Verrucosum Var Research Articles

Influence of selected soil saprotrophes on gas exchange, growth and yield of Solanum tuberosum

The influence of saprotrophic soil fungi: Aspergillus versicolor, Penicillium frequentans, Penicillium verrucosum var. cyclopium, and Trichocladium asperum on development, wholesomeness, gas exchange and yield of potato cv. Mila was studied in pot experiments during 1998–2000. The presence of each of the mentioned fungi species in soil accelerated potato germination and stimulated growth of overground plant parts in comparison with control plants. Additionally, the presence of the tested saprotrophes in soil prologed the potato growing period by inhibiting chloroses of necroses. The tested saprotrophic fungi also modified plant physiological processes, such as transpiration and assimilation. The contact of plant root system with soil saprotrophes diminished significantly assimilation and transpiration intensity of overground parts in comparison with the control plants, in all the years of the experiment. However, this response did not reduce the yield of tubers.

Effect of fungicides on the growth of fungi isolated from in vitro propagated fruit-bearing plants

The aim of the work was to determine the effect of fungicides: Topsin M 70 WG, Bravo 500 SC, and Sportak 45 EC in two concentrations on the growth of fungi: Aspergillus niger, Epicoccum purpurascens, Cladosporium sphaerospermum, Mortierella isabellina and Penicillium verrucosum var. verrucosum on PDA and Murashige-Skoog medium (MS). The smallest index of linear growth rate of the fungi had Topsin M 70 WG for fungi: E. purpurascens and P. verrucosum var. verrucosum on PDA and MS medium and for M. isabellina and C. sphaerospermum on MS in concentrations of 71.42 mg/l and 107.13 mg/l. The highest index of linear growth had Bravo 500 SC in concentrations of 0.5 ml/l and 0.75 ml/l on PDA for E. purpurascens and A. niger. The lowest index of linear growth on MS for E. purpurascens, C. sphaerospermum and P. verrucosum var. verrucosum was noted down. The highest effectiveness in control of linear growth all tested species of fungi was found for fungicide Sportak 45 EC in concentration of 0.55 ml/l and 0.825 ml/l on MS and PDA. Among all tested fungicides used in vitro propagation fungicides from imidazoles group are recommended.

Immunochemical method for cyclopiazonic acid.

Cyclopiazonic acid (CPA) Fig. 1) is a toxic, indole tetramic acid that was originally isolated from Penicillium cyclopium Westling () and subsequently reported to be produced by numerous species of Penicillium and Aspergillus (). Among the species of Aspergillus that produce CPA is A. flavus, which is primarily known as a producer of the aflatoxins and is a frequent contaminant of corn, peanuts, and other commodities. The taxonomy of Penicillium species that produce CPA has undergone several revisions, but Pitt et al. () concluded that the correct name for most saprophytic Penicillia that produce CPA is P. commune with P. palitans as a synonym. This would include the original isolate variously identified as P. cyclopium (), P. griseofulvum (4), and P. verrucosum var. cyclopium (). Pitt et al. () also classified all molds used in the manufacture of white cheeses that produce CPA as P. camembertii. Based primarily on chemotaxonomical features coupled with conidial colors on Czapek yeast autolysate agar, Lund () concluded that P. palitans was not just synonymous with P. commune, but was actually a distinct species. Despite some confusion with regard to the taxonomy of CPA-producing Penicillia, the fact remains that the various species of Penicillium and Aspergillus that produce CPA are ubiquitous and abundant in nature and are common contaminants of commodities that go into foods and feeds. Therefore, the potential for the contamination of commodities with CPA is widespread (). Open image in new window Fig. 1. Chemical structure of cyclopiazonic acid.

Some additions to the desmid flora of New Zealand

Abstract Desmids from two unnamed tarns beside the Routeburn Track and from Peter's Pool, a young kettle-hole near Franz Josef Glacier, included Staurodesmus pachyrhynchus var. nothogeae Skuja (thereby confirming his proposed taxon), Staurastrum osvaldii Skuja var. brevibrachiatum var. nov., and S. pseudassurgens Mask. var. robustum var. nov. More specimens are needed to verify that a new variety of Cosmarium decedens (Reinsch) Racib., a new form of Euastrum binale (Turp.) Ehr., and reduced forms of E. verrucosum var. alpinum (Huber-Pest.) Krieg. were in the samples.

In vivo formation of diazepam-like 1,4-benzodiazepines by Penicillium verrucosum var. verrucosum after administration of 2-aminobenzophenones and glycine.

The in vivo formation of the diazepam-like 1,4-benzodiazepine deschloronordiazepam from its assumed biogenetic precursors, 2-amino-benzophenone and glycine, by the mould strain Penicillium verrucosum var. verrucosum, is described. Deschloronordiazepam formation was established by GC/MSD analysis monitoring characteristic fragment patterns of the benzodiazepine moiety. The identification of deschloronordiazepam was confirmed by feeding experiments of D5-2-aminobenzophenone, as well as its brominated and chlorinated derivatives to the mould. The formation of the 1,4-benzodiazepine was observed to depend on various factors, e.g. the time of application of the precursors, duration of the incubation and kind of cultivation. The results represent the first actual de novo synthesis of such diazepam-like 1,4-benzodiazepines from plausible biosynthetic precursors in a living organism, in agreement with a biosynthetic concept recently established in our group. Such pharmacologically active 1,4-benzodiazepines had been detected in trace amounts in mammalian and plant tissues. Because of their unusual molecular framework, they had previously been considered not to fit into any conventional biosynthetic route.

Isolation and Structure Determination of a New Roquefortine-Related Mycotoxin from Penicillium verrucosum var. cyclopium Isolated from Cassava

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIsolation and Structure Determination of a New Roquefortine-Related Mycotoxin from Penicillium verrucosum var. cyclopium Isolated from CassavaA. Musuku, M. I. Selala, T. de Bruyne, M. Claeys, P. J. C. Schepens, A. Tsatsakis, and M. I. ShtilmanCite this: J. Nat. Prod. 1994, 57, 7, 983–987Publication Date (Print):July 1, 1994Publication History Published online1 July 2004Published inissue 1 July 1994https://doi.org/10.1021/np50109a017RIGHTS & PERMISSIONSArticle Views233Altmetric-Citations15LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (312 KB) Get e-Alerts Get e-Alerts

Microbial contaminants cause swelling and inward collapse of yoghurt packs

A study was carried out on 10 retail samples 01 yoghurt, belonging to 3 different brands (A, Band C), showing a rarely described alteration consisting 01 inward collapse 01 the packs. Microbiological analyses revealed the presence 01 high counts 01 different microbial contaminants: in A sampies Acetobacter aceti was lound at 107 clu/g, while in Band C sampies the main contaminants were Mucor hiemalis Mucor racemosus and Penicillium verrucosum var cyc/opium varying between 102 and 105 clu/g. The responsibility 01 isolated strains lor alteration was conlirmed by inoculating cellular suspensions in non-contaminated yoghurt packs kept at 5°C and 25°C: samples inoculated with A aceti showed an inward collapse alter 20 d at 25°C; packs inoculated with M hiemalis, M racemosus and P verrucosum var cyc/opium kept at 25°C showed swelling alter 5-7 d lollowed by inward collapse alter = 20-35 d. In sampies kept at 5°C the delect did not appear even extending the incubation time to 60 d. The explanation lor the evolution 01 this delect is the 101lowing one; contaminating microorganisms consume oxygen contained in head-space 01 pack and produce CO2 whose re-absorption into the product causes a partial vacuum involving collapse 01 the pack.

Phylogeny of the genera Trichophyton using mitochondrial DNA analysis

Diversity of mitochondrial DNA (mtDNA) was investigated in 92 Trichophyton rubrum strains, 2 T. mentagrophytes var. mentagrophytes, 2 T. m. var. interdigitale, 2 T. m. var. goetzii, 1 T. m. var. erinacei, 2 T. quinckeanum, 2 T. schoenleinii, 1 T. tonsurans, 2 T. verrucosum var. album, 2 T. v. var. discoides, 1 T. violaceum var. violaceum, 1 Arthroderma benhamiae, and 1 A. vanbreuseghemii using endonucleases, Hae III, Msp I, Hind III, Xba I, and Bgl II. Trichophyton species were divided into 7 groups, and a phylogenetic tree was produced based on sequence divergence within mtDNA. The following results were obtained: (1) T. rubrum was divided into 2 groups Type I and Type II, and was suggested to be a complex. (2) A. benhamiae was closely related to T. m. var. erinacei. (3) T. rubrum Type II, T. tonsurans, and A. vanbreuseghemii showed identical restriction profiles, and were suggested to be closely related to each other or identical. (4) T. quinckeanum and T. schoenlenii showed identical restriction profiles, which differed slightly from those of A. vanbreuseghemii. (5) mtDNA analysis was useful in identifying pleomorphic strains.

Spore exposure arising from stored hay, grain and straw

The quantitative and qualitative differences in microbe exposure arising from hay, grain and straw during the end of the indoor feeding period were investigated by using a six-stage fractionating impactor (model 10—800, Andersen Inc.). Straw samples (n = 5) liberated significantly higher amounts of spores (3.7 x 106 cfu/m3 air) in comparison to hay samples (n = 33) and grain samples (n = 2), which liberated 0.6 x 106 cfu/m3 and 0.2 x 106 cfu/m3 , respectively. Thermotolerant and thermophilic microflora were typical of the exposure originating from straw. Hay liberated about 10 % and grain only 0.7 %, the level of spores of thermotolerant fungi liberated from straw. The corresponding percentages of spores of thermophilic actinomycetes were 5 % and 0.4 %. Thermoactinomyces vulgaris was the dominating microbe in the exposure caused by straw; Aspergillus umbrosus was the major species in the microflora liberated from hay and grain. Other Aspergillus (A.) species (A. fumigatus, A. ochraceus, A. flavus, A. repens, A. versicolor) and Penicillium (P.) species (P. expansum, P. piceum, P. citrinum, P. brevicompactum, P. echinulatum, P. verrucosum var. cyclopium) occurred frequently, and in great amounts, in all the analysed materials. Spores of Cladosporium (C.) species (mainly C. herbarum, C. cladosporioides, and C. macrocarpum) were found frequently, and abundantly, during the handling of hay. The present results suggest that not only the traditional causative agents of farmer’s lung disease but also other fungal and actinomycete species may be found in high concentrations during the handling of bedding and feeding stuffs, and that these fungal and actinomycete exposures may cause respiratory symptoms and other health problems in both man and animals. Special attention should be paid to decreasing the moisture content of hay and straw before storing in order to lower the risk of moulding during the indoor feeding period.

Immunological differentiation of Penicillium species.

Antisera were obtained from a rabbit immunized with Penicillium verrucosum var. verrucosum. These antisera were characterized by immunofluorescence and by indirect enzyme-linked immunosorbent assay for their reactivity with 44 strains of moulds. Antigenically, P. verrucosum var. verrucosum (subgenus Penicillium) appears to be similar to strains belonging to subgenus Furcatum, but strongly different from Penicillium frequentans (subgenus Aspergilloides). Specific absorption of antibodies to antigens confirmed the existence of similar biochemical structures on Penicillium frequentans, Aspergillus versicolor, and Aspergillus fumigatus. Immunological procedures may thus significantly contribute to refine the taxonomic classification of moulds.

Verrucofortine, a major metabolite of Penicillium verrucosum var. cyclopium, the fungus that produces the mycotoxin verrucosidin.

Verrucofortine [8], an alkaloid derived from tryptophan and leucine, has been isolated from the fungus Penicillium verrucosum var. cyclopium. The structure and absolute configuration have been established by a combination of spectroscopic and chemical techniques. Its structure is unrelated to that of other major metabolite of the organism, the highly toxic pyrone-type polyketide verrucosidin [1], which was previously reported to be a tremorgen. A second novel metabolite, normethylverrucosidin [3], has also been isolated and identified. Small quantities of several other secondary metabolites, ergosterol, cyclopenin [4], cyclopenol [5], and 3-O-methylviridicatin [6], were isolated. They are known fungal metabolites but had not previously been obtained from this fungus. Studies of verrucofortine toxicity in mice showed no apparent toxic effects at doses as high at 160 mg/kg ip.

Effect of some nutrients on the production of cyclopiazonic acid by Penicillium verrucosum var. cyclopium

The effect of some sugars in different concentrations and some nitrogeneous organic constituents in 2% yeast extract (basal medium) on production of cyclopiazonic acid (CA) by Penicillium verrucosum var. cyclopium was studied at room temperature. Maximum CA production was observed after 14 days in a medium containing 2% yeast extract +2.5% sucrose. Ammonium lactate had a negative effect on the production of CA by the test culture. Nitrogeneous organic constituents such as peptone and tryptone did not enhance the yield of CA in the medium. After an initial drop in the pH, a general increase in pH was observed as the incubation time increased. Curdled milk was also found to be a suitable medium for the production of CA by the mold culture.

The role of moulds in the ripening process of salami

Moulds isolated from salami manufactured in small-scale and industrial establishments were identified and tested. The results confirm that moulds are important in the ripening process of salami. Penetrating deeply with their mycelia, moulds caused a clear decrease in lactic acid and consequently a considerable rise of pH. Uniform moisture content and ease of skin-peeling occurred only in mouldy salami. The most frequent moulds isolated were found to belong to highly toxinogenic species: Penicillium verrucosum var. cyclopium in small-scale and Aspergillus candidus in industrial production. The use of suitable selected moulds is recommended in order to prevent the growth of undesirable moulds, to improve the product and to avoid the rise in contamination with mycotoxins.

Interactions between field, and storage fungi on wheat grain

The effects of different water activities (aw) and temperatures on interaction between groups of field fungi, Aspergillus and Penicillium spp. on wheat grain were measured using direct and dilution plating. Numbers of individual species isolated and the percentage of grain contaminated changed considerably during a four week incubation period. At the end of this period, the relative abundance of each species did not correspond well with that predicted using a numerical Index of Dominance (ID) derived from studies in vitro. When wheat grains were inoculated with different field fungi and incubated for four weeks, Fusarium culmorum became dominant and contaminated most grains at all temperatures (15–30 °C) and 0 · 99 and 0 · 95 aws although the in vitro ID was large only at 15°. Epicoccum nigrum, which had a high in vitro ID at all temperatures, did not compete well on wheat grain at any temperature, while Alternaria alternata which had a low ID, contaminated up to 50% grain after four weeks storage. Of the Aspergillus spp., A. versicolor was dominant at all temperatures and aws tested (0 · 95 and 0 · 90) although it competed poorly in culture. A. repens and A. candidus were also present at 15° and A. nidulans at 25–30† and 0 · 95–0 · 90 aw. The dominance of Penicillium hordei on wheat grain corresponded well with its ID at 15–25° and 0 · 95 aw but less well at 0 · 90 aw. P. piceum was seldom isolated at 15° but was most numerous at 30°. P. verrucosum var. cyclopium (P. aurantiogriseum) and P. brevicompactum competed well at 15–25° and 0 · 95–0 · 90 aw. When groups of Aspergillus and Penicillium spp. were inoculated together on wheat grain, A. versicolor and P. hordei became dominant at 15–25° and 0 · 95 and 0 · 90 aw, while at 30° A. nidulans and A. repens were also numerous.

Immunological detection of moulds in food by using the enzyme-linked immunosorbent assay (ELISA); preparation of antigens

Antigens were isolated from moulds ( Penicillium verrucosum var. cyclopium, Mucor racemosus and Fusarium oxysporum) by a simple water extraction followed by column chromatography using Sepharose CL4B. The antigens obtained were genus-specific, heat-stable and found not to be present in extracts of non-moulded food. Immunoglobulins were produced against these antigens and an enzyme-linked immunosorbent assay (ELISA) was developed. Using the ELISA, moulds were detected in both heated and unheated foods in a sensitive and specific way. The results indicate the possibility of testing whether prepared foods are produced from non-moulded raw materials or not. Heat treatment during processing does not influence the recovery of mould contamination.

Studies on the selection of a suitable packaging material for pre- and post-irradiation storage of cereal grains in Ghana

Twenty different species of fungi belonging to the genera Aspergillus, Cephalosporium, Dreschlera, Fusarium, Mucor, Neurospora, Rhizoctonia, Rhizopus, Penicillium and Trichoderma were isolated from jute and woven polypropylene sacks using the blotter test, solid medium test and the decimal serial dilution technique. There was a highly significant difference (Students' t-test, P < 0.05) between the larger number of fungal colonies associated with jute sacks than with woven polypropylene sacks. Correspondingly, more fungal species (16) were isolated from jute sacks than from woven polypropylene sacks (9). The blotter test showed that in the absence of an exogenous supply of nutrients, 88% of the sections of jute sacks supported in vivo growth of fungal spores whilst woven polypropylene sacks could not support the growth of contaminating spores. Evidence is presented that mould and yeast counts on sections of new-woven polypropylene sacks incubated at 80 and 90% relative humidity (R.H.) for four months increased by less than 1 log cycle, whilst in similar sections hung on a line under ambient conditions (75 ± 10% R.H. and 28 ± 3°C) viable counts of spores decreased. Sections of fresh jute sacks similarly treated supported 1 log cycle increase in mould and yeast counts at 80% R.H. and 2 log cycles increase at 90% R.H. after four months of storage. Gamma-ray irradiation (4.0 kGy) reduced the mould and yeast counts on new jute and new woven polypropylene sacks by 1 and 2 log cycles, respectively, but post-irradiation storage at 80% R.H. allowed moulds like Aspergillus flavus, A. niger, Fusarium nivale and Penicillium verrucosum var. cyclopium to commence growth on jute sacks. This presumably, may act as a springboard for infecting grain contents of jute sacks. Inert woven polypropylene sacks failed to support fungal growth.

Penicillium species associated with barley grain in the U.K.

Thirty-three Penicillium spp. and their teleomorphs, isolated from barley grain during ripening and subsequent storage, have been identified. Few species were isolated from the grain before harvest and these were mostly species characteristic of storage, but P. pedemontanum and Eupenicillium spp. (including E. shearit) were found only in the field. However, lodging could allow abundant development of P. hordei, P. granulatum and P. verrucosum var. cyclopium with probable penetration of grain tissue. P. hordei, P. piceum, P. roquefortii and P. verrucosum and its var. cyclopium were those most frequently isolated from stored grain. Penicillium spp., initially P. brevicompactum , increased only when grain was stored with more than 0.87 water activity ( a w ; = 18% water content). P. verrucosum occurred above 0.88 a w and other species were found as the water activity increased. Spontaneous heating occurred above 0.9 a w and limited growth of all except P. capsulatum, P. piceum, Talaromyces emersonii (P. emersonii) and T. thermophilus (P. dupontii). P. verrucosum became abundant when grain was incubated at 2–20 °C with 0.90 to 0.98 a w , and formed ochratoxin, especially at 0.98 a w and 10°. Restricting the aeration of stored grain enabled P. roquefortii to become abundant, especially at 1.00 a w causing the grain to become toxic.

Effect of water activity, temperature and substrate on interactions between field and storage fungi

Field and storage fungi demonstrated a wide range of interactions on malt and wheat extract agars. A numerical Index of Dominance ({itI{in d }}) was derived for individual fungi. This was found to vary with water activity ({ita w }), temperature and substrate. Epicoccum nigrum and Fusarium culmorum were the only field fungi that competed successfully against other fungi on both substrates while Alternaria alternata, Cladosporium species and Verticilliutn lecanii were all uncompetitive, intermingling freely with many Aspergillus and Penicillium spp. Of the Penicillium spp., P. brevicompactum and P. hordei were most dominant although P. verrucosum var. cyclopium and P. roquefortii were favoured by malt and wheat extract, respectively. P. piceum competed well against both field and storage fungi but only at 30 °C. A. candidus and A. nidulans were the most competitive of the Aspergillus spp. but only at 25 and 30° while A. fumigatus was competitive at 30° only. A. repens and A. versicolor were uncompetitive regardless of {ita w }. Variations in temperatures between 15 and 30° were accompanied by changes in {itI{in d }} scores. Total {itI{in d }} scores of the most dominant fungi were usually lower on wheat extract than on the richer malt agar. Detailed microscopic examination of the interaction zones revealed granulation and vacuolation of hyphal cells and increased branching but no changes in permeability of the affected cells, loss of metabolic activity or cell death.

ChemInform Abstract: VERRUCOSIDIN, A TREMORGEN FROM PENICILLIUM VERRUCOSUM VAR CYCLOPIUM

AbstractDas Neurotoxin Verrucosidin besitzt aufgrund von chemischen und spektroskopischen Untersuchungen die Struktur (l).

Factors determining the microflora of stored barley grain

SUMMARYColonisation of barley grain has been studied during storage at different water contents and with and without restriction of the air supply to simulate conditions in unsealed silos. Grain stored with a water activity &gt;0·9 aw (20% water content) heated spontaneously when aeration was unrestricted, the maximum temperature attained increasing with aw to 58 °C at 1·0 aw (39% water content). The presence of many unripe grains increased the tendency to heat at a given mean water content. Although heating was prevented by sheeting to restrict the air supply, it could occur subsequently when the sheeting was removed. Both heating and restriction of the air supply were associated with increased carbon dioxide (to &gt;25%) and decreased oxygen concentrations (to &lt;5%). Germination of grain after 6·9 months storage was correlated with aw; germination levels approaching 100% were retained only at about 0·7 aw (13·5% water content). Colonisation by Aspergillus species was correlated with aw and temperature and similar correlations with Penicillium species were also found, with P. verrucosum var. cyclopium abundant at 0·85‐0·90 aw (17·20% water content) and P. piceum, P. funiculosum and P. capsulatum at 0·90‐0·95 aw (20–25% water content). In sealed containers P. roquefortii occurred at 1·00 aw (39% water content) and P. hordei at 0·90‐0·92 aw (20–22% water content). Spores of fungi and actinomycetes formed during spontaneous heating of grain survived 6 months sealed storage although Absidia corymbifera and Micropolyspora faeni may have declined in numbers. Fungicides applied to the ripening grain had only limited effect on the colonisation of the grain during storage.