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

Mingchen Xia; Han Zhou; Charles Amanze; Lan Hu; Li Shen; Runlan Yu; Yuandong Liu; Miao Chen; Jiaokun Li; Xueling Wu; Guanzhou Qiu; Weimin Zeng

doi:10.1016/j.chemosphere.2021.133185

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

Chemosphere. 2022 Feb:289:133185. doi: 10.1016/j.chemosphere.2021.133185. Epub 2021 Dec 6.

Authors

Mingchen Xia¹, Han Zhou¹, Charles Amanze¹, Lan Hu¹, Li Shen², Runlan Yu², Yuandong Liu², Miao Chen³, Jiaokun Li², Xueling Wu², Guanzhou Qiu², Weimin Zeng⁴

Affiliations

¹ School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China.
² School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China.
³ CSIRO Process Science and Engineering, Clayton, Victoria, 3168, Australia; Centre for Advanced Materials and Industrial Chemistry, RMIT University, Melbourne, 3000, Australia.
⁴ School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China; CSIRO Process Science and Engineering, Clayton, Victoria, 3168, Australia. Electronic address: zengweimin1024@126.com.

PMID: 34883128
DOI: 10.1016/j.chemosphere.2021.133185

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.

Keywords: Bacillus subtilis ZHX3; Bioflocculant; Dyes decolorization; Flotation reagent removal; Heavy metals adsorption.

MeSH terms

Bacillus subtilis*
Environmental Pollutants*
Flocculation
Hydrogen-Ion Concentration
Polysaccharides

Substances

Environmental Pollutants
Polysaccharides