| an insect parasitoid carrying an ochratoxin producing fungus. | the insect parasitoid prorops nasuta has been introduced from africa to many coffee-producing countries in an attempt to control the coffee berry borer. in this paper, we report on the sequencing of the its lsu-rdna and beta-tubulin loci used to identify a fungus isolated from the cuticle of a p. nasuta that emerged from coffee berries infected with the coffee berry borer. the sequences were compared with deposits in genbank and the fungus was identified as aspergillus westerdijkiae. the fungus ... | 2006 | 16555098 |
| agrobacterium-mediated insertional mutagenesis of the ochratoxigenic fungus aspergillus westerdijkiae. | aspergillus westerdijkiae is a potent ochratoxin a (ota) producer that has been found in coffee beans. ota is known to have nephrotoxic effects and carcinogenic potential in animal species. here we report for the first time the agrobacterium-mediated transformation for aspergillus westerdijkiae and the generation of ochratoxin-defective mutants. conidia were transformed to hygromycin b resistance using strain agl-1 of agrobacterium tumefaciens. the obtained transformation frequency was up to 47 ... | 2007 | 17496961 |
| detection and quantification of aspergillus westerdijkiae in coffee beans based on selective amplification of beta-tubulin gene by using real-time pcr. | aspergillus westerdijkiae is a new species of fungus that was recently dismembered from aspergillus ochraceus taxon. most isolates of a. westerdijkiae are able to produce large amounts of a mycotoxin called ochratoxin a (oa). oa has been found in food and beverages, such as coffee. a. westerdijkiae is very similar to a. ochraceus, and several isolates previously identified as a. ochraceus are now identified as a. westerdijkiae. by using sequences of the beta-tubulin gene, we analyzed several iso ... | 2007 | 17900727 |
| isolation, identification and toxigenic potential of ochratoxin a-producing aspergillus species from coffee beans grown in two regions of thailand. | in 2006 and 2007, 32 thai dried coffee bean samples (coffea arabica) from two growing sites of chiang mai province, and 32 thai dried coffee bean samples (coffea canephora var. robusta) from two growing sites of chumphon province, thailand, were collected and assessed for the distribution of fungi with the potential to produce ochratoxin a (ota). the overall percentage of fungal contamination in coffee was 98% and reduced to 60% after surface disinfection. there were remarkable ecological differ ... | 2008 | 18819720 |
| aspergillus westerdijkiae polyketide synthase gene "aoks1" is involved in the biosynthesis of ochratoxin a. | ochratoxin a (ota) is a potential nephrotoxic, teratogenic, immunogenic, hepatotoxic and carcinogenic mycotoxin, produced by aspergillus westerdijkiae nrrl 3174. herein we describe the characterization of a putative ota-polyketide synthase gene "aoks1", cloned by using gene walking approach. the predicted amino acid sequence of the 2kb clone display 34-60% similarities to different polyketide synthase genes including lovastatine biosynthesis gene "lovb" in a. terreus, compactin biosynthesis gene ... | 2009 | 18955151 |
| its-based detection and quantification of aspergillus ochraceus and aspergillus westerdijkiae in grapes and green coffee beans by real-time quantitative pcr. | aspergillus ochraceus and a. westerdijkiae are considered the most important ochratoxin a (ota) producing species included in aspergillus section circumdati which contaminate foodstuffs and beverages for human consumption. in this work a real-time quantitative pcr protocol was developed to detect both species using sybr green and primers designed on the basis of the multicopy its1 region of the rdna. the assay had high efficiency (94%) and showed no inhibition by host or fungal dna other than th ... | 2009 | 19268380 |
| ochratoxin a production by aspergillus westerdijkiae in orange fruit and juice. | to evaluate the incidence of fungi producing ochratoxin a in orange fruit and juice a survey was carried out by challenge test with ochratoxin a producing strains of aspergillus westerdijkiae used as the model system. a. westerdijkiae grew into experimental lesions caused on orange surfaces, in orange natural medium and in orange juice and produced ota in all environments. the higher temperature of 26 degrees c had a greater influence than temperatures of 20 degrees c and 4 degrees c on the grow ... | 2009 | 19447511 |
| cloning and characterization of novel methylsalicylic acid synthase gene involved in the biosynthesis of isoasperlactone and asperlactone in aspergillus westerdijkiae. | aspergillus westerdijkiae is the main producer of several biologically active polyketide metabolites including isoasperlactone and asperlactone. a 5298bp polyketide synthase gene "aomsas" has been cloned in aspergillus westerdijkiae by using gene walking approach and race-pcr. the predicted amino acid sequence of aomsas shows an identity of 40-56% with different methylsalicylic acid synthase genes found in byssochlamys nivea, p. patulum, a. terreus and streptomyces viridochromogenes. based on th ... | 2009 | 19589392 |
| discrimination of the main ochratoxin a-producing species in aspergillus section circumdati by specific pcr assays. | ochratoxin a (ota) is one of the most important mycotoxins because of its high toxicity to both humans and animals and its occurrence in a number of basic foods and agro-products. some of the main ota-producing species belong to aspergillus section circumdati, whose taxonomy has been lately revised with the description of new species. the high morphological similarity of these species (aspergillus ochraceus, aspergillus steynii and aspergillus westerdijkiae) makes difficult discrimination among ... | 2009 | 19819579 |
| Mechanisms involved in reduction of ochratoxin A produced by Aspergillus westerdijkiae using Debaryomyces hansenii CYC 1244. | Aspergillus westerdijkiae is one of the most relevant ochratoxin A (OTA) producing species within the Section Circumdati contaminating a number of agroproducts. The yeast Debaryomyces hansenii CYC 1244 was previously reported to be able to reduce growth and extracellular OTA produced by A. westerdijkiae. In this work, we examined several mechanisms possibly involved in this OTA reduction in in vitro experiments. OTA biosynthesis was evaluated by quantitation of expression levels of pks (polyketi ... | 2011 | 21899908 |
| does fungicide application in vineyards induce resistance to medical azoles in aspergillus species? | this study assessed if the use of sterol demethylase inhibitor fungicides in vineyard production can induce resistance to azoles in aspergillus strains and if it can induce selection of resistant species. we also tried to identify the aspergillus species most prevalent in the vineyards. two vineyards from northern portugal were selected from "vinhos verdes" and "douro" regions. the vineyards were divided into plots that were treated or not with penconazole (pen). in each vineyard, air, soil, and ... | 2014 | 24833021 |
| monitoring the mycobiota of three plants manufacturing culatello (a typical italian meat product). | this study reports the composition of the mycobiota growing on the surface of culatello (a typical italian meat product) and occurring in the environments of three processing plants. samples were collected in both winter and summer. a total of 84 culatelli and 14 samples from the plant environment were examined. a total of 331 (from food samples) and 2030 (from air samples) fungal isolates belonging to six genera and 29 species were identified. the substantial correspondence between air- and pro ... | 2015 | 25791253 |
| efficacy of different caffeine concentrations on growth and ochratoxin a production by aspergillus species. | the objective of this study was to evaluate the effect of different caffeine concentrations (0-4%) on (i) lag phase prior to growth, (ii) growth rates and (iii) ochratoxin a (ota) production by strains from the aspergillus section circumdati and aspergillus section nigri groups, isolated from coffee, when grown on a conducive medium at 0·98 water activity and 30°c. the lag phases prior to growth increased with caffeine concentration. a strain of aspergillus niger and aspergillus carbonarius were ... | 2016 | 27203680 |
| effect of different light wavelengths on the growth and ochratoxin a production in aspergillus carbonarius and aspergillus westerdijkiae. | the effects of light at different wavelengths and photoperiod on growth and ochratoxin a production of aspergillus carbonarius and aspergillus westerdijkiae were studied: far-red (740 nm), red (625 nm), blue (445 nm), and uv-a (366 nm). fungal growth was not significantly affected by photoperiod or light wavelength; the only exception was a. westerdijkiae which showed reduced growth under uv-a light (366 nm). short-wavelength blue light (445 nm) and uv-a light caused a reduction in ochratoxin a ... | 2016 | 27109370 |
| a new in vitro method to detect growth and ochratoxin a-producing ability of multiple fungal species commonly found in food commodities. | the aim of the study was to develop a new screening method to detect growth and ochratoxin a (ota) production by multiple fungi growing in a small quantity of culture media, using microtiter plates. eight ochratoxigenic species were included in the study. the strains were inoculated in sterile 96-well flat-bottom microtiter plates containing yeast extract sucrose broth and czapek yeast extract broth and incubated at 25 °c. growth was daily monitored by absorbance measurements for 4 days and exte ... | 2014 | 25084669 |
| anti-aspergillus activity of green coffee 5-o-caffeoyl quinic acid and its alkyl esters. | the antifungal activities of 5-o-caffeoyl quinic acid (5-cqa) and of methyl, butyl, octyl, and dodecyl esters or 5-cqa, were tested on five toxigenic moulds from the aspergillus genus (aspergillus flavus, aspergillus nomius, aspergillus ochraceus, aspergillus parasiticus, aspergillus westerdijkiae). these mycotoxin producers' moulds may contaminate many types of food crops throughout the food chain posing serious health hazard to animals and humans. the use of chemical methods to decrease mycoto ... | 2013 | 23684728 |
| comparison of five different c18 hplc analytical columns for the analysis of ochratoxin a in different matrices. | the performance of five different c18 chromatography analytical columns with different lengths, particle sizes and porosities were compared for analysis of ochratoxin a (ota) in fungal cultures and raisin samples. chromatographic parameters including retention time, limit of detection, limit of quantification, number of theoretical plates and reduced plate height were obtained and compared. this showed that, compared with traditional columns, shorter ones (100 and 75mm×4.6mm) with 2.7μm solid co ... | 2014 | 25270057 |
| aspergillus westerdijkiae as a major ochratoxin a risk in dry-cured ham based-media. | penicillium nordicum is well known for its ability to produce high amounts of ochratoxin a (ota) in cured meat-derived products. on the other hand, aspergillus westerdijkiae, one of the most relevant ota-producing species of the genus aspergillus, is usually considered a major risk in carbon-rich food matrices of plant origin. the objective of this work was to evaluate, for the first time, the ecophysiological conditions governing growth, ota production and sporulation of a. westerdijkiae (the t ... | 2017 | 27810446 |
| complete genome sequence of the filamentous fungus aspergillus westerdijkiae reveals the putative biosynthetic gene cluster of ochratoxin a. | ochratoxin a (ota) is a common mycotoxin that contaminates food and agricultural products. sequencing of the complete genome of aspergillus westerdijkiae, a major producer of ota, reveals more than 50 biosynthetic gene clusters, including a putative ota biosynthetic gene cluster that encodes a dozen of enzymes, transporters, and regulatory proteins. | 2016 | 27635003 |
| sequencing and functional annotation of the whole genome of the filamentous fungus aspergillus westerdijkiae. | aspergillus westerdijkiae produces ochratoxin a (ota) in aspergillus section circumdati. it is responsible for the contamination of agricultural crops, fruits, and food commodities, as its secondary metabolite ota poses a potential threat to animals and humans. as a member of the filamentous fungi family, its capacity for enzymatic catalysis and secondary metabolite production is valuable in industrial production and medicine. to understand the genetic factors underlying its pathogenicity, enzym ... | 2016 | 27527502 |
| isolation, selection and evaluation of antagonistic yeasts and lactic acid bacteria against ochratoxigenic fungus aspergillus westerdijkiae on coffee beans. | in this study, yeasts and lactic acid bacteria (lab) were isolated from coffee fruits and identified via biochemical and molecular approaches. the isolates represented the pichia, debaryomyces, candida, clavispora, yarrowia, sporobolomyces, klyveromyces, torulaspora and lactobacillus genera. four isolates, namely pichia fermentans lpbyb13, sporobolomyces roseus lpby7e, candida sp. lpby11b and lactobacillus brevis lpbb03, were found to have the greatest antagonist activity against an ochratoxigen ... | 2016 | 26544541 |
| toxic indole alkaloids avrainvillamide and stephacidin b produced by a biocide tolerant indoor mold aspergillus westerdijkiae. | toxic aspergillus westerdijkiae were present in house dust and indoor air fall-out from a residence and a kindergarten where the occupants suffered from building related ill health. the a. westerdijkiae isolates produced indole alkaloids avrainvillamide (445 da) and its dimer stephacidin b (890 da). it grew and sporulated in presence of high concentrations of boron or polyguanidine (phmb, phmg) based antimicrobial biocides used to remediate mold infested buildings. the boar sperm cells were used ... | 2015 | 25804991 |
| aspergillus steynii and aspergillus westerdijkiae as potential risk of ota contamination in food products in warm climates. | aspergillus steynii and aspergillus westerdijkiae are the main ochratoxin a (ota) producing species of aspergillus section circumdati. due to its recent description, few data are available about the influence of ecophysiological factors on their growth and ota production profiles. in this work, the effect of temperature (20, 24 and 28 °c) and water activity (aw) (0.928, 0.964 and 0.995) on growth, sporulation and ota production by these fungi was examined in cya and media prepared from paprika, ... | 2015 | 25475281 |
| westerdijkin a, a new hydroxyphenylacetic acid derivative from deep sea fungus aspergillus westerdijkiae scsio 05233. | a new methyl 2-(4-((2-hydroxy-3-methylbut-3-en-1-yl)oxy)phenyl) acetate 1, together with five known compounds 2-6, was isolated from the culture of the deep sea-derived fungus aspergillus westerdijkiae scsio 05233. the new structure was determined by nmr ((1)h and (13)c nmr, hsqc, hmbc and ms) and optical rotation analysis. compound 5 displayed weak inhibitory activities towards k562 and promyelocytic hl-60 with ic50 values of 25.8 and 44.9 μm, and compound 6 showed strong antifouling activity w ... | 2015 | 25325177 |
| antifouling potentials of eight deep-sea-derived fungi from the south china sea. | marine-derived microbial secondary metabolites are promising potential sources of nontoxic antifouling agents. the search for environmentally friendly and low-toxic antifouling components guided us to investigate the antifouling potentials of eight novel fungal isolates from deep-sea sediments of the south china sea. sixteen crude ethyl acetate extracts of the eight fungal isolates showed distinct antibacterial activity against three marine bacteria (loktanella hongkongensis ust950701-009, micro ... | 2014 | 24532297 |
| identification of genes differentially expressed between ochratoxin-producing and non-producing strains of aspergillus westerdijkiae. | approximately 70 % of aspergillus westerdijkiae strains are able to produce ochratoxin a (ota), a nephrotoxic and carcinogenic mycotoxin which have been found in cereal and food commodities. despite of its importance there is, up to now, no information available about which genes are differentially expressed between a. westerdijkiae ochratoxin-producing and non-producing strains. using cdna rda approach we successfully sequenced 231 raw ests expected to be enriched in the ochratoxin-producing st ... | 2014 | 24426165 |
| alkaloids from the deep-sea-derived fungus aspergillus westerdijkiae dffscs013. | two new benzodiazepine alkaloids, circumdatins k and l (1, 2), two new prenylated indole alkaloids, 5-chlorosclerotiamide (3) and 10-epi-sclerotiamide (4), and one novel amide, aspergilliamide b (5), together with six known alkaloids were isolated from the deep-sea-derived fungus aspergillus westerdijkiae dffscs013. their structures were elucidated by extensive spectroscopic analysis. all of the compounds were tested for cytotoxicity toward human carcinoma a549, hl-60, k562, and mcf-7 cell lines ... | 2013 | 23701598 |
| kinetics of mould growth in the stored barley ecosystem contaminated with aspergillus westerdijkiae, penicillium viridicatum and fusarium poae at 23-30 °c. | owing to the lack of a rapid method for determining fungi on cereals, the best way to enhance the safety and nutritive value of stored grain is to develop prognostic tools based on the relationship between easily measurable online parameters, e.g. water activity (a(w)) and temperature (t) of grain, and fungal growth. this study examined the effect of unfavourable temperature (23 and 30 °c) and humidity (0.80-0.94 a(w)) storage conditions on mould growth in the stored barley ecosystem with its ad ... | 2013 | 22903624 |
| microbiological quality of argentinian paprika. | the aim of this study was to evaluate the microbiological quality of paprika produced in catamarca, argentina. microbiological analyses were carried out for the enumeration of total aerobic mesophilic bacteria, coliforms, yeasts and molds, and the detection of salmonella in samples obtained from different local producers during three consecutive years. the mycobiota was identified paying special attention to the mycotoxigenic molds. standard plate counts of aerobic mesophilic bacteria ranged fro ... | 2017 | 28571612 |