title: Optimization of medium composition for enhancing growth of Lactobacillus rhamnosus PEN using response surface methodology.
abstract: Response surface methodology was used to optimize media components such as carbon and nitrogen (simple and complex) sources, mineral agents and growth factors (B vitamins, amino acids) for enhancing the biomass production of Lactobacillus rhamnosus PEN. For screening experiment the following carbon sources were selected: glucose, glucose+pyruvate, glucose+citrate, glucose+lactate, galactose, fructose, lactose, sucrose, maltose, lactulose, fructooligosaccharides, maltodextrins DP 4-7 and DP 13-17. Nitrogen sources such as yeast extract, meat extract and peptone K were used in lower concentrations than in MRS medium which served as a control. All experiments were run at 37 degrees C for 24-48 h under stationary conditions. Constituents chosen after the first screening experiments were further screened by the Plackett-Burman design. Glucose and sodium pyruvate, meat extract, potassium phosphate, sodium acetate, and ammonium citrate were chosen as promising medium components for further optimization studies. By solving the regression equation and analyzing the response surface carton, optimal concentrations of the components were determined as: glucose (13.4 g/l), sodium pyruvate (3.4 g/l), meat extract (7.2 g/l), potassium phosphate (2.0 g/I), sodium acetate (5.0 g/1) and ammonium citrate (2.0 g/l). In comparison to MRS broth the optimal medium contained fewer ingredients and in modified amounts but Lb. ihamnosus PEN showed better growth activity. Biomass concentration (as dry cell weight) of bacteria cultivated in optimal medium at bioreactor conditions was 5.5 g/l after 16 h of incubation, being higher in comparison with bacterial growth in MRS medium (1.9 g/l) under the same conditions. Moreover, the new medium was less expensive.
authors: Department of Biotechnology, Human Nutrition and Science of Food Commodities University of Life Sciences in Lublin, Lublin, Poland. 3mj@wp.pl
authors: Magdalena
authors: M
authors: Polak-Berecka
authors: Adam
authors: A
authors: Waśko
authors: Monika
authors: M
authors: Kordowska-Wiater
authors: Marcin
authors: M
authors: Podleśny
authors: Zdzisław
authors: Z
authors: Targoński
authors: Agnieszka
authors: A
authors: Kubik-Komar
mesh_terms: D003470:Culture Media / Q000737:chemistry* / Q000191:economics / Q000378:metabolism; D005163:Factor Analysis, Statistical; D052201:Lacticaseibacillus rhamnosus / Q000737:chemistry* / Q000254:growth & development* / Q000378:metabolism; D015233:Models, Statistical
chemical_list: D003470:Culture Media