一株耐盐菌Halomonas sp. A20的分离及降解糖精钠废水的特性

Isolation of the salt-tolerant bacterium Halomonas sp.A20 and its degradation of saccharin sodium wastewater

摘要:

【背景】糖精钠废水是一种难处理的高盐有机工业废水。【目的】为了提高糖精钠废水的生物降解效果，需要研究糖精钠废水降解菌的特性。【方法】采用纯培养技术从处理糖精钠废水的多级生物接触氧化系统内的活性污泥中分离筛选糖精钠废水降解菌，对分离菌株的形态特征、生理生化特性和16S rRNA基因序列进行分析，利用单因素实验和响应面法考察分离菌株降解糖精钠废水的最佳条件。【结果】筛选获得一株糖精钠废水降解菌A20，归属于盐单胞菌属(Halomonas)，当糖精钠废水的盐分为5%，菌接种量为15%，pH值为8.0，温度为30 ℃时，菌株A20对糖精钠废水中的化学需氧量(chemical oxygen demand，CODcr)去除率在60%以上；通过响应面法优化，菌株A20降解糖精钠废水的最佳条件为：pH 8.0，温度为30.3 ℃，接种量为14.1%，其CODcr去除率为65.4%。【结论】分离到一株能高效降解糖精钠废水中有机物的耐盐菌Halomonas sp. A20，可为高盐、高浓度糖精钠废水的处理提供优良的微生物菌种资源。

关键词:糖精钠废水;盐度;降解菌;降解特性;菌种资源

Abstract:

[Background] Saccharin sodium wastewater,one type of organic industrial wastewater with high salt,is difficult to be treated.[Objective] To improve the biodegradation of this wastewater,it is in urgent need to study the characteristics of the saccharin sodium wastewater degrading bacteria.[Methods] A bacterial strain A20 capable of degrading saccharin sodium wastewater was isolated by pure culture technology from the activated sludge in the multistage biological contact oxidation system.It was identified based on morphological characteristics,physiological and biochemical properties,and 16s rRNA gene sequence analysis.The optimum conditions for strain A20 to degrade saccharin sodium wastewater were investigated by single factor experiment and response surface method.[Results] The strain A20 belonged to Halomonas.When the salinity of saccharin sodium wastewater in 5%,pH 8.0,and the temperature of 30℃,inoculum ratio at 15%,the chemical oxygen demand (CODcr) removal efficiency was more than 60%.Through the optimization with response surface method,the optimum conditions for Halomonas sp.A20 to degrade the saccharin sodium wastewater:pH 8.0,temperature of 30.3℃,and inoculum ratio of 14.1%.Under this optimum condition,the CODcr removal efficiency was 65.4%.[Conclusion] The salt-tolerant strain A20 obtained in this study can efficiently degrade the organic matter in saccharin sodium wastewater,which can provide excellent microbial strain resources for the treatment of high-salt and high-concentration saccharin sodium wastewater.

Key words:saccharin sodium wastewater;salinity;degrading bacteria;degradation characteristics;strain resources