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Article
Diversity of Dominant Bacterial Taxa in Activated Sludge Promotes Functional Resistance Following Toxic Shock Loading
Microbial Ecology
  • Pascal E. Saikaly
  • Daniel B. Oerther, Missouri University of Science and Technology
Abstract
Examining the relationship between biodiversity and functional stability (resistance and resilience) of activated sludge bacterial communities following disturbance is an important first step towards developing strategies for the design of robust biological wastewater treatment systems. This study investigates the relationship between functional resistance and biodiversity of dominant bacterial taxa by subjecting activated sludge samples, with different levels of biodiversity, to toxic shock loading with cupric sulfate (Cu[II]), 3,5-dichlorophenol (3,5-DCP), or 4-nitrophenol (4-NP). Respirometric batch experiments were performed to determine the functional resistance of activated sludge bacterial community to the three toxicants. Functional resistance was estimated as the 30 min IC50 or the concentration of toxicant that results in a 50% reduction in oxygen utilization rate compared to a referential state represented by a control receiving no toxicant. Biodiversity of dominant bacterial taxa was assessed using polymerase chain reaction-terminal restriction fragment length polymorphism (PCR-T-RFLP) targeting the 16S ribosomal RNA (16S rRNA) gene. Statistical analysis of 30 min IC50 values and PCR-T-RFLP data showed a significant positive correlation (P<0.05) between functional resistance and microbial diversity for each of the three toxicants tested. To our knowledge, this is the first study showing a positive correlation between biodiversity of dominant bacterial taxa in activated sludge and functional resistance. In this system, activated sludge bacterial communities with higher biodiversity are functionally more resistant to disturbance caused by toxic shock loading.
Department(s)
Civil, Architectural and Environmental Engineering
Sponsor(s)
National Science Foundation (U.S.)
Keywords and Phrases
  • Activated Sludge Bacteria,
  • Diversity,
  • Dominant Bacterial Taxa,
  • Sludge
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2011 Springer Verlag, All rights reserved.
Publication Date
4-1-2011
Citation Information
Pascal E. Saikaly and Daniel B. Oerther. "Diversity of Dominant Bacterial Taxa in Activated Sludge Promotes Functional Resistance Following Toxic Shock Loading" Microbial Ecology Vol. 61 Iss. 3 (2011) p. 557 - 567 ISSN: 00953628
Available at: http://works.bepress.com/daniel_oerther/14/