1. Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
3. College of Engineering, Northeast Agricultural University, No.600, Changjiang Road, Xiangfang District, Harbin, Heilongjiang 150030, P. R. China
4. Biogas Institute of Ministry of Agriculture, Chengdu 610041, China