Thermophilic Fungi in Sun-Heated Soils

Abstract

Thermophilic and thermotolerant fungi were isolated from soils of south-central Indiana (U.S.A.) in the following order of decreasing frequency: Myriococcum albomyces Cooney et Emerson, Aspergillus fumigatus Fres., Talaromyces thermophilus Stolk, Humicola lanuginosa (Griff. et Maubl.) Bunce, Allescheria terrestris Apinis, Malbranchea pulchella var. sulfurea (Miehe) Cooney et Emerson, Thielavia heterothallica Klopotek, Mucor pusillus Lindt, Chaetomium thermophile var. dissitum Cooney et Emerson, Thielavia minor (Rays et Borut) Malloch et Cain, Thermoascus aurantiacus Miehe sensu Apinis, Mucor miehei Cooney et Emerson, Torula thermophila Cooney et Emerson, Humicola stellata Bunce, Acrophialophora nainana Edward, Thielavia sepedonium Emmons, Dactylomyces thermophilus Sopp, and Talaromyces emersonii Stolk. Four unidentified thermophilic fungi were also isolated. Thermophilic and thermotolerant fungi were isolated most frequently from sun-heated soil, less so from grass-shaded soil, and still less so from tree-shaded soil. Isolates were more frequently obtained from a depth of 0-5 cm than from 10-20 cm. Data concerning numerical values for population numbers and soil pH, moisture, temperature, and percent organic matter are given for samples from the two soil levels for each of 15 consecutive months. Results of special procedures for enrichment of thermophilic and theromotolerant fungi are described, as well as results of air sampling.