Characterizations of Denitrifying Polyphosphate-accumulating Bacterium Paracoccus sp. Strain YKP-9

• Published in: Journal of microbiology and biotechnology Vol. 18; no. 12; pp. 1958 - 1965
• Main Authors: Lee, H.W. (Louisiana State University, Baton Rouge, LA, U.S.A.), E-mail: proteole@lsu.edu, Park, Y.K. (Korea University, Seoul, Republic of Korea)
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society for Applied Microbiology 01.12.2008; 한국미생물·생명공학회
• Subjects: Anaerobiosis; Biological and medical sciences; Biotechnology; Culture Media; Denitrifying polyphosphate-accumulating bacterium; Fundamental and applied biological sciences. Psychology; Kinetics; Microscopy, Electron, Transmission; Nitrates - metabolism; Nitrites - metabolism; Paracoccus - genetics; Paracoccus - metabolism; Paracoccus - ultrastructure; PHA synthesis; Phylogeny; POLIFOSFATOS; Polyhydroxyalkanoates - metabolism; POLYPHOSPHATE; polyphosphate granule; POLYPHOSPHATES; Polyphosphates - metabolism; RNA, Ribosomal, 16S - genetics; Sewage - microbiology; 생물학; Characterization; PHA synthesis; polyphosphate granule; Paracoccus; Denitrifying polyphosphate-accumulating bacterium; Denitrification; Bacteria; Polyphosphates
• ISSN: 1017-7825
• DOI: 10.4014/jmb.0800.162

A denitrifying polyphosphate-accumulating bacterium (YKP-9) was isolated from activated sludge of a 5-stage biological nutrient removal process with step feed system. This organism was a Gram-negative, coccus-shaped, facultative aerobic chemoorganotroph. It had a respiratory type of metabolism with oxygen, nitrate, and nitrite as terminal electron acceptors. The 16S rRNA gene sequence of strain YKP-9 was most similar to the 16S rRNA gene sequence of Paracoccus sp. OL18 (AY312056) (similarity level, 97%). Denitrifying polyphosphate accumulation by strain YKP-9 was examined under anaerobic-anoxic and anaerobic-oxic batch conditions. It was able to use external carbon sources for polyhydroxyalkanoates (PHA) synthesis and to release phosphate under anaerobic condition. It accumulated polyphosphate and grew a little on energy provided by external carbon sources under anoxic condition, but did neither accumulate polyphosphate nor grow in the absence of external carbon sources under anoxic condition. Cells with intracellular PHA cannot accumulate polyphosphate in the absence of external carbon sources under anoxic condition. Under oxic condition, it grew but could not accumulate polyphosphate with external carbon sources. Based on the results from this study, strain YKP-9 is a new-type denitrifying polyphosphate-accumulating bacterium that accumulates polyphosphate only under anoxic condition, with nitrate and nitrite as the electron acceptors in the presence of external carbon sources.