解淀粉芽孢杆菌对鱼腥藻的抑藻效果分析与机理初探

Ability of Bacillus amyloliquefaciens to inhibit growth of Anabaena flos-aquae and the inhibition mechanism

解淀粉芽孢杆菌(Bacillus amyloliquefaciens)在自然界广泛分布,可通过分泌抗生素、抗菌蛋白或多肽类物质起到生物防治作用,但在抑藻方面的研究还处于空白状态.本研究从滇池富营养化水体中分离得到一株溶藻细菌DC1,对该菌的抑藻效果和溶藻机理进行了研究,并通过16SrRNA序列分析方法对其进行种属鉴定.结果表明,溶藻菌株DC1为解淀粉芽孢杆菌,对水华鱼腥藻具有高效抑藻效果,当初始藻液叶绿素a浓度为0.23～1.92mg·L-1、DC1菌体浓度为108cells·mL-1时,6d后藻液平均抑藻率为93.5%,最高为95.54%、最低为91.35%.DC1对水华鱼腥藻的抑藻效果受菌体浓度和藻液初始浓度影响明显,菌体浓度越大,对水华鱼腥藻的去除效果越明显.解淀粉芽孢杆菌主要是通过分泌胞外物质的间接方式起到溶藻作用,该抑藻物质具有很强的热稳定性,属非蛋白类物质.

An algae-lysing bacterial strain DC1 was isolated from Dianchi Lake and identified as Bacillus amyloliquefaciens using 16S rRNA sequence analysis.It was widely distributed in the natural environment.This bacterium can produce antibiotics,antibacterial proteins and polypeptides to achieve biological control.However,its algae-lysing ability has not been previously reported.In this study,the algae-inhibiting effect and algicidal mechanism were investigated.The results showed that DC1 has especially good effects on lysing Anabaena flos-aquae.When the DC1 density was 108 cells · mL-1 and the initial concentration of Chlorophyll a ranged from 0.23~1.92 mg · L-1,the removal rate reached 95.54%~91.35%（average 93.5%） after 6 days.The density of Bacillus amyloliquefaciens was related to the removal rate.An extracellular substance produced by this strain had algae-lysing ability,and it was identified as a thermo-stable,non-protein substance.