The Serial Phosphotransferase System for Sucrose Utilization in Mannheimia succiniciproducens

Abstract

Mannheimia succiniciproducens MBEL55E, a gram-negative facultative capnophilic rumen bacterium, produces mainly succinate by metabolizing a wide range of carbon sources. Of those, fermentation studies have shown that M. succiniciproducens produces equal or higher titers of succinic acid using sucrose rather than the other carbon sources. Hence, we identified genes involved in the sucrose transport and utilization.The sucrose-utilizing phenotype was examined both for the parent strain and the deletion mutant of each gene. The corresponding enzymes were further characterized by measuring enzyme activities. As a consequence, it was revealed that M. succiniciproducens uses a sucrose phosphotransferase system (PTS), sucrose 6-phosphate hydrolase, and a fructose PTS for the transport and utilization of sucrose.Strategies evolved from this characterization of the sugar metabolism were also suggested in detail.