除锰细菌的分离鉴定及其固定化除锰研究

Isolation and identification of manganese removal bacteria and study on its manganese removal by immobilization

自含锰土壤中筛选得到2株具有除锰能力的革兰氏阳性菌S1、S2,比对16S rRNA序列结果,推测2株细菌可能为巨大芽孢杆菌(Baciulls megaterium)和嗜麦芽寡养单胞菌(Stenotrophomonas maltophilia)。在质量浓度为260 mg/L的Mn^(2+)培养基中培养6 d后,2株细菌对Mn^(2+)的去除率均可达95%以上。扫描电镜能谱(SEM-EDS)分析、X射线衍射(XRD)分析表明这2株细菌是通过将Mn^(2+)转化为MnCO3实现对Mn^(2+)的去除。采用海藻酸钠和活性炭作为包埋剂将菌体制成固定化微胶囊,在含锰废水Mn^(2+)质量浓度为150 mg/L时胶囊固定菌的除锰率远高于游离菌相应的值,利用正交实验优化胶囊固定菌的除锰条件后菌株的除锰率均高于96%,3轮循环除锰实验后胶囊固定菌仍有较好的除锰率,可见胶囊固定菌具备一定的重复利用性能。

Two Gram-positive bacteria S1 and S2 with manganese removal ability were screened from manganesecontaining soil,and the comparison of 16S rRNA sequences showed that the two bacteria might be Baciulls megaterium,Stenotrophomonas maltophilia.The removal rate of Mn^(2+)could reach more than 95%after 6 days of culture in the medium with the mass concentration of Mn^(2+)of 260 mg/L.Scanning electron microscopy energy dispersive spectroscopy(SEM-EDS)and X-ray diffraction(XRD)analysis showed that the two bacteria could remove Mn^(2+)by transforming Mn^(2+)into MnCO3.Sodium alginate and activated carbon were used as embedding agents to prepare immobilized microcapsules,when the mass concentration of Mn^(2+)in manganese-containing wastewater was 150 mg/L,the manganese removal rates of capsule-immobilized bacteria were much higher than those of free bacteria.The manganese removal rates could reach 96%after optimizing the manganese removal conditions of immobilized bacteria in capsules by orthogonal test.After three rounds of circulating manganese removal experiments,the immobilized bacteria in capsules still had a good manganese removal rates.It could be seen that the immobilized bacteria in capsules have certain reusability.