铜离子对甲基单胞菌ZR1生长代谢的影响

Effects of Copper Ion on Growth and Metabolism of Methylomonas sp. ZR1

甲烷是温室气体,它的利用和减排受到广泛关注。甲基单胞菌ZR1能利用甲烷生长。本研究以甲烷为碳源探究了铜离子(Cu^(2+))对甲基单胞菌ZR1生长和甲烷氧化菌素分泌的影响。结果表明,铜离子能够显著提高甲基单胞菌ZR1的生物量和代谢途径的酶活。在含有7.5μmol/L Cu^(2+)的培养基中,碳固定以及酶生成中涉及的基因表达的研究表明,可溶性甲烷单加氧酶(sMMO)相关基因sMMO-Aα、sMMO-Aβ、sMMO-Aγ在铜存在时逐渐下调,而颗粒型甲烷单加氧酶(pMMO)相关基因pMMO-3-A、pMMO-3-B和pMMO-3-C基因上调并且随着时间的增长表达量增加,在铜离子影响下甲醇脱氢酶和甲酸脱氢酶活性加强,甲醛脱氢酶相关代谢途径也加强。Cu^(2+)含量的增加影响碳固定和各生长代谢途径基因表达,存在促进作用。

Methane is a greenhouse gas,so its use and emission reduction have received widespread attention.Methylomonas sp.ZR1 can use methane for growth.In this study,methane was used as the carbon source to explore the effect of copper ions on the growth of Methylomonas sp.ZR1 and the secretion of methane oxidizing bacteria,and results showed that copper ions can significantly improve the biomass and metabolic pathway enzyme activity of Methylomonas sp.ZR1.In a medium containing 7.5μmol/L Cu^(2+),studies on the expression of genes involved in carbon fixation and enzyme production have shown that soluble methane monooxygenase(sMMO)related genes sMMO-Aα,sMMO-Aβ,and sMMO-Aγare gradually down-regulated in the presence of copper.The particulate methane monooxygenase(pMMO)related genes pMMO-3-A,pMMO-3-B and pMMO-3-C genes are up-regulated and their expression increases over time.Enzyme activities of methanol dehydrogenase and formate dehydrogenase are enhanced under the influence of copper ions,and formaldehyde dehydrogenase related metabolic pathways are also enhanced.The results showed that increasing Cu^(2+)content affects carbon fixation and gene expression of various growth and metabolism pathways,and had a positive effect.