Soil mycoflora in tomato fields

Density and species richness of fungal communities in soils ofFusarium infested and non-infested tomato-growing localities were studied by comparison of rhizoplanes, rhizospheres, and root-free soils. The rhizosphere soils harbored the highest counts of fungi, followed by root-free soil and rhizoplanes in both localities. Species richness was high in the rhizosphere and root-free soil but distinctly low in the rhizoplane. The population density of the zhizosphere and the rhizoplane showed a significant difference between infested and non-infested localities.     

The mycoflora of gari

Mycological studies have been carried out on market samples of gari, a ready-to-use staple fermentation product of cassava ( Manihot esculenta cranz ). Commercial and industrial samples were analysed. The moisture contents of samples varied from 7% to 17% while the water activity ( a _w) varied from 0·52 to 0·85 and the pH of samples ranged from 3·9 to 7·26. Several fungi were isolated from the commercial samples while the industrial packaged samples were relatively mould-free. Moulds isolated were mainly Aspergillus spp., Penicillium spp., and several Mucorales, e.g. Rhizopus sp., Syncephalastrum sp., Mucor sp. and Circinella sp.     

Associated mycoflora of rye bread

F. Lund, O. Filtenborg, S. Westall And J.C. Frisvad. 1996. Penicillium roqueforti (27%), P. corylophilum (20%) and Eurotium (15%) made up the important mycoflora associated with rye bread on 3425 identified fungi isolates. These fungi were dominant as spoilers of packaged rye bread in almost every month of a 4 year investigation. Penicillium decumbens (3%), Paecilomyces variotii (8%) and Aspergillus flavus (5%) were found more rarely, but were the major species found over periods of a few months. Penicillium commune (5%), P. Solitum (4%), A. niger (4%) and Mucor species (2%) were a constant, but small, part of the mycoflora of rye bread. Identification of the fungi in the production environmentl in a rye bread factory showed the locality of potential contamination sources. Eliminationl of the contmination sources lby improved cleaning and disinfection procedures quickly resulted in a significant reduction in the frequency of mould growth in the packaged rye bread.     

Soil mycoflora from the Dead Sea Oases of Ein Gedi and Einot Zuqim (Israel)

Samples were taken from the top 10 cm of soils from 24 points in the Ein Gedi area. Among 329 isolates, 142 species were identified: 11 genera of ascomycetes, one genus of coelomycetes, 28 genera of hyphomycetes, 7 genera of zygomycetes and one yeast, in addition to some unidentified basidiomycetes. The hyphomycetes were represented by 17 dematiaceous, 9 mucedinaceous and two tuberculariaceous. Melanconiaceous and stilbellaceous genera were not found. Two new varieties of Microascus recently described were reisolated. No strict thermophiles or halophiles were obtained. There is apparently no very characteristic or specific fungal flora of the Dead Sea Oases although it was different from that found in the desert soil surrounding this area.     

The mycoflora of the subhuman primates

Summary For documentation of the mycoflora of the baboon, 127 vaginal and 165 rectal swabs were taken from males and females in captivity. A total of 176 and 171 yeast isolates were obtained from the vagina and rectum respectively.Candida was found to be the yeast most frequently found in both of these sites.C. albicans formed 14.6 % of the rectal yeasts and 7.9 % of the vaginal yeasts.No significant differences were found between the rectal isolates from the males and those from the females in the baboons. Furthermore, there is a strong indication that the mycoflora of both the rectum and the vagina of the baboon is similar to that of human beings, from both a qualitative and a quantitative point of view.This study was supported by U.S.P.H.S. Grant 5-R01-HE-3834-07.     

The mycoflora of the subhuman primates

Summary Culture studies revealed that 54.3 % of 70 mouth samples and 15.1 % of 371 throat samples from captive male and female baboons contained yeasts.Candida albicans was found to be the highest single species isolated from the oral cavity of both sexes, with the exception ofTrichosporon, which was slightly higher in the mouths of female baboons.There is a slight indication that the yeast flora of the female oral cavity is higher than that of the male. Similarly, there is a close parallelism between the oral mycoflora of human beings and that of the baboons studied.     

Peanut-pod mycoflora and kernel infection

Summary The mycoflora in soil clinging to dry pods of peanuts of the Spanish variety Argentine was sampled in 2 experiments by serially washing pods for increasing periods in changes of sterile water. Of the 9 principal fungi found,Aspergillus niger, A. flavus, A. terreus, Rhizopus spp. andSclerotium bataticola were present initially in relatively small numbers and decreased rapidly in subsequent dilutions. This decrease paralleled a decrease in weight of suspended material and in percentage of soil and organic particles greater than 0.016 mm in size.Penicillium funiculosum, P. rubrum, P. citrinum, andFusarium spp. were found in large numbers and increased or slowly decreased in numbers in subsequent dilutions. In some instances variations in numbers followed trends of percentages of soil and organic particles less than 0.016 mm in size.When dry pods with this known mycoflora were allowed to hydrate over a 6-day period at 26°, 32°, or 38°C, there was extensive pod penetration and kernel infection byA. niger, A. flavus, S. bataticola andRhizopus spp. but not by other fungi. The degree ofA. flavus andA. niger infection increased with increasing temperatures.Approved by the Director as Journal Series Paper No. 135.     

Endoglucanase production by paper-degrading mycoflora

Fourteen fungal species, namely Aspergillus flavus, A. fumigatus, A. niger, A. ustus, Penicillium islandicum, P. wortmannii, Memnoniella echinata, Cladosporium herbarum, Stachybotrys atra, Chaetomium globosum, Fusarium oxysporum, Torula herbarum, Alternaria alternata and Curvularia uncinata were isolated from different grades of paper. They differ in their distribution on various kinds of paper and also in relative occurrence. While seasonal influence on mycoflora was observed, most of the moulds were capable of growing in all three seasons examined (summer, winter, rainy season). The moulds were cellulolytic in nature and endoglucanase activity was greatest in Aspergillus flavus, A. niger, A. fumigatus, P. wortmannii and P. islandicum.     

The mycoflora of the subhuman primates

Summary Swabs were collected from both nose and ear of a total of 105 male and female baboons. Samples were collected within 72 hours after the arrival of the animal from Kenya, and at 1, 2, 3, 6, 9, 12, 18, 24, 30, and 36 months thereafter. Similarly contents from large and small intestines of 29 sacrificed captive baboons and 162 free-living animals were studied for their yeast flora.A total of 505 and 588 yeast isolates were obtained from the ear and nose respectively. The intestinal contents, yielded a total of 109 isolates. The total yeast indices of the ear and nose were very similar quantitatively, and much higher than either of the small or large intestinal contents indices.There was no significant differences of mycological flora collected from females and males.     

Study on the mycoflora of Egyptian soils

Fifty genera and 155 species, in addition to three varieties of Aspergillus nidulans, were isolated from 100 soil samples collected from different localities in Egypt. Aspergillus (33 species in addition to 3 varieties of A. nidulans), Penicillium (46 species), Fusarium (6 species) and Mucor (4 species) were of high occurrence, from which A. niger, A. fumigatus, A. terreus, M. racemosus, P. notatum, P. chrysogenum and A. flavus were dominant. Five genera were of moderate occurrence and these were Humicola, Myrothecium, Rhizopus, Cochliobolus and Alternaria. Fourteen genera were of low occurrence namely, Cunninghamella, Chaetomium, Stachybotrys, Cladosporium, Syncephalastrum, Paecilomyces, Trichoderma, Scolecobasidium, Circinella, Curvularia, Ulocladium, Botryotrichum, Sepedonium and Gliocladium. Twenty-seven genera were of rare occurrence.Fourteen species were of moderate occurrence and these were A. sydowii, M. verrucaria, P. funiculosum, A. versicolor, H. grisea, F. oxysporum, A. nidulans, F. moniliforme, A. alternata, F. solani, M. hiemalis, A. candidus, R. nigricans and A. ochraceus. The remaining species were of low or rare occurrence in soils tested.Comparison between the present results and those of others showed that there is no fungal flora characteristic cultivated soils.     

Thermophilic mycoflora of cigarettes and cured tobacco leaves

Nine species of thermophilic fungi were obtained from retailed packets of imported and locally manufactured brands of cigarettes and from cured tobacco leaves. They include known human pathogens such asThermoascus aurantiacus Miehesensu Apinis,Mucor pusillus Lindt andMucor miehei Cooney and Emerson. Chaetomium thermophile La Touche,Humicola insolens Cooney and Emerson,Thermoascus crustaeus (Apinis and Chesters) Stolk andMucor miehei have not been previously reported on tobacco products.Fewer species were obtained from foreign cigarettes than from locally manufactured brands. A mean moisture content of 19% was recorded for imported cigarettes and 37% for Nigerian brands. The potential health hazards posed to man by the unrestricted use of tobacco products are discussed.     

Mould mycoflora of some Turkish cereals and cereal products

Summary To determine the extent of mould contamination and the mycoflora of some cereals and cereal products such as barley, corn, rice, wheat,bulgur and flour, a total of 242 samples were collected from different agricultural regions of Turkey. Mould contamination of samples varied between 10³ and 10⁶ colonies/g. Moisture contents of the samples were found to range between 12.65 and 13.97%. Most commonly isolated moulds werePenicillium (46%),Aspergillus (22%),Cladosporium (9%),Rhizopus (6%),Aureobasidium (5%) andEurotium (4%) species. Results have been evaluated to assess the kinds of mycotoxins that can be produced by these mycoflora and the effect of seed moisture on growth of the relevant fungi.

---

Resumen A fin de determinar la extensión de la contaminación por mohos, y la microflora presente en algunos cereales y derivados tales como; avena, maíz, arroz, trigo, bulgar y harina, se recogieron 242 muestras de distintas regiones agrícolas de Turquía. La contaminación por mohos varió entre 10³ y 10⁶ colonias/g, y el porcentaje de humedad entre 12.65 y 13.97%. Los mohos que se aislaron con mayor frecuencia fueron especies dePenicillium (46%),Aspergilus (22%),Cladosporium (9%),Rhizopus (6%),Aureobasidium (5%) yEurotium (4%). Los resultados se han evaluado para determinar el tipo de micotoxinas que esta micoflora puede producir y el efecto de la humedad de las semillas en el crecimiento de los hongos más importantes.

---

Résumé Un total de 242 échantillons a été récolté dans différentes régions agricoles de Turquie, afin de déterminer l'étendue de la contamination par moisissures ainsi que la mycoflore de certaines céréales et produits céréaliers tels l'orge, le maïs, le riz, le froment, le bulgur et la farine. La contamination par moisissures a varié de 10³ à 10⁶ colonies par g. L'humidité des échantillons variait entre 12.65 et 13.97%. Les moisissures les plus communément isolées sont lesPencillium (46%), lesAspergillus (22%), lesCladosporium (9%), lesRhizopus (6%), lesAureobasidium (5%) et lesEurotium (4%). Les résultats ont été examinés pour déterminer les types de mycotoxines qui pouvaient être produites par cette mycoflore et l'effet de l'humidité de la graine sur la croissance des moisissures idoines.

     

Natural occurrence of mycotoxins and mycoflora of argentinien popcorn

Argentina is the first popcorn exporting country worldwide. In 1997-1998 harvest season, 40,000 ha were sown with a production of 125,000 tons; 120,000 tons of this production were exported to more than 40 countries. The objectives of this study were to isolate and to identify the fungi present in this cereal and to assess the occurrence of mycotoxins in freshly harvested popcorn in Buenos Aires province, Argentina, in 1999. All popcorn samples showed fungal contamination. A total of 4,211 isolates were recovered from popcorn kernel samples. The prevalent species isolated wasFusarium verticillioides followed byPenicillium funiculosum, F. graminearum andAlternaria alternata. No aflatoxins, zearalenone, deoxynivalenol or ochratoxin A were detected in the 42 popcorn simples. All samples but one were contaminated with fumonisins (FB) in a range in ug/kg of (not detected-529) for FB₁; (not detected-216) for FB₂ and (not detected-103) for FB₃. Fumonisin contamination levels in Argentinean popcorn were lower than observed in flint corn. No significant differences in fungal and fumonisins contamination levels were observed in the different tested hybrids.     

Survey of the mycoflora of barley grains in Egypt

The fungi of 40 samples of barley grains collected from Upper Egypt were estimated using the dilution- and the grain-plate methods. 33 genera and 109 species, in addition to 2 varieties of Aspergillus nidulans, one variety of Aspergillus flavus and one variety of Penicillium cyclopium were identified. The spectrum of fungal genera and species collected by the grain-plate method (29 genera and 94 species+3 varieties) was broader than by the dilutionplate method (27 genera and 71 species+3 varieties), but the order of frequency of occurrence of fungal genera and species was basically similar in the two methods. The most frequent genera were Aspergillus (25 species+3 varieties), Penicillium (32 species+1 variety), Rhizopus (2 species), Alternaria (2 species), Fusarium (6 species) and Drechslera (5 species) and were represented (as assayed by the grainplate method) in 100 %, 77.5 %, 85 % 62,5 %, 60 % and 52.5 % of the samples constituting 60.4 %, 10.2 %, 7.7 %, 3.7 %, 5 % and 2.3 % of the gross total count of fungi respectively. From the preceding genera A. niger, A. fumigatus, A. flavus, A. sydowii, P. notatum, P. citrinum, F. oxysporum, F. moniliforme, F. solani, R. stolonifer, A. alternata and D. spicifera were the most frequent.