New nirS-Harboring Denitrifying Bacteria Isolated from Activated Sludge and Their Denitrifying Functions in Various Cultures
New nirS-Harboring Denitrifying Bacteria Isolated from Activated Sludge and Their Denitrifying Functions in Various Cultures
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从活性污泥中分离出的新的带有 nirS 的反硝化细菌及其在不同培养物中的反硝化功能
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发表时间：
2005
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影响因子：
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通讯作者：
Y. Park
中科院分区：
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作者：
Soo;Sang Hyon Lee;Y. Park
采用nirS基因引物进行PCR，从某弱城市污水处理厂的活性污泥中新分离出3株携带nirS的反硝化细菌（菌株N6、菌株N23和菌株R13）。基于小亚基rRNA基因的分析表明，菌株N6、菌株N23和菌株R13分别与节杆菌属、葡萄球菌属和芽孢杆菌属密切相关。为了确定它们在污水中生物硝酸盐和亚硝酸盐去除中的作用，我们研究了它们在不同培养物中对 NO - 3 和 NO - 2 的比反硝化率 (SDNR)。每种分离的带有 nirS 的细菌菌株的所有纯培养物都可以同时高效去除 NO - 3 和 NO - 2 ，并且菌株 N6 和菌株 R13 去除 NO - 3 的碳需求量非常低，分别为 3.1 和 4.1 g COD/g NO 3 N。在菌株（N6+N23、N6+R13、N23+R13 和 N6+N23+R13）混合培养的情况下，它们对 NO - 3 的 SDNR 也是有效的，并且它们去除 NO - 3 的碳需求在 3.0-3.8 g COD/g NO 3 N 时也是有效的。然而，所有测试的混合培养物都在其培养基中积累了 NO - 2。另一方面，与菌株N6的纯培养物相比，与菌株N6混合的活性污泥的连续培养显示出NO - 3 去除率没有显着增加。这些结果表明，生物废水处理中硝酸盐和亚硝酸盐的去除可能取决于复杂的细菌相互作用，包括本研究中分离出的几种有效的反硝化细菌，而不是活性污泥中存在的特定细菌类型和细菌类型的数量。
By using PCR with nirS gene primers, three nirS-harboring denitrifying bacteria (strain N6, strain N23, and strain R13) were newly isolated from activated sludge of a weak municipal wastewater treatment plant. Small-subunit rRNA gene-based analysis indicated that strain N6, strain N23, and strain R13 were closely related to Arthrobacter sp., Staphylococcus sp., and Bacillus sp., respectively. In an attempt to identify their roles in biological nitrate and nitrite removal from sewage, we investigated their specific denitrification rates (SDNRs) for NO - 3 and NO - 2 in various cultures. All pure-cultures of each isolated nirS-harboring bacterial strain could remove NO - 3 and NO - 2 simultaneously in high efficiency, and the carbon requirements for NO - 3 removal of strain N6 and strain R13 were effectively low at 3.1 and 4.1 g COD/g NO 3 N, respectively. In the case of mix-cultures of the strains (N6+N23, N6+R13, N23+R13, and N6+N23+R13), their SDNRs for NO - 3 were also effective, and their carbon requirements for NO - 3 removal were also effective at 3.0- 3.8 g COD/g NO 3 N. However, all tested mix-cultures accumulated NO - 2 in their culture media. On the other hand, the continuous culture of activated sludge mixed with strain N6 showed no significant increase of NO - 3 removal in comparison with strain N6's pure culture. These results suggest that nitrate and nitrite removal in biological wastewater treatment might be dependent on complicated bacterial interactions, including several effective denitrifying bacteria isolated in this study, rather than the specific bacterial types present and the number of bacterial types in activated sludge.