1. Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, P. R. China
2. Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, P. R. China
3. College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
4. College of Science, Tianjin University of Science and Technology, Tianjin 300457, P. R. China