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The production of celulases by a soil yeast belonging to the genus Trichosporon and by microscopic fungi of various systematic groups was studied. The yeast synthesized relatively small amounts of cellulases in contrast to microscopic fungi. The active culture producing cellulases was the fungus Trichoderma longibrachiatum 7-26.
Hydrochemical analysis and the occurrence of aquatic fungi at the 3 stands in the upper course of the river Szeszupa were the aim of the studies of the authors. Out of 22 species of fungi found the following appeared to be new for Poland's hydromycoflora: Olpidium rotiferum, Nephrochytrium buttermerense and Achlya orion.
The growth-temperature relations and thermal tolerance of the asexual spores of thermophilic fungi commonly found in composting plant materials were determined. The optimum temperature range for germination of the spores was 40 degrees - 50 degrees C. The spores of Humicola lanuginosa (GRIFFON and MAUBLANC) BUNCE were able to survive 60 min exposure to 68 degrees C while those of Mucor pusillus COONEY and EMERSON survived only 5 min exposure to 68 degrees C. A determination of the thermal death rates of the spores at 65 degrees C showed a rapid loss of viability of those of Torula thermophila COONEY and EMERSON. The thermal tolerance of the propagules of thermophilic fungi in relation to their special ecological niche is discussed.
In the years 1991-1995 the authors investigated the mycoflora and the effect of environmental factors of 36 lakes and 4 rivers in the Western Suwałki Lake District. In addition the effect of environment factors on the occurrence of various aquatic fungi was analysed. Altogether of 109 fungi species were recorded. Twenty two species new the mycoflora of Poland were noted. The presence of Tripospermum myrti in Lake Oleckie Wielkie is noteworthy.
We examined the growth of six fungi during 18 days at 4 degrees C in a corneal preservation medium containing 2.5% chondroitin sulfate (K-Sol). The number of viable organisms decreased with time for all six fungi, the average decrease being 65%. The risk of transplanting fungal organisms with a donor cornea stored for up to 18 days at 4 degrees C in preservation media containing chondroitin sulfate is no greater than that with the same cornea stored for only one day.
Transposons are ubiquitous genetic elements discovered so far in all investigated prokaryotes and eukaryotes. In remarkable contrast to all other genes, transposable elements are able to move to new locations within their host genomes. Transposition of transposons into coding sequences and their initiation of chromosome rearrangements have tremendous impact on gene expression and genome evolution. While transposons have long been known in bacteria, plants, and animals, only in recent years has there been a significant increase in the number of transposable elements discovered in filamentous fungi. Like those of other eukaryotes, each fungal transposable element is either of class or of class II. While class I elements transpose by a RNA intermediate and employ reverse transcriptases, class II elements transpose directly at the DNA level. We present structural and functional features for such transposons that have been identified so far in filamentous fungi. Emphasis is given to specific advantages or unique features when fungal systems are used to study transposable elements, e.g., the evolutionary impact of transposons in coenocytic organisms and possible experimental approaches toward horizontal gene transfer. Finally, we focus on the potential of transposons for tagging and identifying fungal genes.
The vapors of peppermint oil and two of its major constituents (menthol and menthone), and sweet basil oil and two of its major constituents (linalool and eugenol), were tested against Sclerotinia sclerotiorum (Lib.), Rhizopus stolonifer (Ehrenb. exFr.) Vuill and Mucor sp. (Fisher) in a closed system. These fungi cause deterioration and heavy decay of peach fruit during marketing, shipping and storage. The essential oils, their major individual aroma constituents and blends of the major individual constituents at different ratios inhibited the growth of the fungi in a dose-dependent manner. Menthol was found to be the individual aroma constituent responsible for the antifungal properties of peppermint essential oil, while menthone alone did not show any effect at all doses. In the case of basil oil, linalool alone showed a moderate antifungal activity while eugenol showed no activity at all. Mixing the two components in a ratio similar to their concentrations in the original oil was found to enhance the antifungal properties of basil oil indicating a synergistic effect.
The prevention of wound infection after major contaminated head and neck surgery is a critical issue for the head and neck surgeon. The proper interpretation of cultures taken from wounds is uncertain. Multiple organisms are invariably isolated from this nonsterile site including indigenous aerobic and anaerobic flora, aerobic gram-negative rods, and fungi. We present evidence from controlled antibiotic trials that demonstrate the pathogenicity of oropharyngeal anaerobic flora. The presence of aerobic gram-negative rods and fungi generally represent colonization and antibiotic coverage need not routinely be directed at these organisms. On the other hand, the antibacterial spectrum of an agent used for head and neck would prophylaxis should include coverage for pathogenic oral flora, namely the gram-positive aerobic cocci (especially streptococci) and anaerobic bacteria.
Twenty-six identified and three unidentified species belonging to eight genera of zoosporic fungi were recovered from seventy-six mud samples of Egyptian lakes using sesame seeds as baits. Nineteen samples were collected along the borders of four major lakes. Pythium, Phytophthora and Allomyces, yielded the highest spectra of zoosporic species, while Aqualinderella, Blastocladia and Dictyuchus, had one species. Pythium, Aphanomyces, Allomyces, Aqualinderella, Phytophthora and Saprolegnia were the dominant zoosporic genera while Blastocladia and Dictyuchus were rare. The most prevalent species of zoosporic fungi were Aqualinderella fermentans, Aphanomyces laevis and unidentified Pythium species while the other isolated species in this study were rare. Menzalah was the richest lake with zoosporic species followed by Borolous and Karoon. Some zoosporic fungal genera were recovered from the mud of the four tested lakes (participator genera) and others from three lakes or from only two lakes. Physicochemical characteristics of the mud samples (pH, total soluble salts and organic matter) revealed no correlation with the fungal occurrence and distribution in these lakes.
Resistance of pathogenic bacteria to antibiotics leads scientists to discover new antibacterial drugs. Ninety samples of wood-colonizing fungi were cultivated on agar plates, and their extracts tested for antibacterial activity using the Vibrio fischeri bioluminescence test. Two fungi species, Serpula lacrymans and Nectria vilior, were found to be a potential new source of thermostable antibiotics. Vibrio fischeri bioluminescence test was found to be a useful method for antibacterial activity screening from the samples of natural origin.
The Atlantic Rainforest is a Brazilian ecosystem that is being rapidly being destroyed, along with the abiotic and biotic factors present in it. Among the biotic factors, the fungi are found in the soil which, besides being of major importance in terms of ecological niches, also have broad and significant applications in biotechnology. In order to assess the biodiversity of these microorganisms in this type of ecosystem, the Banhado Grande region was chosen at the Jureia-Itatins Ecology Station, in the state of Sao Paulo, Brazil. Within this region, two areas were delimited for study, one covered with natural (primary) vegetation and the other containing vegetation that regenerated following the planting of rice crops, referred to here as secondary. Collection of compound soil samples were taken (depth 0-15 cm) over a period of two and a half years, with the litter first being removed, during dry/cold and humid/hot periods. After sifting the samples, they were appropriately processed using the serial dilution technique to isolate the fungi from the soil. Six different culture media were used, having pHs of 4.5, 7.0 and 9.0. Altogether, 1,211 strains were isolated, divided into the following groups: Hyphomycetes, the most abundant followed by Ascomycetes, Zygomycetes, Coelomycetes, and Oomycetes. From these, 112 species were identified, 8 down to the genus level, and those that did not produce conidia were grouped as Mycelia sterilia. Among the strains, 67 were cellulolytic, 32 originated solely in soil under natural vegetation, and 26 originated solely in soil under secondary vegetation.
Endophytic fungi were isolated from leaves, flowers and fruit of healthy apple trees (Malus domestica , Borkh.) growing in southern Brazilian orchards under three different cultivation systems (conventional, integrated and organic), during two vegetative cycles. The greatest total number of endophytic isolates was obtained from the orchards under organic cultivation when compared to integrated and conventional cultivation systems. Filamentous fungi from the genera Colletotrichum , Xylaria and Botryosphaeria were the most frequent ones and the most representative yeast genera were Sporobolomyces , Rhodotorula , Debaryomyces and Cryptococcus . It is suggested that some isolates may be used as indicators of the different management systems.
Samples were collected from 44 pens under animals and birds for the estimation of keratinophilic fungi using the hair-baiting technique. Thirty-nine species which belong to eighteen genera were recovered. Chrysosporium, Aspergillus, and Penicillium were the most frequent genera. From keratinophilic fungi, Myceliophthora anamorph of Corynascus sepedonium, Myceliophthora anamorph of Corynascus novoguinensis, Microsporum boullardii, M. gypseum, Trichophyton metagrophytes and Arthroderma sp. were recovered in different frequencies.
Using the soil plate technique, thirty one species appertaining to twenty three genera were recovered from 160 samples of rabbit claws which were collected from a rabbit farm at Assiut. Of the true keratinophilic fungi Chrysosporium tropicum was the most prevalent where it colonized 56.25% of the samples. Microsporum gypseum was rarely isolated in this study. Among the non-keratinophilic fungi Penicillium funiculosum. P. jenseni and Paccilomyces lilacinus were of low incidence (20%, 19.37% and 14.37% of the samples, respectively).
Seventy-six species belonging to 29 genera were collected from 320 samples of cloven-hooves and horns of goats and sheep. Chrysosporium was the most common genus on the various substrates and comprehended the following species: C. asperatum, Chrysosporium anamorph of Arthroderma cuniculi, Chrysosporium anamorph of Arthroderma curreyi, C. georgii, C. indicum, C. keratinophilum, C. lobatum, C. lucknowense, C. pannicola, C. pseudomerdarium, C. queenslandicum, Chrysosporium state of Thielavia sepedonium and C. tropicum. Some interesting fungi were isolated: Myceliophthora anamorph of Arthroderma tuberculatum, Myceliophthora anamorph of Corynoascus novoguineensis, Myceliophthora anamorph of Ctenomyces serratus, Trichosporon cutaneum, Trichophyton terrestre and T. verrucosum. Also, several saprobic filamentous fungi tolerating high levels of cycloheximide were isolated of which numerous members of Acremonium, Aspergillus, Chaetomium, Fusarium, Penicillium, Scopulariopsis and several others.
A total of 506 isolates of mesophilic, thermophilic and thermotolerant fungi isolated from the poultry feed ingredients included soybean meals, ground maize, cottonseed cake, wheat bran and fish meal, on glucose-Czapek's agar, Littman oxgall agar at 28 degrees C and yeast starch agar (YPSs) at 45 degrees C, were screened for their ability to produce hydrolytic protease enzyme on solid media. Most of the fungal isolates were able to produce such enzymes but with variable capabilities. The highest proteolytic activity was exhibited by some isolates of Penicillium chrysogenum, Aspergillus flavus, Thermoascus thermophilus and Rhizopus chizopodifarmis. Of all fungal isolates screened for proteolytic activity, Penicillium chrysogenum and Thermoascus thermophilus produced the highest amounts of proteases. These two isolates were used to study the effect of some environmental and nutritional factors on their proteolytic activity. It was found that the highest yield of protease by P. chrysogenum (12.5 units) was achieved 3 days after incubation at 30 degrees C. Marked reduction in protease activity was observed at 37 degrees C. The thermophilic fungus T. thermophillus exhibited maximum (18 units) proteolytic activity 6 days after incubation at 45 degrees C. The enzyme yield was reduced to 13 units at 50 degrees C. Among the seven carbon sources tested, sucrose was the most appropriate for maximum protease production by both P. chrysogenum and T. thermophilus (13.2 and 12.8 units, respectively). Of the sixteen nitrogen sources investigated, NaNO3 was the best inorganic additive nitrogenous salt which induced the highest proteolytic activity by P. chrysogenum and T. thermophilus, whereas DL-tryptophan was the most preferable organic nitrogen compound for maximum protease production by the two fungi tested.
Thirty-nine species belonging to 13 genera of zoosporic fungi were collected from 33 water samples on sesame and hemp seeds as baits at 22 degrees C. Five genera were isolated in high occurrence: Allomyces (2 species), Achlya (9 species), Dictyuchus (4 species), Pythium (5 species) and Saprolegnia (5 species). Aphanomyces (4 species) and Isoachlya (2 species) were of moderate frequencies. The remaining six genera were less frequent: Anisolpidium, Brevilegnia, Calyptralegnia, Leptolegnia, Pythiopsis and Thraustotheca. Sixty-six species and 2 varieties belonging to 34 genera were identified on glucose-(24 genera and 52 species + 1 variety) and cellulose (31 genera and 48 species + 2 varieties) Czapek Dox agar at 28 degrees C. The most common species on the two media were Acremonium strictum, Aspergillus flavus, A. fumigatus, A. niger, Fusarium moniliforme, F. oxysporum, F. solani, Mucor racemosus, Penicillium chrysogenum and P. corylophilum. Some fungi were common only on cellulose agar medium such as Chaetomium globosum, C. spirale and Memnoniella echinata.
The fungal microflora of a dry valley in Southern Victoria Land near McMurdo Sound, Antarctica, was investigated. Samples were collected from introduced objects such as a mummified penguin and spent chewing tobacco in addition to the sparse soil found in rock fissures, isolated moss colonies, shoreline deposit materials, CaCO3 precipitates, and microbial mat debris obtained from the frozen surface of the lake in the basin of Taylor Valley. Using conventional media and techniques, all collection sites yielded populations of yeasts and filamentous fungi. Water samples and live microbial mats from beneath the lake ice yielded species of fungi along with an abundance of bacteria.