Zooplankton and aggregates as refuge for aquatic bacteria: protection from UV, heat and ozone stresses used for water treatment
Article first published online: 16 SEP 2010
© 2010 Society for Applied Microbiology and Blackwell Publishing Ltd
Volume 13, Issue 2, pages 378–390, February 2011
How to Cite
Tang, K. W., Dziallas, C. and Grossart, H.-P. (2011), Zooplankton and aggregates as refuge for aquatic bacteria: protection from UV, heat and ozone stresses used for water treatment. Environmental Microbiology, 13: 378–390. doi: 10.1111/j.1462-2920.2010.02335.x
- Issue published online: 1 FEB 2011
- Article first published online: 16 SEP 2010
- Received 28 May, 2010; accepted 31 July, 2010.
Aggregates and zooplankton may provide refuge for aquatic bacteria against external hazards. The ability of attached bacteria to survive and recover from stressors commonly used for water treatment was tested in the laboratory. Without zooplankton or aggregates, both UV and ozone significantly reduced abundance of free-living bacteria in both freshwater and marine medium. The presence of zooplankton carcasses and aggregates, however, allowed some of the attached bacteria to survive and recover quickly within 3 days. Heat exposure was the least effective as both free-living and attached bacteria were able to recover quickly. Selective survival of bacterial phylotypes led to large changes in bacterial community composition after stress exposures, and some of the bacteria that recovered belonged to groups with known pathogens. This study demonstrates that zooplankton and aggregates protected various aquatic bacteria from external stressors, and organic remains generated from zooplankton and aggregates after stress exposure even enabled the surviving bacteria to quickly regrow and subsequently be released into the surrounding water. Hence, water disinfection treatments that overlooked the potential persistence of bacteria associated with organisms and aggregates may not be effective in preventing the spread of undesirable bacteria.