METABOLISM AND PHYSIOLOGICAL BEHAVIOR OF LEUCONOSTOC-MESENTEROIDES SUBSP MESENTEROIDES GROWING ON RAFFINOSE

The alpha-galactosidase activities of 11 strains of Leuconostoc mesent eroides subsp. mesenteroides grown on glucose, lactose or raffinose we re determined. The inductive effects of lactose and raffinose differed depending on the strain. In four of the strains, alpha-galactosidase activity of cells grown on lactose was higher than that of cells grown on raffinose, while the reverse was true for one other strain. The st udy of two strains exhibiting a different behaviour was extended to al l raffinose-component sugars: melibiose, sucrose, glucose, galactose a nd fructose. The apparent fermentation yields with raffinose-component sugars complied with heterofermentation theory, except for sucrose, w here there was a 40% deficit in fermentation products. Raffinose hydro lysis enzymes (alpha-galactosidase and beta-fructosidase) underwent a catabolic repression by glucose. Growth on raffinose was considerably stimulated if the inoculum was first grown on melibiose or raffinose ( induction of alpha-galactosidase).