title: Improvement of mannitol production by Lactobacillus brevis mutant 3-A5 based on dual-stage pH control and fed-batch fermentations.
abstract: Lactobacillus brevis 3-A5 was isolated and expected to produce mannitol efficiently by regulating pH in batch and fed-batch fermentations. In 48 h batch fermentations with free and constant pH, the optimal pH for cell growth and mannitol production in the first 24 h of incubation was 5.5, whereas that for mannitol production in the second 24 h of incubation was 4.5. To achieve high cell density and mannitol yield simultaneously, a dual-stage pH control strategy was proposed based on the kinetic analysis of mannitol production. The pH value was controlled at 5.5 for the first 12 h of fermentation and subsequently shifted to 4.5 until the fermentation was completed. Under dual-stage pH control fermentation, a 103 g/L yield of mannitol with a volumetric production rate of 3.7 g/L/h was achieved after 28 h. The dual-stage pH control fed-batch fermentation strategy was further developed to improve mannitol yield, wherein the yield increased by 109 % to 215 g/L after 98 h of fermentation. This value is the highest yield of mannitol ever reported using L. brevis.
authors.affiliation: Natural Products and Glyco-Biotechnology Research Group, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Yue
authors.forename: Hailong
authors.initials: H
authors.lastname: Cao
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhang
authors.forename: Shuguang
authors.initials: S
authors.lastname: Li
authors.forename: Yanyu
authors.initials: Y
authors.lastname: Meng
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Lishuxin
authors.initials: L
authors.lastname: Huang
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Du
mesh_terms: D003470:Culture Media / Q000737:chemistry*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods*; D052196:Levilactobacillus brevis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D008353:Mannitol / Q000378:metabolism*
chemical_list: D003470:Culture Media; D008353:Mannitol