Kinetics of a hydrogen-oxidizing, perchlorate-reducing bacterium

详细信息    查看全文

• 作者：Robert Nerenberg ; Yasunori Kawagoshi and Bruce E. Rittmann
• 关键词：Perchlorate ; Chlorate ; Hydrogen ; Biodegradation ; Kinetics ; S_min ; Competitive inhibition
• 刊名：Water Research
• 出版年：2006
• 出版时间：October 2006
• 年：2006
• 卷：40
• 期：17
• 页码：3290-3296
• 全文大小：269 K

文摘

This paper provides the first kinetic parameters for a hydrogen-oxidizing perchlorate-reducing bacterium (PCRB), Dechloromonas sp. PC1. The q_max for perchlorate and chlorate were 3.1 and 6.3 mg/mgDW-day, respectively. The K for perchlorate was 0.14 mg/L, an order of magnitude lower than reported for other PCRB. The yields Y on perchlorate and chlorate were 0.23 and 0.22 mgDW/mg, respectively, and the decay constant b was 0.055/day. The growth-threshold, S_min, for perchlorate was 14 μg/L, suggesting that perchlorate cannot be reduced below this level when perchlorate is the primary electron-acceptor, although it may be possible when oxygen or nitrate is the primary acceptor. Chlorate accumulated at maximum concentrations of 0.6–4.3 mg/L in batch tests with initial perchlorate concentrations ranging from 100 to 600 mg/L. Furthermore, 50 mg/L chlorate inhibited perchlorate reduction with perchlorate at 100 mg/L. This is the first report of chlorate accumulation and inhibition for a pure culture of PCRB. These Chlorate effects are consistent with competitive inhibition between perchlorate and chlorate for the (per)chlorate reductase enzyme.