Physiology of the Wood-Rotting Basidiomycetes. I. Growth and Nutrition in Submerged Culture in Synthetic Media

Abstract

A quantitative comparative study was made of the growth and nutrition[long dash]particularly the utilization of known N compounds[long dash]of 42 common species of wood-destroying Basidiomycetes, both brown-rot and white-rot types, in submerged (shake) culture in synthetic media. None of the organisms required organic N, although usually growth was greater in organic N than in NH4 salts, the known N compounds being used on a comparable "utilizable" N basis. For two amino acids investigated, only the L-isomer was utilized. For 15 representative species, statistically-significant differences in the order of average growth-supporting ability of single amino acids compared with casein hydrolyzate in the basal medium were as follows: casein hydrolyzate, DL-valine, glutamine> DL-aspartic acid, L-glutamic acid, L-arginine, L-asparagine, glycine, L-proline, DL-alpha alanine, DL-ornithine >L-hydroxy-proline, L-tryptophane, DL-serine, DL-threonine, L-leucine, DL-phenylalanine, DL-methionine, DL-isoleucine >L-histidine, DL-norleucine, L-tyrosine, L-cystine >beta alanine, L-lysine, L-cysteine. The L-cysteine medium supported growth only when its Eh was raised with ascorbic acid. With inorganic N compounds, urea or casein hydrolyzate singly in the basal medium, only the following statistically-significant difference in average growth-supporting ability was shown: casein hydrolyzate >NH4NO3, (NH4)2CO3, (NH4)2SO4, urea. Utilization of nitrite or nitrite N could not be demonstrated under the conditions used; growth in NH4Cl medium took place in the presence but not in the absence of succinic acid. Differences in utilization of amino acids seemed to be related to molecular structure other than isomerism, when the latter was taken into account experimentally; e.g., to the length of the C chain. Utilization of amino acids as C sources could not be demonstrated. Synthetic media more nearly optimal for growth than the standard basal medium were developed for 9 species.