Biodegradation and extracellular enzymatic activities of Pseudomonas aeruginosa strain GF31 on β-cypermethrin.
Pseudomonas aeruginosa strain GF31, isolated from a contaminated soil, can effectively degrade β-cypermethrin (β-CP), as well as fenpropathrin, fenvalerate, and cyhalothrin. The highest level of degradation (81.2 %) was achieved with the addition of peptone. Surprisingly, the enzyme responsible for degradation was mainly localized to the extracellular areas of the bacteria, in contrast to the other known pyrethroid-degrading enzymes, which are intracellular. Although intact bacterial cells function at about 30 °C for biodegradation, similar to other degrading strains, the crude extracellular extract of strain GF31 remained biologically active at 60 °C. Moreover, the extract fraction showed good storage stability, maintaining >50 % of its initial activity following storage at 25 °C for at least 20 days. Significant differences in the characteristics of the crude GF31 extracellular extract compared with the known pyrethroid-degrading enzymes indicate the presence of a novel pyrethroid-degrading enzyme. Furthermore, the identification of 3-phenoxybenzoic acid and 2,2-dimethylcyclopropanecarboxylate from the degradation products suggests the possibility that β-CP degradation by both the strain and the crude extracellular fraction is achieved through a hydrolysis pathway. Further degradation of these two metabolites may lead to the development of an efficient method for the mineralization of these types of pollutants.
School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning, Guangxi, China.
Aixing
A
Tang
Bowen
B
Wang
Youyan
Y
Liu
Qingyun
Q
Li
Zhangfa
Z
Tong
Yingjun
Y
Wei
D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001565:Benzoates; D001673:Biodegradation, Environmental; D002262:Carboxy-Lyases / Q000737:chemistry / Q000378:metabolism; D004785:Environmental Pollutants / Q000737:chemistry / Q000378:metabolism; D007306:Insecticides / Q000737:chemistry / Q000378:metabolism*; D009570:Nitriles; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D010802:Phylogeny; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics; D011722:Pyrethrins / Q000737:chemistry / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D001426:Bacterial Proteins; D001565:Benzoates; D004785:Environmental Pollutants; D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; C017160:cypermethrin; C017618:3-phenoxybenzoic acid; C044267:fenpropathrin; D010088:Oxidoreductases; D002262:Carboxy-Lyases; C021520:lysine decarboxylase; C037304:cyhalothrin; C017690:fenvalerate