Selective and faster nicotine biodegradation by genetically modified Pseudomonas sp. JY-Q in the presence of glucose.
Selective and faster nicotine biodegradation by genetically modified Pseudomonas sp. JY-Q in the presence of glucose.
复制标题
转基因假单胞菌可选择性且更快地生物降解尼古丁。
DOI：
10.1007/s00253-018-9445-z
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发表时间：
2019
影响因子：
5
通讯作者：
Zhong Weihong
中科院分区：
文献类型：
--
作者：
Zhang Hui;Zhao Rui;Huang Chaochao;Li Jun;Shao Yunhai;Xu Jian;Shu Ming;Zhong Weihong
假单胞菌属JY-Q是从烟草废料提取物（TWE）中分离到的一株烟碱降解菌。在TWE中，尼古丁是一种有毒的化学物质，需要去除。然而，发现TWE中的葡萄糖抑制尼古丁的降解。对JY-Q全基因组进行生物信息学分析，发现5个编码葡萄糖代谢第一步酶的基因，即1个葡萄糖激酶（gck，AA098_22370）和4个葡萄糖脱氢酶（gdh，AA098_12490，22860，11910，05800）。采用同源重组策略，将JY-Q基因组中的5个基因逐一删除。结果表明，该菌株在葡萄糖为唯一碳源时不生长，在葡萄糖共存的培养基中选择性降解尼古丁。对五元突变体进行单互补分析，结果表明只有gck和gdh-05800基因对葡萄糖代谢的起始阶段有显著影响。在葡萄糖和烟碱共存的基本无机培养基（BSM）中，JY-Q/5菌株的生长较差，但单位细胞重的烟碱降解速率高达12.68mg/mg/h，约为野生型菌株的4倍。在BSM与葡萄糖共存的条件下，JY-Q/5菌株的静息细胞对烟碱的降解能力也明显优于野生型。在含0.8g/L尼古丁的5% TWE中，JY-Q/5菌株的静息细胞在24 h内完全降解尼古丁，比野生型菌株快20%。JY-Q/5 ️具有在葡萄糖-尼古丁共存环境中选择性降解尼古丁的潜力。
Pseudomonassp. JY-Q is a nicotine-degrading strain isolated from tobacco waste extract (TWE). In TWE, the nicotine is a toxic chemical and requires removal. However, it was found that glucose in TWE inhibited the degradation of nicotine. Bioinformatics analysis of JY-Q complete genome found five genes encoding the first-step enzymes of glucose metabolism, one glucokinase (gck, AA098_22370) and four glucose dehydrogenases (gdh, AA098_12490, 22860, 11910, and 05800). Homogonous recombinant strategy was utilized to delete all the five genes from JY-Q genome one by one. The resultant quinary mutant strain JY-Q/5∆ exhibited no growth on glucose as the sole carbon source and selective degradation of nicotine in medium coexisting with glucose. The result of single complementation in the quinary mutant showed that onlygckandgdh-05800 genes exhibited significant effect on the initial steps of glucose metabolism. Although the growth of JY-Q/5∆ seemed worse in basic inorganic medium (BSM) with coexisting glucose and nicotine, the nicotine degradation rate per cell weight of JY-Q/5∆ reached 12.68 mg/mg/h, about four times higher than that of the wild-type strain. The resting cells of JY-Q/5∆ also showed better ability of nicotine degradation than the wild type in BSM coexisting with glucose. In 5% diluted TWE containing 0.8 g/L nicotine, the resting cells of JY-Q/5∆ degraded all nicotine within 24 h, 20% faster than the wild-type strain. JY-Q/5∆ is potential to selectively degrade nicotine in glucose-nicotine coexisting environment.