Biodegradation of alkyl branched aromatic alkanoic naphthenic acids by Pseudomonas putida KT2440
Biodegradation of alkyl branched aromatic alkanoic naphthenic acids by Pseudomonas putida KT2440
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DOI：
10.1016/j.ibiod.2011.11.008
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发表时间：
2013-07-01
影响因子：
4.8
通讯作者：
Whitby, Corinne
中科院分区：
文献类型：
--
作者：
Johnson, Richard J.;Smith, Ben E.;Whitby, Corinne
世界上大部分原油储量是尚未完全开采的高度生物降解的重质、超重质原油和油砂。这些巨大的资源含有复杂的羧酸混合物，即环烷酸（NAs）。NAs会造成严重的环境和经济问题，因为它们具有顽固性、腐蚀性和毒性。虽然芳香酸在大多数NA混合物中只占很小的比例，但它们对某些生物（例如某些细菌和藻类）具有明显的毒性，理想情况下需要通过修复来去除或减少。本研究分析了恶臭假单胞菌1（12440）对高度难降解的芳香酸的降解能力，如烷基苯烷酸（4′-丁基苯基）-4-丁酸（t-BPBA）和更易降解的（4′-正丁基苯基）-4-丁酸（n-BPBA）。14天后，n-BPBA被完全代谢，产生一种持久性代谢物，鉴定为（4'-正丁基苯基）乙酸（BPEA），这是由于从羧基侧链上去除两个碳原子（β -氧化），正如之前在混合联合体中观察到的那样。然而，当n-BPBA浓度增加2倍时，降解率下降了56%，细胞数量减少了6倍，这表明在更高浓度下，n-BPBA可能对p.p putida KT2440有毒性。相比之下，p.p putida KT2440即使在49天后也无法降解高度顽固的t-BPBA。这些发现对NA在环境中的生物修复具有重要意义。爱思唯尔有限公司版权所有版权所有。
The majority of the world's crude oil reserves consist of highly biodegraded heavy and super heavy crude oils and oil sands that have not yet been fully exploited. These vast resources contain complex mixtures of carboxylic acids known as naphthenic acids (NAs). NAs cause major environmental and economic problems, as they are recalcitrant, corrosive and toxic. Although aromatic acids make up a small proportion of most NA mixtures, they have demonstrable toxicities to some organisms (e.g. some bacteria and algae) and ideally need to be removed or reduced by remediation. The present study analysed the ability of Pseudomonas putida 1(12440 to degrade highly recalcitrant aromatic acids, as exemplified by the alkyl phenylalkanoic acid (4'-t-butylphenyl)-4-butanoic acid (t-BPBA) and the more degradable (4'-n-butylphenyl)-4-butanoic acid (n-BPBA). n-BPBA was completely metabolized after 14 days, with the production of a persistent metabolite identified as (4'-n-butylphenyl)ethanoic acid (BPEA) which resulted from removal of two carbon atoms from the carboxyl side chain (beta-oxidation) as observed previously with a mixed consortium. However, when n-BPBA concentration was increased two-fold, degradation decreased by 56% with a concomitant six-fold decrease in cell numbers, suggesting that at greater concentrations, n-BPBA may be toxic to P. putida KT2440. In contrast, P. putida KT2440 was unable to degrade the highly recalcitrant t-BPBA even after 49 days. These findings have implications for NA bioremediation in the environment. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.