几株絮凝剂产生菌的特性研究

STUDIES ON BIOFLOCCULANT-PRODUCING MICROORGANISMS

筛选到８３株絮凝剂产生菌，其中絮凝活性最高的四株分属于芽孢乳杆菌属、节细菌属、假单胞菌属、气单胞菌属。四株菌在生长过程中均可产生胞外絮凝物质，在最适培养条件下絮凝剂产量为０．５－０．９ｇ／Ｌ。纯化后的四种絮凝剂中，三种为核蛋白，一种为糖蛋白，均为高分子量物质（ＭＷ＞１０＾６）。四株菌均不含质粒。１２－３０ｇ／Ｌ的絮凝剂在１小时内对所有供试材料均有较好的絮凝效果。动物急性毒性实验表明。

The 83 strains of microorganisms including molds, bacteria, yeast and actinomycetes, which were isolated from soil and active sludge were found to produce the substances which can flocculate kaolin clay. Among them, four strains with high flocculating activity was identified as Sporolactobacillus sp. (GC3), Arthrobacter sp. (SB6),Pseudomonas sp. (SB8) , Aeromonas sp. (GC24). Growth study in shaking flasks was conducted for obtaining high flocculant production. The highest level of flocculating substance accumulation (0. 5-0. 9g/L) were attained after 65h cultivation at 30℃ with initial medium pH 7.5-8. 5 and proper aeration. These bioflocculants were purified by ethanol precipitation, gel chromatography and dialysis. The isolated polymers possessed chemical characteristics of nucleoprotein (MF-3, MF-6, MF-8) and polyglucoprotein (MF-24). Their molecular weights were larger than 106 dalton and they have widely flocculating activity against both organic and inorganic materials. It was detected by experiments that neither of the four strains has plasmids. The pathogenicity of their cells and toxicity of the bioflocculants had also been studied.