矿化垃圾中氧化甲烷兼性营养菌的筛选与生物特性研究

从填埋了10 a的矿化垃圾中分离得到1株能以甲烷为碳源和能源生长的菌株DH,经NCBI比对发现,该菌株的16S rDNA序列与微杆菌(Microbacterium sp.)3个菌株的同源性在99%以上.目前该菌株已经在中国典型培养物保藏中心申请了专利保藏,保藏号为M2010099.微杆菌DH具有极强的温度耐受性,最佳培养pH为6.5,以甲烷为碳源可实现高密度生长,菌液D560 nm值可达到1.1～1.2.微杆菌DH对甘露糖、果糖和葡萄糖3种单糖以及蔗糖和乳糖2种双糖的利用效果较好.当以蔗糖和甘露糖为碳源时,菌液D560 nm值分别达到了0.758和0.742.与对照组相比,喷洒DH菌液可以提高矿化垃圾的甲烷氧化率1倍以上.微杆菌DH的发现克服了专一营养甲烷氧化菌难于扩大培养、活性低等工程应用问题,为该类细菌在实际工程应用提供了生物学基础.

Screening and Biological Characteristics of Amphitrophic Methane-Oxidizing Bacteria from Aged-Refuse

A new kind of strain, which can utilize methane as carbon and energy source, was screened from 10-year aged-refuse. According to the biochemical characteristics and the 16S rDNA identification results, the strain belongs to Microbacterium sp. and was named as DH. And the patent preservation of the strain was carried out by China Center for Type Culture Collection(CCTCC NO.M2010099). Microbacterium sp. DH has great tolerance on temperature, and the best pH value of culture is 6.5.High cell density with the D_{560 nm} value of 1.1-1.2 was available with methane as carbon source. Monosaccharide (glucose, mannose and fructose) and disaccharide (lactose and sucrose) can be utilized well by Microbacterium sp. DH. The D_{560 nm} value of medium reached 0.758 and 0.742 with sucrose and mannose as carbon source, respectively. Methane-oxidation rates were enhanced significantly by adding Microbacterium sp. DH into aged-refuse. Compared with the controlled group, the methane-oxidation rates experimental group of increased more than 100%. Problems about the application of obligate methanotrophs were overcome due to the discovery of the new bacteria.