Comparative physiology of some representatives of the Gymnoascaceae.

Abstract

A comparative nutritional study was made of the following fungi:Arachniotus reticulatus, Myxotrichum uncinatum, Eidamella deflexa, Gymnoascus reessii, Ctenomyces serratus andPenicillium spiculisporum. Sodium nitrate, ammonium nitrate, ammonium sulfate, asparagine, glycine, casein hydrolysate and an amino acid mixture were supplied singly as sources of nitrogen. All of the fungi grew on the organic nitrogen sources. The amino acid mixture was the best source for growth ofM. uncinatum, G. reessii, C. serratus andA. reticulatus. Asparagine was the best source forE. deflexa andP. spiculisporum, although the latter grew on all 7 sources of nitrogen tested. Of the inorganic nitrogen sources tested sodium nitrate was assimilated only byM. uncinatum andE. deflexa. Glucose, fructose, galactose, maltose, sucrose, lactose, raffinose, xylose, dextrin and sodium lactate were the ten carbon sources which were tested.Myxotrichum uncinatum failed to assimilate only lactose, and grew best on raffinose, dextrin and sucrose.Eidamella deflexa used all carbohydrates but not sodium lactate.Gymnoascus reessii either did not grow at all or else grew only poorly on all carbon sources tested.Ctenomyces serratus assimilated only fructose.Arachniotus reticulatus grew on maltose, fructose and glucose in that order.Penicillium spiculisporum used galactose, sucrose, xylose, glucose, maltose, dextrin and raffinose and failed to use lactose and sodium lactate. Thiamin, biotin, inositol, pyridoxine and calcium pantothenate were used in vitamin requirement studies.Myxotrichum uncinatum andEidamella deflexa appeared to be autotrophic for all vitamins,G. reessii was heterotrophic for biotin and pyridoxine,C. serratus for thiamin andA. reticulatus for thiamin and pyridoxine.Penicillium spiculisporum showed a partial deficiency for pyridoxine and pantothenate. The trace elements which were tested included iron, zinc, copper and manganese. Probably only the results withE. deflexa are valid since the carbon and nitrogen sources were inadequate forG. reessii, C. serratus andA. reticulatus. Zinc and copper were essential for growth ofE. deflexa. Manganese and copper seemed essential for growth ofP. spiculisporum, while zinc was toxic.