Xia Siqing, Zhang Zhiqiang, Wang Xuejiang, Yang Aming, Chen Ling, Zhao Jianfu, Leonard Didier, Jaffrezic-Renault Nicole
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Bioresour Technol. 2008 Sep;99(14):6520-7. doi: 10.1016/j.biortech.2007.11.031. Epub 2007 Dec 26.
A bioflocculant TJ-F1 with high flocculating activity, produced by strain TJ-1 from a mixed activated sludge, was investigated with regard to its production and characterization. By 16S rDNA sequence and biochemical and physiological characteristics, strain TJ-1 was identified as Proteus mirabilis. The most preferred carbon source, nitrogen source and C/N ratio (w/w) for strain TJ-1 to produce the bioflocculant were found to be glucose, peptone and 10, respectively. TJ-F1 production could be greatly stimulated by cations Ca(2+), Mg(2+) and Fe(3+). The optimal conditions for TJ-F1 production were inoculum size 2 per thousand (v/v), initial pH 7.0, culture temperature 25 degrees C, and shaking speed 130r/min, under which the flocculating activity of the bioflocculant reached 93.13%. About 1.33 g of the purified bioflocculant, whose molecular weight (MW) was 1.2 x 10(5) Da, could be recovered from 1.0 l of fermentation broth. Chemical analysis of bioflocculant TJ-F1 indicated that it contained protein (30.9%, w/w) and acid polysaccharide (63.1%, w/w), including neutral sugar, glucuronic acid and amino sugar as the principal constituents in the relative weight proportions of 8.2:5.3:1. Scanning electron microscopy (SEM) image of the purified solid-state TJ-F1 showed that it had a crystal-linear structure. Spectroscopic analysis of the bioflocculant by Fourier-transform infrared (FTIR) spectrometry indicated the presence of carboxyl, hydroxyl and amino groups preferred for the flocculation process.
研究了从混合活性污泥中筛选出的菌株TJ-1所产生的具有高絮凝活性的生物絮凝剂TJ-F1的生产及特性。通过16S rDNA序列以及生化和生理特性分析，菌株TJ-1被鉴定为奇异变形杆菌。发现菌株TJ-1产生生物絮凝剂的最适宜碳源、氮源和碳氮比（w/w）分别为葡萄糖、蛋白胨和10。阳离子Ca(2+)、Mg(2+)和Fe(3+)能极大地促进TJ-F1的产生。TJ-F1产生的最佳条件为接种量2‰（v/v）、初始pH 7.0、培养温度25℃、摇床转速130r/min，在此条件下生物絮凝剂的絮凝活性达到93.13%。从1.0 L发酵液中可回收约1.33 g纯化后的生物絮凝剂，其分子量（MW）为1.2×10(5) Da。生物絮凝剂TJ-F1的化学分析表明，它含有蛋白质（30.9%，w/w）和酸性多糖（63.1%，w/w），其中中性糖、葡萄糖醛酸和氨基糖为主要成分，相对重量比例为8.2:5.3:1。纯化后的固态TJ-F1的扫描电子显微镜（SEM）图像显示其具有晶体线性结构。通过傅里叶变换红外（FTIR）光谱对生物絮凝剂进行光谱分析表明，存在对絮凝过程有利的羧基、羟基和氨基基团。
