Abstract:
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 7.5 μmol/L Cu2+, 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-Aγ are 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 Cu2+content affects carbon fixation and gene expression of various growth and metabolism pathways, and had a positive effect.