Utilization of amino acids as sole nitrogen sources by thermophilic fungi

Abstract

AbstractThe organic nitrogen requirements of six thermophilic fungi were examined in liquid shake cultures at 45 °C. The fungi used were Mucor pusillus LINDT, Humicola lanuginosa (GRIFFON and MAUBLANC) BUNCE, Thermoascus aurantiacus MIEHE sensu APINIS, Thermoascus crustaceus (APINIS and CHESTERS) STOLK, Chaetomium thermophile var. coprophile COONEY and EMERSON, and Chaetomium thermophile var. dissitum COONEY and EMERSON. The organic nitrogen sources tested were casein hydrolysate (vitamin‐free), L‐proline, L‐glutamic acid, DL‐serine, L‐alanine, DL‐valine, L‐threonine, L‐arginine, DL‐aspartic acid, L‐asparagine, DL‐glutamine, glycine, L‐leucine, DL‐isoleucine, L‐lysine, DL‐methionine, DL‐phenylalanine, and L‐histidine. Growth was determined by the mycelial dry weight method. All the organisms grew well on casein hydrolysate. M. pusillus grew well on all the single amino acids, while H. lanuginosa grew well on all, but six of them. T. aurantiacus and T. crustaceus gave a fair yield of mycelium on about 50% of the single amino acids tested, while the other 50% served as poor sources of nitrogen. All the single amino acids were poorly utilized by C. thermophile var. coprophile and C. thermophile var. dissitum.