Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/232520

Title

Analysis of the microbial community structure and function of a laboratory scale enhanced biological phosphorus removal reactor

Author(s)

Levantesi, Caterina;  Serafim, Luisa S.;  Crocetti, Gregory R.;  Lemos, Paulo C.;  Rossetti, Simona;  Blackall, Linda L.;  Reis, Maria A. M.;  Tandoi, Valter

Abstract

A laboratory scale sequencing batch reactor (SBR) operating for enhanced biological phosphorus removal (EBPR) and fed with a mixture of volatile fatty acids (VFAs) showed stable and efficient EBPR capacity over a four-year-period. Phosphorus (P), poly-β-hydroxyalkanoate (PHA) and glycogen cycling consistent with classical anaerobic/aerobic EBPR were demonstrated with the order of anaerobic VFA uptake being propionate, acetate then butyrate. The SBR was operated without pH control and 63.67 ± 13.86 mg P I-1 was released anaerobically. The P percent of the sludge fluctuated between 6 percent and 10 percent over the operating period (average of 8.04 ± 1.31 percent). Four main morphological types of floc-forming bacteria were observed in the sludge during one year of intensive microscopic observation. Two of them were mainly responsible for anaerobic/aerobic P and PHA transformations. Fluorescence in situ hybridization (FISH) and post-FISH chemical staining for intracellular polyphosphate and PHA were used to determine that 'Candidatus Accumulibacter phosphatis' was the most abundant polyphosphate accumulating organism (PAO), forming large clusters of coccobacilli (1.0-1.5 μm) and comprising 53 percent of the sludge bacteria. Also by these methods, large coccobacillus-shaped gammaproteobacteria (2.5-3.5 μm) from a recently described novel cluster were glycogen-accumulating organisms (GAOs) comprising 13 percent of the bacteria. Tetrad-forming organisms (TFOs) consistent with the 'G bacterium' morphotype were alphaproteobacteria, but not Amaricoccus spp., and comprised 25 percent of all bacteria. According to chemical staining, TFOs were occasionally able to store PHA anaerobically and utilize it aerobically.

Publication type

Journal article

Source

Environmental Microbiology, Vol. 4, no. 10 (Oct 2002), pp. 559-569

Publication year

2002

FOR Code(s)

0605 Microbiology

Keyword(s)

Alphaproteobacteria;  Amaricoccus;  Anaerobic bacteria;  Bacteria microorganisms;  Environmental biodegradation;  Gammaproteobacteria;  Glycogen;  Phosphorus;  Refuse disposal;  Sewage

Publisher

Blackwell

ISSN

1462-2912

Publisher URL

http://dx.doi.org/10.1046/j.1462-2920.2002.00339.x

Copyright

Copyright © 2002 Blackwell Science Ltd.

Peer reviewed