Studies on airborne fungi at Qena

The air-borne fungi were studied in one hundred and fifty-six exposures made over one year at two levels (2 meter and 20 meter). Aspergillus was the only air-borne fungus identified at 45 °C. It was recovered in 33.3% and 28.2% of the exposures and was represented by four species at low level and three at high level.A. fumigatus was extremely dominant and constituted 76.4% abd 73.3% of the total count of fungi at the low and the high levels respectively.     

Studies on pathogenic dematiaceous fungi

Two hundred and twenty-six samples of woody materials, vegetable matter and soil were processed by the direct plating and mouse inoculation technique for the isolation of pathogenic dematiaceous fungi. The species of fungi isolated were Fonsecaea pedrosoi — 13, Cladosporium carrionii — 7 and Phialophora verrucosa — 4 isolates. The mouse inoculation technique was found to be much better than direct plating for the recovery of these fungi. Woody plant materials proved to be a good sample source for pathogenic dematiaceous fungi contributing about 90% of the isolates. All the isolates were pathogenic for mice as evidenced by the presence of dark nodular lesions containing fungal elements in the organs of experimentally infected animals.     

Studies on thermophilic cellulolytic fungi

Three thermophilic cellulolytic fungi, Chaetomium thermophile var. coprophile, Sporotrichum thermophile, and Thermoascus aurantiacus were studied to determine the conditions for a high rate of cellulose degradation. The range of temperature over which good growth occurred was determined first in a temperature gradient incubator; the optimum temperature was then established in shake flask cultures. T. aurantiacus had the highest optimum growth temperature range (46 to 51 C), whereas S. thermophile had the broadest range over which good growth occurred (36 to 43 C). Optimum temperatures for the three organisms, T. aurantiacus, S. Thermophile, and C. thermophile were 48, 40, and 40 C, respectively. It was found that the addition of an organic carbon and nitrogen source to a cellulose mineral solution medium markedly increased the rate of cellulose degradation. The surfactant, Tween 80, which has been reported to be of value in the production and recovery of the enzyme, cellulase, was shown to be detrimental to the degradation of cellulose in culture. In the medium used, S. thermophile gave the highest rate of substrate utilization; 56% of the cellulose was hydrolyzed in 72 h. The average degree of polymerization of cellulose decreased from 745 to 575.     

Studies on the air-borne fungal spores in Amritsar: Their role in keratomycosis

An aerial survey for fungal spores in Amritsar has been carried out by petri plate exposure method for a period of one year. A total of 23 fungi appeared in the plates. Out of these Aspergillus was the commonest fungus representing 21.69% of the total colony count followed by Alternaria, Curvularia and Fusarium. There was seasonal variation in the prevalence of fungal spores. A comparison of the prevalence of fungi in diseased and healthy eyes and the atmosphere of Amritsar appeasrs to support the view that these fungi are transient residents in the eyes depending on their availability in the atmosphere.Part of the data presented at the XXXVIII All India Ophthalmological Conference held at Amritsar from January 5–8, 1979.     

Studies on fungi cultivated by ants

A collection of 36 fungi cultivated by leaf-cutting ants has been established at The New York Botanical Garden. These fungi grow on a variety of natural media and on a synthetic medium with mineral salts, dextrose, casein hydrolysate, purine and pyrimidine bases and vitamins. Tests of the fungi for antibacterial activity were all negative againstStaphylococcus aureus andEscherichia coli. Only four isolates of ant fungi, each cultivated by a different species of ant, produced basidiocarps on oatmeal agar. Taxonomic studies indicate that these belong to the same species of fungus (Lepiota sp.). Eighteen isolates produced bromatia characteristic of the form species,Attamyces bromatificus Kreisel, one produced a mycelium with clamp connections, and thirteen produced sterile mycelia without clamped hyphae and without bromatia.     

Studies on coprophilous fungi. IIChaetomium

Two new species ofChaetomium, viz.,C. globisporum andC. rajasthanense, are described.C. globisporum was isolated from a steamed sample of rat dung.C. rajasthanense was isolated from tiger excreta.     

Studies on mevinolin production by some fungi

The potentiality of 25 fungal species, belonging to fourteen genera isolated from Egyptian soils, to produce mevinolin, a hypocholesterolaemic agent, when grown on selected substrates was tested. Samples of culture filtrates were tested by thin layer chromatography and the positive results were further assessed by high pressure liquid chromatography analysis. It was found that nearly one-third of the fungi showed positive results for production of mevinolin. Aspergillus terreus was distinguished by its capacity to produce mevinolin when cultivated on selected media. Some factors influencing mevinolin production and the growth of A. terreus were also studied. The maximal mevinolin yields were achieved after 8 days incubation at 30 degrees C. An initial pH value of 5-6 was the optimum for growth of A. terreus and mevinolin production.     

Studies on the synnematous fungi imperfecti II

Summary Albosynnema with the type species,A. elegans, andSolheimia with the type species,S. costaspora, are described as new synnematous taxa. A species ofNegeriella, N. panamensis, is described as new. All of these new taxa produce phragmospores. In addition, new distribution records forCalostilbella Calostilbe, Stromatographium stromaticum, Vrikshopama swetasakha, andIsaria tenuipes are listed.This study was supported by a grant from the National Science Foundation (GB-2433).     

Studies on fungi in the root region

Summary Aqueous extracts of adventitious roots ofAllium sativum L. (garlic), seedling roots ofAllium porrum L. (leek), and both adventitious and seedling roots ofAllium cepa L. (onion), were tested for antibiotic activity against three root-surface fungi,Cylindrocarpon radicicola Wollenw.,Gliocladium roseum (Link) Thom andFusarium culmorum (W. G. Smith) Sacc. by means of two different techniques.With a filter-paper disc technique, root extracts sterilised by membrane-filtration produced zones of inhibition of the test fungi, whereas root extracts sterilised by autoclaving showed no activity. Garlic root extract produced inhibition zones with all the test fungi, whereas extracts of onion adventitious roots and leek seedling roots produced inhibition zones with only one of the test fungi. The extract of onion seedling roots produced no inhibition zones. Root extracts of all theAllium species, when sterilised by membrane filtration, generally inhibited spore-germination of all the test fungi.     

Studies on fungi in the root region

Summary Data are given on the fungi isolated from 30-day-old adventitious roots and seedling roots of severalAllium species by means of the root-washing technique. These fungi were typical root-surface forms includingCylindrocarpon, Fusarium, and sterile forms. The amount of root colonization observed, however, was not so great as with other higher plant roots.The nature and role of bulb surface contaminants is discussed in relation to the colonization of young roots, and is compared with the role of seed-coat contaminants in such colonization.     

Studies on fungi in the root region

Summary Tabulated information on the colonization of roots of barley, cabbage and dwarf bean by fungi during the first 10 days of root development is given. These data, obtained by isolation and direct observation studies, are discussed in relation to previous observations on the association of fungi with the roots of healthy crop plants.The results indicate that initial root colonization may be by any of a wide range of soil fungi, but that this mixed population rapidly gives way to a stable and typical root-surface mycoflora (dominated by such fungi asFusarium spp.,Cylindrocarpon radicicola, Gliocladium spp., andPenicillium spp.     

Studies on the solubilization of German coal by fungi

Summary The capability of seven basidiomycetes (Trametes versicolor, Poria placenta, Pleurotus florida, P. ostreatus, P. sajor-caju, P. eryngii, Stropharia sp.), one ascomycete (Chaetomium globosum) and five hyphomycetes and moulds (Humicola grisea, Trichoderma viride, Aspergillus terreus, Paecilomyces varioti, Papulaspora immersa) to solubilize medium and high volatile bituminous coals (types A and B) as well as four types of lignite B from Germany was tested in surface cultures. The intensity of bioliquefaction was determined by estimating the rate of droplet formation and by measuring the loss of weight of the coal granules gravimetrically. The bituminous coals with a relative high degree of coalification were only moderately converted by Trametes versicolor, Pleurotus florida, P. ostreatus and P. sajor-caju. The three species of Pleurotus caused the greatest rate of biosolubilization of lignite, yielding a loss of weight of the coal granules of more than 5.8% with a maximum of 7.6% with P. florida. The non-basidiomycetes proved to be less active with a liquefaction rate of up to 3.5% with Trichoderma viride. In general, the geologically younger lignite coals were more effectively solubilized than the older hard coals. The volatile matter and the oxygen content proved to be the principal factors influencing the intensity of bioconversion.     

Studies on cytochromes of lichenized fungi under optimized culture conditions

Cytochromes are membrane-bound hemoproteins responsible for the generation of ATP via the electron transport system to fuel the metabolic processes of the organism for their growth. This study reports the properties of cytochromes present in the isolated lichenized fungi of the cultured lichen Usnea ghattensis under optimized conditions. The fungal partner of the cultured lichen Usnea ghattensis contains a, b and c types of cytochromes. The concentrations of a, b and c type cytochromes were found to be significantly high (0.0967, 0.0900, and 0.1030 mM/mg protein, respectively) in the isolated fungal symbiont of cultured lichen grown in malt-yeast extract medium supplemented with 0.01 mol/l sucrose and 0.01 mol/l polyethylglycol. The results suggest that supplementation of additional carbon sources may play a role in optimizing the growth via activating the cytochrome respiratory system in lichenized fungi.