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. Twenty-one species, in addition to an unidentified species, which belong to sixteen genera were collected. Chrysosporium indicum, C. tropicum, C. keratinophilum, and Microsporum gypseum were the most frequent fungal species recovered from the baited soils. The soil samples collected from the salt marshes of the coastal Mediterranean area were completely free from any keratinolytic fungi, whereas the soil samples collected from cultivated soils contributed species, ranging from one to four species.     

Keratinolytic and keratinophilic fungi in the soils of Papua New Guinea

A study was made of soil samples collected during an expedition to the Highlands of Papua New Guinea. Fungi were isolated from the samples by the method of hair baiting (To-Ka-Va). Of the 33 species isolated, about half showed keratinolytic activity. Such activity is previously unreported for Mucor hiemalis f. hiemalis, Myrothecium roridum, Paecilomyces carneus, P. marquandii, Penicillium brevicompactum, Rhinocladiella mansonii and Verticillium lecanii. The species most active keratinolytically were Chrysosporium an. Arthroderma cuniculi, C. an. A. curreyi, C. indicum, Myceliophthora vellerea and Trichophyton ajelloi. The spectrum of fungi with keratinolytic activity isolated from the different sites differed considerably according to the frequency of use by man, heaviest use being correlated with greatest activity. The pH of the soil (varying from 5.8–7.5) had little influence on the type of such fungi isolated.     

Keratinolytic fungi in sewage sludge

Sewage sludge from the Upper Silesia Region of Poland were surveyed for keratinolytic fungi. Out of 100 Petri dishes examined, 89 were positive for these micro-organisms. Altogether, 185 fungal appearances belonging to 10 species were observed. Trichophyton terrestre with its teleomorph Arthroderma quadrifidum, T. ajelloi with A. uncinatum, Microsporum gypseum with Arthroderma sp., and Chrysosporium keratinophilum with Aphanoascus keratinophilus prevailed in the sludges. The sewage treatment technologies together with the sludge structure, humidity and pH were found to be critical factors determining the occurrence of keratinolytic fungi in the sludge environment. The qualitative and quantitative composition of keratinolytic fungi could be a useful tool in evaluation of sludge treatment processes.     

Keratinolytic fungi of wadi Qena in Egypt

Forty-six soil samples collected from different sites of wadi Qena were examined for keratinophilic fungi using the hair baiting technique. Thirty-two species in addition to one variety of each ofA. nidulans andA. flavus which belong to eighteen genera were recovered.Aspergillus, Chrysosporium, Penicillium, Microsporum andFusarium were the most frequent genera developed from baited soils.     

Keratinolytic and keratinophilic fungi of children's sandpits in the city of Turin

Soils rich in keratinic residues constitute a permanent or occasional reservoir for dermatophytes and keratinolytic and keratinophilic fungi, and are a source of potential infection for man and animals.The keratinolytic and keratinophilic mycoflora of 28 sandpits in Turin was studied to evaluate the risk of fungal skin infections that is run by children as they play in public parks and to lay the ground-work for a next epidemiological study of soil- and animal-inhabiting dermatophytes found in cities, and their impact on human dermatophytoses. Fifty seven species were isolated and a high percentage (52%) showed keratinolytic activity. Species of Microsporum, Trichophyton, Mariannaea, Aphanoascus, Chrysosporium, Malbranchea and Geomyces showed the most active keratinolysis.Work n. 315 performed under the auspices of the Centro di Studio sulla Micologia del Terreno del C.N.R. at the Dipartimento di Biologia vegetale dell Università di Torino.     

Screening of ethylene-producing root-infecting fungi in Egyptian soil

Of 86 fungal species isolated from diseased roots in Egypt, 25 produced ethylene concentration varying from 0.4 to over 380 ppm. Methionine and ethionine were the most effective substrates on C₂H₄ formation, but glucose was also required for maximal C₂H₄ production. However, sucrose and starch promote C₂H₄ formation by Fusarium oxysporum and Pythium ultimum, while acetate and succinate promote ethylene biosynthesis by Penicillium cyclopium.     

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.     

Toxicity of heavy metals to Egyptian soil fungi

Changes in the composition of the soil mycoflora after soil treatment with 500, 2000 and 5000 ppm of mercury, zinc, lead, copper, nickel and cadmium, were determined on Czapek's glucose agar at intervals up to 15 weeks. Treatment of soil with mercuric chloride and lead nitrate significantly reduced the fungal population counts for soil treated with zinc or copper sulphate, and with nickel or cadmium chloride counts were increased on some treatments and reduced on others. When heavy metals were incorporated into the isolation medium, they depressed the total count of fungi, as well as affecting individual species.     

Soil amendments to correct iron availability in Egyptian soils

The aim of the present study is a trial to establish some effective soil management and amendments procedures that can help in curing Fe malnutrition in some Egyptian soils rich in natural reserves and poor in available iron. The main results being drawn from this investigation could be summarized as follows:

1. The acid treatment affected the levels of mobile iron significantly at about pH 4. Maximum values of mobile iron were obtained by the further rise in soil acidity to pH 3.10 and 3.25. When further acidification was performed, it was noticed a turn-over in the quantities of mobile iron.
2. In a study on the effect of waterlogging the soil and application of organic matter on the mode of releases of available iron were obtained with passage of time whether in the control treatment or in any special organic matter treatment. Under waterlogging conditions, it is noticed that a moderate level of organic matter increases available Fe, while higher amounts of organic matter depressed the release of Fe from its labile pool.

     

Incidence of keratinophilic fungi in rice-field soils

Soil samples from rice-fields, collected at monthly intervals, were analysed by baiting technique for the incidence of keratino-philic fungi. Nine species, among a total of 102 species isolated by various methods, were keratinophilic species (8.8%). These were recorded from 38 out of 45 samples collected. The distribution pattern of the different keratinophilic fungi and their significance are discussed.     

Microbiological production of gluconic acid by Egyptian mould fungi

Summary A local strain of Asp. phoenicis proved to be a good gluconic acid producer. Previous experiments carried out on this organism were extended to investigate the influence of some culture conditions on the acid production when the submerged technique was applied. These included the investigation of the influence of the nature and concentration of the nutritive constituents of the fermentation medium.     

Further study on seasonal fluctuations of Egyptian soil fungi

The seasonal fluctuations of fungi were studied in 72 soil samples collected at 10-day intervals between January 1972 and December 1973. The richest periods in the fungal population were January, March and September–December 1972, and April, May, September, November and December 1973. The poorest months were consistently June and July of 1972 and 1973 and August 1973 which are all summer months. Thirty-nine genera were isolated of which Aspergillus, Penicillium, Fusarium, Mucor, Rhizopus and Humicola were of high seasonal occurrence. Seven genera were of moderate occurrence and these were Cochliobolus,Stachybotrys, Paecilomyces, Cunninghamella, Myrothecium, Chaetomium and Sepedonium. The remaining genera were of low or rare seasonal occurrence. Aspergillus showed its highest prevalence during the periods May-September 1972 and April-August 1973. Twenty-four species of Aspergillus in addition to two varieties of A. nidulans were isolated, of which A. niger, A. fumigatus, A. terreus, A. nidulans and A. sydowii were dominant. Thirty species of Penicillium were identified, of which P. notatum, P. funiculosum and P. chrysogenum were of high seasonal occurrence. Penicillium predominated during winter and spring months. Fusarium showed its highest percentage populations during the periods February, March, April, October, November and December 1972 and February, August, September, October and November 1973. Four species of Mucor were recorded of which M. racemosus was the commonest; and its highest percentage populations were recorded in November 1972; and February, March and November 1973 which are moderate temperature months. Rhizopus was represented by two species of which R. nigricans was of high seasonal occurrence. Three species of Humicola were isolated of which H. grisea was the most common.     

A preliminary study of the occurrence of actidione-resistant fungi in sediments of Catalonian river mouths (Spain). I. Keratinolytic fungi and related Onygenales

Sediments from eight river mouths along the Catalonian coast (Spain) were surveyed for keratinolytic fungi and related Onygenales. The actidione plating technique was employed. Of 532 actidione-treated sediment samples, 268 (50.3%) were positive for the fungi. Altogether, 384 fungal strains from 35 species were isolated from the samples. Narasimhella marginospora, Aphanoascus fulvescens, Neoarachnotheca keratinophila with its anamorph Myriodontium keratinophilum, Narasimhella hyalinospora, Beauveria alba, Sporothrix schenckii, Chrysosporium lobatum and Gymnoascus littoralis were the predominant species in sediments. Abundance of N. marginospora was clearly correlated with the degree of water pollution with sewage. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effect of the herbicide ametryn on cellulose-deeomposing fungi in Egyptian soil

Ametryn exerted a depressive effect on the total count of cellulose-decomposing fungi after 1 and 3 weeks of treatment with a high dose (54 mg active ingredient per kg dry soil), and 5 weeks after treatment with medium (27 mg) and high doses. This inhibitory effect was alleviated after 8 weeks, while after 12 weeks it was changed into promotion by a low dose (5.4 mg). When incorporated in the agar medium, this herbicide was toxic to the total count and to the counts of almost all fungal genera and species at the three doses (25, 125, 250 ppm). The decomposition of ametryn-treated calico buried in untreated soil was significantly and regularly inhibited by medium and high doses after all experimental periods. The growth and sporulation of test fungal species were partially or completely inhibited by the three doses, except,Aspergillus niger, Chaetomium globosum, andGliocladium roseum which were not affected by the low dose     

Effect of dithane M-45 on cellulose-decomposing fungi in Egyptian soil

The fungicide Dithane M-45 when applied to the soil was regularly and significantly toxic to the total count of fungi at all doses used (4·48, 22·4 and 44·8 mg active ingredient per kg dry soil). The toxicity was regularly increased with dose and persisted till the end of the experiment (15 weeks). When Dithane M-45 was incorporated into the agar medium all test fungi were eliminated by the high dose (24·0 ppm). The low and medium doses were tolerated by some fungi. The decay of filter paper buried in the fungicide-treated soil was significantly reduced by the high dose after 1 and 3 weeks of incubation, while the decay of filter paper treated with this fungicide and buried in untreated soil was significantly retarded by the high dose only after all experimental periods of incubation (up to 15 weeks). The growth and sporulation of nine test fungi were eliminated by the three doses of Dithane M-45 except Chaetomium globosum, Fusarium moniliforme and Trichoderma viride which could grow restrictedly at the low dose only. Production of endo-1,4β-d-glucanase and mycelial dry weight were not significantly affected by the three doses in the case of Aspergillus niger, and by the low dose in the case of Alternaria alternata, Fusarium solani and Myrothecium verrucaria. In the case of other test fungi and other doses, endo-1,4β-glucanase production and mecelial dry weight were significantly inhibited.