1. Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture; College of Life Sciences, Nanjing Agricultural University; Nanjing 210095 People's Republic of China
2. College of Food Science and Technology; Nanjing Agricultural University; Nanjing 210095 People's Republic of China
3. School of Civil and Environmental Engineering; Georgia Institute of Technology; Atlanta GA 30332-0512 USA