一株甲烷利用菌的分离及其在甲烷气体测定中的应用

Isolation of a methane-utilizing bacterium and its application in measuring methane gas

从山西太原晋阳湖水样中分离得到一株能以甲烷为唯一碳源生长的菌株ME16。气相色谱分析表明ME16菌株能利用甲烷。ME16菌株的16S rDNA序列与铜绿假单胞菌（Pseudomonas aeruginosa，ATCC 10145，AF094713）相似性为99％。该菌株最适培养条件为30℃、2％接种量、25％甲烷含量和培养基pH为6．0。用电化学法研究了ME16固定化细胞体系中不同含量甲烷对溶氧的响应时间以及溶氧变化与甲烷含量的关系。结果表明，加入固定化细胞后，溶氧变化在100s内达到平衡，溶氧消耗量与通入甲烷气体含量在0～16％呈线性关系，相关系数为0．9954。对样品气体8次测量，RSD为3．34％，表明该反应体系重现性良好，为该菌株进一步研究甲烷传感器奠定基础。

A bacterial strain ME16 was isolated from Jinyang Lake in Taiyuan of Shanxi Province, China. Gas chromatography analysis showed that the strain could use methane as the sole carbon and energy source. Based on 16S rDNA sequence analysis, the strain was identified as Pseudomonas aeruginosa. Effects of inoculum size, temperature, methane content and initial pH of media on cell growth were studied. In addition, we examined the response time of methane gas to dissolved oxygen and the relationship between consumption of dissolved oxygen and different methane gas content with PVA-H3BO3 immobilized cell of ME16 using electrochemical method. The optimal conditions for cell growth were 2% inoculum size, 25% methane content, 30℃ and pH 6.0. Response time was within 100 s after adding of immobilized cells to reaction system. The linear range of measured methane content was from 0 to 16%, with the correlation coefficient 0.9954. Hence, this strain has potential application in developing of methane biosensor.