title: Enhanced 2,3-butanediol production in fed-batch cultures of free and immobilized Bacillus licheniformis DSM 8785.
abstract: 2,3-Butanediol (2,3-BD) is a valuable bulk chemical with particular use in industry. 2,3-BD has a potential as solvent and fuel additive, as carrier for pharmaceuticals, or as feedstock for the production of synthetic rubber. Until now, the highest 2,3-BD concentrations were obtained with risk group 2 microorganisms (e.g., Klebsiella oxytoca). In this study, the nonpathogenic bacterium Bacillus licheniformis DSM 8785 was used for 2,3-BD production from glucose. In batch experiments, a maximum 2,3-BD concentration of 72.6 g/L was reached from 180 g/L glucose after 86 h. The yield was 0.42 g/g glucose and the productivity was 0.86 g/(L h). During fed-batch cultivation, 2,3-BD production could be increased up to 144.7 g/L, with a productivity of 1.14 g/(L h). Additionally, repeated batch/fed-batch experiments were conducted using immobilized B. licheniformis in the form of LentiKats®. Results showed a high activity and stability of the immobilizates even after multiple medium replacements, as well as 2,3-BD concentrations, yields, and productivities similar to those obtained with free cells. To our knowledge, these results show the highest 2,3-BD concentration reported so far using a risk group 1 microorganism in general and B. licheniformis in particular. Furthermore, productivity lies in the same range with data reported from risk group 2 strains, which makes B. licheniformis DSM 8785 a suitable candidate for large-scale fermentation processes.
authors.affiliation: Department of Biotechnology, Institute for Biochemistry, Biotechnology and Bioinformatics, Braunschweig University of Technology, Spielmannstr. 7, 38106, Braunschweig, Germany.
authors.forename: Ileana-Maria
authors.initials: IM
authors.lastname: Jurchescu
authors.forename: Jan
authors.initials: J
authors.lastname: Hamann
authors.forename: Xiye
authors.initials: X
authors.lastname: Zhou
authors.forename: Tim
authors.initials: T
authors.lastname: Ortmann
authors.forename: Anja
authors.initials: A
authors.lastname: Kuenz
authors.forename: Ulf
authors.initials: U
authors.lastname: Prüße
authors.forename: Siegmund
authors.initials: S
authors.lastname: Lang
mesh_terms: D001407:Bacillus / Q000378:metabolism*; D002072:Butylene Glycols / Q000378:metabolism*; D003470:Culture Media; D005285:Fermentation
chemical_list: D002072:Butylene Glycols; D003470:Culture Media; C026978:2,3-butylene glycol