一株耐碱溶藻菌耐受力及其溶藻特性研究

Study on an Alkaline Resistant Algae-bacteria:Its Environmental Tolerance and Lytic Characteristics

溶藻微生物能引起水华蓝藻的快速消亡,从而达到控制淡水水华之目的。黄河三角洲盐碱地区采集水样后富集培养,采用涂布平板法,分离获得一株高效耐碱溶藻细菌菌株(编号RZ14),对该菌株进行了细胞学、环境耐受能力和溶藻特性的研究,并对铜绿微囊藻(Microcystis aeruginosa)丙二醛含量进行了分析。结果表明,该菌株细胞呈短杆状,革兰氏染色阳性,芽孢中生;在所试温度及pH条件下,RZ14菌株均可生长,最适温度36℃,最适pH为10。对盐度耐受能力较好,在0.5%~2%的盐度内生长良好,最适盐度0.5%;对高NH_4^+环境耐受能力较差,在低于1 mol/L可生长,最适NH_4^+浓度为0.5 mol/L。RZ14菌株无菌滤液溶藻效果显著,可促进铜绿微囊藻细胞内丙二醛含量大幅度升高。该菌株是一株耐碱性强的产芽孢菌,具有迟缓的溶藻效果,溶藻方式为间接溶藻,对环境的耐受能力较广,有望开发为盐碱地区治理水华的溶藻生物制剂。

Algicidal microorganisms can rapidly kill cyanobacteria that usually cause algal bloom in fresh water bodies. This study focused on the algicidal microorganisms that can tolerate alkalinity,for which water sample in saline alkali area was collected in the Yellow River Delta to screen algicidal bacteria by using spread plate method after enrichment culture. A high alkali algicidal bacteria strain was screened（named RZ14）,its cytology,the tolerance and algicidal characteristics were studied,and MDA content of Microcystis aeruginosa cell was analyzed. The results showed that the strain cells were rod-shaped,gram positive,and in spore. Strain RZ14 grew very well under the test temperature and pH conditions,while the optimum temperature was 36 ℃,the optimal pH 10. The strain grew perfectly in salinity ranging from 0.5 to 2%,and the optimum salinity was 0.5%. However,in the environment of high NH_4~＋the tolerance ability of the strains was poor：NH_4~＋below 1 mol/L was tolerated,the optimum NH_4~＋concentration being 0.5 mol/L. MDA content of Microcystis aeruginosa cell was increased significantly by bacteria-free filtrate of RZ14 strains. RZ14 strain could produce spore of strong alkali resistance,its algicidal effect on Microcystis aeruginosa was slow with indirect algicidal mode;RZ14 strain had an ability to accommodate the wide change of the environment,was hopefully a biological agent for controlling algal bloom in the saline alkali area.