No abstract

3-Chlorobenzoate grown cells ofPseudomonas strain B 13 readily co-oxidize 3-methylbenzoate yielding 82% (+)-2,5-dihydro-4-methyl- and 9% (+)-2,5-dihydro-2-methyl-5-oxo-furan-2-acetic acid (compounds I and II, X=CH3). The concentration of the products in the culture fluid exceed 11 g per liter without affecting the activity of the cells. The products were formed in 89% and 93% yield when 3- or 4-methylcatechol is cometabolized correspondingly. The lactonization of methyl- and halomuconic acids is discussed with regard to the mechanism of halide elimination during utilization of chlorosubstituted aromatic compounds

Pseudomonas sp. B13 was grown in continuous culture on 4-chlorophenol as the only carbon source. Maximum growth rate of 0.4 h(-1) was observed at a substrate concentration of greater than 0.01 mM and less than 0.15 mM. In addition to the enzymes of phenol catabolism, high specific 1,2-dioxygenase activities with chlorocatechols as substrates were found. The isomeric monochlorinated phenols were also totally degraded by 4-chlorophenol grown cells. (+)-2,5-Dihydro-4-methyl- and (+)-2,5-dihydro-2-methyl-5-oxo-furan-2-acetic acid were formed in high yield as dead-end catabolites from cooxidation of cresoles. Several dichlorophenols except 2,6-dichlorophenol were removed from the culture fluid by chlorophenol grown cells. Ring cleavage of chlorinated catechols were shown to be one of the critical steps in chlorophenol catabolism. A catabolic pathway for isomeric chlorophenols is discussed.