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.

Culture conditions affect Lactobacillus reuteri DSM 17938 ability to perform glycerol bioconversion into 3-hydroxypropionic acid

“…growth temperature, pH or the base used for pH control) to improve cell growth and further bioconversion is also challenging. The temperature for L. reuteri growth is generally established at 37 °C (18,24,32). However, the optimum temperature for growth may differ from that maximizing a given metabolic activity.…”

Complete genome sequence of Lactobacillus rhamnosus Pen, a probiotic component of a medicine used in prevention of antibiotic-associated diarrhoea in children

“…Other properties, such as adhesion ability [ 6 ], survival rate in acidic pH [ 7 ], antiradical activity [ 8 ] and production of extracellular ferulic acid esterase [ 9 ] have also been analysed. Optimisation of medium composition to enhance growth of L. rhamnosus Pen using response surface methodology was reported by Polak-Berecka et al [ 10 ].…”

Wheat and Sugar Beet Coproducts for the Bioproduction of 3-Hydroxypropionic Acid by Lactobacillus reuteri DSM17938

“…The method enables to obtain a large amount of data from a reduced number of experiments and to study the influence of different input variables on a specific response, including the interactions between the studied factors. RSM has been successfully used for the optimization of culture media for different microorganisms including lactobacillus species [15][16][17][18][19].…”