Effects of gum arabic on the growth of lactobacillus plantarum L9 by using statistical approach / Nur Nazihah Mustafa

Optimization of biomass production between the interaction of different concentrations of Lactobacilus plantarum L9 and gum Arabic was carried out using response surface methodology. A three square (32) full factorial design followed by statistical response and analysis of variance (ANOVA) was employed for experimental design and analysis of results and process of optimization. Nine inoculums were randomly performed to optimize the biomass growth of L. plantarum L9 in de Man Rogosa and Sharpe (MRS) carbohydrate-free medium supplemented with three different concentrations of gum Arabic as prebiotics (1%, 3% and 5% , w/v) and three different concentrations of L. plantarum L9 (5%, 10% and 15%, w/v). The optimal process parameters obtained from achieving the maximum yield of biomass L9 were temperature at 37 'C, anaerobically for up to 24 h incubation in the shake flask. Biomass production was analysed by using three different responses including maximum colony forming unit (CFU), specific growth rate and mean doubling time. The maximum value for maximum CFU was 4.07E8, specific growth rate was 1.19 n' and shortest mean doubling time was 0.58 h. The response surface graph predicted the optimal concentration of gum Arabic was 3.0% and L9 concentration 15.0 %. ANOVA result showed that only L. plantarum L9 could give significance difference to the biomass production. So, it is suggested that further study could reduce the concentration range either for L9 or gum Arabic, thus experiment data would be more precise and reliable for future references and researches.