产微生物絮凝剂的菌株筛选、鉴定及发酵条件优化

微生物絮凝剂是一类新型的水处理制剂,因其具有高效、无毒、易降解等特点,已成为水处理剂开发的研究热点。为了扩大微生物絮凝剂的种类,本研究从活性污泥和土壤样品中筛选絮凝剂产生菌,最终获得一株具有絮凝活性的菌株,通过16S rDNA鉴定,该菌株为蒙氏假单胞菌(Pseudomonas monteilii),因此命名为P. monteilii YR-1。利用单因素实验和正交试验对该菌株的发酵条件进行了优化,其最佳碳、氮源分别为25 g/L葡萄糖和2 g/L复合氮源(酵母浸粉:尿素:硫酸铵=5:5:2),培养基初始pH值为10,培养温度为28℃,发酵时间为72 h。在最佳培养条件下,其发酵液的絮凝率从37.68%提高到63.52%。这是关于蒙氏假单胞菌产絮凝剂的首次报道。

Screening and Identification of Microbial Flocculant Producing Strain and Optimization of Fermentation Conditions

Microbial flocculant(MBF) is a new type of water treatment agent, which has become a research hotspot of water treatment agent development with characteristics of high efficiency, nontoxicity and easy degradation. In order to expand the types of MBF, a strain with flocculation activity was finally obtained from activated sludge and soil samples. The strain was identified as Pseudomonas monteilii by 16 S r DNA, and named P. monteilii YR-1. The fermentation conditions of the strain were optimized by single factor experiment and orthogonal test. The optimum carbon and nitrogen sources were 25 g/L glucose and 2 g/L complex nitrogen sources(yeast extract fermentation: urea:ammonium sulfate=5: 5: 2). The initial p H of the culture medium was 10, the culture temperature was 28℃ and the fermentation time was 72 h. Under the optimum conditions, the flocculation rate of fermentation broth increased from37.68% to 63.52%. This was the first report on the production of flocculants by P. monteilii.