Abstract
Chondroitin sulfate lyase (EC 4.2.2.4) was present constitutively at low levels (0.06 to 0.08 U/mg of protein) in cells of Bacteroides thetaiotaomicron which were growing on glucose or other monosaccharides. When these uninduced bacteria were incubated with chondroitin sulfate A (5 mg/ml), chondroitin sulfate lyase specific activity increased more than 10-fold within 90 min. Synthesis of ribonucleic acid and of protein was required for induction, and induction was sensitive to oxygen. The disaccharides which resulted from chondroitinase action did not act as inducers, nor did tetrasaccharides or hexasaccharides obtained by digestion of chondroitin sulfate with bovine testicular hyaluronidase. None of these substances was taken up by uninduced cells; they may not have been able to penetrate the outer membrane. The smallest oligomer capable of acting as an inducer was the outer membrane. The smallest oligomer capable of acting as an inducer was the octassacharide. Oligomers larger than the octassacharide induced chondroitin lyase activity nearly as well as intact chondroitin sulfate.