Study On Anaerobic Oxidation Of Short-chain Gaseous Alkanes And Changes Of Microbial Community In Tengchong Hot Spring,Yunnan Province

Yunnan Tengchong Hot Spring is a volcanic terrestrial hot spring.According to previous studies,it emits a large amount of greenhouse gases such as carbon dioxide and methane into the atmosphere every year.It is a good place to study the deep carbon cycle and carbon emissions of the earth.The hot spring's high temperature,oxygen-deficient and sulfur-containing environment has shaped the unique microbial group in this environment,which is of great significance for the study of microbial carbon cycle in extreme environments.In this thesis,through anaerobic culture and 16S r RNA high-throughput sequencing analysis,the anaerobic oxidation of short-chain gaseous alkanes and the response of microorganisms to short-chain gaseous alkanes and electron acceptors in the hot spring of Tengchong,Yunnan are studied,which is useful for revealing the hot spring.The community structure of microorganisms in the environment and the metabolic mechanism of short-chain alkanes have important value and significance.The main knowledge and results obtained in this thesis are as follows:1)Tengchong Hamazui and Wenguangting Hot Spring both degrade methane,ethane,propane and butane to varying degrees under anaerobic conditions.When NO₃^-and Fe³⁺are used as electron acceptors,short-chain gaseous alkanes are both There is obvious degradation;under different electron acceptor conditions,the degradation trend of short-chain gaseous alkanes in the same hot spring is the same,and the degradation trend of short-chain gaseous alkanes in different hot springs is different;when SO₄^2-is used as the electron acceptor,different hot springs The degradation of different short-chain gaseous alkanes is different.Accompanied by the degradation of alkanes,correspondingly,electron acceptors are also consumed significantly.2)Addition of different short-chain gaseous alkanes and different electron acceptors to the two hot spring samples affected the microbial species abundance.Microbial diversity of microbial community reduced with varying degrees after 1-year cultivation.Especially after adding different short-chain gaseous alkanes separately,the relative abundance of Parcubacteria in the Hamazui hot spring cultures and the Thermoplasmatels in the Wenguangting hot spring cultures were significantly enriched.These two groups of microorganisms are potentially the dominant microorganisms in the anaerobic oxidation of short-chain alkanes in Hamazui Hot Spring and Wenguangting Hot Spring,respectively.3)Functional prediction based on the 16S rRNA gene sequencing results showed that,after cultivation with short-chain gaseous alkanes and different electron acceptors,the corresponding functions related to hydrocarbon metabolism and reduction of electron acceptors significantly enhanced.