LACTOSE METABOLISM

作者：William J. Rutter, R.G. Hansen · 发表于：Journal of Biological Chemistry · 年份：1953 · DOI：10.1016/s0021-9258(19)57132-0 · 被引用次数：12 · 研究领域：Microbial Metabolic Engineering and Bioproduction、Microbial Metabolites in Food Biotechnology、Enzyme Catalysis and Immobilization

Snell et al. ( 1) have shown that LactobaciZZus bulguricus strain Gere A grows in a medium containing lactose or other p-galactosides as the carbon source, but does not grow initially in a medium containing galactose or glucose or mixtures of the two.Only after prolonged incubation with these monosaccharides, and presumably through adaptation, can this microorganism utilize galactose or glucose for growth.The carbohydrate metabolism of microorganisms giving evidence of utilizing lactose by some other means than through hydrolysis is of interest in connection with the mechanisms of "direct" utilization of disaccharides (2, 3) and may perhaps lend information concerning the general biochemical problem of lactose metabolism.Accordingly, the purpose of this report is to describe certain aspects of the metabolism of L. bulgaricus Gere A with particular reference to lactose and its constituent monosaccharides, glucose and galactose. MethodsBacteriological-Cultures of L. bulgaricus Gere A were obtained through the kindness of Dr. E. E. Snell and Dr. W. B. Sarles.Cells were grown by transfer of inocula to suitable quantities of the medium of Snell et al.(1).When the bacteria were consistently derived from media containing lactose, they were termed unadapted cells.In certain experiments, galactose-adapted or glucose-adapted cells were used.These were grown in the same medium except that the appropriate sugar was substituted for lactose.The cells were harvested at the end of the logari...