Solubilization of the extracellular membranous carboxymethylcellulase of Bacteroides succinogenes by trypsin

Abstract

It was previously reported that 50 to 62% of the extracellular carboxymethylcellulase (CMCase) activity of cultures of Bacteroides succinogenes grown on cellulose was associated with membrane fragments or vesicles. It has now been found that most of the membranous CMCase can be released from the membrane fragments by treatment with bovine pancreatic trypsin at 25 °C. Trypsin also releases most of the membranous xylanase activity. Over 90% of each of the CMCase and xylanase activities released by trypsin was associated with components of molecular weights less than 43 000. The low molecular weight CMCase released by trypsin appeared heterogeneous in charge, although not in size. This CMCase component was slightly smaller than the low molecular weight CMCase naturally present in the crude extracellular fraction. Treatment of intact cells with trypsin did not release an appreciable portion of the cell-bound CMCase activity of cells grown on either cellobiose or cellulose.