School of Engineering, University of British Columbia (Okanagan), 4261 EME Building, 3333 University Way, Kelowna, British Columbia, Canada.
Environ Sci Technol. 2013 Aug 6;47(15):8666-73. doi: 10.1021/es400835t. Epub 2013 Jul 10.
Salt-tolerant perchlorate-reducing bacteria can be used to regenerate ion-exchange brines or resins exhausted with perchlorate. A salt-tolerant perchlorate-reducing Marinobacter vinifirmus strain P4B1 was recently purified. This study determined the effects of Na(+) and Mg(2+) concentrations on the perchlorate reduction rate of P4B1. The results showed that strain P4B1 could utilize perchlorate and grow in the presence of 1.8% to 10.2% NaCl. Lower NaCl concentrations allowed faster perchlorate reduction. The addition of Mg(2+) to the culture showed significant effects on perchlorate reduction when perchlorate was the sole electron acceptor. A molar Mg(2+)/Na(+) ratio of ∼0.11 optimized perchlorate degradation and cell growth. When perchlorate and nitrate were both present, nitrate reduction did not start significantly until perchlorate was below 100 mg/L. Tests with washed cell suspensions indicated that strain P4B1 had both perchlorate and nitrate reduction enzymes. When the culture was exposed to both perchlorate and nitrate, the nitrate reduction enzyme activity was low. The maximum specific substrate utilization rate (Vm) and the half saturation coefficient (KS) for P4B1 (30 g/L NaCl) determined in this study were 0.049 ± 0.003 mg ClO4(-)/mg VSS-h and 18 ± 4 mg ClO4(-)/L, respectively.
耐盐高氯酸盐还原菌可用于再生耗尽高氯酸盐的离子交换盐水或树脂。最近纯化了一株耐盐高氯酸盐还原 Marinobacter vinifirmus 菌株 P4B1。本研究确定了 Na(+) 和 Mg(2+) 浓度对 P4B1 高氯酸盐还原率的影响。结果表明，菌株 P4B1 可以在 1.8%至 10.2%NaCl 的存在下利用高氯酸盐并生长。较低的 NaCl 浓度允许更快的高氯酸盐还原。当高氯酸盐是唯一的电子受体时，向培养物中添加 Mg(2+) 对高氯酸盐还原有显著影响。当高氯酸盐和硝酸盐都存在时，只有当高氯酸盐低于 100mg/L 时，硝酸盐还原才会显著开始。用洗涤细胞悬浮液进行的测试表明，菌株 P4B1 具有高氯酸盐和硝酸盐还原酶。当培养物暴露于高氯酸盐和硝酸盐时，硝酸盐还原酶活性较低。本研究确定的 P4B1（30g/LNaCl）的最大比基质利用速率（Vm）和半饱和系数（KS）分别为 0.049±0.003mgClO4(-)/mgVSS-h 和 18±4mgClO4(-)/L。
