Mycotoxin-producing potential of fungi associated with qat (Catha edulis) leaves in yemen

Forty-four fungal species belonging to 20 genera were isolated from 30 samples of qat leaves. The most frequent genera wereAspergillus, Alternaria, Penicillium, andCladosporium followed byFusarium, Drechslera, Chœtomium, andMucor. The most prevalent species in above genera wereAspergillus niger, A. flavus, A fumigatus, Alternaria alternata, Penicillium chrysogenum, P. citrinum, Cladosporium cladosporioides, andFusarium verticillioides. From these fungi, 17 species (39%) related to 7 genera (35%) proved to be true endophytes. Eleven out of 75 isolates were mycotoxigenic.A. alternata produced alternariol and alternariol monomethyl ether whereasA. flavus produced aflatoxins B₁ and B₂. Ochratoxin A, sterigmatocystin, citrinin and T-2 toxin were produced byA. ochraceus, A. versicolor, P. citrinum andF. oxysporum, respectively. The presence of such toxigenic fungi associated with qat leaves is considered to be a threat to public health.     

Identification of different species ofPenicillium causing deterioration of the Moroccan table grapes during storage

Penicillium glabrum, P. purpurescens, P. decumbens, P. expansum, P. chrysogenum, P. crustosum andP. aurantiogriseum are responsible for some of the alterations noticed on Moroccan table grapes cold stored. Contamination of these table grapes withPenicillium species occurs in the vineyard and inside the cooling station where other fruits which are often fungus-contaminated are also kept. All of thesePenicillium species were able to grow at 0°C apart fromP. glabrum andP. purpurescens. Consequently, refrigeration of grapes during long-term storage is not sufficient in itself in preserving their initial qualities.     

Studies on the fungus flora of three grains in Egypt

In wheat, corn and sorghum grains twenty-six genera and seventy-seven species including sixteen ofAspergillus and twenty-one ofPenicillium were identified.In grain samples adjusted to various moisture levels (up to 18.8 % on a dry-weight basis) and stored for 4 months at 8, 20 and 30 C seed-borne fungi were monthly identified and counted, and the germinability of the grains was tested. In the control samples (moisture content 7.1–8.2 %) temperature had no effect on the fungal counts and on the precentage germination. With the rise of temperature and moisture content the fungal counts markedly increased and the germinability declined.The list of fungi dominant in one or more of the experiments, included eight species ofAspergillus, six ofPenicillium, two ofFusarium and one each ofAlternaria andCurvularia. The order of dominance of these fungi varied according to the type of grain, the length of storage and the treatment.A. niger was the dominant organism in the control samples of the three grains. It could grow successfully at high moisture contents but above 15 %, it was usually overgrown by other fungi. In wheatP. citrinum andA. sydowii, in cornP. citrinum andA. terreus, and in sorghumA. terreus andA. niger were the dominant fungi at moisture contents above 15 % after four months storage at 30 C. When stored at 8 CPenicillium species tended to predominate over other fungi in grains with high moisture contents.In surface-sterilized grains adjusted to 15 % moisture content, inoculated with six dominant fungi separately and incubated at 30 C,A. niger, P. citrinum andP. variabile caused severe deterioration in the three grains;A. ochraceus in wheat only andF. moniliforme in wheat and corn;C. spicifer was slightly injurious to the three grains.     

Aflatoxin: A metabolic product of several fungi

Summary Culture extracts produced by 107 fungi isolated from corn grains were assayed by thin layer chromatography for aflatoxin. Certain isolates ofAspergillus flavus, A. niger, A. parasiticus, A. ruber, A. wentii, Penicillium citrinum, andP. variabile produced aflatoxin.Penicillium frequentans andP. puberulum elaborated this toxin only in trace amounts. Bioassays of extracts from 4 of these fungi showed that only the extract fromA. parasiticus was highly toxic.     

Low occurrence of patulin‐ and citrinin‐producing species isolated from grapes

Aims: To assess the ability of fungi isolated from grapes to produce patulin and citrinin. Methods and Results: A total of 446 Aspergillus isolates belonging to 20 species and 101 Penicillium isolates were inoculated in Czapek yeast extract agar and yeast extract sucrose agar and incubated for 7 days at 25°C. Extracts were analysed for patulin and citrinin by thin‐layer chromatography. None of the isolates of Aspergillus spp. produced either patulin or citrinin. Patulin was produced by three isolates of Penicillium expansum and two of Penicillium griseofulvum. Citrinin was produced by five isolates of P. expansum, two of Penicillium citrinum and one of Penicillium verrucosum. Conclusions: Our results show that the Aspergillus and Penicillium species commonly isolated from grapes are not a source of the mycotoxins, patulin and citrinin. Significance and Impact of the Study: The possibility of co‐occurrence of patulin and citrinin with ochratoxin A in grapes and grape products remain low, owing to the low frequency of isolation of potentially producing species.     

Penicillium Mycobiota in Arctic Subglacial Ice

Fungi have been only rarely isolated from glacial ice in extremely cold polar regions and were in these cases considered as random, long-term preserved Aeolian deposits. Fungal presence has so far not been investigated in polar subglacial ice, a recently discovered extreme habitat reported to be inhabited exclusively by heterotrophic bacteria. In this study we report on the very high occurrence (up to 9000 CFU L⁻¹) and diversity of filamentous Penicillium spp. in the sediment-rich subglacial ice of three different polythermal Arctic glaciers (Svalbard, Norway). The dominant species was P. crustosum, representing on the average half of all isolated strains from all three glaciers. The other most frequently isolated species were P. bialowiezense, P. chrysogenum, P. thomii, P. solitum, P. palitans, P. echinulatum, P. polonicum, P. commune, P. discolor, P. expansum, and new Penicillium species (sp. 1). Twelve more Penicillium species were occasionally isolated. The fungi isolated produced consistent profiles of secondary metabolites, not different from the same Penicillium species from other habitats. This is the first report on the presence of large populations of Penicillium spp. in subglacial sediment-rich ice.     

Mould biodiversity in homes I. Air and surface analysis of 130 dwellings

Summary Air and surface sampling to quantify and identify fungi were conducted over a 10-year period in 130 Belgian homes, including flats and houses. Homes were selected based on the medical files of allergic, mostly asthmatic patients to assess possible mould responsibility in the aetiology of the disease. Air sampling was done with Reuter centrifugal air sampler using different sampling times and incubation temperatures to detect mesophilic and thermotolerant or thermophilic fungi. More than 50 genera were detected, withCladosporium, Penicillium andAspergillus being the most common. The main species detected wereAspergillus versicolor, several species ofPenicillium, Cladosporium sphaerospermum andCladosporium herbarum. Surface sampling was conducted concomitant with air sampling. Surfaces with and without visible mould growth were tested equally by Rodac contact plates or swabs. AlthoughCladosporium herbarum was shown to be a common species in indoor environments by air sampling, it was not detected by surface sampling from visible mould growth. This finding suggests that its presence in dwellings is from an outdoor origin and not indicative of indoor proliferation.Aspergillus versicolor, Cladosporium sphaerospermun, andPenicillium chrysogenum were the most common species isolated from surfaces showing visible mould growth.     

Diversity and enzyme activity of <Emphasis Type="Italic">Penicillium</Emphasis> species associated with macroalgae in Jeju Island

A total of 28 strains of 19 Penicillium species were isolated in a survey of extracellular enzyme-producing fungi from macroalgae along the coast of Jeju Island of Korea. Penicillium species were identified based on morphological and β-tubulin sequence analyses. In addition, the halo-tolerance and enzyme activity of all strains were evaluated. The diversity of Penicillium strains isolated from brown algae was higher than the diversity of strains isolated from green and red algae. The commonly isolated species were Penicillium antarcticum, P. bialowiezense, P. brevicompactum, P. crustosum, P. oxalicum, P. rubens, P. sumatrense, and P. terrigenum. While many strains showed endoglucanase, β-glucosidase, and protease activity, no alginase activity was detected. There was a positive correlation between halo-tolerance and endoglucanase activity within Penicillium species. Among 19 Penicillium species, three species–P. kongii, P. olsonii, and P. viticola–have not been previously recorded in Korea.     

Marine-derived Penicillium in Korea: diversity,enzyme activity,and antifungal properties

The diversity of marine-derived Penicillium from Korea was investigated using morphological and multigene phylogenetic approaches, analyzing sequences of the internal transcribed spacer region, β-tubulin gene, and RNA polymerase subunit II gene. In addition, the biological activity of all isolated strains was evaluated. We tested for the extracellular enzyme activity of alginase, endoglucanase, and β-glucosidase, and antifungal activity against two plant pathogens (Colletotrichum acutatum and Fusarium oxysporum). A total of 184 strains of 36 Penicillium species were isolated, with 27 species being identified. The most common species were Penicillium polonicum (19.6 %), P. rubens (11.4 %), P. chrysogenum (11.4 %), and P. crustosum (10.9 %). The diversity of Penicillium strains isolated from soil (foreshore soil and sand) and marine macroorganisms was higher than the diversity of strains isolated from seawater. While many of the isolated strains showed alginase and β-glucosidase activity, no endoglucanase activity was found. More than half the strains (50.5 %) showed antifungal activity against at least one of the plant pathogens tested. Compared with other strains in this study, P. citrinum (strain SFC20140101-M662) showed high antifungal activity against both plant pathogens. The results reported here expand our knowledge of marine-derived Penicillium diversity. The relatively high proportion of strains that showed antifungal and enzyme activity demonstrates that marine-derived Penicillium have great potential to be used in the production of natural bioactive products for pharmaceutical and/or industrial use.     

Airborne Penicillium in the grain shops of Nagpur (India)

The airborne Penicillium spp. and total airborne fungal spore concentration was investigated in the grain shops of Nagpur city, India, using a volumetric Hi‐Air sampler system Mark II (Hi Media Laboratories Ltd., India). The mycotoxins were analysed from the Penicillium isolates obtained from the seeds by thin layer chromatography.

The mean concentration of the total fungi isolated from different grain shops ranged from 7.8×10² to 1.1×10³ CFU/m³. The mean concentration of Penicillium isolated from the air of grain shops ranged from 8.6×10¹ CFU/m³ (10.8%) to 1.7×10² CFU/m³ (19.9%). Among the 13 species of Penicillium which were isolated, P. citrinum Thom was the most prevalent species (24.2%), followed by P. oxalicum Currie & Thom (16.5), P. digitatum Saccardo (8.9%), P. janthinellum Biourge (8.7%), P. funiculosum Thom (8.3%), P. chrysogenum Thom (6.4%), P. purpurogenum Stoll (6.2%), P. brevicompactum Dierckx (4.8%), P. frequentans Westling (4.2%), P. italicum Wehmer (3.8%), P. rubrum Stoll (3.4%), P. expansum Link (2.9%) and P. cyclopium Westling (1.6%).

Penicillium species were also isolated from seeds such as wheat, maize, soybean, and groundnut. The mycotoxins roquefortin C, citrinin, rubratoxin B, cyclopiazonic acid, verrucosidin, mitorubrinic acid and two unknown metabolites were isolated from Penicillium isolates.     

Identification of Ochratoxin A Producing Fungi Associated with Fresh and Dry Liquorice

The presence of fungi on liquorice could contaminate the crop and result in elevated levels of mycotoxin. In this study, the mycobiota associated with fresh and dry liquorice was investigated in 3 producing regions of China. Potential toxigenic fungi were tested for ochratoxin A (OTA) and aflatoxin B1 (AFB1) production using liquid chromatography/mass spectrometry/mass spectrometry. Based on a polyphasic approach using morphological characters, β-tubulin and RNA polymerase II second largest subunit gene phylogeny, a total of 9 genera consisting of 22 fungal species were identified, including two new Penicillium species (Penicillium glycyrrhizacola sp. nov. and Penicillium xingjiangense sp. nov.). The similarity of fungal communities associated with fresh and dry liquorice was low. Nineteen species belonging to 8 genera were detected from fresh liquorice with populations affiliated with P. glycyrrhizacola, P. chrysogenum and Aspergillus insuetus comprising the majority (78.74%, 33.33% and 47.06% of total) of the community from Gansu, Ningxia and Xinjiang samples, respectively. In contrast, ten species belonging to 4 genera were detected from dry liquorice with populations affiliated with P. chrysogenum, P. crustosum and Aspergillus terreus comprising the majority (64.00%, 52.38% and 90.91% of total) of the community from Gansu, Ningxia and Xinjiang samples, respectively. Subsequent LC/MS/MS analysis indicated that 5 fungal species were able to synthesize OTA in vitro including P. chrysogenum, P. glycyrrhizacola, P. polonicum, Aspergillus ochraceus and A. westerdijkiae, the OTA concentration varied from 12.99 to 39.03 µg/kg. AFB1 was absent in all tested strains. These results demonstrate the presence of OTA producing fungi on fresh liquorice and suggest that these fungi could survive on dry liquorice after traditional sun drying. Penicillium chrysogenum derived from surrounding environments is likely to be a stable contributor to high OTA level in liquorice. The harvesting and processing procedure needs to be monitored in order to keep liquorice free of toxigenic fungi.     

Isolation of endophytic fungi from Cannabis sativa and study their antifungal potential

A systemic study of fungal endophytes associated with different plant parts of Cannabis sativa and their antifungal activity was investigated in the present study. A total of 281 plant segments, including 91 leaves, 93 stem and 97 petioles samples, were screened for the isolation of endophytic fungi. Totally, 212 (77.65%) segments were found colonised by different fungi. Highest colonisation frequency were observed in stem parts (84.94%), then leaves (82.41%) and lowest 59.79% in petiole. Total eight fungal genera belonging to 12 species were isolated. Aspergillus is recorded as the most frequently occurring genera with three species Aspergillus niger, Aspergillus flavus and Aspergillus nidulans followed by Penicillium with two species Penicillium chrysogenum and Penicillium citrinum, while Phoma, Rhizopus, Colletotrichum, Cladosporium and Curvularia with single species. The antifungal potential of A. niger and A. flavus – two most frequently isolated endophytic fungi – was evaluated against two common plant pathogen, Colletotrichum gloeosporioides and Curvularia lunata. Different plant and fungal extracts individually and in combinations showed variations in antifungal activity against both the pathogens. The primary results obtained on antifungal activity of endophytes show their possible role in plant defence mechanism but it is a preliminary approach and more extensive research is still required.     

Collagenolytic activity in several species of deuteromycetes under various storage conditions

The ability of deuteromycetes of the genera Penicillium, Aspergillus, and Botrytis to retain collagenolytic activity was studied after both 2 and 10 years of storage on a Czapek medium under a layer of mineral oil at 4°C, as well as in silica gel granules at 20 and ?60°C. The enzymatic activity of several species, including Botrytis terrestris, Penicillium janthinellum, Penicillium chrysogenum, and Penicillium citrinum, was retained under both conditions of storage. Aspergillus repens retained enzymatic activity only if stored under a layer of mineral oil. The viability of conidia and the collagenolytic activity of Botrytis terrestris, P. janthinellum, P. chrysogenum, and Penicillium citrinum, maintained on silica gel for 10 years, depended on the storage temperature. The viability of the test strains improved after storage on a silica gel at ?60°C. A strain of Aspergillus repens lost its ability to dissolve collagen at various storage tempeatures on the silica gel. The index of lysis for three strains of Penicillium deuteromycetes (Penicillium janthinellum, Penicillium chrysogenum, and Penicillium citrinum) increased after a 10-year storage on silica gel at ?60°C.     

The sequence of the isoepoxydon dehydrogenase gene of the patulin biosynthetic pathway in <Emphasis Type="Italic">Penicillium</Emphasis> species

Interest in species of the genus Penicillium is related to their ability to produce the mycotoxin patulin and to cause spoilage of fruit products worldwide. The sequence of the isoepoxydon dehydrogenase (idh) gene, a gene in the patulin biosynthetic pathway, was determined for 28 strains representing 12 different Penicillium species known to produce the mycotoxin patulin. Isolates of Penicillium carneum, Penicillium clavigerum, Penicillium concentricum, Penicillium coprobium, Penicillium dipodomyicola, Penicillium expansum, Penicillium gladioli, Penicillium glandicola, Penicillium griseofulvum, Penicillium paneum, Penicillium sclerotigenum and Penicillium vulpinum were compared. Primer pairs for DNA amplification and sequencing were designed from the P. griseofulvum idh gene (GenBank AF006680). The two introns present were removed from the nucleotide sequences, which were translated to produce the IDH sequences of the 12 species for comparison. Phylogenetic relationships among the species were determined from rDNA (ITS1, 5.8 S, ITS2 and partial sequence of 28S rDNA) and from the idh nucleotide sequences minus the two introns. Maximum parsimony analysis showed trees based on rDNA and idh sequences to be congruent. It is anticipated that the genetic information obtained in the present study will aid in the design of probes, specific for patulin biosynthetic pathway genes, to identify the presence of these mycotoxigenic fungi. The U.S. Government's right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

Status of airborne spores and pollen in a coir factory in Kerala,India

The prevalence of airborne fungal spores and pollen grains in the indoor and outdoor environments of a coir factory in Thiruvananthapuram district of Kerala state, India was studied using the Burkard Personal Sampler and the Andersen 2-stage Sampler for 2 years (September 1997 to August 1999). The concentration of pollen grains was remarkably lower than that of fungal spores (ratio of 1:28). There was no large difference in the concentrations and types of fungal spores between the indoor and outdoor environments, with 26 spore types found to be present indoors and 27 types outdoors; of these, 22 were common to both the environments. Aspergillus/Penicillium, Cladosporium, ‘other basidiospores’ and ascospores were the dominant spore types. The total spore concentration was highest in February and lowest in September, and it was significantly higher in 1998–1999 than in 1997–1998. Twenty viable colony-forming types were isolated from inside the coir factory. The most dominant viable fungi isolated were Penicillium citrinum, Aspergillus flavus and Aspergillus niger. The total pollen concentration was higher in the outdoor environment of the coir factory than indoors, with 15 and 17 pollen types, respectively. Grass and Cocos nucifera pollen types were dominant. The dominant spore and pollen types trapped in the two environments of the coir factory are reportedly allergenic and, consequently, workers are at risk of catching respiratory/allergic diseases.     

Relationships betweenAspergillus flavus,A. niger and some other fungi in the mycoflora of groundnut kernels

Summary The relationships betweenAspergillus flavus, A. niger, Penicillium funiculosum, P. rubrum, andFusarium solani have been studied in 234 samples and 5850 plates from fresh and stored kernels derived from 2 years' groundnut crops in Israel.Numerical relations between these fungi, as obtained by totalling the number of colonies developing in all the 25 platings made for each sample, did not always give reliable indications of potential antagonism between the species. But consideration of the number of colonies developing in individual plates showed pronounced antagonism betweenA. flavus andA. niger, and slightly less but still marked antagonism between each of these species andP. funiculosum, P. rubrum andF. solani.This research is supported by Grant Number FG-Is-161 of the United States Department of Agriculture to whom the author is indebted.     

Fungi in flour and refrigerated dough products

Summary Fungal counts of 19 flour samples and 11 wheat samples from 11 flour mills of the Kansas-Nebraska and Pacific Northwest wheat-growing areas were made over a period of 2 years. In addition, 50 spoiled and 22 fresh samples of refrigerated dough products were examined for their fungal content. Methods for obtaining counts of fungi from flour and refrigerated dough were improved through the use of tetracycline as a bacterial inhibitor. Fungal counts ranged from 85 to 8,100 per gram in flour and from 90 to 1,400 in wheat. Generally, mold counts were higher in the flour than in the wheat. Judging from earlier reports, improved handling of wheat and better milling practices are effecting a gradual reduction in fungal counts in commercial flours. More than 500 fungi were isolated from the flours and doughs and were identified. Except for a few Fungi Imperfecti and Mucorales, the majority of the species from the flours belong in the generaAspergillus andPenicillium. Not only do they belong to these genera, but to specific groups in each. In the genusAspergillus, representatives of theA. candidus, A. glaucus, A. flavus-oryzae, andA. versicolor groups were the only ones present. InPenicillium the series commonly found wereP. cyclopium, P. citrinum, andP. urticae, and the remaining species were scattered among various series. Fungal counts of both fresh and spoiled dough samples were comparatively low. Essentially, the fungal flora of the doughs was a reflection of the flour microflora. Spoilage of the dough products did not appear to be of fungal origin.This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Survey of airborne mold flora in Panama

Summary A survey of the airborne fungi was carried out for one year. Petri plates containing Sabouraud's medium were exposed, eight times monthly, at each of six collection sites. A total of 3306 colonies were recovered. Cladosporium (27.2%),Aspergillus (21.4%) andPenicillium (19.8%) were the most commonly encountered fungi and accounted for 68.6% of all colonies.Total mold counts showed a single peak in July and August and a low during the months of November, December, January and February.This material has been reviewed by the Office of The Surgeon General, Department of the Army, and there is no objection to its presentation and/or publication. This review does not imply any indorsement of the opinions advanced or any recommendation of such products as may be named.     

Isolation and metabolite production by Penicillium roqueforti,P. paneum and P. crustosum isolated in Canada

Penicillium roqueforti, P. crustosum and P. paneum grow on ensiled grain and recycled feed unless properly treated. The former two species occur also on cut lumber in Canada. These are known to produce a number of secondary metabolites including roquefortine. In cooler dairy production areas, including Scandinavia and North America, cattle toxicosis has been associated with silage contaminated by these fungi. We collected strains associated with cow or cattle toxicoses. The principal metabolites were determined making use of a new extraction method and analysis combining HPLC, LC/MS/MS, and LC/NMR. Penicillium roqueforti and P. crustosum required amino acid nitrogen for metabolite formation and their toxins were formed under conditions of low oxygen (20–30% saturation). Production of roquefortine C occurred on depletion of the available nitrogen and penitrem A on depletion of carbon source. Yield was reduced by excess carbon. Medium osmotic tension (a_w) affected metabolite production by the two species differently. Penicillium paneum was associated with ill-thrift of dairy cows and P. roqueforti was associated with more serious symptoms. Our data suggest a physiological basis for the common occurrence of roquefortine C in silage without serious consequences and the alternative, the presence of roquefortine C and toxicoses. The strain isolated from lumber was the best producer of the toxins studied. This is the first report of the toxigenic potential of P. roqueforti and P. paneum from Canada.     

The effect of three species of mites upon fungal growth on wheat

Every week, for 20 weeks, the growth of naturally occurring grain storage fungi on wheat infested with the three commonest British grain storage mites,Acarus siro, Glycyphagus destructor andTyrophagus longior, was compared with that on uninfested wheat.The number of colonies of theAspergillus glaucus group per gram were always less on grain infested with mites than on uninfested grain.Penicillium spp. were also less numerous on grain which was infested withA. siro but did not appear to be affected by the other mites. In contrast, two fungi which are pathogenic to mites,Aspergillus restrictus andWallemia sebi, were more abundant in the presence of certain mites. The former was associated withG. destructor, the latter withG. destructor andA. siro.The three species of mites either feed on theA. glaucus group andPenicillium spp., or inhibit them by an unknown secretion. Pathogenic fungi are probably avoided. Mites are therefore an important variable in studies on fungal growth during grain drying and storage.