Production and characteristics of a bioflocculant produced by Bacillus sp. F19

• Published in: Bioresource technology 2008-11, Vol.99 (16), p.7686-7691
• Main Authors: Zheng, Yan, Ye, Zhi-Long, Fang, Xu-Liang, Li, Ya-Hong, Cai, Wei-Min
• Format: Article
• Language: English
• Subjects: Bacillus; Bacillus - genetics; Bacillus - growth & development; Bacillus - isolation & purification; Bacillus - metabolism; Bacillus sp; Bioflocculant; Biological and medical sciences; Carbon - metabolism; Culture Media; Flocculation; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Nitrogen - metabolism; Polysaccharide; RNA, Ribosomal, 16S - genetics; Soil Microbiology; Spectroscopy, Fourier Transform Infrared
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2008.01.068

A bioflocculant-producing bacterium isolated from soil was identified as Bacillus sp. and the bioflocculant produced was named MBFF19. Effects of physico-chemical conditions including pH, carbon sources and nitrogen sources on MBFF19 production were studied. Chemical analyses of the purified bioflocculant MBFF19 indicated that it was a sugar-protein derivative, composed of neutral sugar (3.6%, w/w), uronic acid (37.0%, w/w), amino sugars (0.5%, w/w) and protein (16.4%, w/w). The two neutral sugar components were mannose and glucose and the molar ratio was 1.2:1. Infrared spectrophotometry analysis revealed that MBFF19 contained carboxyl, hydroxyl and methoxyl groups in its structural. Flocculating properties of bioflocculant MBFF19 was examined using kaolin, activated carbon and fly coal suspension. Cation supplement had no positive effects on the flocculating activity whereas the presence of Fe3+ inhibited flocculation. Influences of pH and bioflocculant dosage on the flocculation were also examined.