title: Effect of biofilm formation by Bacillus subtilis natto on menaquinone-7 biosynthesis.
abstract: Bacillus subtilis natto is the key microorganism for the industrial production of menaquinone-7. The fermentation of this bacterium in static culture is associated with biofilm formation. The objective of this study was to determine the effect of biofilm formation on menaquinone-7 production to develop a suitable bio-reactor for the production of menaquinone-7. In the static culture, menaquinone-7 biosynthesis showed a linear correlation with biofilm formation (R (2) = 0.67) and cell density (R (2) = 0.7). The amount of biofilm, cell density and menaquinone-7 formation were a function of nutrient and processing conditions. Glycerol, soy peptone, and yeast extract mixture and 40 °C were found to be the optimum nutrients and temperature for accelerating both biofilm and menaquinone-7 biosynthesis in static culture. However, glucose, mixture of soy peptone and yeast extract and 45 °C were found to be the optima for cell density. As compared to the static culture, the biofilm formation was significantly inhibited when a shaken fermentation was used. However, shaking caused only a small decrease on menaquinone-7 production. These results demonstrate that the biofilm formation is not essential for menaquinone-7 biosynthesis. This study underlines the feasibility of using large scale stirred fermentation process for menaquinone-7 production.
authors: School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, Australia. aydin.berenjian@sydney.edu.au
authors: Aydin
authors: A
authors: Berenjian
authors: Natalie Li-Cheng
authors: NL
authors: Chan
authors: Raja
authors: R
authors: Mahanama
authors: Andrea
authors: A
authors: Talbot
authors: Hubert
authors: H
authors: Regtop
authors: John
authors: J
authors: Kavanagh
authors: Fariba
authors: F
authors: Dehghani
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D002244:Carbon / Q000378:metabolism; D002452:Cell Count; D003470:Culture Media; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D014176:Protein Biosynthesis; D045730:Soy Foods; D013696:Temperature; D024482:Vitamin K 2 / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D003470:Culture Media; D024482:Vitamin K 2; D002244:Carbon; C062629:menaquinone 7; D005947:Glucose; D009584:Nitrogen; D005990:Glycerol