Use of microelectrodes to investigate the effects of 2-chlorophenol on microbial activities in biofilms.
In order to assess the applicability of using microelectrodes as a tool for inhibition tests, temporal and spatial inhibitory effects of 2-chlorophenol (2-CP) on O(2) respiration and nitrification activities in municipal wastewater biofilms were investigated using microelectrodes for O(2) and NH(4)(+). The time-course microelectrode measurements demonstrated that 2-CP inhibited O(2) respiration and nitrification activities within 6-18 min. The microbial activities were inhibited only in the upper 400 microm of the biofilms by 2-CP, and the bacteria present in the deeper parts of the biofilms were still active, probably due to limited penetration of 2-CP. These results could reasonably explain the difference in inhibitory ratios of the O(2) respiration and nitrification activities in the biofilms. O(2) respiration activity was incompletely inhibited, which was attributed to the presence of O(2) respiration activities in the deeper parts of the biofilm. In contrast, nitrification activity was significantly inhibited because ammonia-oxidizing bacteria were present in the upper parts of the biofilm. These results indicate that the microelectrodes with a very quick response time and a high spatial resolution are useful tools to study temporal and spatial inhibitory effects of inhibitors on in situ microbial activities in biofilms.
Satoh
Hisashi
H
Department of Environmental and Civil Engineering, Hachinohe Institute of Technology, Hachinohe, Aomori 031-8501, Japan. qsatoh@hi-tech.ac.jp
Sasaki
Yuichi
Y
Nakamura
Yoshiyuki
Y
Okabe
Satoshi
S
Suzuki
Takuya
T
D018407:Bacterial Physiological Phenomena / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002733:Chlorophenols / Q000494:pharmacology*; D015169:Colony Count, Microbial / Q000379:methods*; D004563:Electrochemistry / Q000379:methods; D008839:Microelectrodes; D009584:Nitrogen / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D014871:Water Microbiology
D002733:Chlorophenols; C030683:2-chlorophenol; D009584:Nitrogen; D010100:Oxygen