H. M. Abdel-Fattah

Studies on mycoflora of salt marshes in Egypt. i. sugar fungi

Thirty-four genera and 92 species, in addition to two varieties of Aspergillus nidulans, were isolated from 74 soil samples collected from different localities of salt marshes in Egypt. Aspergillus (17 species in addition to 2 varieties of A. nidulans) and Penicillium (17 species) were of high occurrence, from which A. niger, A. fumigatus, A. terreus and P. notatum were dominant. Five genera were of moderate occurrence and these were Cladosporium, Fusarium, Alternaria, Mucor and Rhizopus. Nine genera were of low occurrence, namely, Drechslera, ?Trimmatostroma, Paecilomyces, Stachybotrys, Cephalosporium, Humicola, Botryotrichum, ? Geolegnia and Scopulariopsis. Statistical analyses reveal that soil samples poor in total fungi were significantly higher in total soluble salts, Na and K content than samples with numerous fungi. The difference in organic matter content between poor and rich samples was non-significant.In newly reclaimed fields along the borders of salt marshes, Fusarium was the most numerous fungal genera from soil followed by Aspergillus whereas Cladosporium was completely absent.Comparison between the present results and those of the other studies showed that there is no fungal flora characteristic of salt marshes.

Aflatoxin and aflatoxicosis

A wide range of fungi, amounting to fifty-six species belonging to twenty-two genera, have been recovered from animal feeds and foodstuffs.The most frequent fungi were Aspergillus niger, and A. flavus, followed by Mucor racemosus, Alternaria alternata, Rhizopus stolonifer, Penicillium corylophilum and P. notatum. Three genera were found to be of moderate occurrence, namely, Mucor, Rhizopus and Alternaria. The three following genera were of low occurrence: Cladosporium, Fusarium, and Neurospora.The fluorescence method of detecting aflatoxin-producing strains demonstrated that only one isolate of A. flavus possesses this property. Certain species of Penicillium and Aspergillus produced fluorescent substances (metabolites) similar in color to B and G aflatoxin. These substances were subsequently proved not to be aflatoxin by (TLC) chromatography.The animal and public health significance from such toxins was also discussed.

Selective effects of two triazine herbicides on Egyptian soil fungi

Bladex (Cyanazine), when applied to the soil was poisonous to the counts of total fungi and of Aspergillus, 20 days after treatment with the low dose and 40 days after treatment with the low and the medium doses. This effect was alleviated after 80 days. In the agar medium, Bladex promoted the counts of total fungi, Aspergillus, A. terreus and A. flavus. In liquid medium, it exerted no significant effect on the growth of all test fungi.Gesaprim-Combi (Atrazine) depressed the total count of fungi, 2 and 5 days after treatment with the 3 doses. This toxic effect was completely alleviated after 40 and 80 days. In the agar medium, it significantly promoted the total count of fungi by the 3 doses used. The mycelium growth, of Alternaria alternata, Trichoderma viride, Myrothecium verrucaria, Cunninghamella echinulata, Gliocladium roseum and Penicillium verruculosum was significantly suppressed.

Fungi of wheat and broad-bean straw composts. II. Thermophilic fungi.

Thirteen thermohilic genera and 19 species in addition to one variety of each of M. pulchella and H.grisea were collected from wheat and broad-bean straw composts at 45 °C. In wheat and broad-bean, all thermophilic fungi were completely checked between 4–9 days, and 1–8 days composting when the temperature ranged between 58 ° and 67 °C, and 58 ° and 70 °C respectively, and reappeared, represented by P. duponti, M. albomyces, T. lanuginosus and S. thermophile, after 9 or 10 days composting when the temperature decreased to 51.5 °–54 °C. Wheat and broad-bean straw composts were analyzed biochemically to follow the changes in ethanol and diastase soluble, hemicellulose, cellulose and lignin fractions during composting.

Studies on air-borne fungi at Qena

Statistical analysis of the results revealed no relevant correlation between the wind velocity and the counts of air-borne fungal spores, estimated by the sedimentation plate method at two sites and levels 2 and 20 meters of sampling.

Fungi of wheat and broad-bean straw composts

Twenty-two genera and 56 species were recovered from wheat and broad-bean composts at 22.5 °C. All fungi on wheat and broad-bean composts were completely checked between 4–11 days, and 1–11 days when the temperature ranged between 52° and 67 °C, and 52° and 70 °C respectively. A. fumigatus began to reappear after 12 days when the temperature fell down to 50.5°–51.5 °C. With the lengthening of composting period several fungal species succeeded to colonize straw composts and the best colonizer (based on count) after 35, 60 and 215 days composting of wheat straw was A. fumigatus after the three experimental periods, and of broad-bean straw were A. fumigatus, A. flavus, and Acremonium strictum respectively.

Effect of Bavistin, Cotoran and Curacron on Egyptian soil fungi

Tests were conducted to determine the effects of the fungicide Bavistin (Carbendazim), the herbicide Cotoran (Fluometuron) and the insecticide Curacron on Egyptian soil fungi when applied at the recommended field dose, and four and eightfold field doses.Bavistin when added to the soil induced a regular significant inhibition of the total count of fungi by the 3 doses after 5 and 40 days and by the higher doses after 80 days. The response ofAspergillus to this fungicide was almost similar to that of the total count.Cotoran was of no significant effect on the total count of fungi after 2 days at all doses, but after 5 days the herbicide was significantly depressive at the medium and the high doses. After 80 days the effect changed into significant promotion at the field dose only.Curacron was significantly toxic to the total count of soil fungi, after the shorter and longer periods at the 3 doses.

Effect of Treatment of Soil with Keratinaceous Material on Soil Fungi

In the early periods of soil storage, the total number of fungi almost regularly and significantly increased with the concentration of keratinaceous material (ground buffalo hooves) between 1% and 10%. A concentration of 20% was stimulative after 7 days and became toxic after 15 days and remained so through the end of the experiment. With increase in the storage period, the beneficial effect of all concentrations was lost and in the case of high concentrations (5–20%) toxic ammonia was produced.

Selective effects of two systemic fungicides on soil fungi

BAS 317 00F was not toxic to the total count of fungi after 2 days but was regularly significantly toxic at the three doses after 5, 20 and 40 days and toxic at the low and the high doses after 80 days. In the agar medium, it was toxic to the counts of total fungi, Aspergillus, A. terreus, Rhizopus oryzae and Mucor racemosus at the high dose. Only the mycelial growth of Trichoderma viride which was significantly inhibited by the three doses when this fungicide was added to the liquid medium.Polyram-Combi induced two effects on the total population of soil fungi. One inhibitory and this was demonstrated almost regularly after 2, 10 and 40 days and the other stimulatory after 80 days of treatment with the low and the high doses. In the agar medium, this fungicide was very toxic to total fungi and to almost all fungal genera and species at the three doses. Several fungi could survive the high dose. In liquid medium, the test fungi showed variable degree of sensitivity and the most sensitive was Gliocladium roseum which was completely eradicated by the three doses.

Keratinolytic Fungi in Egyptian Soils

The frequency of occurrence of keratinolytic fungi in seventy soil samples, collected from different sites in Upper Egypt and in the coastal area of the Mediterranean, was determined by baiting with human and animal hairs and pigeon feathers.