The Synthesis of Vitamin B6 by some Mutant Strains of Escherichia coli

SUMMARY: Escherichia coli B166 synthesizes as much vitamin B6 when growing on serine or glycine plus glycolaldehyde as does its parent (E. coli B) on unsupplemented medium. Suspensions of strain B166 harvested after growth on serine+ glycine plus glycolaldehyde, and incubated with glucose and NH4 +, only synthesize vitamin B6 when glycolaldehyde is added; serine + glycine increases the synthesis. Strain 22–99 produces more vitamin B6 when grown on glycolaldehyde plus serine + glycine than when it is grown on the amino acids alone, while, depending upon the conditions of growth, vitamin B6 synthesis by suspensions is absolutely or partially dependent on serine+ glycine plus glycolaldehyde. However, serine + glycine plus glycolaldehyde have little effect on the biosynthesis of vitamin B6 by wild-type E. coli during growth, or in washed suspensions.