潮间带污泥产絮凝细菌W17分离与絮凝性质分析

Isolation and Characterization of a Flocculant-producing Bacterium W17 from Marine Intertidal Sludge

对采自天津潮间带的污泥进行富集培养,从混合菌群中筛选高效产絮凝细菌。经过5次平板分离,获得一株对高岭土悬浊液具有较高絮凝活性的产絮凝细菌W17。根据形态观察和16S r RNA基因序列分析,该菌株鉴定为Enterococcus sp.W17（Genebank号KP198609）。在不同碳源（葡萄糖、果糖、木糖、乳糖、纤维素和淀粉）、起始p H值（5.0~10.0）和盐度（4‰~70‰）等培养条件下,分别测定菌株W17生长和产絮凝性质。结果表明,菌株W17能够利用多种碳源进行生长和产絮凝,其中葡萄糖是菌株W17生长和产絮凝的最适碳源。在起始p H值5.0~10.0范围内,菌株W17产絮凝的最适起始p H值是6.0,絮凝率可达到（91±5.83）%。菌株W17在设定盐度范围内,都能够生长并具有产絮凝性质,该菌株表现出较强的耐盐性。在淡水和海水培养条件下,菌株W17的产絮凝率分别是（94±5.50）%和（87±5.67）%。产絮凝菌株W17有望应该用于废水特别是高盐废水的处理。

Sludge, collected from intertidal zone in Tianjin, was enriched for isolation of a novel flocculant-producing bacterium. A bacterium named as strain W17 was isolated for high bioflocculant production after five cycles of replating onto the agar plates. The strain was identified as Enterococcus sp. W17 （Genebank KP198609） by the methods of light microscopic examination and 16S rRNA gene sequence analysis. This study examined the flocculant producing ability of strain W17 under different carbon sources such as glucose, fructose, xylose, lactose, cellulose, starch, initial pH value 5.0 -10.0 and salt concentrations 4%0~70%0. Strain W17 was able to produce flocculants using various carbon sources and glucose was found to be favorable for high bioflocculant activity. Moreover, this strain W17 could produce bioflocculant at initial pH from 5.0 to 10.0, with an optimum initial pH bioflocculant activity of （91±5.83）% at 6.0. In addition, strain W17 could grow and produce bioflocculant at the test range of salt concentration and showed the strong salt tolerance. The highest bioflocculant activity by strain W17 was （94±5.50）% and （87±5.67）% respectively in fresh and marine culture conditions. This result demonstrated that the flocculant-producing bacterium W17 has a wide application potential in actual fresh and marine wastewater treatment.