1. State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, P. R. China
2. Advanced Water Management Centre, The University of Queensland, St. Lucia, QLD 4072, Australia
3. Laboratory for Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium