1. Shandong Industrial Engineering Laboratory of Biogas Production & Utilization, Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, Shandong, China
2. University of Chinese Academy of Science, Beijing 10049, China
3. Ocean University of China, Qingdao 266110, China