title: Harvesting of freshwater microalgae with microbial bioflocculant: a pilot-scale study.
abstract: BACKGROUND
  Nowadays, bioflocculation is considered as a potential technology that could be able to alleviate microalgae dewatering cost regarded as the cornerstone hindrance of their full-scale application. However, most bioflocculation studies reported are laboratory scales. This study examined a pilot-scale and in situ flocculation of freshwater microalgae Desmodesmus brasiliensis by microbial bioflocculant. Biochemical composition of microalgal biomass was analyzed to evaluate the applicability of bioflocculation for microalgae-based biofuel production.
  
  
  RESULTS
  The flocculation efficiency >98 % was achieved at both pilot-scale and in situ treatment. Bioflocculation is simple, effective, economic, and environmentally friendly. Even though total proteins recovered from biomass harvested by centrifugation and that harvested by bioflocculation were significantly different, there was no significant difference in total carbohydrates and total lipids recovered from either biomass harvested by centrifugation or biomass harvested by bioflocculation.
  
  
  CONCLUSIONS
  The results herein presented, doubtlessly demonstrated that the γ-PGA bioflocculant produced by Bacillus licheniformis CGMCC 2876 is applicable for commercial-scale microalgae harvesting. In addition, bioflocculation process cost could greatly be reduced by in situ operation as no investment cost is needed for a separate flocculation tank and mixing device. Furthermore, bioflocculation method developed is a worthy microalgae harvesting method for algal-based biofuel production.Graphical abstractThe addition of bioflocculant to microalgae cultures followed by mixing elicits, the formation of heavy flocs which settle out by gravity sedimentation in a relatively short settling time.
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China.
authors.forename: Theoneste
authors.initials: T
authors.lastname: Ndikubwimana
authors.affiliation: College of Energy, Xiamen University, 361005 Xiamen, China ; The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, 361005 Xiamen, China.
authors.forename: Xianhai
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China.
authors.forename: Theophile
authors.initials: T
authors.lastname: Murwanashyaka
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Manirafasha
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China ; The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, 361005 Xiamen, China.
authors.forename: Ning
authors.initials: N
authors.lastname: He
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China.
authors.forename: Wenyao
authors.initials: W
authors.lastname: Shao
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China ; The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, 361005 Xiamen, China.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Lu
keywords: Biochemical composition; Bioflocculant; In situ flocculation; Microalgae; Pilot scale