ENHANCED PRODUCTION OF CELLULASES BY CELLULOMONAS STRAINS GROWN ON DIFFERENT CELLULOSIC RESIDUES

Cellulomonas strains consumed commercial cellulose, cellulosic residue s, xylan, cellobiose and carboxymethyl cellulose (CMC) as carbon sourc es in liquid culture, the growth being the most on cellobiose medium. All three components of the cellulase complex of Cellulomonas were pro duced when the organisms utilized all substrates as sole carbon and en ergy sources. The filter-paper cellulase (FPase) and endo-glucanase (C MCase) activities were higher in media containing alpha-cellulose and cellulosic residues than in media containing CMC, cellobiose, and xyla n. Cell-free supernatants of all organisms exhibited greater CMC hydro lyzing activity than filter paper and beta-glucoside hydrolyzing activ ities. All strains synthesized beta-glucosidase maximally on cellobios e followed by commercial cellulose and cellulosic residues. C. biazote a produced the highest FPase and CMCase activity during growth on alph a-cellulose. It was followed by C. flavigena, C. cellasea, and C. fimi . Endo-glucanase and FPase from all organisms were secreted into the m edium; 10-13 % became adsorbed on the surface of the insoluble substra tes and could be successfully eluted using Tween 80. beta-Glucosidase was located in cell extracts from all organisms. C. biazotea produced FPase and beta-glucosidase activities several-fold greater than those produced by many other strains of Cellulomonas and some other cellulol ytic bacteria and fungi.