title: Enhanced poly(γ-glutamic acid) fermentation by Bacillus subtilis NX-2 immobilized in an aerobic plant fibrous-bed bioreactor.
abstract: To enhance poly(γ-glutamic acid) (PGA) production, a novel aerobic plant fibrous-bed bioreactor (APFB) was constructed for immobilized fermentation. Based on the analysis of the kinetics of immobilized-cell fermentation using the APFB and conventional free-cell fermentation, immobilized-cell fermentation exhibited more efficient PGA production. Furthermore, repeated fed-batch cultures for PGA production were conducted to evaluate the stability of the APFB system. Average final PGA concentration and productivity of 71.21±0.83g/L and 1.246±0.008g/L/h were respectively achieved by cells immobilized in bagasse during APFB, which was reused eight times over a period of 457±18h. Analysis of the membrane phospholipids and the key enzyme activities indicated that APFB-adapted cells had better productivity than original cells. Thus, this study demonstrated the significant potential of the APFB culture system in future industrial applications.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China; College of Food Science and Light Industry, Nanjing University of Technology, Nanjing 211816, PR China.
authors.forename: Zongqi
authors.initials: Z
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China; College of Food Science and Light Industry, Nanjing University of Technology, Nanjing 211816, PR China. Electronic address: fengxiaohai@njut.edu.cn.
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China; College of Food Science and Light Industry, Nanjing University of Technology, Nanjing 211816, PR China; School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai 200240, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China; College of Food Science and Light Industry, Nanjing University of Technology, Nanjing 211816, PR China.
authors.forename: Bao
authors.initials: B
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China; College of Food Science and Light Industry, Nanjing University of Technology, Nanjing 211816, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China; College of Food Science and Light Industry, Nanjing University of Technology, Nanjing 211816, PR China.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China; College of Food Science and Light Industry, Nanjing University of Technology, Nanjing 211816, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
mesh_terms: D000332:Aerobiosis; D001412:Bacillus subtilis / Q000378:metabolism* / Q000648:ultrastructure; D019149:Bioreactors; D002482:Cellulose / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D007218:Industrial Microbiology / Q000295:instrumentation / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D013997:Time Factors
chemical_list: C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D002482:Cellulose; C027433:bagasse; D005947:Glucose
keywords: Aerobic plant fibrous-bed bioreactor; Bacillus subtilis NX-2; Cell membrane permeability; Poly(γ-glutamic acid); Repeated fed-batch fermentation