有效微生物群(EM)中抑藻酵母及其活性物质特性

采用选择性培养基从有效微生物群(EM)中富集出酵母菌,通过向对数增长期的混合藻液中加入酵母菌、葡萄糖、酵母菌+葡萄糖、经酵母菌发酵除菌后的葡萄糖溶液分别考察了其对水华藻的抑制效应.结果表明,混合酵母菌自身对于水华藻没有抑制作用,单独添加葡萄糖的水华藻甚至出现快速增殖;而在添加葡萄糖+酵母菌或酵母菌发酵液的实验中水华藻近似被完全抑制,最大抑制率达97%.据此可知,抑制水华藻增殖的并非酵母菌自身,而是具有高热稳定性的胞外分泌物.HPLC-SEC与三维荧光光谱分析表明,酵母菌发酵液中含有明显的芳环类羧酸及蛋白质物质,但由于其在高温灭菌后仍有良好的抑藻活性,因而进一步确定其抑藻活性物质为含苯环的有机酸.此外,依据对实验中水华藻细胞形态的显微镜观察,该酸性胞外物可能是通过破坏藻细胞的叶绿体结构来达到抑藻效果的.

Inhibition of algae with yeast in effective micro-organisms(EM) and their active extracellular matters

In this study, yeasts in Effective Micro-organisms(EM) as well as their extracellular matters were used to inhibit the growth of algae. According to the results of inhibition experiment with yeasts, glucose, yeast + glucose, as well as the zymolytic glucose solution, extracellular organic matters were determined as the active fractions in the inhibition of bloom-algae, which maintained the chlorophyll concentration below the initial concentration during the 20 days experiment. With the help of high press liquid chromatography-size exclusion chromatography(HPLC-SEC) and Excitation-Emission Fluorescence(EEM), the active fractions were further determined as carboxylic acid containing with aromatic unit. Moreover, observation of algal cell with microscope revealed that structures of inhibited algal cells were still intact, but the chlorophylls in cells were decreased greatly. Therefore, algae might be inhibited by the damage of chlorophyll with the aromatic carboxylic acid.