title: Co-metabolic biodegradation of DBP by Paenibacillus sp. S-3 and H-2.
abstract: Two di-n-butyl phthalate (DBP)-degrading strains, designated as S-3 and H-2, were isolated from DBP-polluted soil and both identified as Paenibacillus sp. When DBP was provided as the sole carbon source, about 45.5 and 71.7 % of DBP (100 mg/L) were degraded by strain S-3 and H-2, respectively, after incubation for 48 h. However, DBP (100 mg/L) was degraded completely by co-culture of strain S-3 and H-2 after incubation for 60 h. Four phthalic acid (PA) esters could be utilized by co-metabolism in the study and the degradation rates followed the order of dimethyl phthalate > diethyl phthalate > DBP > dioctyl phthalate. The metabolic pathway of DBP was elucidated based on the results of metabolites identification and enzyme assays. For strain S-3, DBP was degraded into butyl hydrogen phthalate which was degraded to PA by carboxyesterase further. But PA could be not hydrolyzed further because strain S-3 lacked 3,4-phthalate dioxygenase. Different with S-3, strain H-2 could hydrolyze PA into 3,4-dihydroxy-PA by 3,4-phthalate dioxygenase. Then 3,4-dihydroxy-PA was converted to protocatechuate and benzoic acid. Finally, the aromatic ring was cleavage and mineralized to CO2 and H2O. Above all, co-metabolism could increase the activity of 3,4-phthalate dioxygenase and accelerated the degradation of DBP. This study highlights an important potential use of co-metabolic biodegradation for the in situ bioremediation of DBP and its metabolites-contaminated environment.
authors: Marine Fishery Research Institute of Zhejiang Province, Zhejiang Province Key Lab of Mariculture & Enhancement, Zhoushan, 316100, Zhejiang Province, China, jinlei2388@126.com.
authors: Lei
authors: L
authors: Jin
authors: Xiumei
authors: X
authors: Sun
authors: Xiaojun
authors: X
authors: Zhang
authors: Yuanming
authors: Y
authors: Guo
authors: Hui
authors: H
authors: Shi
mesh_terms: D001711:Biotransformation; D002245:Carbon Dioxide / Q000378:metabolism; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D003993:Dibutyl Phthalate / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D008969:Molecular Sequence Data; D056507:Paenibacillus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013997:Time Factors; D014867:Water / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; D014867:Water; D002245:Carbon Dioxide; D003993:Dibutyl Phthalate