title: Vitamin B6 metabolism in microbes and approaches for fermentative production.
abstract: Vitamin B6 is a designation for the six vitamers pyridoxal, pyridoxine, pyridoxamine, pyridoxal 5'-phosphate (PLP), pyridoxine 5'-phosphate, and pyridoxamine. PLP, being the most important B6 vitamer, serves as a cofactor for many proteins and enzymes. In contrast to other organisms, animals and humans have to ingest vitamin B6 with their food. Several disorders are associated with vitamin B6 deficiency. Moreover, pharmaceuticals interfere with metabolism of the cofactor, which also results in vitamin B6 deficiency. Therefore, vitamin B6 is a valuable compound for the pharmaceutical and the food industry. Although vitamin B6 is currently chemically synthesized, there is considerable interest on the industrial side to shift from chemical processes to sustainable fermentation technologies. Here, we review recent findings regarding biosynthesis and homeostasis of vitamin B6 and describe the approaches that have been made in the past to develop microbial production processes. Moreover, we will describe novel routes for vitamin B6 biosynthesis and discuss their potential for engineering bacteria that overproduce the commercially valuable substance. We also highlight bottlenecks of the vitamin B6 biosynthetic pathways and propose strategies to circumvent these limitations.
authors.affiliation: Department of General Microbiology, Georg-August-University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rosenberg
authors.affiliation: Department of Plant Biochemistry, Georg-August-University of Göttingen, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Ischebeck
authors.affiliation: Department of General Microbiology, Georg-August-University of Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany. Electronic address: fcommic1@gwdg.de.
authors.forename: Fabian M
authors.initials: FM
authors.lastname: Commichau
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D005285:Fermentation / Q000502:physiology*; D007218:Industrial Microbiology / Q000379:methods*; D060847:Metabolic Engineering / Q000379:methods*; D025101:Vitamin B 6 / Q000032:analysis / Q000737:chemistry / Q000378:metabolism
chemical_list: D025101:Vitamin B 6
keywords: Bacillus subtilis; Co-culture engineering; Escherichia coli; Laboratory evolution; Metabolic crosstalk; Metabolic engineering; Promiscuous enzyme; Vitamin B6