脱氮硫杆菌对硫酸盐还原菌生长的抑制作用

Inhibition of Thiobacillus denitrificans on SRB Growth

为了研究脱氮硫杆菌（Thiobacillus denitrificars，TDN）对硫酸盐还原菌（sulfate-reducing bacteria、SRB）生长的影响，将从污水中分离到的硫酸盐还原菌和从pH为2～3的酸性土壤中分离到的脱氮硫杆菌（TDN）用于含适当浓度硫酸盐和硝酸盐的模拟污水的处理，并测定单菌或混菌培养后系统中硫酸盐、硝酸盐浓度的变化以及硫化氢的产量。结果表明，在仅接种硫酸盐还原菌的培养系统中，硫酸盐和硝酸盐的含量分别降低4．8％和1．0％；而在同时接种脱氮硫杆菌和硫酸盐还原菌的系统中硫酸盐的含量升高了4．7％，但硝酸盐氮含量降低了25％，这一作用随着培养基中硝酸盐起始浓度的提高而得到加强。另外，混菌培养系统的硫化氢浓度比单一硫酸盐还原菌培养系统降低了65．93％。由此推断，在混菌培养系统中，脱氮硫杆菌通过其反硝化过程产生的代谢产物使硫酸盐还原菌的生长环境条件发生改变，从而抑制其生长并减少了硫化氢的产生。这对预防硫酸盐还原菌带来的不利影响提供了有效的措施。

In this paper, SRB strain screened from sewage and Thiobacillus denitrificans strain screened from acidic soil （pH 2-3） were seeded into simulative wastewater containing suitable concentration of sulfate and nitrate to evaluate the effect of Thiobacillus denitrificans on the growth of SRB. After incubated, the concentration of sulfate and nitrate, and the yield of hydrogen sulfide were determined. The results showed that in the culture system with SRB only, the concentration of sulfate and nitrate were decreased by 4.8% and 1%, respectively; howev- er, in the mixed culture system with SRB and TDN, the concentration of sulfate was increased by 4.7%, but the concentration of nitrate was decreased by 25% and the effectiveness was strengthened with the increase of initial concentration of nitrate in medium. In addition, compared with the culture system with SRB only, the concentration of hydrogen sulfide generated in the mixed system was reduced by 65.93%. It inferred that in the mixed system, those metabolites produced by the denitrification process of TDN may altered the environmental conditions, thus inhibited the growth of SRB and reduced the production of hydrogen sulfide. It provides an effective measure to prevent the adverse effect caused by SRB.