title: Bioresources inner-recycling between bioflocculation of Microcystis aeruginosa and its reutilization as a substrate for bioflocculant production.
abstract: Bioflocculation, being environmental-friendly and highly efficient, is considered to be a promising method to harvest microalgae. However, one limitation of this technology is high expense on substrates for bioflocculant bacteria cultivation. In this regard, we developed an innovative method for the inner-recycling of biomass that could harvest the typical microalgae, Microcystis aeruginosa, using a bioflocculant produced by Citrobacter sp. AzoR-1. In turn, the flocculated algal biomass could be reutilized as a substrate for Citrobacter sp. AzoR-1 cultivation and bioflocculant production. The experimental results showed that 3.4 ± 0.1 g of bioflocculant (hereafter called MBF-12) was produced by 10 g/L of wet biomass of M. aeruginosa (high-pressure steam sterilized) with an additional 10 g/L of glucose as an extra carbon source. The efficiency of MBF-12 for M. aeruginosa harvesting could reach ~95% under the optimized condition. Further analysis showed that MBF-12, dominated by ~270 kDa biopolymers, contributed the bioflocculation mechanisms of interparticle bridging and biosorption process. Bioflocculant synthesis by Citrobacter sp. AzoR-1 using microalga as a substrate, including the polyketide sugar unit, lipopolysaccharide, peptidoglycan and terpenoid backbone pathways. Our research provides the first evidence that harvested algae can be reutilized as a substrate to grow a bioflocculant using Citrobacter sp. AzoR-1.
authors.affiliation: School of Environment, Northeast Normal University, Changchun 130117, China.|Jilin Institute of Chemical Technology, Jilin, 132022, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.affiliation: School of Environment, Northeast Normal University, Changchun 130117, China.
authors.forename: Mingxin
authors.initials: M
authors.lastname: Huo
authors.affiliation: School of Environment, Northeast Normal University, Changchun 130117, China.
authors.forename: Caiyun
authors.initials: C
authors.lastname: Sun
authors.affiliation: School of Environment, Northeast Normal University, Changchun 130117, China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Cui
authors.affiliation: School of Environment, Northeast Normal University, Changchun 130117, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Brook Byers Institute for Sustainable Systems, and School of Civil &Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Crittenden
authors.affiliation: School of Environment, Northeast Normal University, Changchun 130117, China.
authors.forename: Wu
authors.initials: W
authors.lastname: Yang
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism; D002954:Citrobacter / Q000378:metabolism*; D005427:Flocculation; D005947:Glucose / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism; D058086:Microalgae / Q000378:metabolism*; D046931:Microcystis / Q000378:metabolism*; D010457:Peptidoglycan / Q000378:metabolism; D059027:Recycling; D013729:Terpenes / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; D010457:Peptidoglycan; D013729:Terpenes; D002244:Carbon; D005947:Glucose