Improvement of NaNO2-Oxidizing Activity in Nitrobacter vulgaris by Coentrapment in Polyacrylamide Containing Polydimethylsiloxane Copolymer and DEAE-Sephadex
Improvement of NaNO2-Oxidizing Activity in Nitrobacter vulgaris by Coentrapment in Polyacrylamide Containing Polydimethylsiloxane Copolymer and DEAE-Sephadex
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DOI：
10.1128/aem.71.10.5888-5892.2005
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发表时间：
2005-10
影响因子：
4.4
通讯作者：
Songping Zhang;O. Norrlöw;E. Dey
中科院分区：
文献类型：
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作者：
Songping Zhang;O. Norrlöw;E. Dey
摘要饮用水中亚硝酸盐和硝酸盐的去除由于暴露于受污染的地下水和地表水而引起的人类健康风险，近年来引起了人们的极大关注。因此，我们已经测试了一个模型亚硝酸盐氧化系统coentraping的NaNO 2氧化剂硝酸菌与聚二甲基硅氧烷（PDMS）共聚物和DEAE-Sephadex在聚丙烯酰胺凝胶。共聚物和阴离子交换剂分别促进氧气和NaNO 2扩散到凝胶基质中。为了测试亚硝酸盐氧化活性，将截留的细胞与热传感器偶联。共包埋的5%（重量/体积）DEAE-Sephadex与普通硝化菌的亚硝酸盐氧化活性增加了3.7倍，单独包埋细胞相比，并通过添加0.86%（重量/体积）的人工氧载体PDMS共聚物的活性进一步提高到4.3倍。操作和储存稳定性的共同包埋的小球藻也有所改善。这表明，这种增强的固定化细胞系统也可以用于饮用水中的亚硝酸盐氧化为硝酸盐作为在线热监测生物反应器。
ABSTRACT Removal of nitrite and nitrate from drinking water has attracted great attention in recent years because of the human health risk induced by the exposure to contaminated groundwater and surface water. We have therefore tested a model nitrite oxidation system by coentrapping the NaNO2 oxidizer Nitrobacter vulgaris with polydimethylsiloxane (PDMS) copolymer and DEAE-Sephadex in a polyacrylamide gel. The copolymer and the anion exchanger facilitate the diffusion of oxygen and NaNO2, respectively, into the gel matrix. To test the nitrite-oxidizing activity, the entrapped cells were coupled to a thermal sensor. Coentrapment of 5% (wt/vol) DEAE-Sephadex with Nitrobacter vulgaris increased the nitrite-oxidizing activity by a factor of 3.7 compared to entrapped cells alone, and by the addition of 0.86% (wt/vol) artificial oxygen carrier PDMS copolymer increased the activity further to 4.3 times higher. Operational and storage stability of the coentrapped N.vulgaris also improved. This suggests that this enhanced immobilized cell system can also be used for nitrite oxidation to nitrate in drinking water as an on-line thermally monitored bioreactor.