溶藻细菌L7代谢物对水华鱼腥藻的溶藻效应

从等体积不同密度的溶藻细菌L7菌液中提取胞内、胞外代谢物,分别加入等体积等密度的水华鱼腥藻中连续培养7d,研究L7代谢物对水华鱼腥藻的溶藻效应。2.78×105~2.78×10 7cfu/mL的L7胞内代谢物能显著促进藻生长和异形胞分化,到培养结束藻密度为对照组的1.7~1.98倍;异形胞数最大可为对照组的2.31倍。2.78×10 8、2.78×10 9cfu/mL的L7胞内代谢物能抑制藻生长,藻密度最低为对照组的58%;能极显著抑制异形胞分化,可不形成异形胞。2.78×10 5~2.78×109 cfu/mL的L7胞外代谢物能极显著抑制藻生长和异形胞分化,藻密度最低为对照组的0.63%,不形成异形胞;藻丝的藻细胞间隔变模糊,藻细胞变大变形,并有大量的单个球形藻体散落。L7主要通过分泌胞外代谢物溶藻,菌胞内代谢物对藻生长有"低促高抑"的作用。

Algicidal Effect of Metabolites of Algicidal Bacteria Strain L7 on Anabaena Flosaquae

To study the effect of metabolites of algicidal bacteria strain L7 on anabaena flosaquae, intracellular and extracellular metabolites were extracted from equal volume of different densities algicidal bacteria strain L7 broth, then added separately to equal volume and density Anabaena flosaquae culture medium , cultured 7 days continuously. Intracellular metabolites of the 2.78x10%2.78x107 cfu/mL bacteria can stimulate algae growth significantly, at the end of the culture, the density of algal was 1.7-1.98 times of the control group; they can also extremely stimulate heterocyst differentiation significantly, heterocyst can be 2.31 times of the control group. Intracellular metabolites of the 2.78×10^8-2.78×10^9 cfu/mL bacteria can inhibit algae growth, the lowest density of algal can be only 58% of the control group ; they can also extremely inhibit heterocyst differentiation significantly, even no heterocyst formation. Extracellnlar metabolites of the 2.78×10^5-2.78×10^9 cfu/mL bacteria can extremely inhibit algae growth and heterocyst differentiation significantly, the lowest density of algal can be 0.63% of the control group, no heterocyst formation; the intervals between algae cells on the filaments become blurred, algae cells become larger and deformed, with amounts of single algae cells scattered. Algicidal bacteria strain L7 mainly secrete extracellular metabolites to dissolve algaes, intracellular metabolites of low- density bacteria can stimulate algae growth, while intracellular metabolites of high-density bacteria can inhibit algae growth.