土壤中反硝化细菌的分离与脱氮性能初步研究

A preliminary study on the screening of denitrifiers and their denitrification performance in soil

使用稀释平板法对土壤中微生物进行分离培养,共得到不同形态菌株20株,使用硝酸盐葡萄糖反硝化培养基进行培养,格里斯试剂和二苯胺试剂对菌株进行反硝化显色筛选,并经含有溴百里酚蓝指示剂的反硝化鉴定培养基验证,共得到具有反硝化效果的菌株6株,分别标记为QLLGFXH01-QLLGFXH06。对其进行了形态观察和理化性质研究,监测了在不同碳源条件下的生长曲线,探讨了各个菌株生长的最适碳源,给出了最适碳源下生长曲线的Logistic拟合结果,并对各菌株在葡萄糖为碳源的DM培养基中的反硝化性能进行了研究。结果表明3、4、5三株反硝化细菌其反硝化能力较强,72 h硝酸盐氮去除百分率分别达到了90. 57%、97. 27%和96. 80%。5号在发酵24～48 h和6号在发酵48～72 h出现中间产物亚硝酸盐氮积累,其最高积累量分别为0. 059 mg/L和0. 24 mg/L,其余菌株在硝酸盐氮去除过程中未出现亚硝酸盐氮的积累。总氮去除研究表明1、2、3、6号的72 h总氮去除率均在70%左右,脱氮性能较好。

20 different strains were separated by using dilution plate method,and6strains among which were proven to be denitrifying strains after having been cultured with nitrate glucose denitrification medium and verified with Griess reagent,diphenylamine regent and bromothymol blue indicator.The6denitrifying strains were then marked as QLLGFXH01-06.The morphology,physicochemical property,growth curve under different carbon sources was then studied.The optimum carbon source and growth curve fitting under optimum carbon were obtained.And the denitrification capability of each strain in DM medium with glucose as carbon source was also studied.The result indicated that strain3,4and5has strong capability of denitrification,with72h nitrate nitrogen removal rate up to90.57%,97.27%and96.80%respectively.Nitrite accumulation occurred in the course of fermentation for strain5during the24-48h and strain6during48-72h.The maximum accumulation concentrations of nitrite nitrogen were0.059mg/L and0.24mg/L respectively.Strain1,2,3,6showed a good denitrification performance with TN removal rate of70%approximately.