title: Physical structure changes of solid medium by steam explosion sterilization.
abstract: Physical structure changes of solid medium were investigated to reveal effects of steam explosion sterilization on solid-state fermentation (SSF). Results indicated that steam explosion changed the structure of solid medium at both molecular and three-dimensional structural levels, which exposed hydrophilic groups and enlarged pores and cavities. It was interesting to find that pores where capillary water located were the active sites for SSF, due to the close relationship among capillary water relaxation time, specific surface area and fermentation performance. Therefore, steam explosion sterilization increased the effective contact area for microbial cells on solid medium, which contributed to improving SSF performance. Combined with the previous research, mechanisms of SSF improvement by steam explosion sterilization contained both chemical and physical effects.
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China. Electronic address: wanglan@ipe.ac.cn.
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China.
authors.forename: Hong-Zhang
authors.initials: HZ
authors.lastname: Chen
mesh_terms: D001412:Bacillus subtilis / Q000254:growth & development; D061249:Batch Cell Culture Techniques / Q000295:instrumentation*; D005285:Fermentation; D055595:Mechanical Phenomena; D060327:Solid-Phase Synthesis Techniques / Q000295:instrumentation*; D013227:Steam; D013242:Sterilization / Q000295:instrumentation / Q000379:methods*; D013499:Surface Properties; D014867:Water
chemical_list: D013227:Steam; D014867:Water
keywords: Low-field nuclear magnetic resonance (LF-NMR); Microstructure; Solid medium; Solid-state fermentation; Steam explosion sterilization