Enhanced degradation of perfluorooctanoic acid by a genome shuffling-modified Pseudomonas parafulva YAB-1
Enhanced degradation of perfluorooctanoic acid by a genome shuffling-modified Pseudomonas parafulva YAB-1
复制标题
基因组改组修饰的副黄假单胞菌 YAB-1 增强了全氟辛酸的降解
DOI：
10.1080/09593330.2018.1466918
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发表时间：
2019-10-28
影响因子：
2.8
通讯作者：
Chai，Liyuan
中科院分区：
文献类型：
--
作者：
Yi，Langbo;Peng，Qingzhong;Chai，Liyuan
摘要 全氟辛酸（PFOA）作为一种新兴的持久性有机污染物，因其物理化学性质稳定，难以用常规方法降解。微生物转化是预防和清除 PFOA 污染的一种有吸引力的修复方法。迄今为止，据报道，一些野生微生物菌株降解PFOA的能力有限，迫切需要选择降解PFOA的优良菌株。在这里，我们报道了基因组改组在改善 PFOA 降解细菌 Pseudomonas Parafulva YAB-1 中的应用。菌株YAB1的初始突变体群体分别通过亚硝基胍和紫外线诱变产生，产生突变体YM-9和YM-19，其PFOA降解能力略有提高。 YM-9和YM-19用作三轮递归原生质体融合的起始菌株。在含有不同浓度PFOA的无机盐培养基平板上筛选阳性突变体，并根据摇瓶发酵试验中PFOA的降解情况进行选择。经过三轮基因组改组后，分离出性能最佳的重组 F3-52。分批发酵时，突变体F3-52对PFOA的降解率高达58.6%，是亲本菌株YAB1的1.8倍，是初始突变体YM-9和YM-19的1.6倍。传代试验表明F3-52遗传性状稳定。结果表明，基因组改组是改善Pseudomonas Parafulva YAB1 PFOA降解的有效方法。选育的突变体F3-52对PFOA的降解率为58.6%，可用于PFOA污染物的环境控制。图解摘要
ABSTRACT Perfluorooctanoic acid (PFOA) as an emerging persistent organic pollutant is hard to be degraded by conventional methods because of its stable physical and chemical properties. Microbial transformation is an attractive remediation approach to prevent and clean up PFOA contamination. To date, several strains of wild microbes have been reported to have limited capacity to degrade PFOA, selection of superior strains degrading PFOA become urgently necessary. Here, we report the application of genome shuffling to improve the PFOA-degrading bacterium Pseudomonas Parafulva YAB-1. The initial mutant populations of strain YAB1 were generated by nitrosoguanidine and ultraviolet irradiation mutagenesis respectively, resulting in mutants YM-9 and YM-19 with slightly improved PFOA-degrading ability. YM-9 and YM-19 were used as the starting strains for three rounds of recursive protoplast fusion. The positive mutants were screened on inorganic salt medium plates containing different concentrations of PFOA and selected based on their PFOA degradability in shake-flask fermentation test. The best performing recombinant F3-52 was isolated after three rounds of genome shuffling. In batch fermentation, the PFOA degradation rate of mutant F3-52 was up to 58.6%, which was 1.8-fold higher than that of the parent strain YAB1, and 1.6-fold higher than the initial mutants YM-9 and YM-19. Pass-generation test indicated that the heredity character of F3-52 was stable. The results demonstrated that genome shuffling was an efficient method for improving PFOA degradation of Pseudomonas Parafulva YAB1. The bred mutant F3-52 with 58.6% PFOA-degrading rate could be used for the environmental control of PFOA pollutant. GRAPHICAL ABSTRACT