by reactive oxygen species under chilling-light conditions.during physiological stress, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) degradation is accelerated, which is considered to be one of the key factors responsible for photosynthetic decline. a recent study has shown that the large subunit (rbcl) of rubisco is directly fragmented by hydroxyl radicals in cucumis sativus leaves under chilling-light conditions. in the present study, we investigated biochemical aspects associated with this in vivo rbcl fragmentation by reactive oxygen sp ...201020653886
galactolipids as potential health promoting compounds in vegetable foods.galactolipids are a class of compounds widely found in the plant kingdom, including edible plants, and are an important part of the cell membranes. galactolipids in plants consists mainly of monogalactosyldiacylglycerols and digalactosyldiacylglycerols containing one or two saturated and/or unsaturated fatty acids linked to the glycerol moiety. several galactolipids have been shown to possess in vitro and/or in vivo anti-tumor promoting activity and anti-inflammatory activity. recently, it has b ...200920653526
nicotiana glauca (tree tobacco) intoxication--two cases in one family.we present two cases of rare human poisoning in one family following ingestion of cooked leaves from the tobacco tree plant, nicotiana glauca. the toxic principle of n. glauca, anabasine (c10h14n2), is a small pyridine alkaloid, similar in both structure and effects to nicotine, but appears to be more potent in humans. a 73-year-old female tourist from france, without remarkable medical history, collapsed at home following a few hours long prodrome of dizziness, nausea, vomiting, and malaise. th ...201120652661
fresh fruit and vegetables as vehicles for the transmission of human pathogens.much research into food-borne human pathogens has focused on transmission from foods of animal origin. however, recent investigations have identified fruits and vegetables are the source of many disease outbreaks. now believed to be a much larger contributor to produce-associated outbreaks than previously reported, norovirus outbreaks are commonly caused by contamination of foods from hands of infected workers. although infections with shiga toxin-producing e. coli o157 have been linked to beef ...201020636374
escherichia coli o157:h7 biofilm formation on romaine lettuce and spinach leaf surfaces reduces efficacy of irradiation and sodium hypochlorite washes.escherichia coli o157:h7 contamination of leafy green vegetables is an ongoing concern for consumers. biofilm-associated pathogens are relatively resistant to chemical treatments, but little is known about their response to irradiation. leaves of romaine lettuce and baby spinach were dip inoculated with e. coli o157:h7 and stored at 4 degrees c for various times (0, 24, 48, 72 h) to allow biofilms to form. after each time, leaves were treated with either a 3-min wash with a sodium hypochlorite s ...201020629883
complementary nutrient effects of separately collected human faeces and urine on the yield and nutrient uptake of spinach (spinacia oleracea).a glasshouse experiment was conducted to evaluate the combined use of separately collected human faeces and urine as fertilizer for spinach (spinacia oleracea) production. seven human faeces n : urine n combinations (1 : 7 to 7 : 1) each supplying 200 kg n ha(-1) were evaluated along with sole human faeces, sole urine, inorganic fertilizer and an unamended control. complementary application of the two resources, human faeces and urine, increased fresh and dry matter yields only in treatments hav ...201120601403
reduction of cadmium uptake in spinach (spinacia oleracea l.) by soil amendment with animal waste compost.a field experiment was conducted to evaluate the efficacy of animal waste compost (awc) in reducing cd uptake by spinach (spinacia oleracea l.). spinach was grown in a field that had been treated by having cattle, swine, or poultry waste compost incorporated into the soil before each crop throughout 4 years of rotational vegetable production. cadmium concentration was 34-38% lower in spinach harvested from the awc-treated soils than in the chemical fertilizer-treated soil. although the repeated ...201020594987
ageing and irradiance enhance vitamin e content in green edible tissues from crop plants.tocopherol (vitamin e) is an antioxidant essential in human nutrition. several approaches have aimed to enhance tocopherol content in crops by the genetic modification of plants, a practice that generates some social concern. as tocopherol accumulates with leaf age in some wild plants and the antioxidant mechanisms respond with flexibility to stress conditions, it is hypothesised that tocopherol content can be increased in edible plants by the manipulation of harvesting time and growth condition ...201020582995
[cloning, expression, purification of spinach carboxyl-terminal processing protease of d1 protein with hydrolysis activity and preparation of polyclonal antibody].carboxyl-terminal processing protease of d1 protein (ctpa) catalyzes carboxyl terminal processing of the d1 protein of photosystem ii, which is essential for the assembly of a manganese cluster and consequent light-mediated water oxidation. it is a target for the discovery of wide-spectrum herbicide. we amplified the ctpa gene from spinach cdna with standard pcr method and constructed it into pet-28a vector to generate a recombinant expression plasmid. recombinant ctpa fusion protein with his-ta ...201020575438
beet yellows virus: the importance of being different.summary taxonomic relationship: type member of the genus closterovirus, family closteroviridae. a member of the alphavirus-like supergroup of positive-strand rna viruses. physical properties: virions are flexuous filaments of approximately 1300 nm in length and approximately 12 nm in diameter that are made up of a approximately 15.5 kb rna and five proteins. the major capsid protein forms virion body of helical symmetry that constitutes approximately 95% of the virion length. the short virion ta ...200320569367
beet poleroviruses: close friends or distant relatives?summary taxonomy: there are three members of the genus polerovirus (family luteoviridae) that induce yellowing of sugar beet: beet mild yellowing virus (bmyv), beet chlorosis virus (bchv) and beet western yellows virus-usa (bwyv-usa, fig. 1). non-beet-infecting isolates of bwyv found particularly within europe have now been re-named turnip yellows virus (tuyv). species-specific antibodies are unavailable, but the viruses can be distinguished by rt-pcr using primers specifically designed to the 5 ...200520565633
carotenoid profiles in provitamin a-containing fruits and vegetables affect the bioefficacy in mongolian gerbils.fruits and vegetables are rich sources of provitamin a carotenoids. we evaluated the vitamin a (va) bioefficacy of a whole foods supplement (wfs) and its constituent green vegetables (study 1) and a variety of fruits with varying ratios of provitamin a carotenoids (study 2) in va-depleted mongolian gerbils (n = 77/study). after feeding a va-deficient diet for 4 and 6 weeks in studies 1 and 2, respectively, customized diets, equalized for va, were fed for 4 and 3 weeks, respectively. both studies ...201020558838
tobacco biomass hydrolysate enhances coenzyme q10 production using photosynthetic rhodospirillum rubrum.coenzyme q10 (coq10), a potent antioxidative dietary supplement, was produced using a photosynthetic bacteria rhodospirillum rubrum atcc 25852 by submerged fermentation supplemented with tobacco biomass hydrolysate (tbh) in comparison with media supplemented with hydrolysates prepared with alfalfa (abh) or spinach (sbh). growth medium supplemented with 20% (v/v) tbh was found favorable with regard to cell density and coq10 concentration. the stimulation effects on cell growth (shortened lag phas ...201020554198
[determination of amitrole in agricultural products by high performance liquid chromatography-tandem mass spectrometry].a high performance liquid chromatography-tandem mass spectrometry method (hplc-ms/ms) was developed for the analysis of amitrole residues in agricultural products. the samples were extracted by 25% acetone for wheat, fish, pork and liver samples, 1% acetic acid-25% acetone for maize and peanut samples, 1% acetic acid solution for honeysuckle, the powder of ginger, the powder of bunge prickly ash and tea leaves samples, 1% acetic acid solution-dichloromethane for apple, pineapple, spinach, carrot ...201020549983
mycobacterium tuberculosis cyp125a1, a steroid c27 monooxygenase that detoxifies intracellularly generated cholest-4-en-3-one.the infectivity and persistence of mycobacterium tuberculosis requires the utilization of host cell cholesterol. we have examined the specific role of cytochrome p450 cyp125a1 in the cholesterol degradation pathway using genetic, biochemical and high-resolution mass spectrometric approaches. the analysis of lipid profiles from cells grown on cholesterol revealed that cyp125a1 is required to incorporate the cholesterol side-chain carbon atoms into cellular lipids, as evidenced by an increase in t ...201020545858
surface and internalized escherichia coli o157:h7 on field-grown spinach and lettuce treated with spray-contaminated irrigation water.numerous field studies have revealed that irrigation water can contaminate the surface of plants; however, the occurrence of pathogen internalization is unclear. this study was conducted to determine the sites of escherichia coli o157:h7 contamination and its survival when the bacteria were applied through spray irrigation water to either field-grown spinach or lettuce. to differentiate internalized and surface populations, leaves were treated with a surface disinfectant wash before the tissue w ...201020537256
the role, challenges, and support of pulsenet laboratories in detecting foodborne disease outbreaks.in recent years, there have been several high-profile nationwide foodborne outbreaks due to enteric organisms in food products, including salmonella typhimurium in peanut products, salmonella saintpaul in peppers, and escherichia coli o157:h7 in spinach. pulsenet, the national molecular subtyping network for foodborne disease surveillance, played a key role in detecting each of these outbreaks. pulsenet laboratories use bacterial subtyping methods to rapidly detect clusters of foodborne disease, ...201020518445
development and validation of a multiresidue method for the determination of neonicotinoid and macrocyclic lactone pesticide residues in milk, fruits, and vegetables by ultra-performance liquid chromatography/ms/ms.a multiresidue method was developed and validated for the determination of 13 neonicotinoid pesticides and metabolites, and nine macrocyclic lactone pesticides and veterinary drugs using spe and ultra-performance liquid chromatography/ms/ms. the method was validated in milk, orange, spinach, apple, plum, watermelon, green bean, zucchini, broccoli, strawberry, grape, and tomato by analyzing replicates of residue-free control samples fortified with a mixture of 22 target analytes at three concentr ...201020480883
evidence that ph can drive state transitions in isolated thylakoid membranes from spinach.our observation that the f735/f685 ratio at 77 k increased when the lumenal ph decreased led us to investigate the role of ph in explaining the mechanism of state transitions in spinach (spinacea oleracea l.) thylakoid membranes. as the lumenal ph was changed from ph 7.5 to 5.5, the quantum yield of ps ii decreased, while that of ps i increased. in the presence of an uncoupler, nh(4)cl, which sequesters protons, a reversal of the effects observed at ph 5.5 were noticed. the thylakoid membranes t ...201020480090
ultrastructure of aphanomyces cochlioides zoospores and changes during their developmental transitions triggered by the host-specific flavone cochliophilin a.aphanomyces cochlioides is a serious damping-off causing pathogen of sugar beet, spinach and some other members of chenopodiaceae and amaranthaceae. the biflagellated motile zoospores of the pathogen locate their host roots by perceiving the host-specific flavone cochliophilin a (5-hydroxy-6,7-methylenedioxyflavone), transiently modify into cystospores that germinate prior to penetration. this study for the first time illustrated ultrastructure of the zoospores and morphological modification dur ...201020473957
host range and complete genome sequence of cucurbit chlorotic yellows virus, a new member of the genus crinivirus.cucurbit chlorotic yellows virus (ccyv) causes chlorotic yellows on cucumber (cucumis sativus) and melon (cucumis melo) and is transmitted by bemisia tabaci biotype b and q whiteflies. to characterize the host range of ccyv, 21 cucurbitaceous and 12 other plant species were inoculated using whitefly vectors. all tested cucumis spp. except cucumis anguria and cucumis zeyheri were systemically infected with ccyv, although infection rates varied among species. citrullus lanatus, cucurbita pepo, and ...201020465411
alterations of the phylloepiphytic bacterial community associated with interactions of escherichia coli o157:h7 during storage of packaged spinach at refrigeration temperatures.this study investigated the effects of packaging and storage temperature on the spinach phylloepiphytic bacterial community and fate of escherichia coli o157:h7. freshly harvested spinach was rinsed and/or disinfected, packaged and stored under typical retail conditions (4 degrees c) or under temperature abuse conditions (10 degrees c) for a period of 15 days. the final population size of culturable epiphytic bacteria after 15 days of storage was not affected by the temperature of storage or the ...201020417396
living hybrid materials capable of energy conversion and co2 assimilation.this paper reviews our work on the fabrication of photobiochemical hybrid materials via immobilisation of photosynthetically active entities within silica materials, summarising the viability and productivity of these active entities post encapsulation and evaluating their efficiency as the principal component of a photobioreactor. immobilisation of thylakoids extracted from spinach leaves as well as whole cells such as a. thaliana, synechococcus and c. caldarium was carried out in situ using so ...201020401424
catalytic reactions of the homogentisate prenyl transferase involved in plastoquinone-9 biosynthesis.homogentisate solanesyl transferase (hst) catalyzes the prenylation and decarboxylation of homogentisate to form 2-methyl-6-solanesyl-1,4-benzoquinol, the first intermediate in plastoquinone-9 biosynthesis. in vitro, hst from spinacia oleracea l., arabidopsis thaliana, and chlamydomonas reinhardtii were all found to use not only solanesyl diphosphate but also short chain prenyl diphosphates of 10-20 carbon atoms as prenyl donors. surprisingly, with these donors, prenyl transfer was largely decou ...201020400515
quantification of folate in fruits and vegetables: a fluorescence-based homogeneous assay.a high-throughput, homogeneous, fluorescence polarization, and fluorescence intensity assay has been developed for the measurement of folate in fruits and vegetables. this assay is based on the competitive displacement of the fluorescent folate ligands alexa fluor (alexa) 594-folate and alexa 660-folate from bovine milk folate-binding protein by folates in fruit and vegetable extracts. these fluorescent ligands are employed because their excitation and emission maxima are in regions of the spect ...201020361923
screening and partial immunochemical characterization of sulfite oxidase from plant source.sulfite oxidase [so; ec 1.8.3.1] catalyses the physiologically vital oxidation of sulfite to sulfate, the terminal reaction in degradation of sulfur containing amino acids, cysteine and methionine. sulfite oxidase from vertebrate sources is among the best studied molybdenum enzymes. existence of so in plants has been established recently by identification of a cdna from arabidopsis thaliana encoding a functional so. the present study was undertaken to identify herbaceous and woody plants (viz., ...201020358871
monitoring programme on nitrates in vegetables and vegetable-based baby foods marketed in the region of valencia, spain: levels and estimated daily intake.this study was carried out to determine the current levels of nitrates in vegetables and vegetable-based baby foods (a total of 1150 samples) marketed in the region of valencia, spain, over the period 2000-2008, and to estimate the toxicological risk associated with their intake. average (median) levels of nitrate in lettuce, iceberg-type lettuce and spinach (1156, 798 and 1410 mg kg(-1) w/w, respectively) were lower than the maximum limits established by european union legislation. thirteen fre ...201020234964
visualizing the mobility and distribution of chlorophyll proteins in higher plant thylakoid membranes: effects of photoinhibition and protein phosphorylation.the diffusion of proteins in chloroplast thylakoid membranes is believed to be important for processes including the photosystem-ii repair cycle and the regulation of light harvesting. however, to date there is very little direct information on the mobility of thylakoid proteins. we have used fluorescence recovery after photobleaching in a laser-scanning confocal microscope to visualize in real time the exchange of chlorophyll proteins between grana in intact spinach (spinacia oleracea l.) and a ...201020230505
functional analysis of b and c class floral organ genes in spinach demonstrates their role in sexual dimorphism.evolution of unisexual flowers entails one of the most extreme changes in plant development. cultivated spinach, spinacia oleracea l., is uniquely suited for the study of unisexual flower development as it is dioecious and it achieves unisexually by the absence of organ development, rather than by organ abortion or suppression. male staminate flowers lack fourth whorl primordia and female pistillate flowers lack third whorl primordia. based on theoretical considerations, early inflorescence or f ...201020226063
carnation mottle virus, an important viral agent infecting carnation cut-flower crops in mahallat of iran.one of the most important cut-flower crops grown worldwide on commercial scale is carnation (dianthus caryophyllus l.). it's the main production of mahallat where is one of the most important ornamental plants production centers of iran. infection of carnation with pathogens like viral agents causes economic losses in carnation cut-flower crop. one of the viral agents of this flower is carnation mottle virus (carmv) which is the type member of genus carmovirus and belongs to the tombusviridae fa ...200920222573
infrequent internalization of escherichia coli o157:h7 into field-grown leafy greens.several sources of contamination of fresh produce by escherichia coli o157:h7 (o157) have been identified and include contaminated irrigation water and improperly composted animal waste; however, field studies evaluating the potential for internalization of o157 into leafy greens from these sources have not been conducted. irrigation water inoculated with green fluorescent plasmid-labeled shiga toxin-negative strains (50 ml of 10(2), 10(4), or 10(6) cfu of o157 per ml) was applied to soil at the ...201020202336
vidas salmonella (slm) assay method easyslm with chromid salmonella (sm2) agar. performance tested method 020901.a method modification study was conducted for the vidas salmonella (slm) assay (aoac performance tested method 020901) using the easyslm method to validate a matrix extension for peanut butter. the vidas easyslm method is a simple enrichment procedure compared to traditional salmonella methods, requiring only pre-enrichment and a single selective enrichment media, salmonella xpress 2 (sx2) broth. sx2 replaces the two selective broths in traditional methods and eliminates the m broth transfer, in ...200920166608
traditional leafy vegetables in senegal: diversity and medicinal uses.six administrative regions of senegal were investigated. forty species of vegetable leaves which are traditionally consumed in senegal have been inventoried. all species are members of twenty-one families the most numerous of which are amaranthaceae juss., malvaceae juss., moraceae link., the papilionaceae giseke and tiliaceae juss. the species are subdivided into three groups: cultivated leafy vegetables, plants gathered annually, perennial sub-ligneous and ligneous species. the gathered specie ...200720161914
effect of protein modification by malondialdehyde on the interaction between the oxygen-evolving complex 33 kda protein and photosystem ii core proteins.previously we observed that the oxygen-evolving complex 33 kda protein (oec33) which stabilizes the mn cluster in photosystem ii (psii), was modified with malondialdehyde (mda), an end-product of peroxidized polyunsaturated fatty acids, and the modification increased in heat-stressed plants (yamauchi et al. 2008). in this study, we examined whether the modification of oec33 with mda affects its binding to the psii complex and causes inactivation of the oxygen-evolving complex. purified oec33 and ...201020157726
the proteome map of spinach leaf peroxisomes indicates partial compartmentalization of phylloquinone (vitamin k1) biosynthesis in plant peroxisomes.leaf peroxisomes are fragile, low-abundance plant cell organelles that are difficult to isolate from one of the few plant species whose nuclear genome has been sequenced. leaf peroxisomes were enriched at high purity from spinach (spinacia oleracea) and approximately 100 protein spots identified from 2-dimensional gels by a combination of liquid chromatography-tandem mass spectrometry (lc-ms/ms) and de novo sequencing. in addition to the predominant enzymes involved in photorespiration and detox ...201020150517
population analyses of the vascular plant pathogen verticillium dahliae detect recombination and transcontinental gene flow.the fungal pathogen verticillium dahliae has resulted in significant losses in numerous crops in coastal california, but lettuce remained unaffected until the mid-1990s. since then outbreaks have decimated entire fields, but the causes of this sudden susceptibility of lettuce remain elusive. the population structure of v. dahliae isolated from coastal california (n=123) was investigated with 22 microsatellite markers, and compared with strains from tomato in central california (n=60), spinach se ...201020149887
histamine, cadaverine, and putrescine produced in vitro by enterobacteriaceae and pseudomonadaceae isolated from spinach.a total of 364 bacterial isolates, obtained from spinach leaves, were assayed in a decarboxylase broth containing histidine, lysine, and ornithine to check their ability to produce biogenic amines, and then quantified by high-performance liquid chromatography. among these isolates, 240 formed cadaverine, 208 formed putrescine, and 196 formed histamine, in widely varying amounts. they frequently produced more than one biogenic amine. klebsiella pneumoniae subsp. pneumoniae and morganella morganii ...201020132689
reduction of escherichia coli o157:h7 in fresh spinach, using lactic acid bacteria and chlorine as a multihurdle intervention.a 12-day shelf life study was conducted at 7 degrees c to determine whether escherichia coli o157:h7 on spinach can be controlled effectively by selected strains of lactic acid bacteria (lab) alone or in combination with chlorine as a multihurdle intervention. the multihurdle intervention consisted of both lab and chlorine and was applied to spinach as a rinse and evaluated in comparison to lab alone and chlorine and water rinses. reductions achieved by all treatments also were compared with tho ...201020132683
behavior of escherichia coli o157:h7 on damaged leaves of spinach, lettuce, cilantro, and parsley stored at abusive temperatures.recent foodborne illness outbreaks associated with the consumption of leafy green produce indicates a need for additional information on the behavior of pathogenic bacteria on these products. previous research indicates that pathogen growth and survival is enhanced by leaf damage. the objective of this study was to compare the behavior of escherichia coli o157:h7 on damaged leaves of baby romaine lettuce, spinach, cilantro, and parsley stored at three abusive temperatures (8, 12, and 15 degrees ...201020132665
relationship between fresh-packaged spinach leaves exposed to continuous light or dark and bioactive contents: effects of cultivar, leaf size, and storage duration.current retail marketing conditions allow produce to receive artificial light 24 h per day during its displayed shelf life. essential human-health vitamins [ascorbic acid (vit c), folate (vit b(9)), phylloquinone (vit k(1)), alpha-tocopherol (vit e), and the carotenoids lutein, violaxanthin, zeaxanthin, and beta-carotene (provit a)] also are essential for photosynthesis and are biosynthesized in plants by light conditions even under chilling temperatures. spinach leaves, notably abundant in the ...201020131793
amelioration of asthmatic inflammation by an aqueous extract of spinacia oleracea linn.inflammation of the respiratory tract is a crucial process in immune diseases, including asthma, and atopic rhinitis. to establish whether an aqueous extract of spinacia oleracea linn (sol) has a beneficial influence in terms of anti-asthmatic activity, we examined its effects on an ovalbumin-induced asthmatic model. mice sensitized to ovalbumin were orally administered the sol extract, and their lungs examined by hematoxylin and eosin staining to determine il-4/13 cytokine expression. the sol e ...201020127046
investigating the activity spectrum for ring-substituted 8-hydroxyquinolines.in this study, a series of fourteen ring-substituted 8-hydroxyquinoline derivatives were prepared. the synthesis procedures are presented. the compounds were analyzed using rp-hplc to determine lipophilicity. they were tested for their activity related to inhibition of photosynthetic electron transport (pet) in spinach (spinacia oleracea l.) chloroplasts. primary in vitro screening of the synthesized compounds was also performed against four mycobacterial strains and against eight fungal strains ...201020110891
streptomyces coelicolor a3(2) cyp102 protein, a novel fatty acid hydroxylase encoded as a heme domain without an n-terminal redox partner.the gene from streptomyces coelicolor a3(2) encoding cyp102b1, a recently discovered cyp102 subfamily which exists solely as a single p450 heme domain, has been cloned, expressed in escherichia coli, purified, characterized, and compared to its fusion protein family members. purified reconstitution metabolism experiments with spinach ferredoxin, ferredoxin reductase, and nadph revealed differences in the regio- and stereoselective metabolism of arachidonic acid compared to that of cyp102a1, excl ...201020097805
lipolysis of natural long chain and synthetic medium chain galactolipids by pancreatic lipase-related protein 2.monogalactosyldiacylglycerol (mgdg) and digalactosyldiacylglycerol (dgdg) are the most abundant lipids in nature, mainly as important components of plant leaves and chloroplast membranes. pancreatic lipase-related protein 2 (plrp2) was previously found to express galactolipase activity, and it is assumed to be the main enzyme involved in the digestion of these common vegetable lipids in the gastrointestinal tract. most of the previous in vitro studies were however performed with medium chain syn ...201020083229
effect of spinacia oleraceae l. and perilla frutescens l. on antioxidants and lipid peroxidation in an intervention study in healthy individuals.daily consumption of fruits and vegetables is frequently recommended to prevent several diseases. this health-promoting effect is considered to be in part due to the antioxidant content of fruits and vegetables and their ability to decrease oxidative stress. to investigate whether the ingestion of preparations from spinach or perilla, two carotenoid-rich leafy vegetables, is followed by an increase in carotenoid concentration and/or affects parameters of oxidative stress in human blood plasma. 1 ...201020052549
effects of copper on the photosynthesis of intact chloroplasts: interaction with manganese.highly purified, intact chloroplasts were prepared from pea (pisum sativum l.) and spinach (spinacia oleracea l.) following an identical procedure, and were used to investigate the cupric cation inhibition on the photosynthetic activity. in both species, copper inhibition showed a similar inhibitor concentration that decreases the enzyme activity by 50% (ic(50) approximately 1.8 microm) and did not depend on the internal or external phosphate (pi) concentration, indicating that copper did not in ...201020051028
spinacia oleracea modulates radiation-induced biochemical changes in mice testis.the present study is an attempt to investigate the radioprotective efficacy of spinach against radiation induced oxidative stress, since its leaves are rich in antioxidants like carotenoids (beta-carotene, lutein and zeaxanthin) and high content of proteins, minerals, vitamin c. for the experimental study, healthy swiss mice were selected from an inbred colony and divided into four groups. group i (normal) it did not receive any treatment. group ii (drug treated) was orally supplemented with ext ...200820046739
enzymatic properties of the ferredoxin-dependent nitrite reductase from chlamydomonas reinhardtii. evidence for hydroxylamine as a late intermediate in ammonia production.the ferredoxin-dependent nitrite reductase from the green alga chlamydomonas reinhardtii has been cloned, expressed in escherichia coli as a his-tagged recombinant protein, and purified to homogeneity. the spectra, kinetic properties and substrate-binding parameters of the c. reinhardtii enzyme are quite similar to those of the ferredoxin-dependent spinach chloroplast nitrite reductase. computer modeling, based on the published structure of spinach nitrite reductase, predicts that the structure ...201020039132
enantioselective oxidation of 2-hydroxy carboxylic acids by glycolate oxidase and catalase coexpressed in methylotrophic pichia pastoris.glycolate oxidase (go; (s)-2-hydroxyacid oxidase, ec 1.1.3.15) is a flavin mononucleotide (fmn)-dependent enzyme, which catalyzes the oxidation of 2-hydroxy carboxylic acids to the corresponding 2-keto acids. catalase has been used as cocatalyst to decompose hydrogen peroxide produced in the reaction, thus limiting peroxide-based side reactions and go deactivation. go from spinach and catalase t from saccharomyces cerevisiae previously coexpressed in pichia pastoris strain nrrl y-21001, was perm ...201020014430
hydrogen bond interactions of the pheophytin electron acceptor and its radical anion in photosystem ii as revealed by fourier transform infrared difference spectroscopy.the primary electron acceptor pheophytin (pheo(d1)) plays a crucial role in regulation of forward and backward electron transfer in photosystem ii (psii). it is known that some cyanobacteria control the pheo(d1) potential in high-light acclimation by exchanging the d1 proteins from different copies of the psba genes. to clarify the mechanism of the potential control of pheo(d1), we studied the hydrogen bond interactions of pheo(d1) in the neutral and anionic states using light-induced fourier tr ...201020000330
opioid peptides derived from food proteins suppress aggregation and promote reactivation of partly unfolded stressed proteins.a new view of the opioid peptides is presented. the potential of small peptides derived from precursor food proteins, to bind to partly unfolded stressed proteins to prevent their irreversible aggregation and inactivation has been demonstrated in various in vitro test systems: dithiothreitol-induced aggregation of alpha-lactalbumin (la), heat-induced aggregation of alcohol dehydrogenase (adh), and aggregation and inactivation of bovine erythrocyte carbonic anhydrase (ca) in the process of its re ...201019954758
[determination of 107 pesticide residues in vegetables using off-line dispersive solid-phase extraction and gas chromatography-tandem mass spectrometry].a screening method was developed for the determination of 107 pesticide residues in vegetables using off-line dispersive solid-phase extraction (dspe) and gas chromatography-tandem mass spectrometry (gc-ms/ms). the pesticides interested were extracted from the samples with acetonitrile (saturated by n-hexane) containing 1% acetic acid and simultaneously separated by liquid-liquid partitioning with adding anhydrous magnesium sulfate plus sodium acetate following by a simple cleanup step known as ...200919938491
spinacia oleracea l. leaf stomata harboring cryptosporidium parvum oocysts: a potential threat to food safety.cryptosporidium parvum is a cosmopolitan microscopic protozoan parasite that causes severe diarrheal disease (cryptosporidiosis) in mammals, including humans and livestock. there is growing evidence of cryptosporidium persistence in fresh produce that may result in food-borne infection, including sporadic cases as well as outbreaks. however, drinking and recreational waters are still considered the major sources of cryptosporidium infection in humans, which has resulted in prioritization of stud ...201019933348
investigating biological activity spectrum for novel styrylquinazoline analogues.in this study, series of ring-substituted 2-styrylquinazolin-4(3h)-one and 4-chloro-2-styrylquinazoline derivatives were prepared. the syntheses of the discussed compounds are presented. the compounds were analyzed by rp-hplc to determine lipophilicity. they were tested for their inhibitory activity on photosynthetic electron transport (pet) in spinach (spinacia oleracea l.) chloroplasts. primary in vitro screening of the synthesized compounds was also performed against four mycobacterial strain ...200919924061
inactivation of escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on spinach leaves by x-ray.several recent foodborne disease outbreaks associated with leafy green vegetables, including spinach, have been reported. x-ray is a non-thermal technology that has shown promise for reducing pathogenic and spoilage bacteria on spinach leaves. inactivation of inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on spinach leaves using x-ray at different doses (0.1, 0.2, 0.3, 0.5, 0.75, 1.0, 1.5 and 2.0 kgy) was studied. the effect of x-ray on col ...201019913687
survival of hepatitis a virus in spinach during low temperature storage.spinach leaves are frequently consumed raw and have been involved with past foodborne outbreaks. in this study, we examined the survival of hepatitis a virus (hav) on fresh spinach leaves in moisture- and gas-permeable packages that were stored at 5.4 +/- 1.2 degrees c for up to 42 days. different eluents including phosphate-buffered saline (pbs), ph 7.5 (with and without 2% serum), and 3% beef extract (ph 7.5 and 8) were compared for how efficiently they recovered viruses from spinach by using ...200919903406
effects of plant maturity and growth media bacterial inoculum level on the surface contamination and internalization of escherichia coli o157:h7 in growing spinach leaves.the incidence of foodborne outbreaks linked to fresh produce has increased in the united states. particularly noteworthy was the 2006 escherichia coli o157:h7 outbreak associated with prepackaged baby spinach. this study aimed to determine whether e. coli o157:h7 would be present in the aerial leaf tissue of a growing spinach plant when introduced at various plant maturities and different inoculum levels in a greenhouse setting. spinach seeds of a commercial variety were sown in 8-in. (20.32-cm) ...200919903394
[transfer of pesticide residues to crops via cardboard boxes].cardboard boxes used to transport crops are often reused in the distribution process, and therefore transfer of pesticides between crops might occur. so, we designed model experiments to investigate whether or not transfer of pesticide residues from crops to other crops via cardboard boxes occurs. under severe experimental conditions, 6.2% of the pesticide residues of grapefruit was found to be transferred to spinach via cardboard boxes. in the case of the mandarin orange, 0.57% was transferred. ...200919897948
asp157 is required for the function of psbo, the photosystem ii manganese stabilizing protein.psbo, the photosystem ii manganese stabilizing protein, contains an aspartate residue [asp157 (spinach numbering)], which is highly conserved in eukaryotic and prokaryotic psbos. the homology model of the psii-bound conformation of spinach psbo presented here positions asp157 in the large flexible loop of the protein. we have characterized site-directed mutants (d157n, d157e, and d157k) of spinach psbo that were rebound to psbo-depleted psii to probe the role of asp157. structural data revealed ...200919894760
raffinose in chloroplasts is synthesized in the cytosol and transported across the chloroplast envelope.in chloroplasts, several water-soluble carbohydrates have been suggested to act as stress protectants. the trisaccharide raffinose (alpha-1,6-galactosyl sucrose) is such a carbohydrate but has received little attention. we here demonstrate by compartmentation analysis of leaf mesophyll protoplasts that raffinose is clearly (to about 20%) present in chloroplasts of cold-treated common bugle (ajuga reptans l.), spinach (spinacia oleracea l.) and arabidopsis [arabidopsis thaliana (l.) heynh.] plant ...200919880397
persistence of enterohaemorrhagic and nonpathogenic e. coli on spinach leaves and in rhizosphere soil.survival of escherichia coli o157:h7 and nonpathogenic e. coli on spinach leaves and in organic soil while growing spinach in a growth chamber was investigated.201019878527
oxalate content of silver beet leaves (beta vulgaris var. cicla) at different stages of maturation and the effect of cooking with different milk sources.the work presented here indicates that people who have a tendency to develop kidney stones should avoid consuming regrowth and developed silver beet (beta vulgaris var. cicla) leaves. soluble oxalate contents of leaves range from 58% of the total oxalate for the mature leaves up to 89% for the regrowth tissue, with regrowth tissue containing the highest levels of soluble oxalate at 7267+/-307 mg/100 g of dry matter (dm). leaves cooked in milk contained significantly (p<0.05) lower levels of solu ...200919877639
characterization of the haem oxygenase protein family in arabidopsis thaliana reveals a diversity of functions.hos (haem oxygenases) catalyse the oxidative cleavage of haem to bv (biliverdin), iron and carbon monoxide. in plants, the product of the reaction is bv ixalpha, the precursor of the phy (phytochrome) chromophore and is thus essential for proper photomorphogenesis. arabidopsis thaliana contains one major biochemically characterized ho (hy1) and three additional putative hos (ho2, ho3 and ho4). all four proteins are encoded in the nucleus but contain chloroplast translocation sequences at their n ...201019860740
enteric viruses in raw vegetables and groundwater used for irrigation in south korea.raw vegetables irrigated with groundwater that may contain enteric viruses can be associated with food-borne viral disease outbreaks. in this study, we performed reverse transcription-pcr (rt-pcr) and cell culture-pcr to monitor the occurrence of enteric viruses in groundwater samples and in raw vegetables that were cultivated using that groundwater in south korea. samples were collected 10 times from three farms located in gyeonggi province, south korea. rt-pcr and cell culture-pcr were perform ...200919854919
influences of major nutrient elements on pb accumulation of two crops from a pb-contaminated soil.to know about the effect of major nutrient elements on various forms of pb and metal extraction, a greenhouse experiment was conducted to assess the effects of various major nutrient elements on pb accumulation in two crops (spinacia oleracea, so and sonchus arvensis, sa) in changchun, china. results indicated that, for so, the pb concentrations in both shoots and roots had no difference with increasing nutrients except for low nutrient treatment (1/2h). for sa, high nutrient treatments (2h and ...201019854574
inactivation of escherichia coli o157:h7 on the intact and damaged portions of lettuce and spinach leaves by using allyl isothiocyanate, carvacrol, and cinnamaldehyde in vapor phase.antimicrobials in the vapor phase might be more effective in inactivating escherichia coli o157:h7 cells attached to leafy greens than aqueous antimicrobials. we determined the activity of allyl isothiocyanate (ait), cinnamaldehyde, and carvacrol against e. coli o157:h7 on intact and damaged lettuce and spinach tissue. samples were treated with various concentrations of antimicrobial in the vapor phase at 0, 4, and 10 degrees c in an enclosed container. on intact lettuce surface, the vapor of th ...200919833026
fate of escherichia coli o157:h7 in the presence of indigenous microorganisms on commercially packaged baby spinach, as impacted by storage temperature and time.this study investigated the effect of storage temperature and time on the survival and growth of escherichia coli o157:h7, the growth of indigenous microorganisms, and the changes in product quality of packaged baby spinach. commercial packages of spinach within 2 days of processing were cut open at one end, sprayed with fine mists of e. coli o157:h7 inoculum, resealed, and then stored at 1, 5, 8, and 12 degrees c for 12 days until their labeled best-if-used-by dates. microbial enumeration and p ...200919833025
a study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.the growths of the african catfish (clarias gariepinus) and water spinach (ipomoea aquatica) were evaluated in recirculation aquaponic system (ras). fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (hlr) was assessed. fish production did not differ significantly between hydraulic loading rates. in contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. fish pr ...201019819130
pulsed odors from maize or spinach elicit orientation in european corn borer neonate larvae.lepidoptera larvae are capable of orienting towards or away from plants by using odors as cues but whether this attraction is innate or secondarily acquired remains unknown. we tested the hypothesis that european corn borer (ecb) neonate larvae express an innate attraction towards odors released from maize, and avoidance towards odors from spinach. neonate larvae were placed on a locomotion compensator within a constant stream of humidified air that was loaded intermittently with airborne odors ...200919787404
structural and functional analysis of the intrinsic inhibitor subunit epsilon of f1-atpase from photosynthetic organisms.the epsilon subunit, a small subunit located in the f1 domain of atp synthase and comprising two distinct domains, an n-terminal beta-sandwich structure and a c-terminal alpha-helical region, serves as an intrinsic inhibitor of atp hydrolysis activity. this inhibitory function is especially important in photosynthetic organisms as the enzyme cannot synthesize atp in the dark, but may catalyse futile atp hydrolysis reactions. to understand the structure-function relationship of this subunit in f1 ...200919785575
air-borne heavy metal contamination to dietary vegetables: a case study from india.contamination of edible parts of three dietary vegetables, spinach (spinacia oleracea l.), radish (raphanus sativus l.), and tomato (lycopersicon esculentum mill.) by air-borne cadmium (cd), chromium (cr), copper (cu), nickel (ni), and lead (pb) was determined using pot culture experiments at three sites in the city of varanasi, india. the data revealed that although cr and cu in vegetables remained below their safe limits, about 68% of the total samples contained cd, ni, and pb above their resp ...200919771380
phytoecdysteroid c2-hydroxylase is microsomal in spinach, spinacia oleracea l.an enzyme involved in the biosynthesis of phytoecdysteroids, the c2-hydroxylase, has been investigated in spinach, spinacia oleracea. this enzyme is microsomal and its k(m) has been determined using 2-deoxy-20-hydroxyecdysone as substrate (k(m)=3.72 microm). it is much more efficient with 2-deoxy-20-hydroxyecdysone than with 2-deoxyecdysone and, conversely, the c20-hydroxylase is more active on 2-deoxyecdysone than on ecdysone. these data support the conclusion that c20-hydroxylation precedes c2 ...200919750551
variation in cadmium accumulation among 30 cultivars and cadmium subcellular distribution in 2 selected cultivars of water spinach (ipomoea aquatica forsk.).to reduce the influx of cadmium (cd), a toxic heavy metal, into the human food chain through vegetable intake, a pot experiment for the selection of a pollution-safe cultivar (psc) of water spinach (ipomoea aquatica forsk.) was carried out. the experiment with 30 tested cultivars revealed that the maximum differences in cd concentration between the cultivars containing the highest and the lowest cd were 3.0-3.9-fold under low-cd treatment (soil cd = 0.593 mg kg(-1)), 2.7-3.5-fold under middle-cd ...200919739670
investigating the foliar uptake and within-leaf migration of phenanthrene by moss (hypnum cupressiforme) using two-photon excitation microscopy with autofluorescence.mosses have the potential to play a significant role in the global cycling and fate of semivolatile organic compounds (svocs), due to their extensive distribution at high latitudes and the long-range atmospheric transport of svocs. unlike vascular plants mosses lack a substantial cuticle, vascular system, or root structure, taking up water, nutrients and svocs primarily from the atmosphere. mosses have thus been effectively used as passive air samplers for many svocs in urban and rural locations ...200919731673
electron spin resonance studies of ribulosebisphosphate carboxylase: identification of activator cation ligands.ribulosebisphosphate carboxylase (rubp carboxylase)forms a stable model complex containing stoichiometric amounts of enzyme sites, activator c0(2), divalent activator cation, and the transition-state analogue carboxyarabinitol bisphosphate (cabp). incorporation of mn(2+) in the model complex permits investigation of the environment of the activator cation by electron spin resonance (esr)techniques. measurements at 9 ghz on the mn(2+)-containing complex prepared by using dimeric rhodospirillum ru ...198419725189
ultrasound enhanced sanitizer efficacy in reduction of escherichia coli o157:h7 population on spinach leaves.the use of ultrasound to enhance the efficacy of selected sanitizers in reduction of escherichia coli o157 : h7 populations on spinach was investigated. spot-inoculated spinach samples were treated with water, chlorine, acidified sodium chlorite (asc), peroxyacetic acid (poaa), and acidic electrolyzed water with and without ultrasound (21.2 khz) for 2 min at room temperature. the effects of ultrasound treatment time and acoustic energy density (aed) were evaluated at an asc concentration of 200 ...200919723216
validation of iq-check e. coli o157:h7 real-time pcr test kit for detection of escherichia coli o157:h7 in selected foods.iq-check e. coli o157:h7 (bio-rad laboratories, hercules, ca) is a real-time pcr kit for detection of e. coli o157:h7 from selected foods. specific fluorescent oligonucleotide probes are used to detect target dna during the amplification, by hybridizing to the amplicons. these fluorescent probes are linked to a fluorophore which fluoresces only when hybridized to the target sequence. three foods (ground beef, apple cider, fresh spinach) were selected to compare the performance of iq-check e. col ...200919714978
a rubisco mutant that confers growth under a normally "inhibitory" oxygen concentration.ribulose-1,5-bisphosphate (rubp) carboxylase/oxygenase (rubisco) is a globally significant biocatalyst that facilitates the removal and sequestration of co2 from the biosphere. rubisco-catalyzed co2 reduction thus provides virtually all of the organic carbon utilized by living organisms. despite catalyzing the rate-limiting step of photosynthetic and chemoautotrophic co2 assimilation, rubisco is markedly inefficient as the competition between o2 and co2 for the same substrate limits the ability ...200919705820
dimerization and endocytosis of the sucrose transporter stsut1 in mature sieve elements.the sucrose transporter stsut1 from solanum tuberosum was shown to be regulated post-translationally by redox reagents. its activity is increased at least 10-fold in the presence of oxidizing agents if expressed in yeast. oxidation has also an effect on plasma membrane targeting and dimerization of the protein. in response to oxidizing agents, stsut1 is targeted to lipid raft-like microdomains and sut1 protein is detectable in the detergent resistant membrane fraction of plant plasma membranes. ...200819704459
involvement of extracellular cu/zn superoxide dismutase in cotton fiber primary and secondary cell wall biosynthesis.extracellular cu/zn superoxide dismutases (csds) that catalyze the conversion of superoxide to hydrogen peroxide have been suggested to be involved in lignification of secondary walls in spinach, pine and aspen. in cotton fibers, hydrogen peroxide was proposed to be involved in the induction of secondary cell wall biosynthesis. recently, we identified extracellular csds from developing cotton fibers using both immunological and epitope tagging techniques. since cotton fibers are not lignified, w ...200819704453
defining the far-red limit of photosystem ii in spinach.the far-red limit of photosystem ii (psii) photochemistry was studied in psii-enriched membranes and psii core preparations from spinach (spinacia oleracea) after application of laser flashes between 730 and 820 nm. light up to 800 nm was found to drive psii activity in both acceptor side reduction and oxidation of the water-oxidizing camn(4) cluster. far-red illumination induced enhancement of, and slowed down decay kinetics of, variable fluorescence. both effects reflect reduction of the accep ...200919700631
mineral contents of organically and conventionally grown spinach (spinacea oleracea l.) during two successive seasons.spinach (spinacea oleracea l.) plants were grown organically and conventionally during two successive seasons (late autumn and early winter) in order to examine the nutrient content of the plants. in a series of 17 organic applications including chicken manure (cm), farmyard manure (fm), blood meal (bm), and one mineral fertilizer treatment and one control, collectively 19 treatments, were used at each season. the optimum doses to be recommended should be divided into groups depending on the min ...200919685878
factors impacting the regrowth of escherichia coli o157:h7 in dairy manure compost.the environmental variables affecting escherichia coli o157:h7 regrowth in dairy manure compost were investigated. factors evaluated were moisture content, strain variation, growth medium of inoculum, level of background microflora and inoculum, different days of composting, and acclimation at room temperature. a mathematical model was applied to describe e. coli o157 regrowth potential in compost. repopulation occurred in autoclaved compost with a moisture content as low as 20% (water activity ...200919681288
microbial antagonists of escherichia coli o157:h7 on fresh-cut lettuce and spinach.fresh-cut lettuce and spinach can become contaminated with pathogens at numerous points from the field to the retail market. natural microflora present on fresh produce may help reduce the pathogen load. the objective of this study was to isolate natural microflora from fresh-cut iceberg lettuce and baby spinach and to determine whether these bacteria were antagonistic toward escherichia coli o157:h7. samples were collected under conditions that mimicked actual practices between production and r ...200919681287
use of the systems approach to determine the fate of escherichia coli o157:h7 on fresh lettuce and spinach.lettuce and spinach inoculated with escherichia coli o157:h7 were processed and handled in ways that might occur in commercial situations, including variations in holding times before and after product cooling, transportation conditions and temperatures, wash treatments, and product storage temperatures and times. populations of background microflora and e. coli o157:h7 were enumerated after each step in the system. data analysis was done to predict response variables with a combination of indep ...200919681286
association of escherichia coli o157:h7 with filth flies (muscidae and calliphoridae) captured in leafy greens fields and experimental transmission of e. coli o157:h7 to spinach leaves by house flies (diptera: muscidae).the recent outbreak of escherichia coli o157:h7 infection associated with contaminated spinach led to an investigation of the role of insects, which frequent fields of leafy greens and neighboring rangeland habitats, in produce contamination. four leafy greens fields adjacent to cattle-occupied rangeland habitats were sampled using sweep nets and sticky traps. agromyzid flies, anthomyiid flies, and leafhoppers were caught consistently in both rangeland and leafy greens production fields at all s ...200919681284
inactivation of escherichia coli o157:h7 and natural microbiota on spinach leaves using gaseous ozone during vacuum cooling and simulated transportation.the aim of this study was to integrate an ozone-based sanitization step into existing processing practices for fresh produce and to evaluate the efficacy of this step against escherichia coli o157:h7. baby spinach inoculated with e. coli o157:h7 (approximately 10(7) cfu/g) was treated in a pilot-scale system with combinations of vacuum cooling and sanitizing levels of ozone gas (sanvac). the contribution of process variables (ozone concentration, pressure, and treatment time) to lethality was in ...200919681283
interaction of escherichia coli o157:h7 with leafy green produce.enterohemorrhagic escherichia coli (ehec) is a foodborne pathogen responsible for human diarrheal disease. ehec lives in the intestinal tract of cattle and other farm and wild animals, which may be the source of environmental contamination particularly of agricultural fields. human infections are associated with consumption of tainted animal products and fresh produce. how the bacteria interact with the plant phyllosphere and withstand industrial decontamination remain to be elucidated. the goal ...200919681282
effect of route of introduction and host cultivar on the colonization, internalization, and movement of the human pathogen escherichia coli o157:h7 in spinach.human pathogens can contaminate leafy produce in the field by various routes. we hypothesized that interactions between escherichia coli o157:h7 and spinach are influenced by the route of introduction and the leaf microenvironment. e. coli o157:h7 labeled with green fluorescent protein was dropped onto spinach leaf surfaces, simulating bacteria-laden raindrops or sprinkler irrigation, and survived on the phylloplane for at least 14 days, with increasing titers and areas of colonization over time ...200919681281
a novel approach to investigate the uptake and internalization of escherichia coli o157:h7 in spinach cultivated in soil and hydroponic medium.internalization of escherichia coli o157:h7 into spinach plants through root uptake is a potential route of contamination. a tn7-based plasmid vector was used to insert a green fluorescent protein gene into the atttn7 site in the e. coli chromosome. three green fluorescent protein-labeled e. coli inocula were used: produce outbreak o157:h7 strains rm4407 and rm5279 (inoculum 1), ground beef outbreak o157:h7 strain 86-24h11 (inoculum 2), and commensal strain hs (inoculum 3). these strains were cu ...200919681280
a novel approach to enhance food safety: industry-academia-government partnership for applied research.an independent collaborative approach was developed for stimulating research on high-priority food safety issues. the fresh express produce safety research initiative was launched in 2007 with $2 million in unrestricted funds from industry and independent direction and oversight from a scientific advisory panel consisting of nationally recognized food safety experts from academia and government agencies. the program had two main objectives: (i) to fund rigorous, innovative, and multidisciplinary ...200919681279
light absorption by isolated chloroplasts and leaves: effects of scattering and 'packing'.light absorption was quantified in the following systems: isolated chloroplasts and leaves of spinach (spinacea oleracea l.), a mutant of geranium (pelargonium zonale l.) widely differing in pigment content, and coleus (coleus blumei benth.) at different stages of leaf ontogenesis. for these species and pea (pisum sativum l.), scattering-compensated absorption spectra of chloroplast suspensions are presented. comparison of leaf and chloroplast spectra showed considerable changes in the extent of ...200919672688
a multifactorial risk prioritization framework for foodborne pathogens.we develop a prioritization framework for foodborne risks that considers public health impact as well as three other factors (market impact, consumer risk acceptance and perception, and social sensitivity). canadian case studies are presented for six pathogen-food combinations: campylobacter spp. in chicken; salmonella spp. in chicken and spinach; escherichia coli o157 in spinach and beef; and listeria monocytogenes in ready-to-eat meats. public health impact is measured by disability-adjusted l ...201019671103
transcriptomic response of escherichia coli o157:h7 to oxidative stress.chlorinated water is commonly used in industrial operations to wash and sanitize fresh-cut, minimally processed produce. here we compared 42 human outbreak strains that represented nine distinct escherichia coli o157:h7 genetic lineages (or clades) for their relative resistance to chlorine treatment. a quantitative measurement of resistance was made by comparing the extension of the lag phase during growth of each strain under exposure to sublethal concentrations of sodium hypochlorite in luria- ...200919666735
determination of lead and cadmium concentration limits in agricultural soil and municipal solid waste compost through an approach of zero tolerance to food contamination.cadmium and lead are important environmental pollutants with high toxicity to animals and human. soils, though have considerable metal immobilizing capability, can contaminate food chain via plants grown upon them when their built-up occurs to a large extent. present experiment was carried out with the objective of quantifying the limits of pb and cd loading in soil for the purpose of preventing food chain contamination beyond background concentration levels. two separate sets of pot experiment ...201019662502
dry deposition of gaseous radioiodine and particulate radiocaesium onto leafy vegetables.radionuclides released to the atmosphere during dry weather (e.g. after a nuclear accident) may contaminate vegetable foods and cause exposure to humans via the food chain. to obtain experimental data for an appropriate assessment of this exposure path, dry deposition of radionuclides to leafy vegetables was studied under homogeneous and controlled greenhouse conditions. gaseous (131)i-tracer in predominant elemental form and particulate (134)cs-tracer at about 1 mum diameter were used to identi ...200919640563
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