一株螺旋藻溶藻菌的分离、鉴定及溶藻特性初步研究

Isolation,identification and characterization of algicidal bacteria against Spirulina platensis

从黄化的螺旋藻体中分离出一株溶藻菌ES1,经形态、生理生化、16S rDNA序列分析鉴定为盐单胞菌属(Halomonas sp.)。该菌对螺旋藻有较好的溶解效果,能在24h使螺旋藻絮凝成团、黄化死亡,加入15%体积分数的菌液2d后螺旋藻去除率就可达到70.71%。实验表明,经0.22μm的微孔滤膜过滤,高温、低温灭菌处理的滤液,仍能强烈抑制螺旋藻生长,说明起溶藻作用的是ES1菌株的代谢产物,且该代谢产物在高温121℃和低温-80℃下稳定。ES1菌株生长速度快,对盐、碱有较强的耐受性,并能通过自身代谢产物调节pH至适合其生长的9.2左右,该菌的存在会使螺旋藻在短时间内大量死亡,对螺旋藻的大规模工业化养殖危害极大。

An algicidal bacteria ES1 was isolated from death Spirulina platensis.On the basis of analysis of its physiological characteristics and 16S rDNA gene sequence,it was identified as Halomonas sp.The strain had excellent algicidal effect on Spirulina platensis that could cause the cells to agglomerate,become yellow and dead in 24h.70.71% of Spirulina platensis had been removed 2d after addition of the bacterial culture.Under the laboratory conditions,the growth of Spirulina platensis was strongly inhibited by the filtrate of the bacterial culture,or by the heated or the refrigerated bacterium cultures,which indicated that the bacterium lysed Spirulina platensis indirectly and the algicidal factors produced by this strain was of extracellular and thermo-stable.The strain ES1 grew faster,had better alkali resistance and salt resistance.Also,the pH could be adjusted to 9.2 by itself to be suitable for the cell growth by extracellular.This sort of bacteria would make Spirulina platensis dead in a short period,it was harmful to the large-scale industrial production of Spirulina platensis.