Transport and metabolism of vitamin B6 in lactic acid bacteria.

摘要: Streptococcus faecalis 8043 concentrates extracellular [3H]pyridoxal or [3H]pyridoxamine primarily as the corresponding 5'-phosphates. Accumulation of pyridoxamine requires an exogenous energy source and is inhibited by glycolysis inhibitors. A membrane potential not required for transport pyridoxamine, artificially generated does drive uptake in this organism. Based on other evidence, it concluded that S. accumulates facilitated diffusion conjunction with trapping pyridoxal kinase. Pyridoxamine-P concentrated, but equilibrates provided externally. Lactobacillus casei 7469 radioactivity only from pyridoxal, which appears internally pyridoxal-P, suggesting too absorbs vitamin plus trapping. The specificity growth requirement L. B6 parallels systems these organisms. delbrueckii 7469, however, specifically pyridoxamine-P pyridoxal-P growth, both compounds pyridoxine-P medium, apparently active transport, pyridoxine, pyridoxal. While are interconvertible organism, further metabolized, thus accounting requirement. These previous results show (a) different organisms may employ quite machinery utilization a given external nutrient, (b) form frequently arises internal metabolism also plays significant role some