Cereal straw and pure cellulose as carbon sources for growth and production of plant cell-wall degrading enzymes by Sporotrichum thermophile.

Sporotrichum thermophile grew well and produced plant cell-wall degrading enzymes on straw (barley and wheat) of different particle sizes and Avicel as carbon sources. Comparable activities of endoglucanase, Avicelase and cellobiase were produced on each substrate. In contrast, activities of xylanase, aryl-β-glucosidase, β-xylosidase, esterase and α-L-arabinofuranosidase were higher on straw (either wheat or barley) than on Avicel. The enzyme systems produced on barley straw of different particle sizes degraded finely milled barley straw in vitro more rapidly and to a greater extent than those produced on Avicel. In contrast, the enzyme systems produced on Avicel and very coarse barley straw hydrolysed Avicel to about the same extent while that produced on fine barley straw was slightly less effective. The main hydrolysis product in all cases was glucose. Isoelectric focusing revealed that the plant cell-wall degrading enzyme system produced by S. thermophile on barley straw was qualitatively and quantitatively superior to that produced on Avicel.