Degradation of quinoline-4-carboxylic acid by Microbacterium sp

From soil enrichment culture of quinoline-4-carboxylic acid-degrading bacterium was isolated. The organism was identified as Microbacterium sp. Mutants were induced with N-methyl-N'-nitro-N-nitrosoguanidine. One mutant accumulated successively two metabolites which were identified as 2-oxo-1,2-dihydro-quinoline-4-carboxylic acid and 8-hydroxy-2-oxo-2H-1-benzopyran-4-carboxylic acid.