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论文类型：期刊论文

发表时间：2011-11-01

发表刊物：WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY

收录刊物：Scopus、SCIE、EI

卷号：27

期号：11

页面范围：2559-2565

ISSN号：0959-3993

关键字：Compound bioflocculant; Polysaccharide; Flocculation; Mechanism

摘要：A compound bioflocculant CBF-F26, produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its physicochemical and flocculating properties. It was identified as a polysaccharide bioflocculant composed of rhamnose, mannose, glucose, and galactose, respectively, in a 1.3: 2.1: 10.0: 1.0 molar ratio. The average molecular weight was determined as 4.79 x 10(5) Da by gel-permeation chromatography. Infrared spectrum and X-ray photoelectron spectroscopy revealed the presence of carboxyl, hydroxyl and amino groups in its structure. Thermostability test suggested that CBF-F26 was thermostable and high flocculating activity was maintained. Thermogravimetric property, intrinsic viscosity and surface morphology of CBF-F26 were also studied. CBF-F26 was effective under neutral and weak alkaline conditions (pH 7.0-9.0), and flocculating activities of higher than 90% were obtained in the concentration range of 8-24 mg l(-1) at pH 8.0. The flocculation could be stimulated by cations Ca(2+), Zn(2+), Fe(2+), Al(3+), and Fe(3+). In addition, the probable flocculation mechanisms were proposed.