title: Non-selective Separation of Bacterial Cells with Magnetic Nanoparticles Facilitated by Varying Surface Charge.
abstract: Recovering microorganisms from environmental samples is a crucial primary step for understanding microbial communities using molecular ecological approaches. It is often challenging to harvest microorganisms both efficiently and unselectively, guaranteeing a similar microbial composition between original and separated biomasses. A magnetic nanoparticles (MNPs) based method was developed to effectively separate microbial biomass from glass fiber pulp entrapped bacteria. Buffering pH and nanoparticle silica encapsulation significantly affected both biomass recovery and microbial selectivity. Under optimized conditions (using citric acid coated Fe3O4, buffering pH = 2.2), the method was applied in the pretreatment of total suspended particle sampler collected bioaerosols, the effective volume for DNA extraction was increased 10-folds, and the overall method detection limit of microbial contaminants in bioaerosols significantly decreased. A consistent recovery of the majority of airborne bacterial populations was demonstrated by in-depth comparison of microbial composition using 16S rRNA gene high-throughput sequencing. Surface charge was shown as the deciding factor for the interaction between MNPs and microorganisms, which helps developing materials with high microbial selectivity. To our knowledge, this study is the first report using MNPs to separate diverse microbial community unselectively from a complex environmental matrix. The technique is convenient and sensitive, as well as feasible to apply in monitoring of microbial transport and other related fields.
authors.affiliation: Shenzhen Graduate School, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of TechnologyShenzhen, China; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution ControlShenzhen, China.
authors.forename: Xin-Lei
authors.initials: XL
authors.lastname: Gao
authors.affiliation: Shenzhen Graduate School, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of TechnologyShenzhen, China; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution ControlShenzhen, China.
authors.forename: Ming-Fei
authors.initials: MF
authors.lastname: Shao
authors.affiliation: State-Key Laboratory of Chemical Engineering, East China University of Science and Technology Shanghai, China.
authors.forename: Yi-Sheng
authors.initials: YS
authors.lastname: Xu
authors.affiliation: College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University Tianjin, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Shenzhen Graduate School, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of TechnologyShenzhen, China; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution ControlShenzhen, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Shenzhen Graduate School, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of TechnologyShenzhen, China; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution ControlShenzhen, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Ouyang
authors.affiliation: Shenzhen Graduate School, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of TechnologyShenzhen, China; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution ControlShenzhen, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Li
keywords: adsorption; bioaerosols; glass fiber filter; magnetic nanoparticle; microbial community; surface charge