Isolation of pentoxazone-transforming microorganisms from soil: Their characteristics and metabolites

Five microbial strains which have pentoxazone [3-(4-chloro-5-cyclopentyloxy -2-fluorophenyl)-5-isopropylidene-1,3-oxazolidine-2,4-dione]-transforming a bilities were isolated from Ushiku paddy field soil. These strains, designa ted as 1B, 2B, 7B, 21B and 9A, have been tentatively identified by their mo rphological and physiological characteristics: Pseudomonas fluorescens, Bra dyrhizobium japonicum, two pathovars of Xanthomonas oryzae and Bacillus sp. , respectively. These isolates favored or tolerated the lower oxygen concen tration than air though they belong to aerobes. These isolates partly modif ied pentoxazone molecule to afford five different metabolites. Strains 1B a nd 2B produced A-0505 [N-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)-2-oxo-3 -methylbutanamide]. Strain(s) 7B and 21B produced, respectively, A-0480 (4- chloro-5-cyclopentyloxy-2-fluoroaniline) and A-1374 [N-(4-chloro-5-cyclopen tyloxy-2-fluorophenyl)-2-hydroxy-3-methylbutanamide] after their transient accumulation of A-0505. Strain 9A produced two monohydroxylated compounds o n cyclopentyl moiety: hydroxylated-pentoxazone and hydroxylated-A-0505. Str ains 7B, 21B and 9A were able to transform A-0505 when it was provided as t he initial substrate. This indicates that A-0505 could be a metabolic inter mediate of these strains.