Multiple Roles for Two Efflux Pumps in the Polycyclic Aromatic Hydrocarbon-Degrading Pseudomonas putida Strain B6-2 (DSM 28064)
Multiple Roles for Two Efflux Pumps in the Polycyclic Aromatic Hydrocarbon-Degrading Pseudomonas putida Strain B6-2 (DSM 28064)
复制标题
两个外排泵在多环芳烃降解恶臭假单胞菌菌株 B6-2 (DSM 28064) 中的多重作用
DOI：
10.1128/aem.01882-17
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发表时间：
2017-10
影响因子：
4.4
通讯作者：
Xu Ping
中科院分区：
文献类型：
--
作者：
Yao Xuemei;Tao Fei;Zhang Kunzhi;Tang Hongzhi;Xu Ping
ABSTRACT Microbial bioremediation is a promising approach for the removal of polycyclic aromatic hydrocarbon (PAH) contaminants. Many degraders of PAHs possess efflux pump genes in their genomes; however, their specific roles in the degradation of PAHs have not been clearly elucidated. In this study, two efflux pumps, TtgABC and SrpABC, were systematically investigated to determine their functions in a PAH-degrading Pseudomonas putida strain B6-2 (DSM 28064). The disruption of genes ttgABC or srpABC resulted in a defect in organic solvent tolerance. TtgABC was found to contribute to antibiotic resistance; SrpABC only contributed to antibiotic resistance under an artificial overproduced condition. Moreover, a mutant strain without srpABC did not maintain its activity in long-term biphenyl (BP) degradation, which correlated with the loss of cell viability. The expression of SrpABC was significantly upregulated in the course of BP degradation. BP, 2-hydroxybiphenyl, 3-hydroxybiphenyl, and 2,3-dihydroxybiphenyl (2,3-DHBP) were revealed to be the inducers of srpABC. 2,3-DHBP was verified to be a substrate of pump SrpABC; SrpABC can enhance the tolerance to 2,3-DHBP by pumping it out. The mutant strain B6-2ΔsrpS prolonged BP degradation with the increase of srpABC expression. These results suggest that the pump SrpABC of strain B6-2 plays a positive role in BP biodegradation by pumping out metabolized toxic substances such as 2,3-DHBP. This study provides insights into the versatile physiological functions of the widely distributed efflux pumps in the biodegradation of PAHs. IMPORTANCE Polycyclic aromatic hydrocarbons (PAHs) are notorious for their recalcitrance to degradation in the environment. A high frequency of the occurrence of the efflux pump genes was observed in the genomes of effective PAH degraders; however, their specific roles in the degradation of PAHs are still obscure. The significance of our study is in the identification of the function and mechanism of the efflux pump SrpABC of Pseudomonas putida strain B6-2 (DSM 28064) in the biphenyl degradation process. SrpABC is crucial for releasing the toxicity caused by intermediates that are unavoidably produced in PAH degradation, which enables an understanding of how cells maintain the intracellular balance of materials. The findings from this study provide a new perspective on PAH recalcitrance and shed light on enhancing PAH degradation by genetic engineering.
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DOI：
10.1128/mr.59.2.201-222.1995
发表时间：
1995-06
期刊：
Microbiological Reviews
影响因子：
--
作者：
J. Sikkema;J. D. de Bont;B. Poolman
通讯作者：
J. Sikkema;J. D. de Bont;B. Poolman
影响因子：
4.1
作者：
Fangli Xie;Stephen A Koziar;M. Lampi;D. Dixon;W. Norwood;U. Borgmann;Xiao-dong Huang;B. Greenberg
通讯作者：
Fangli Xie;Stephen A Koziar;M. Lampi;D. Dixon;W. Norwood;U. Borgmann;Xiao-dong Huang;B. Greenberg
多环芳烃和二恶英类化合物超级降解菌恶臭假单胞菌 B6-2 菌株的基因组序列
影响因子：
3.2
作者：
Tang, Hongzhi;Yu, Hao;Xu, Ping
通讯作者：
Xu, Ping
影响因子：
2.8
作者：
Kieboom, J;de Bont, JAM
通讯作者：
de Bont, JAM
影响因子：
4.4
作者：
J. Volmer;C. Neumann;Bruno Bühler;A. Schmid
通讯作者：
J. Volmer;C. Neumann;Bruno Bühler;A. Schmid