絮凝菌株Shinella sp. xn-1对铜绿微囊藻的絮凝效果

Abstract

【目的】研究絮凝功能细菌xn-1对有害水华藻--铜绿微囊藻的絮凝效果,以期为有害水华的治理提供新的选择。【方法】采用涂布划线法从藻际分离纯化絮凝; 功能微生物;基于16S; rRNA基因序列确定进化地位;通过不同金属离子确定絮凝机制;梯度醇沉法获得絮凝物质;以酶标仪测定絮凝效率。【结果】菌株xn-1确定属于申氏杆菌属; (Shinella),且命名为Shinella sp.; xn-1。在添加Ca~(2+)作为促凝剂的条件下对铜绿微囊藻表现出高效的絮凝效果,其絮凝效果主要来源于胞外上清,而表现出高效的絮凝效果所需要的胞; 外上清添加量为3.0%。从胞外上清中获得的絮凝物质以0.5; g/L的添加量作用于藻细胞后表现出高效的絮凝效果,且随着处理时间增加,絮凝团的体积增大。【结论】Shinella sp.; xn-1通过分泌胞外絮凝物质对铜绿微囊藻表现出高效的絮凝效果,在絮凝作用下藻细胞聚集在一起形成大体积的絮凝团,该研究有利于治理有害水华。

[Objective] To study the flocculation effect of bacterial strain xn-1 on; water bloom causing species-Microcystis aeruginosa, to control water; bloom. [Methods] Flocculation bacterium was isolated from phycosphere; based on plate spread and streak technique; 16S rRNA gene was applied to; determine the evolutionary status. Flocculation mechanism was confirmed; by addition of different metal ions as coagulants. Bioflocculant was; obtained by gradient alcohol precipitation. Microplate reader was used; to study flocculation activity. [Results] Strain xn-1 was determined as; a species of the genus Shinella, designated as Shinella sp. xn-1. Strain; xn-1 exhibited high flocculation activity on M. aeruginosa with adding; Ca~(2+) as coagulants, and the flocculation activity was originated from; extracellular supernatant, showing high flocculation efficiency with the; concentration of 3.0%. Bioflocculant isolated from extracellular; supernatant could exhibit high flocculation effect with the addition of; 0.5 g/L, and the algal flocs became huger with the increase of; processing time. [Conclusion] Shinella sp. xn-1 shows high flocculation; activity on M. aeruginosa through secreting extracellular bioflocculant,; and the flocs with large volume are formed under the flocculation; effect. This study is a useful option to control water blooms in the; future.