一株兼性嗜冷产甲烷八叠球菌的分离鉴定及系统发育分析

为了提高低温条件下沼气发酵的效率，本文利用Hungate厌氧操作技术从新疆库尔勒越冬沼气池污泥中分离出一株生长温度范围为8～40℃的兼性嗜冷产甲烷菌株ZG-2。该菌株革兰氏染色为阳性，呈不规则球状叠放在一起，不运动，能够利用H。／C（]2混合物、甲醇、甲胺、乙酸盐作为单一碳源底物进行厌氧发酵生产甲烷。最适生长条件：温度为25～30℃，生长pH为6；NaCl浓度为0．2mol／L；不能耐受链霉素和卡那霉素。根据菌株形态特征和生理生化特性以及16SrDNA序列分析，初步认为菌株ZG-2为兼性嗜冷巴氏产甲烷八叠球菌（Methanosarcina barkeri）。

Isolation,Identification and Phylogenetic Analysis of an Amphipsychrophilic Methanosarcina

In order to improve the efficiency of biogas fermentation under low temperature conditions, an amphipsychrophilic methanogen ZG-2 with growth temperature between 8 and 40~C was isolated by Hungate tube technique from the sludge of methane tank in Korla, Xinjiang, China. The cells of strain ZCr2 were aggregated, non-motile and gram-positive. This strain could use H2/CO2 mixture, ethanol, methylamine,dimethylamine or trimethylamine as the sole carbon source for its growth and methanogenesis. The optimum growth conditions were temperature of 25 to 30 ℃, pH 6.0 and NaCI concentration of 0.2 mol/ L. It was sensitive to streptomycin and Kanamycin. Morphological and physio-biochemical characteristics combined with 16S rD- NA sequence analysis demonstrated that ZG-2 belonged to Methanosarcina barkeri.