1. State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, Jimo, Qingdao 266237, P. R. China
2. State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, P. R. China