[Isolation of vitamin B2 auxotroph and preliminary genetic mapping in Salmonella typhimurium]

Abstract

The first independent vitamin B2 auxotrophs of Salmonella typhimurium were obtained by using selective medium containing extraordinarily high concentration of B2 (300 micrograms/ml) after mutagenesis. Transduction analysis showed that 21 B2 auxotrophs could be divided into four groups, which were unlinked to each other. It means that at least 4 structural genes were involved in B2 biosynthetic pathway. Preliminary genetic mapping indicated that 2 genes located in 7'-22' and other 2 located in 22'-34' and 61.5'-69' region on the genetic map of S. typhimurium respectively.