Optimisation of growth conditions for Lactobacteria isolated from clinically obese individuals in medium supplemented

Abstract

Lactobacteria is a lactic acid bacteria (LAB) found in human gastrointestinal tract in which the microbial distribution previously documented to vary significantly between normal and obese individuals; creating conditions known as dysbiosis. Dysbiosed gut microbiome give rise to gut microbiota complications such as obesity. Obesity can be treated by surgery and prolonged use of medications which are costly and has significant effect for long time use. Alternatively, prebiotic gum arabic in obesity is gaining interest. Therefore, this study intended to enhance the growth of Lactobacteria that plays significant role in restoring microbiota of obese individuals. Characterization of Lactobacteria was performed by macroscopic, microscopic and biochemical test. Gram positive bacteria, rod-shaped in chain arrangement were obtained. The qualitative and quantitative analysis were performed to determine the bioactive compounds that presence in the gum arabic. DPPH, flavonoid, carbohydrate and saponin test resulting in positive reaction while negative in terpenoid test. The total flavonoid and total phenolic content were 21.9 mg QE/g and 14.3 mg GAE/g. The optimization of fermentation medium for the growth of Lactobacteria was conducted using Central Composite Design (CCD). The results were then analysed by Analysis of Variance (ANOVA). The optimal condition for Lactobacteria growth was obtained based on parameters set via numerical optimization with pH of 4.85, temperature of 37.13oC and 1.066 % concentration of gum arabic with experimental response of 1.5577. The experimental result obtained was accepted as it within the range of ± 0.05. This findings suggested that gum arabic has potential to be explored in application as dietary supplements in treating obesity.