Patterns of utilization of different carbon sources by Chytridiomycota

Abstract

A phylogenetically diverse set of seventeen isolates of Chytridiomycota were selected for a study of the utilization of common carbohydrates as sole carbon sources in synthetic media. Rhizophlyctis rosea AUS 13 is capable of the digestion of crystalline cellulose in the form of lens paper, filter paper and powdered filter paper and grows well with noncrystaline carboxymethyl cellulose or cellobiose, but cannot use starch or maltose as sole carbon sources in liquid and on solid media. None of the other sixteen isolates tested can digest crystalline cellulose, but all grow well on starch and maltose and several can also use cellobiose and/or sucrose as a sole carbon source. Four of the other sixteen isolates could also digest carboxymethyl cellulose slowly. Glucose is an excellent sole source of carbon in synthetic media for all seventeen isolates in the present study. In general, these data suggest variability in the ability of zoosporic true fungi to use carbohydrates other than glucose as sole sources of carbon. Four patterns of carbohydrate utilization emerged from this study of seventeen isolates. R. rosea degrades cellulose over a relatively wide pH range which suggests that the cellulase enzymes are stable over a wide pH range.