A novel polysaccharides-based bioflocculant produced by Bacillus subtilis ZHX3 and its application in the treatment of multiple pollutants. (February 2022)

• Record Type: Journal Article
• Authors: Xia, Mingchen; Zhou, Han; Amanze, Charles; Hu, Lan; Shen, Li; Yu, Runlan; Liu, Yuandong; Chen, Miao; Li, Jiaokun; Wu, Xueling; Qiu, Guanzhou; Zeng, Weimin
• Is Part Of: Chemosphere. Volume 289(2022)
• Publication Date: 2022-02
• Subjects: Bacillus subtilis ZHX3 -- Bioflocculant -- Dyes decolorization -- Heavy metals adsorption -- Flotation reagent removal; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.133185
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: A high bioflocculant-producing bacterial strain was identified and named Bacillus subtilis ZHX3. Single-factor experiments suggested that 10 g/L starch and 5 g/L yeast extract were optimal for strain ZHX3 to produce bioflocculant MBF-ZHX3. The maximum flocculating rate reached 95.5%, and 3.14 g/L product was extracted after 3 days of cultivation. MBF-ZHX3 was mainly composed of polysaccharides (77.2%) and protein (14.8%). The polysaccharides contained 28.9% uronic acid and 3.7% amino sugar. Rhamnose, arabinose, galactose, glucose, mannose, and galacturonic acid in a molar ratio of 0.35:1.83:3.09:12.66:0.46:3.81 were detected. MBF-ZHX3 had a molecular weight of 10, 028 Da and contained abundant groups (-OH, CO, >PO, C–O–C) contributing to flocculation. Adsorption and bridging was considered as the main flocculation mechanism. MBF-ZHX3 was more effective in decolorizing dyes, removing heavy metals and flotation reagents compared to polyacrylamide. The results implied that MBF-ZHX3 has the potential to substitute polyacrylamide in wastewater treatment because of its excellent biological and environmental benefits. Graphical abstract: Image 1 Highlights: Bacillus subtilis ZHX3 produced a novel polysaccharides-based bioflocculant. Maximum flocculating rate reached 95.5% after 3 days of cultivation. Flocculation mechanism was proved to be adsorption and bridging. Bioflocculant ZHX3 exhibited excellent activity in removing multiple pollutants.