GENETIC-STUDY OF BIOTIN BIOSYNTHESIS IN THE OBLIGATE METHANOL-OXIDIZING BACTERIUM METHYLOBACILLUS-FLAGELLATUM

Twenty-seven mutants defective in the biosynthesis of biotin were gene rated by N-methyl-N'-nitro-N-nitrosoguanidine treatment of the obligat e methylotrophic bacterium 'Methylobacillus flagellatum'. The metaboli c lesion in some of these mutants was determined in cross-feeding expe riments using known Escherichia coli bio mutants. R-prime plasmids car rying various fragments of the 'M. flagellatum' chromosome were used f or complementation of bio mutations in 'M. flagellatum' and E. coli. B y complementation analysis and cross-feeding experiments,'M. flagellat um' Bio- mutants were classified into five groups: bioA, bioB, bioD bi oH. and a group with unidentified bio mutations (bioF or/and bioC). Us ing R-prime complementation mapping and also Hfr-like mapping, most of the bio genes of 'M. flagellatum' identified in this study were local ized on the 'M. flagellatum' chromosome.