Thermophile Var Research Articles

Isolation of Thermophilic Fungi from Alligator Nesting Material

SUMMARYThermophilic fungi isolated from partially decomposed vegetation from the interior of a recently used alligator (Alligator mississipiensis) nest included Chaetomium thermophile var. coprophile Cooney & Emerson, C. thermophile var. dissitum Cooney & Emerson, Humicola lanuginosa (Griffon & Maublanc) Bunce, Talaromyces thermophilus Stolk, and Thermoascus aurantiacus Miehe sensu Apinis. The thermotolerant fungi Aspergillus fumigatus Fresenius and Burgoa-Papulaspora sp. were also isolated. The ontogeny of bulbils of the latter isolate is described. Alligator nesting material provides a habitat suitable for the thermophilic fungi, where the heat required for growth of these fungi is not provided by the body heat of the nest builder. These data suggest that habitats suitable for the origin and evolutionary survival of obligately thermophilic fungi have existed for long periods of time.

Effect of Temperature on Growth Rate and Development of the Thermophilic Fungus Chaetomium Thermophile

Rates of growth of seven strains of Chaetomium thermophile var. dissitum and one strain of C. thermophile var. coprophile were determined over a wide range of temperature by measurement of increase in colony diameter on Emerson YpSs Agar. After a lag phase, increase in diameter occurred at a constant rate. Growth rates and cardinal points differed among the strains. Ability to grow, form mycelial pigmentation, and produce immature and mature perithecia at extreme temperatures differed significantly among the strains for a given character, and within a strain for different characters. The range of temperature suitable for sexual reproduction was small and was much less than that for vegetative growth and pigmentation. The two taxonomic varieties differed significantly from one another in their responses to extreme temperatures, and one strain of variety dissitum had lower growth rates and more restricted morphogenetic capacity than other strains of the variety.

Effects of Nutrients, Temperature and Relative Humidity on Germination and Longevity of the Ascospores of Chaetomium thermophile var. coprophile

SUMMARYAscospores of C. thermophile var. coprophile germinated in distilled water; addition of nutrients increased the percent germinating and also shortened the latent period. A vesicle emerged through the pore, quickly protruding one or two germ tubes if nutrients were present. The vesicle did not form in distilled water. Approximately 75% germinated after 6 hr at 50 C. Germination occurred between 30 and 59 C; the optimum was 50–55 C. Spore concentration had no significant effect upon germination. A short maturation period is required since ascospores from 4- and 6-day-old cultures germinated in a lower percentage than those from older cultures. However, they require no activation treatment. The ascospores are not thermoduric and failed to survive 1 hr exposure to 63 C. The thermal death point (all cells killed in 10 min) was between 65 and 67 C. Exposure to temperatures above the maximum invoked a delay in germination when the ascospores were reincubated at an optimum temperature. Ascospores in a dry state and stored at low relative humidities retained their viability longer and could survive longer exposures to high temperatures than when suspended in water or stored dry at high relative humidities.

Effects of Nutrients, Temperature and Relative Humidity on Germination and Longevity of the Ascospores of Chaetomium Thermophile Var. Coprophile

SUMMARYAscospores of C. thermophile var. coprophile germinated in distilled water; addition of nutrients increased the percent germinating and also shortened the latent period. A vesicle emerged through the pore, quickly protruding one or two germ tubes if nutrients were present. The vesicle did not form in distilled water. Approximately 75% germinated after 6 hr at 50 C. Germination occurred between 30 and 59 C; the optimum was 50–55 C. Spore concentration had no significant effect upon germination. A short maturation period is required since ascospores from 4- and 6-day-old cultures germinated in a lower percentage than those from older cultures. However, they require no activation treatment. The ascospores are not thermoduric and failed to survive 1 hr exposure to 63 C. The thermal death point (all cells killed in 10 min) was between 65 and 67 C. Exposure to temperatures above the maximum invoked a delay in germination when the ascospores were reincubated at an optimum temperature. Ascospores in a dry state and stored at low relative humidities retained their viability longer and could survive longer exposures to high temperatures than when suspended in water or stored dry at high relative humidities.

Isolation of Thermophilic Fungi from Self-Heated, Industrial Wood Chip Piles

Thermophilic fungi isolated from self-heated wood chips stored at a paper factory included Chaetomnium thermophile var. coprophile Cooney & Emerson, C. thermophile var. dissitum Cooney & Emerson, Humicola grisea var. thermoidea Cooney & Emerson, H. lanuginosa (Griffon & Maublanc) Bunce, Sporotrichum thermophile Apinis, Talaromyces emersonii Stolk, T. thermophilus Stolk, and Thermoascus aurantiacus Miehe sensu Apinis. Fewer species were present in fresh chips and in chips from unheated piles. The thermotolerant fungus Aspergillus fumigatus Fresenus was recovered from all chip samples. Incubation of whole or ground chips at 50 C on Emerson YpSs Agar (Difco), on 2% malt agar, and in damp chambers was necessary and sufficient for enrichment and detection of thermophilic species present in the samples. Use of a lower temperature or of only a single enrichment medium resulted in incomplete detection of species present. Enriching in atmospheres of tank N2 and of C02-supplemented air, and plating on a variety of nutritionally restrictive media, failed to increase the number of thermophiles isolated. Dilution-streak plating was the most efficient and effective method for isolation and purification; addition of 100 units per ml of both streptomycin sulphate and penicillin G to isolation media facilitated purification. It was concluded that thermophilic fungi are abundant in selfheated wood chips, and together with thermotolerant fungi contribute to heating and biodeterioration.

Isolation of Thermophilic Fungi from Self-Heated, Industrial Wood Chip Piles

Thermophilic fungi isolated from self-heated wood chips stored at a paper factory included Chaetomium thermophile var. coprophile Cooney & Emerson, C. thermophile var. dissitum Cooney & Emerson, Hu...

The Cellulolytic Activity of Thermophilic Fungi and Actinomycetes

SUMMARYThe thermophilic molds showed greater cellulolytic ability than did the thermophilic actinomycetes. Chaetomium thermophile var. coprophilc. C. thermophile var. dissitum, Himicola grisea var. thermoidea, H. insolens. Myriococcum albomyees, Sporotrichum thermophile, and Torula thermophila were able to degrade filter paper and utilize soluble carboxymethyl cellulose (CMC). Malbranchea pulchella var. sulfurea, Stilbella thermimephila and Talaromyees thermophilus could not degrade filter paper, but their cell-free filtrates contained the Cx enzyme that could hydrolyze soluble carboxymethyl cellulose to reducing sugars. Humicola lanuginosa, H. stellata, Mucor mechei, M. pusillus and Thermoascus aurantiacus could not degrade filter paper nor hydrolyze CMC. Streptomyces thermovielaceus var. pingens was the only actinomycete to significantly degrade filter paper. Thermomonospora curvata caused a slight loss in weight. Cell-free filtrates from these two, plus filtrates from Pseudonocardia thermophila, Streptomyces rectus, and S. thermovulgaris were able to hydrolyze CMC. Micromonospora chalcea, Streptomyees violaceoruber. Thermoactinomyees glaucus, T. vulgaris and Thermomonospora viridis could not degrade filter paper or hydrolyze CMC. The Cx enzyme is an induced enzyme, since none of the microorganisms produced it in a medium lacking cellulose.

The Cellulolytic Activity of Thermophilic Fungi and Actinomycetes

The thermophilic molds showed greater cellulolytic ability than did the thermophilic actinomycetes. Chaetomium thermophile var. coprophilc. C. thermophile var. dissitum, Himicola grisea var. thermo...