1. College of Food Science and Engineering; Shanxi Agricultural University; Taigu Shanxi China
2. State Key Laboratory for Agrobiotechnology and Department of Microbiology; China Agricultural University; Beijing China
3. Hebei Foreing Studies University; Shijiazhuang Hebei China
4. Faculty of Medicine; School of Biomedical Sciences; The Chinese University of Hong Kong; Shatin, New Territories Hong Kong China