Metabolic Analysis of a Phosphotransferase System-deficient Strain of Lactobacillus plantarum NCIMB 8826

Abstract

　It is important to consider not only biosynthetic pathways but also the sugar-transport system in order to construct a substrate production system for bacterial fermentation. A phosphotransferase system (PTS) -deficient strain of Lactobacillus plantarum NCIMB 8826 was obtained, and its sugar-transport properties were compared with those of the wild-type strain. Based on metabolic analysis, the wild-type strain was found to utilize 13 kinds of sugar via the PTS. Four kinds of sugar, which are thought to be taken up via non-phosphotransferase systems, were also utilized via the PTS. Since the PTS-deficient mutant was able to utilize only glucose and maltose as carbon sources, non-phosphotransferase systems were considered to be functional in the mutant. The PTS-deficient mutant lost the ability to utilize several sugars. Thus, the ability of the wild-type strain to utilize a variety of sugars depends on its PTS. We also found that disruption of the PTS affects the biosynthesis of lactic acid in the mutant strain.