| a modified tube method for the cultivation and enumeration of anaerobic bacteria. | a new type of tube (the lee tube) has been developed for use in the cultivation and enumeration of obligate anaerobes. the lee tube is a double-walled, screw-capped tube which allows the formation of a thin cylinder of agar medium between the two walls. anaerobiosis is achieved through deoxygenation of the deep cylinder of agar during sterilization, a minimum of head space, and use of a reducing agent to absorb oxygen introduced during the inoculation procedure. for several species of clostridiu ... | 1979 | 396020 |
| biosynthesis and metabolism of cystathionine in astragalus pectinatus. | metabolism of l-[35s]cystathionine, l-[35s]cysteine and l-[35s]homocysteine has been investigated in astragalus pectinatus. the results indicate that cystathionine undergoes both beta and gamma cleavage to give homocysteine and cysteine. results also show that cystathionine is synthesized from both cysteine and homocysteine. furthermore, in addition to the incorporation of 35s into cystathionine, incorporation of 35s from cysteine into methionine and from homocysteine into s-methylcysteine is no ... | 1977 | 836899 |
| isolation and identification of two isomeric glutamylselenocystathionines from the seeds of astragalus pectinatus. | | 1976 | 949500 |
| aspects of mitochondrial activity in the estuarine bivalves crassostrea rhizophorae and lucina pectinatus: a comparative approach. | in identical laboratory conditions, some differences in the endogenous relative activity (mul o2/mg protein/ml/h) were determined by the addition of succinate and alpha-keto-glutarate to the mitochondrial-rich-fraction from heart and both parts of the adductor muscle in oyster (crassostrea rhizophorae) and from heart and adductor muscle in clams (lucina pectinatus). | 1976 | 1013405 |
| phylogenetic and chemotaxonomic characterization of acidaminococcus fermentans. | the phylogenetic position of acidaminococcus fermentans was determined by comparative sequence analysis of the 16s rrna. this gram-negative bacterium is a member of the sporomusa cluster that is defined by other gram-negative bacteria, i.e. sporomusa, megasphaera, selenomonas, butyrivibrio, pectinatus, and zymophilus. the branching point of this group within the radiation of gram-positive bacteria of the clostridium/bacillus subphylum and adjacent to peptococcus niger could be confirmed. chemota ... | 1992 | 1385264 |
| separation and characterization of two chemically distinct lipopolysaccharides in two pectinatus species. | lipopolysaccharides (lps) from the type strains of the anaerobic beer spoilage bacteria pectinatus cerevisiiphilus and p. frisingensis were extracted with the 5:5:8 volume ratio modification of the phenolchloroform-petroleum ether method (h. brade and c. galanos, eur. j. biochem. 122:233-237, 1982). sequential precipitations of lps with water and acetone from the phenol phase yielded lps which differed in that water-precipitable material (lps-h2o; 0.1 to 0.4% of the dry weight of the cells) was ... | 1992 | 1577699 |
| taxonomic study of anaerobic, gram-negative, rod-shaped bacteria from breweries: emended description of pectinatus cerevisiiphilus and description of pectinatus frisingensis sp. nov., selenomonas lacticifex sp. nov., zymophilus raffinosivorans gen. nov., sp. nov., and zymophilus paucivorans sp. nov. | a collection of 47 strains of obligately anaerobic, gram-negative, rod-shaped bacteria that were isolated mainly from spoiled beer and pitching yeast was studied to learn more about their taxonomic positions. a new species of the genus pectinatus, pectinatus frisingensis, a new species of the genus selenomonas, selenomonas lacticifex, and a new genus comprising two species, zymophilus raffinosivorans and zymophilus paucivorans, are described. all of the strains contained directly cross-linked me ... | 1990 | 1699594 |
| experimental test of the influence of aquatic macrophyte cover on the survival of anopheles larvae. | emergent or submergent macrophytes can enhance the survival of anopheles larvae by providing favorable microhabitat and refuge from predation. the relationships among the amount of aquatic macrophyte cover, the density of gambusia affinis, and survivorship of anopheles freeborni larvae were tested experimentally. larval survivorship was positively related to amount of plant cover and negatively related to gambusia density. larval survivorship was lowest in treatments with low plant cover and hig ... | 1989 | 2614408 |
| effects of four agricultural pesticides on daphnia pulex, lemna minor, and potamogeton pectinatus. | | 1985 | 4074929 |
| the fine structure of the mandibular sensory receptors in the brackish water calanoid copepod gladioferens pectinatus (brady). | | 1969 | 4190684 |
| the characterization of the hemoglobins of the bivalve mollusc phacoides pectinatus (gmelin). | | 1965 | 5841606 |
| [concentration of heavy metals in brook trout in comparison to aquatic plants and sediments]. | from 1974 to 1977 the heavy metal content of river water, fishes (salmo trutta fario), three aquatic plants (cladophora glomerata, potamogeton pectinatus, zannichellia palustris), one river-bank plant (phalaris arundinacea), and sediments (clay fraction) taken from the river leine, up and downstream of göttingen, were determined. galvanic-bath sewage containing heavy metals caused an increase (11-60%) in the concentration of nine elements in the water. the average level of heavy metals in the ri ... | 1983 | 6685956 |
| mercury residues in wood ducks and wood duck foods in eastern tennessee. | liver, breast muscle and body fat from 50 juvenile and five adult wood ducks (aix sponsa) collected on the holston river, tennessee were analyzed for total mercury content. black fly larvae (simulium vittatum) sago pondweed (potamogeton pectinatus), tapegrass (vallisneria americanus), water stargrass (heteranthera dubia), elodea canadensis, and river bottom sediments were also analyzed to elucidate the distribution of mercury in the wood duck's environment. liver tissues of juveniles contained t ... | 1983 | 6887432 |
| phylogenetic placement of dialister pneumosintes (formerly bacteroides pneumosintes) within the sporomusa subbranch of the clostridium subphylum of the gram-positive bacteria. | the nucleotide sequence of the 16s rrna gene of the type strain of dialister pneumosintes was determined. phylogenetic analysis revealed that this species belongs to the sporomusa branch of the clostridium subphylum of the gram-positive bacteria and should therefore be excluded from the family bacteroidaceae. within this branch, which encompasses several other gram-negative taxa, such as acidaminococcus, pectinatus, phascolarcobacterium, quinella, selenomonas, and zymophilus, dialister showed a ... | 1995 | 7537075 |
| structures of the o-specific polysaccharide chains of pectinatus cerevisiiphilus and pectinatus frisingensis lipopolysaccharides. | mild acid hydrolysis of the smooth-type lipopolysaccharide (lps) of pectinatus frisingensis afforded no polysaccharide but monomeric 6-deoxy-l-altrose (l-6dalt) which was identified by anion-exchange chromatography in borate buffer, glc/ms, 1h-nmr spectroscopy, and optical rotation. lps was degraded with alkali under reductive conditions to give a completely o-deacylated polysaccharide, which was studied by methylation analysis, 1h-nmr and 13c-nmr spectroscopy, including sequential, selective sp ... | 1995 | 7556206 |
| chemical structure of the lipid a component of lipopolysaccharides of the genus pectinatus. | the chemical structure of the lipid a components of smooth-type lipopolysaccharides isolated from the type strains of strictly anaerobic beer-spoilage bacteria pectinatus cerevisiiphilus and pectinatus frisingensis were analyzed. the hydrophilic backbone of lipid a was shown, by controlled degradation of lipopolysaccharide combined with chemical assays and 31p-nmr spectroscopy, to consist of the common beta 1-6-linked disaccharide of pyranosidic 2-deoxy-glucosamine (glcn), phosphorylated at the ... | 1994 | 8076652 |
| comparative distribution and taxonomic value of cellular fatty acids in thirty-three genera of anaerobic gram-negative bacilli. | cellular fatty acid profiles were determined for species in 33 genera of anaerobic gram-negative bacilli and were confirmed to be a useful taxonomic tool. most of the genera could be differentiated by visual inspection of their profiles. the three genus pairs that were most difficult to distinguish visually (bacteroides and prevotella, pectinatus and megamonas, and serpulina and bilophila) and the species of these genera were differentiated by the midi (microbial id, inc.) identification system. ... | 1994 | 8186100 |
| 4-o-(2-amino-2-deoxy-alpha-d-glucopyranosyl)-3-deoxy-d-manno-2-octulosonic acid, a constituent of lipopolysaccharides of the genus pectinatus. | a disaccharide containing glcn and 3-deoxy-d-manno-2-octulosonic acid (kdo) was detected after acidic methanolysis and peracetylation of hydrofluoric-acid-treated smooth-type and rough-type lipopolysaccharide of pectinatus cerevisiiphilus and pectinatus frisingensis, which are strictly anaerobic bacteria capable of growing in packaged beer. the disaccharide was also found in alkali-treated lipopolysaccharide, but was not directly detectable from intact lipopolysaccharide. this suggested that the ... | 1993 | 8386627 |
| effects of culture conditions on pectinatus cerevisiiphilus and pectinatus frisingensis metabolism: a physiological and statistical approach. | the genus pectinatus has been often reported in beer spoilage with off-flavours. the bacteria are strictly anaerobic, gram-negative rods. propionate and acetate are the main fermentation products from glucose in the two species belonging to the genus, p. cerevisiiphilus and p. frisingensis. amino acids routinely present at a high level in beer were not growth substrates for both species, and a significant accumulation of succinate was observed with lactate as growth substrate. both pectinatus ss ... | 1996 | 8849643 |
| specific spoilage organisms in breweries and laboratory media for their detection. | the gram positive bacteria are generally regarded as the most hazardous beer spoilage organisms in modern breweries, especially the lactobacilli: l. brevis, l. lindneri, l. curvatus, l. casei, l. buchneri, l. coryneformis, l. plantarum, l. brevisimilis, l. malefermentans and l. parabuchneri and the pediococci: p damnosus, p. inopinatus and p. dextrinicus. micrococcus kristinae is the only species within the micrococci relevant to brewing. the gram negative strictly anaerobic bacteria are apparen ... | 1996 | 8913814 |
| schwartzia succinivorans gen. nov., sp. nov., another ruminal bacterium utilizing succinate as the sole energy source. | four strains of gram-negative, anaerobic, non-spore-forming bacteria that were curved rods which were motile by means of flagella originating from the concave side of the cells and which fermented succinate quantitatively to propionate were isolated from high dilutions of rumen ingesta obtained from cows on pasture. the bacteria were asaccharolytic and not proteolytic and did not ferment amino acids or peptides. succinate was the only substrate fermented. rumen fluid together with yeast extract ... | 1997 | 8995818 |
| physiology and development of pectinatus cerevisiiphilus and pectinatus frisingensis, two strict anaerobic beer spoilage bacteria. | the genus pectinatus was isolated recently and the deposited strains were classified as beer spoilage bacteria producing propionate as a major fermentation product. a recent investigation of this genus demonstrated the existence of two species: pectinatus cerevisiiphilus, the type strain and pectinatus frisingensis, a new species with a different pattern of growth substrates. different culture media tested for both species demonstrated a higher specific growth rate for p. cerevisiiphilus. howeve ... | 1997 | 9081223 |
| identification of a common structural motif in the disordered n-terminal region of bacterial flagellins--evidence for a new class of fibril-forming peptides. | flagellin proteins lacking the n- or c-terminus form polymers of reduced filament stability and straight morphology, in contrast to the coiled native flagella. in the present study, the n-terminal amino acid sequence of flagellins of the anaerobic beer spoilage bacteria pectinatus cerevisiiphilus and pectinatus frisingiensis as well as enterobacter aerogenes and pseudomonas sp. were determined. sequence similarity was revealed between these and the n-termini of all known eubacterial flagellins. ... | 1997 | 9431986 |
| detection of beer spoilage bacteria megasphaera and pectinatus by polymerase chain reaction and colorimetric microplate hybridization. | anaerobic bacteria of the genera megasphaera and pectinatus cause beer spoilage by producing off flavours and turbidity. detection of these organisms is complicated by the strict anaerobic conditions and lengthy incubation times required for their cultivation, consequently there is a need for more rapid detection methods. a polymerase chain reaction (pcr) method and a colorimetric microplate hybridization assay were developed for the rapid and specific detection of megasphaera cerevisiae and pec ... | 1998 | 9924942 |
| effect of rapid cooling and acidic ph on cellular homeostasis of pectinatus frisingensis, a strictly anaerobic beer-spoilage bacterium. | pectinatus frisingensis is a strictly anaerobic mesophilic bacterium involved in bottled beer spoilage. cellular volume, adenylate energy charge, intracellular ph and intracellular potassium concentration measurements were performed in late exponential-phase cell suspensions placed in different physiological conditions, to evaluate the capability of this bacterium to maintain cellular homeostasis. the intracellular ph was calculated from the intracellular accumulation of a [carboxyl-14c]benzoic ... | 1999 | 10443538 |
| phylogenetic characterization of centipeda periodontii, selenomonas sputigena and selenomonas species by 16s rrna gene sequence analysis. | the nearly complete 16s rrna gene sequences for oral gram-negative anaerobic motile bacteria, centipeda periodontii, selenomonas sputigena and selenomonas species (formerly s. sputigena type strain), were determined in order to unveil their relationship to other oral motile bacteria. to determine the phylogenetic characterization of these bacteria, their 16s rrna gene sequences were obtained and compared with those from the ribosomal sequence databases previously reported. the 16s rrna gene sequ ... | 1999 | 10464949 |
| epitope mapping of monoclonal antibodies specific for the directly cross-linked mesodiaminopimelic acid peptidoglycan found in the anaerobic beer spoilage bacterium pectinatus cerevisiiphilus. | nineteen monoclonal antibodies (mabs) were isolated based on reactivity with disrupted pectinatus cerevisiiphilus cells. all of the mabs reacted with cells from which the outer membrane had been stripped by incubation with sodium dodecyl sulphate, suggesting the peptidoglycan (pg) layer was involved in binding. mab reactivity with purified pg confirmed this. epitope mapping revealed the mabs in total recognize four binding sites on the pg. mabs specific for each of the four sites also bound stro ... | 1999 | 10526402 |
| nisin, temperature and ph effects on growth and viability of pectinatus frisingensis, a gram-negative, strictly anaerobic beer-spoilage bacterium | pectinatus frisingensis, a gram-negative and strictly anaerobic beer spoilage bacterium is sensitive to nisin. an increase in nisin concentration (0 to 1100 iu ml-1) added to the culture medium prolonged the lag phase, and decreased the growth rate of the bacterium. in addition, late exponential cells of p. frisingensis exposed to low concentrations of nisin lost immediately a part of their intracellular k+. presence of mg2+ up to 15 mmol l-1 did not protect p. frisingensis from nisin-induced lo ... | 1999 | 10540247 |
| a re-evaluation of the taxonomy of the genus anaerovibrio, with the reclassification of anaerovibrio glycerini as anaerosinus glycerini gen. nov., comb. nov., and anaerovibrio burkinabensis as anaeroarcus burkinensis [corrig.] gen. nov., comb. nov. | chemotaxonomic, electron microscopic and 16s rrna gene sequence analyses of the three described species of the genus anaerovibrio demonstrated only remote similarities to each other. the 16s rrna gene sequence similarities between anaerovibrio lipolytica, anaerovibrio glycerini and anaerovibrio burkinabensis and the derived phylogenetic relationships of the three species studied fell below genus level. all three species clustered within the sporomusa-pectinatus-selenomonas phyletic group. each s ... | 1999 | 10555370 |
| 16s-23s rdna spacer of pectinatus, selenomonas and zymophilus reveal new phylogenetic relationships between these genera. | the 16s-23s rdna spacer regions of two pectinatus species, two zymophilus species and one selenomonas species were cloned after pcr amplification. the results of pcr amplification showed that these species had two types of spacer regions which differ in molecular size (long and short). only the long spacer regions in these bacteria contained one or two trna genes (alanine and/or isoleucine). the spacer regions in these bacteria had a relatively high level of homology. homology was particularly h ... | 2000 | 10758900 |
| impact of thermal variations on biochemical and physiological traits in pectinatus sp. | the influence of temperature on cellular fatty acid composition and on heat stress tolerance was studied in the two species of pectinatus, an anaerobic gram-negative bacterium. cellular fatty acid (fa) patterns were determined for pectinatus species cultivated in mrs medium at various defined conditions of temperature and ph. our study shows that fluctuations of growth temperature and ph induced important changes in the ratio of unsaturated fas (ufas) to saturated fas (sfas). the major differenc ... | 2000 | 10791717 |
| reclassification of clostridium quercicolum as dendrosporobacter quercicolus gen. nov., comb. nov. | morphological features, genomic dna base composition and 16s rdna sequence similarities, as well as a distinct phospholipid pattern, whole-cell fatty acid distribution and the occurrence of the lipoquinone 'lipid f', indicate that clostridium quercicolum belongs to the sporomusa-pectinatus-selenomonas phyletic group and possesses only a remote relationship to members of the genus clostridium sensu stricto. on the basis of these results, the new genus and combination dendrosporobacter quercicolus ... | 2000 | 10826792 |
| anoxia tolerance in the aquatic monocot potamogeton pectinatus absence of oxygen stimulates elongation in association with an unusually large pasteur effect. | elongation by stems of overwintered tubers of potamogeton pectinatus (l.) is strongly promoted over several days by oxygen-free conditions. characteristics of the respiration underpinning this unusual response were examined. anaerobic plants produced ethanol and co(2) in approximately equimolar amounts, indicating that glycolysis coupled to alcoholic fermentation was the principal co(2)-producing respiratory pathway. rates of co(2) evolution by aerobic and anaerobic whole plants (shoot and tuber ... | 2000 | 10944155 |
| propionispora vibrioides, nov. gen., nov. sp., a new gram-negative, spore-forming anaerobe that ferments sugar alcohols. | anaerobic enrichment cultures, with erythritol as substrate, resulted in the isolation of a strain with properties not yet found in an existing genus in this combination. the strain, fkbs1, was strictly anaerobic, stained gram-negative and formed spores. cells were small motile vibrios with flagella inserted at the concave side of the cell. spores were located terminally and caused only slight swelling of the cells if compared to related spore-forming genera. fkbs1 fermented fructose, mannitol, ... | 2000 | 11081792 |
| effect of chlorsulfuron on growth of submerged aquatic macrophyte potamogeton pectinatus (sago pondweed). | research has been conducted on the effect of chlorsulfuron on non-target plants but little information is available on its effects on aquatic macrophytes. potamogeton pectinatus (sago pondweed) is an ecologically important submerged aquatic macrophyte found in freshwater bodies. many species of wildlife use this plant as a food source. the objective of this study was to measure the phytotoxic effects of chlorsulfuron on sago pondweed. p. pectinatus plants were exposed to chlorsulfuron at 0, 0.25 ... | 2001 | 11202750 |
| selenium accumulation in submerged aquatic macrophytes potamogeton pectinatus l. and ruppia maritima l. from water with elevated chloride and sulfate salinity. | submerged aquatic macrophyte species potamogeton crispus l. (curlyleaf pondweed) and ruppia maritima l. (widegeongrass) were examined for selenium accumulation from agricultural drainage water in the field and under laboratory conditions. high concentrations of chloride and sulfate salts were found in the drainage water of the constructed wetland at tulare lake drainage district, corcorn, california. samples of p. crispus and r. maritima collected from the field, had similar plant-tissue se conc ... | 2002 | 11800546 |
| transport rate of arsenic, cadmium, copper and zinc in potamogeton pectinatus l.: radiotracer experiments with 76as,109,115cd,64cu and 65,69mzn. | the present study was aimed at obtaining an insight into possible experimental approaches for providing numerical data on both the accumulation of sediment as, cd, cu and zn in the submerged water plant potamogeton pectinatus l., and the possible corresponding metal flows into the water phase. a hydroculture two-compartment system was used as the experimental set-up, and the selected metals were followed by measurements of their radioisotopes 76as, 109cd, 115cd, 64cu, 65zn and 69mzn. all experim ... | 2002 | 11885578 |
| lanthanide concentrations in freshwater plants and molluscs, related to those in surface water, pore water and sediment. a case study in the netherlands. | industrial emissions of lanthanides to aquatic ecosystems increase, but knowledge of the environmental fate of these metals is limited. here we focus attention upon the distribution of lanthanides in freshwater ecosystems, describing lanthanide partitioning between sediment, water and biota. since lanthanides are often used as oxidation-state analogues for actinides, their distribution can reflect long-term behaviour of the radioactive transuranics. concentrations of all 14 naturally occurring l ... | 2002 | 11887873 |
| potamogeton pectinatus is constitutively incapable of synthesizing ethylene and lacks 1-aminocyclopropane-1-carboxylic acid oxidase. | a highly sensitive laser-driven photoacoustic detector responsive to [less than or equal to]2.1 nmol m-3 ethylene (50 parts per trillion [v/v]) was used for ethylene analysis. dark-grown plants of potamogeton pectinatus l. growing from small tubers made no ethylene. exposure of shoots to white light, wounding, submergence in water followed by desubmergence, partial oxygen shortage, indole acetic acid, or carbon dioxide failed to induce ethylene production, although clear effects were observed in ... | 1996 | 12226336 |
| population differentiation of potamogeton pectinatus in the baltic sea with reference to waterfowl dispersal. | forty populations of potamogeton pectinatus l. were sampled from around the baltic sea basin. analysis of 62 issr 'loci' showed that the number of clones per population is very variable but shows a tendency to decrease with latitude. analysis of molecular variance revealed that, overall, just over half the variability is stored within populations and just under half between them (phi(st) 0.496). in pairwise comparisons, most populations are significantly differentiated. genetic distance between ... | 2002 | 12296939 |
| clonal diversity and structure within a population of the pondweed potamogeton pectinatus foraged by bewick's swans. | clonal diversity within plant populations is affected by factors that influence genet (clone) survival and seed recruitment, such as resource availability, disturbance, seed dispersal mechanism, propagule predation and the age of the population. here we studied a population of potamogeton pectinatus, a pseudo-annual aquatic macrophyte. within populations reproduction appears to be mainly asexually through subterranean propagules (tubers), while recruitment via seeds is believed to be relatively ... | 2002 | 12296955 |
| heavy metals in the vicinity of a chlor-alkali factory in the upper negro river ecosystem, northern patagonia, argentina. | a study on heavy metal contents was performed in sediments and biota of the upper negro river (alto valle) aquatic system, northern patagonia, argentina. the irrigation system of the neuquén and negro rivers runs alongside these rivers for 150 km, supporting intensive agricultural and economical activities, mainly related to fruit production. a mercury cell chlor-alkali factory operated between 1951 and 1995. close attention was given to the surroundings of the plant, located next to the main ir ... | 2003 | 12493196 |
| antimicrobial and antioxidant activity of the essential oil and methanol extracts of thymus pectinatus fisch. et mey. var. pectinatus (lamiaceae). | the essential oil, obtained by using a clevenger distillation apparatus, and water-soluble (polar) and water-insoluble (nonpolar) subfractions of the methanol extract of thymus pectinatus fisch. et mey. var. pectinatus were assayed for their antimicrobial and antioxidant properties. no (or slight) antimicrobial activity was observed when the subfractions were tested, whereas the essential oil showed strong antimicrobial activity against all microorganisms tested. antioxidant activities of the po ... | 2003 | 12502386 |
| cadmium accumulation and its phytotoxicity in potamogeton pectinatus l. (potamogetonaceae). | | 2003 | 12592533 |
| structure of the exceptionally large nonrepetitive carbohydrate backbone of the lipopolysaccharide of pectinatus frisingensis strain vtt e-82164. | the structures of the oligosaccharides obtained after acetic acid hydrolysis and alkaline deacylation of the rough-type lipopolysaccharide (lps) from pectinatus frisingensis strain vtt e-82164 were analysed using nmr spectroscopy, ms and chemical methods. the lps contains two major structural variants, differing by a decasaccharide fragment, and some minor variants lacking the terminal glucose residue. the largest structure of the carbohydrate backbone of the lps that could be deduced from exper ... | 2003 | 12846837 |
| studies of the genus thymus. vii. comparison of the diagnostic microscopical characteristics of thymus pectinatus fisch. and thymus zygis linn. | | 1958 | 13571389 |
| biochemical responses of potamogeton pectinatus l. exposed to higher concentrations of zinc. | | 2003 | 14560375 |
| ent-labdane diterpenes from the aquatic plant potamogeton pectinatus. | four new ent-labdane diterpenes were isolated from the freshwater aquatic plant potamogeton pectinatus, together with two known furano-ent-labdanes. the new compounds were assigned the structures methyl-15,16-epoxy-12(r)-acetoxy- 8(17), 13(16),14-ent-labdatrien-19-oate,15,16-epoxy-12(r)-acetoxy-8(17), 13(16),14-ent-labdatrien-19-oic acid, 8(17),13-ent-labdadien-15 --> 16-lactone-19-oic acid and 16-hydroxy-8(17),13-ent-labdadien-15,16-olid-19-oic acid by spectroscopic means. some of these labdane ... | 2003 | 14599530 |
| beer spoilage bacteria and hop resistance. | for brewing industry, beer spoilage bacteria have been problematic for centuries. they include some lactic acid bacteria such as lactobacillus brevis, lactobacillus lindneri and pediococcus damnosus, and some gram-negative bacteria such as pectinatus cerevisiiphilus, pectinatus frisingensis and megasphaera cerevisiae. they can spoil beer by turbidity, acidity and the production of unfavorable smell such as diacetyl or hydrogen sulfide. for the microbiological control, many advanced biotechnologi ... | 2003 | 14623377 |
| ent-labdane glycosides from the aquatic plant potamogeton lucens and analytical evaluation of the lipophilic extract constituents of various potamogeton species. | two new ent-labdane glycosides, one known furano-ent-labdane and a new hydroxylated fatty acid were isolated from the dichloromethane extract of the freshwater aquatic plant potamogeton lucens. the new compounds were assigned the structures of beta-d-glucopyranosyl-8(17),13-ent-labdadien-16,15-olid-18-oate, 18-beta-d-glucopyranosyloxy-8(17),13-ent-labdadien-16,15-olide and 13(r)-hydroxy-octadeca-(9z,11e,15z)-trien-oic acid by spectroscopic means. the algicidal activity of these compounds was tes ... | 2004 | 15081300 |
| effects of herbicides on two submersed aquatic macrophytes, potamogeton pectinatus l. and myriophyllum sibiricum komarov, in a prairie wetland. | clopyralid, picloram, 2,4-d and a mixture of 2,4-d plus picloram, (tordon 202c) were added to the water of 1 m square enclosures in a prairie wetland in saskatchewan, canada to produce concentrations of 0.01 and 0.1 mg active ingredient litre(-1). effects on the submersed macrophytes, potamogeton pectinatus and myriophyllum sibiricum, were monitored by taking repeated measurements of plant weight, flower and tuber production and inspecting for injuries at 30 and 60 days after application. clopyr ... | 1997 | 15093467 |
| the structure of the carbohydrate backbone of the lipopolysaccharide of pectinatus frisingensis strain vtt e-79104. | the structure of the carbohydrate backbone of the lipopolysaccharide from pectinatus frisingensis strain vtt e-79104 was analyzed using chemical degradations, nmr spectroscopy, mass spectrometry, and chemical methods. the lps contains two major structural variants, differing in the presence or absence of an octasaccharide fragment. the largest structure of the carbohydrate backbone of the lps, that could be deduced from experimental results, consists of 20 monosaccharides arranged in a nonrepeti ... | 2004 | 15183738 |
| accumulation of heavy metals in typha angustifolia (l.) and potamogeton pectinatus (l.) living in sultan marsh (kayseri, turkey). | concentrations of heavy metals (cd, pb, cr, ni, zn and cu) were measured in bottom sediments, water and typha angustifolia and potamogeton pectinatus in sultan marsh. sultan marsh is one of the largest and most important wetlands in turkey, middle east and europe, embodying saline and fresh water ecosystems and providing a shelter for 426 bird species. the organs of t. angustifolia have a larger quantity of the measured elements than the p. pectinatus. considerably higher contents of cd were fou ... | 2004 | 15234165 |
| toxic metals in aquatic plants surviving in surface water polluted by copper mining industry. | concentrations of the metals al, ba, cd, co, cr, cu, fe, mn, ni, pb, v, and zn, as well as the macronutrients n, p, k, ca, mg, and s were measured in water, sediments, and the aquatic macrophytes potamogeton pectinatus and myriophyllum spicatum, growing in surface water receiving sewages and solid wastes from a copper smelter and a copper ore processing factory located in the legnica-glogow copper district in southwest poland. the deposition of mineral wastes in this area belong to the largest r ... | 2004 | 15261724 |
| identification of the polar constituents of potamogeton species by hplc-uv with post-column derivatization, hplc-msn and hplc-nmr, and isolation of a new ent-labdane diglycoside. | the polar extracts of potamogeton pectinatus, p. lucens, p. perfoliatus and p. crispus (potamogetonaceae) were analyzed by hplc-uv-ms and their chromatographic profiles were very similar. the polar constituents of p. pectinatus were more exhaustively investigated by hplc-uv with post-column derivatization, hplc-ms(n) and hplc-nmr, which allowed the on-line identification of various known flavones (dereplication). one of these compounds, luteolin 3'-o-glucoside, has never been characterized in th ... | 2004 | 15381014 |
| lipopolysaccharides of anaerobic beer spoilage bacteria of the genus pectinatus--lipopolysaccharides of a gram-positive genus. | bacteria of the genus pectinatus emerged during the seventies as contaminants and spoilage organisms in packaged beer. this genus comprises two species, pectinatus cerevisiiphilus and pectinatus frisingensis; both are strict anaerobes. on the basis of genomic properties the genus is placed among low gc gram-positive bacteria (phylum firmicutes, class clostridia, order clostridiales, family acidaminococcaceae). despite this assignment, pectinatus bacteria possess an outer membrane and lipopolysac ... | 2004 | 15539073 |
| pectinatus portalensis nov. sp., a relatively fast-growing, coccoidal, novel pectinatus species isolated from a wastewater treatment plant. | the genus pectinatus is currently composed by two species, pectinatus cerevisiiphilus and pectinatus frisingensis , both asociated with beer spoilage. this study describes a novel isolate (strain b6) retrieved from a wastewater treatment plant collecting residues from a large number of wineries. based on similarity analysis of 16s rrna gene sequences, strain b6 belongs to the genus pectinatus . strain b6 is a strict anaerobe like other pectinatus species and it presents non-motile, coccoid cells ... | 2004 | 15539928 |
| evolutionary divergence and possible incipient speciation in post-glacial populations of a cosmopolitan aquatic plant. | habitat configuration is expected to have a major influence on genetic exchange and evolutionary divergence among populations. aquatic organisms occur in two fundamentally different habitat types, the sea and freshwater lakes, making them excellent models to study the contrasting effects of continuity vs. isolation on genetic divergence. we compared the divergence in post-glacial populations of a cosmopolitan aquatic plant, the pondweed potamogeton pectinatus that simultaneously occurs in freshw ... | 2005 | 15669957 |
| characterization of the microbial community in indoor environments by chemical marker analysis: an update and critical evaluation. | we published recently an integrated procedure for applying chemical marker analysis to characterize the microbiology of indoor environments comprising a scheme for extraction and analysis of markers of endotoxin, peptidoglycan/bacterial biomass, and fungal biomass. in the present paper, we report some significant improvements and also new possibilities of the described approach. we found that while 3-hydroxy fatty acids (3-oh fas) of 10-14 carbon chain lengths are useful endotoxin markers, longe ... | 2005 | 15910526 |
| cold climate phosphorus uptake by submerged aquatic plants in a sewage treatment free water surface wetland. | in november 2002, biomass phosphorus (p) of submerged aquatic plants with associated epiphyton was measured using p-32 tracer addition in a treatment wetland receiving tertiary treated municipal sewage. the wetland is situated 120 km west of stockholm, sweden receiving tertiary treated municipal sewage. during the experiment, inflow water had a total p concentration of 0.3 and an iron concentration of 0.7 mg 1(-1) with a residence time of 3-3.5 days. samples of submerged plants mainly slender wa ... | 2005 | 15921274 |
| metal accumulation and ecophysiological effects of distillery effluent on potamogeton pectinatus l. | | 2005 | 16097318 |
| physiological and metabolic adaptations of potamogeton pectinatus l. tubers support rapid elongation of stem tissue in the absence of oxygen. | tubers of potamogeton pectinatus l., an aquatic pondweed, over-winter in the anoxic sediments of rivers, lakes and marshes. growth of the pre-formed shoot that emerges from the tuber is remarkably tolerant to anoxia, with elongation of the stem occurring faster when oxygen is absent. this response, which allows the shoot to reach oxygenated waters, occurs despite a 69-81% reduction in the rate of atp production, and it is underpinned by several physiological and metabolic adaptations that contri ... | 2006 | 16284407 |
| the flagellin gene and protein from the brewing spoilage bacteria pectinatus cerevisiiphilus and pectinatus frisingensis. | flagellin genes from the anaerobic gram-negative beer-spoilage bacteria pectinatus cerevisiiphilus and pectinatus frisingensis were sequenced and the flagellin proteins initially characterized. protein microsequencing led to the design of two degenerate pcr primers that allowed the p. cerevisiiphilus flagellin gene to be partially sequenced. a combination of pcr and bubble pcr was then used to sequence the flagellin genes of three isolates from each species. cloning and gene expression, followed ... | 2005 | 16333346 |
| selective-differential medium for isolation and differentiation of pectinatus from other brewery microorganisms. | an agar medium, ll-agar (lactate-lead acetate) was designed to selectively differentiate members of the genus pectinatus (s. y. lee, m. s. mabee, and n. o. jangaard, int. j. syst. bacteriol. 28:582-594, 1978; s. y. lee, m. s. mabee, n. o. jangaard, and e. k. horiuchi, j. inst. brew. 86:28-30, 1980) from other brewery microorganisms. selectivity was achieved by the use of sodium lactate as the sole source of carbon and phenylethyl alcohol as an inhibitor for aerobic gram-negative bacteria and yea ... | 1981 | 16345712 |
| microbiological, biochemical, and electron microscopic characterization of a pectinatus strain. | a spoilage organism isolated from turbid beer is described. the bacterium was gram negative, catalase negative, strictly anaerobic, and rod shaped, having flagella only on one side of the cell. the main metabolic product was propionic acid. in addition acetic, succinic, and lactic acids and acetoin were formed. malonate inhibited the production of propionic acid by the strain studied and by both pectinatus and propionibacterium strains. the guanine-plus-cytosine content of deoxyribonucleic acid ... | 1981 | 16345720 |
| immunological characterization of pectinatus cerevisiophilus strains. | eleven pectinatus cerevisiophilus strains of brewery origin were classified serologically by gel diffusion precipitin tests, immunoelectrophoresis, and the fluorescent antibody staining technique. the pectinatus strains could be assigned immunologically to three different groups. groups i and iii were found to be very closely related, and only some of the antisera used showed differences. the antisera against the strains belonging to group ii contained a common group antigen. a strong precipitat ... | 1983 | 16346412 |
| response surface models to describe the effects of temperature, ph, and ethanol concentration on growth kinetics and fermentation end products of a pectinatus sp. | growth curve data which had been fitted by use of the gompertz and logistic functions have permitted the development of mathematical models to describe the growth of a pectinatus sp. by several variables, namely, temperature, ph, and ethanol concentration. the activation energy of this microorganism was lower at 26 to 35(deg)c than at 15 to 22(deg)c. on the basis of the arrhenius law, growth rate, maximum population density, and cell yield models have been developed by introducing the different ... | 1996 | 16535289 |
| megasphaera paucivorans sp. nov., megasphaera sueciensis sp. nov. and pectinatus haikarae sp. nov., isolated from brewery samples, and emended description of the genus pectinatus. | seven unidentified strictly anaerobic, gram-negative, non-spore-forming bacteria from spoiled beer or the brewery environment were characterized. based on 16s rrna gene sequence analyses, all strains were affiliated to the sporomusa sub-branch of the class 'clostridia'. three of the strains were non-motile cocci, on average 1.5 x 1.2 microm or 1.2 x 1.0 microm, occurring mainly singly or in pairs. they shared nearly identical (>99 %) 16s rrna gene sequences, being most closely related to the spe ... | 2006 | 16585679 |
| australicola pectinatus n. gen. and n. sp. (cestoda: pseudophyllidea) from the deep-sea fish beryx splendens from tasmania. | australicola pectinatus n. gen., n. sp. (pseudophyllidea: triaenophoridae) is proposed to accommodate a new cestode from a deep-sea fish, the splendid alfonsino, beryx splendens lowe, 1834 (beryciformes: berycidae), from the pacific coast of tasmania. the new genus is placed in the triaenophoridae, because it possesses a ventral uterine pore, marginal genital pore, and follicular vitellarium. australicola is characterized by possessing a massive strobila with very short and wide, markedly craspe ... | 2006 | 16629325 |
| effects of iron and oxygen on chlorophyll biosynthesis : i. in vivo observations on iron and oxygen-deficient plants. | corn (zea mays, l.), bean (phaseolus vulgaris l.), barley (hordeum vulgare l.), spinach (spinacia oleracea l.), and sugarbeet (beta vulgaris l.) grown under iron deficiency, and potamogeton pectinatus l, and potamogeton nodosus poir. grown under oxygen deficiency, contained less chlorophyll than the controls, but accumulated mg-protoporphyrin ix and/or mg-protoporphyrin ix monomethyl ester. no significant accumulation of these intermediates was detected in the controls or in the tissue of plants ... | 1982 | 16662138 |
| changes in the activities of ribulose 1,5-bisphosphate and phosphoenolpyruvate carboxylases in submersed aquatic angiosperms during aging. | changes in the activities of ribulose-1,5-bisphosphate carboxylase (rubpcase) and phosphoenolpyruvate carboxylase (pepcase) during aging and senescence of leaves of submersed aquatic angiosperms, potamogeton pectinatus l., vallisneria spiralis l., and hydrilla verticillata (l.f.) royle were studied. the activity of rubpcase decreased with both aging and senescence in three species. pepcase activity increased from young to mature leaves in all three plants and also in old leaves of hydrilla. the ... | 1982 | 16662625 |
| animal-plant-microbe interactions: direct and indirect effects of swan foraging behaviour modulate methane cycling in temperate shallow wetlands. | wetlands are among the most important ecosystems on earth both in terms of productivity and biodiversity, but also as a source of the greenhouse gas ch(4). microbial processes catalyzing nutrient recycling and ch(4) production are controlled by sediment physico-chemistry, which is in turn affected by plant activity and the foraging behaviour of herbivores. we performed field and laboratory experiments to evaluate the direct effect of herbivores on soil microbial activity and their indirect effec ... | 2006 | 16736186 |
| karyotypic differences and evolutionary tendencies of some species from the subgenus obliquodesmus mlad. of genus scenedesmus meyen (chlorophyta, chlorococcales). | karyotype structures of scenedesmus acuminatus (lagerch.) chod. and scenedesmus pectinatus meyen are compared. the karyotype of s. acuminatus (n = 5) is described for the first time. it reveals four large metacentric and one large submetacentric chromosomes (4m + 1sm). the established karyotype differences have been helpful in clarifying the taxonomic position of these two species. the cytological analyses of other related clonal cultures suggest an evolutionary transition from s. pectinatus tow ... | 2006 | 16809838 |
| variability in survival of pectinatus cerevisiiphilus, strictly anaerobic bacteria, under different oxygen conditions. | survival of pectinatus cerevisiiphilus dsm 20466 in pure culture at variable temperatures under different oxygen concentrations was measured. survival of p. cerevisiiphilus in co-culture with saccharomyces cerevisiae under both saturated oxygen and brewing conditions was also studied. the survival of strictly anaerobic bacteria to oxygen seems to follow the classical laws of heat resistance. the d(oxy) values of p. cerevisiiphilus , calculated as a function of oxygen level, shows that the oxygen ... | 1995 | 16887521 |
| geobacter pickeringii sp. nov., geobacter argillaceus sp. nov. and pelosinus fermentans gen. nov., sp. nov., isolated from subsurface kaolin lenses. | the goal of this project was to isolate representative fe(iii)-reducing bacteria from kaolin clays that may influence iron mineralogy in kaolin. two novel dissimilatory fe(iii)-reducing bacteria, strains g12(t) and g13(t), were isolated from sedimentary kaolin strata in georgia (usa). cells of strains g12(t) and g13(t) were motile, non-spore-forming regular rods, 1-2 mum long and 0.6 mum in diameter. cells had one lateral flagellum. phylogenetic analyses using the 16s rrna gene sequence of the n ... | 2007 | 17220454 |
| [macrophytes from some high andean lakes of ecuador and their low potential as bioindicators of eutrophication]. | the occurrence of macrophyte in three high andean lakes of ecuador, lago san pablo, laguna la mica and lago cuicocha was recorded in 5-9 transects per lake. the first two lakes are eutrophic, the third is an extremely oligotrophic caldera lake. the dominant species in eutrophic lakes are ceratophyllum demersum, myriophyllum quitense, polamogeton illinoensis, p. striatus and elodea matthewsii. in the oligotrophic lake p. pectinatus, p. illinoensis, and the characeae chara rusbyana, ch. globularis ... | 2004 | 17354391 |
| [taxonomic list of the asteroids (echinodermata: asteroidea) from the shelf and superior slope from the colombian caribbean]. | between 1998 and 2001 we surveyed the benthic macrofauna of the continental shelf and its upper slope in the colombian caribbean. the invemar-macrofauna i-ii expeditions used a "semi-ballon" net were for 10 minute bottom drags from punta gallinas (guajira) to arboletes (antioquia). these covered seven ecological sectors from the colombian caribbean: guajira (gua), palomino (pal), tayrona (tay), magdalena (mag), archipiélagos coralinos (arco), morrosquillo (mor), and darié (dar). we collected 410 ... | 2005 | 17469252 |
| [methane emission from aquatic vegetation zones of wuliangsu lake, inner mongolia]. | to quantify the variations of methane fluxes from different aquatic vegetation zones, two-year measurements were measured at different aquatic vegetation zones and water depths using static chamber technique during two growing season from april to october in 2003 and 2004. results showed that the average emission flux of ch4 from potamogeton pectinatus (submerged macrophyte) growing zones was (3.44 +/- 1.60) mg x (m2 x h)(-1), 78.06% lower than that from phragmites australis (emergent macrophyte ... | 2007 | 17633615 |
| concentrations of heavy metals and aquatic macrophytes of govind ballabh pant sagar an anthropogenic lake affected by coal mining effluent. | five heavy metals cu, cd, mn, pb and hg were found in high concentration from three sampling sites located in asia's largest anthropogenic lake govind ballabh pant gbp sagar. concentrations of these heavy metals were measured in water, bottom sediment and in different parts of the aquatic macrophytes collected from the reservoir. plants collected from the lake were eichhornia crassipes, azolla pinnata, lemna minor, spirodela polyrrhiza, potamogeton pectinatus, marsilea quadrifolia, pistia strati ... | 2008 | 17674134 |
| syringophilus bi-pectinatus a quill mite of poultry. | | 1932 | 17770547 |
| bioaccumulation of heavy metals by the aquatic plants potamogeton pectinatus l. and potamogeton malaianus miq. and their potential use for contamination indicators and in wastewater treatment. | the concentrations of heavy metals in the leaves of two aquatic plants potamogeton pectinatus l. and potamogeton malaianus miq., and the corresponding water and sediment samples from the donghe river in jishou city of hunan province, china were studied to investigate metal contamination from the intensive industrial activities in the surrounding area. results showed that the concentrations of heavy metals in the sediments, especially cd, mn and pb, were much higher than the eco-toxic threshold v ... | 2008 | 18178241 |
| differences in food assimilation between two coot species assessed with stable isotopes and particle size in faeces: linking physiology and conservation. | the red-knobbed coot fulica cristata experienced a dramatic population decline in spain, where the common coot f. atra does not face conservation problems. this is puzzling because both species have similar ecologies. it has been suggested that habitat alterations affected the quality of food plants, and this impacted differentially both coots. to verify this, we conducted experiments to determine the assimilation efficiency of both species in relation to food quality. two types of diets differi ... | 2008 | 18222102 |
| swan foraging shapes spatial distribution of two submerged plants, favouring the preferred prey species. | compared to terrestrial environments, grazing intensity on belowground plant parts may be particularly strong in aquatic environments, which may have great effects on plant-community structure. we observed that the submerged macrophyte, potamogeton pectinatus, which mainly reproduces with tubers, often grows at intermediate water depth and that p. perfoliatus, which mainly reproduces with rhizomes and turions, grows in either shallow or deep water. one mechanism behind this distributional patter ... | 2008 | 18335250 |
| group-specific pcr-rflp and real-time pcr methods for detection and tentative discrimination of strictly anaerobic beer-spoilage bacteria of the class clostridia. | the strictly anaerobic brewery contaminants of the genera pectinatus, megasphaera, selenomonas and zymophilus in the class clostridia constitute an important group of spoilage bacteria of unpasteurised, packaged beers. the aim of this study was to develop and evaluate group-specific pcr methods to detect and differentiate these bacteria in beer. a group-specific primer pair targeting a 342-bp variable region of the 16s rrna gene was designed and evaluated in end-point pcr with gel electrophoresi ... | 2008 | 18502530 |
| the status of the species pectinatus portalensis gonzalez et al. 2005. request for an opinion. | on the basis of 16s rrna gene sequence analysis and several key phenotypic features, it was ascertained that the cultures cited as the type strain of the species pectinatus portalensis, cect 5841(t) and lmg 22865(t), do not conform to the description, [gonzalez, j. m., jurado, v., laiz, l., zimmerman, j., hermosin, b. & saiz-jimenez, c. (2004). antonie van leeuwenhoek 86, 241-248]. the type strain does not exist in any other established culture collection or with the authors who described this s ... | 2008 | 18523204 |
| psychrosinus fermentans gen. nov., sp. nov., a lactate-fermenting bacterium from near-freezing oxycline waters of a meromictic antarctic lake. | a novel, obligately anaerobic, fermentative bacterium, strain fcf9, was isolated from a 9-m water sample from permanently ice-covered, meromictic lake fryxell, antarctica. a phylogenetic analysis based on 16s rrna gene sequence identity clustered the antarctic isolate within the sporomusa-pectinatus-selenomonas phyletic group, where it was most closely related to pelosinus fermentans (95.5% sequence identity). however, unlike species of pelosinus, strain fcf9 was psychrophilic, with growth occur ... | 2008 | 18673392 |
| oligonucleotide microarrays for the detection and identification of viable beer spoilage bacteria. | the design and evaluation of an oligonucleotide microarray in order to detect and identify viable bacterial species that play a significant role in beer spoilage. these belong to the species of the genera lactobacillus, megasphaera, pediococcus and pectinatus. | 2008 | 18785882 |
| modified multiplex pcr methods for comprehensive detection of pectinatus and beer-spoilage cocci. | specific pcr primers were designed based on the 16s rrna genes of recently proposed beer-spoilage species, pectinatus haikarae, megasphaera sueciensis, and m. paucivorans, and two sets of our previously reported multiplex pcr methods for pectinatus spp. and beer-spoilage cocci were reconstructed. each modified multiplex pcr method was found specifically to detect beer-spoilage species of pectinatus and cocci, including new species. | 2008 | 18838790 |
| characterization of two families of tandem repeated dna sequences in potamogeton pectinatus l. | dna sequences belonging to two families of tandem repeats, ppersa1 (362-364 bp in length, 62% a+t residues) and ppersa2 (355-359 bp in length, 59% a+t residues), have been isolated from the potamogeton pectinatus l. genome. the two sequence families do not share significant nucleotide sequence similarity, even if an evolutionary relationship between them could be assumed. the comparison of the cleaving activity of isoschizomeres that are either sensitive or insensitive to methylation of cytosine ... | 2008 | 18956019 |
| heavy metals in water, sediments and wetland plants in an aquatic ecosystem of tropical industrial region, india. | concentrations of heavy metals (cu, cr, fe, pb, zn, hg, ni, and cd) and macronutrients (mn) were measured in industrial effluents, water, bottom sediments, and wetland plants from a reservoir, govind ballabh (g.b.) pant sagar, in singrauli industrial region, india. the discharge point of a thermal power plant, a coal mine, and chlor-alkali effluent into the g.b. pant sagar were selected as sampling sites with one reference site in order to compare the findings. the concentrations of heavy metals ... | 2009 | 18998227 |
| megamonas rupellensis sp. nov., an anaerobe isolated from the caecum of a duck. | we report here the identification, characterization and culture of a gram-negative to gram-variable, rod-shaped, non-spore-forming anaerobic bacterium (strain fm1025(t)) isolated from the caecum of a duck. phylogenetic analysis based on comparative 16s rrna gene sequencing showed that this strain clustered with species of the family 'acidaminococcaceae', with 94.9 % similarity to megamonas hypermegale dsm 1672(t) and less than 91 % similarity with type strains of pectinatus species. sequence sim ... | 2008 | 19060083 |
| [community structure of edaphic cunaxids (acarina) from a lowland dry forest in chamela, mexico]. | the structure community of cunaxids mites was studied at a tropical dry forest in the chamela biological station, jalisco, mexico. monthly samples of litter and soil were taken during one year (july 1991-may 1992), in two small watersheds. a total of 43 species was recorded. we studied their abundance, species frequency (f), rareness and relative abundance (ar), density (ind m(-2)), species richness (s), shannon's diversity index (h'), and pielou's evenness index (j'). the species richness was s ... | 2007 | 19086395 |
| ecological studies on al-khadoud spring, al-hassa, saudi arabia. | al-khadoud spring is one of the most important water resources in al-hassa governorate, saudi arabia. however, much of its biotic information is still unknown. this study presented preliminary ecological information of this aquatic body. regarding to macrophytes, a total of eight species were observed along the study sites. these species include two submerged aquatic plants (potamogeton pectinatus l. and ceratophyllum demersum l.). the common distributed species are phragmites australis (cav.) t ... | 2007 | 19090280 |
| antimicrobial activity of some macrophytes from lake manzalah (egypt). | the antimicrobial activities of aqueous and organic solvents (chloroform, ethanol and methanol) extracts of four plants ceratophyllum demersum l., eichhornia crassipes, potamogeton crispus and potamogeton pectinatus were tested in vitro against seventeen different microorganisms including gram-positive and gram-negative bacteria and fungi. nine of these identified organisms were obtained from different sources, bacillus subtilis 1020, bacillus cereus 1080, staphylococcus aureus, erwinia carotovo ... | 2008 | 19205264 |
| compensatory growth in an aquatic plant mediates exploitative competition between seasonally tied herbivores. | the degree to which vertebrate herbivores exploitatively compete for the same food plant may depend on the level of compensatory plant growth. such compensation is higher when there is reduced density-dependent competition in plants after herbivore damage. whether there is relief from competition may largely be determined by the life-history stage of plants under herbivory. such stage-specific compensation may apply to seasonal herbivory on the clonal aquatic plant sago pondweed (potamogeton pec ... | 2009 | 19694137 |
| molecular inventory of faecal microflora in patients with crohn's disease. | intestinal microbial community is involved in the pathogenesis of crohn's disease, but knowledge of its potential abnormalities has been limited by the impossibility to grow many dominant intestinal bacteria. using sequence analysis of randomly cloned bacterial 16s ribosomal dna, the dominant faecal species from four crohn's disease patients and four controls were compared. whereas marked inter-individual differences were observed in the faecal microflora of patients, three remained distantly re ... | 2004 | 19712374 |
| above- and below-ground vertebrate herbivory may each favour a different subordinate species in an aquatic plant community. | at least two distinct trade-offs are thought to facilitate higher diversity in productive plant communities under herbivory. higher investment in defence and enhanced colonization potential may both correlate with decreased competitive ability in plants. herbivory may thus promote coexistence of plant species exhibiting divergent life history strategies. how different seasonally tied herbivore assemblages simultaneously affect plant community composition and diversity is, however, largely unknow ... | 2010 | 19756762 |
| a review of the leafhopper genus scaphotettix matsumura (hemiptera: cicadellidae: deltocephalinae), with description of a new genus. | the leafhopper genus scaphotettix matsumura is redescribed, and three new species are described and illustrated: s. striatus dai and zhang, sp. nov. from java (on bamboo) and china; s. bispinosus dai and zhang, sp. nov from china; and s. pectinatus dai and zhang, sp. nov. from vietnam. most other species of scaphotettix were re-examined and found to belong to a new genus also described herein, scaphomonus viraktamath, gen. nov.. the new genus is compared with the superficially similar melanetett ... | 2009 | 19799517 |
| quantitative assessment of ammonia-oxidizing bacterial communities in the epiphyton of submerged macrophytes in shallow lakes. | in addition to the benthic and pelagic habitats, the epiphytic compartment of submerged macrophytes in shallow freshwater lakes offers a niche to bacterial ammonia-oxidizing communities. however, the diversity, numbers, and activity of epiphytic ammonia-oxidizing bacteria have long been overlooked. in the present study, we analyzed quantitatively the epiphytic communities of three shallow lakes by a potential nitrification assay and by quantitative pcr of 16s rrna genes. on the basis of the m(2) ... | 2010 | 20097811 |
| internal dispersal of seeds by waterfowl: effect of seed size on gut passage time and germination patterns. | long distance dispersal may have important consequences for gene flow and community structure. the dispersal of many plants depends on transport by vertebrate seed dispersers. the shapes of seed shadows produced by vertebrates depend both on movement patterns of the dispersers and on the dynamics and effects of passage through the disperser's gut (i.e. the retention time, survival and germination of ingested seeds). a combination of experiments with captive waterbirds and aquatic plant seeds was ... | 2010 | 20428840 |