METABOLIC NONEQUIVALENCE OF THE TWO GLUCOSE MOIETIES OF CELLOBIOSE IN CELLVIBRIO GILVUS

Abstract

Swisher, Elizabeth J. (Virginia Polytechnic Institute, Blacksburg), Waldemar O. Storvick, and Kendall W. King . Metabolic nonequivalence of the two glucose moieties of cellobiose in Cellvibrio gilvus . J. Bacteriol. 88: 817–820. 1964.—Cellobiose was synthesized in 40% yield with uniform C 14 labeling in the reducing glucose moiety and no label in the nonreducing glucosyl. Resting-cell suspensions of Cellvibrio gilvus respiring the labeled cellobiose derived approximately 80% of their respiratory CO 2 from the reducing glucosyl and 20% from the nonreducing glucose. Analysis of isotope content in CO 2 from cells respiring a mixture of labeled cellobiose and unlabeled glucose confirmed that the glucose-1-phosphate produced from phosphorolysis of cellobiose is less extensively converted to CO 2 than is either the glucose released by phosphorolysis of cellobiose or glucose absorbed from the medium. In crude cell extracts, release of glucose from cellobiose was shown to be P i -dependent, the pH optimum of cellobiose phosphorylase being 6.2.