Li, Bing
Yang, Ying
Ma, Liping
Ju, Feng
Guo, Feng
Tiedje, James M
Zhang, Tong
Article History
Received: 19 September 2014
Revised: 6 December 2014
Accepted: 19 March 2015
First Online: 28 April 2015
Competing interests
: The authors declare no conflict of interest.