Diversity of purple nonsulfur bacteria in shrimp ponds with varying mercury levels.
This research aimed to study the diversity of purple nonsulfur bacteria (PNSB) and to investigate the effect of Hg concentrations in shrimp ponds on PNSB diversity. Amplification of the pufM gene was detected in 13 and 10 samples of water and sediment collected from 16 shrimp ponds in Southern Thailand. In addition to PNSB, other anoxygenic phototrophic bacteria (APB) were also observed; purple sulfur bacteria (PSB) and aerobic anoxygenic phototrophic bacteria (AAPB) although most of them could not be identified. Among identified groups; AAPB, PSB and PNSB in the samples of water and sediment were 25.71, 11.43 and 8.57%; and 27.78, 11.11 and 22.22%, respectively. In both sample types, Roseobacter denitrificans (AAPB) was the most dominant species followed by Halorhodospira halophila (PSB). In addition two genera, observed most frequently in the sediment samples were a group of PNSB (Rhodovulum kholense, Rhodospirillum centenum and Rhodobium marinum). The UPGMA dendrograms showed 7 and 6 clustered groups in the water and sediment samples, respectively. There was no relationship between the clustered groups and the total Hg (HgT) concentrations in the water and sediment samples used (<0.002-0.03 μg/L and 35.40-391.60 μg/kg dry weight) for studying the biodiversity. It can be concluded that there was no effect of the various Hg levels on the diversity of detected APB species; particularly the PNSB in the shrimp ponds.
Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand.
Kanokwan
K
Mukkata
Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Bangkok 10330, Thailand.
Duangporn
D
Kantachote
Center of Excellence on Hazardous Substance Management (HSM), Bangkok 10330, Thailand; Faculty of Environmental Management, Prince of Songkla University, Hat Yai 90112, Thailand.
Banjong
B
Wittayaweerasak
National Center for Genetics Engineering and Biotechnology, Bangkok, Thailand; Excellent Center of Waste Utilization and Management, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
Somkiet
S
Techkarnjanaruk
Excellent Center of Waste Utilization and Management, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
Nimaradee
N
Boonapatcharoen
AAPB, aerobic anoxygenic phototrophic bacteria; APB, anoxygenic phototrophic bacteria; Anoxygenic phototrophic bacteria; Diversity; Mercury; PNSB, purple nonsulfur bacteria; PSB, purple sulfur bacteria; Purple bacteria; Shrimp ponds; pufM gene