Carbon source requirements of the thermophilic ascomycete Chaetomium thermophile var. coprophile.

Abstract

The ability of Chaetomium thermophile var. coprophileCOONEY and EMERSON to utilize carbohydrates as carbon sources for growth has been studied in stationary liquid medium at 45 °C. Among the monosaccharides, the highest growth was obtained on mannose, followed by xylose, glucose, and fructose. There was apparently no growth on galactose, sorbose, arabinose, and rhamnose. The oligosaccharides, cellobiose and maltose supported good growth even though growth on the former was much better. The other oligosaccharides tested (sucrose, lactose, melibiose, and raffinose) were not utilized by the fungus. The polysaccharides dextrin and starch were readily available to the fungus, but growth on dextrin was higher. Out of the two remaining carbon sources tested, there was very good growth on malt extract while mannitol was not utilized. The rate of growth and the accompanying pH changes on glucose, mannose, maltose, dextrin, starch, and malt extract were also studied. There was an initial drop, then a rise, and finally a levelling of the pH as growth progressed on all the six carbon sources. The organism grew well and produced abundant fruiting bodies on cellulose, both in liquid and on solid media. Further evidence of its cellulolytic nature was supplied by its ability to clear cellulose in an agar medium.