Nutritional and Molecular Studies of Alkaliphilic Tolerant Potential Amylase Producing Lactic Acid Bacteria Isolated from Indigenous Foods and Dumpsites

Abstract

Alkaliphilic organisms are important in industries but most of these organisms are obtained from Bacillus species and the like that  require special scrutiny before use in fermentation of food related products. Lactic acid bacteria are generally regarded as safe (GRAS)  and are therefore readily applied in industrial fermentation with confidence. Due to high demand for the products of alkaliphilic organisms and industrial acceptability of lactic acid bacteria, there is a need to source for GRAS microorganisms that can withstand pH  ranges. The aim of this study was to isolate alkaliphilic tolerant lactic acid bacteria from fermented cassava mash, `ogi` and dump site  samples with a view to determining their nutritional requirement as well as molecular identity. Lactic acid bacteria were isolated from the  samples using standard methods. The isolates were subsequently characterized morphologically, biochemically and molecularly. Effects  of different carbon, nitrogen sources, initial temperature and pH as well as metal ions (Na⁺, Ca²⁺, Mg²⁺, Zn²⁺ and Cu²⁺) on the growth of  the isolates were examined. Data obtained were analyzed using one-way analysis of variance (ANOVA). Results obtained indicate that  extracted DNA sequence of A3, A7, A8 and A10 were related to those of Lactobacillus brevis FJ476121.1, Pediococcus acidilactici  CP096031.1, Pediococcus pentasaceus AB362605.1 and Pediococcus acidilactici CP053421.1 respectively with the sequences within the GenBank. 1% fructose elicited growth for all the bacteria detected except Lactobacillus brevis and ammonium nitrate was most preferred  by all the bacteria detected apart from Pediococcus pentasaceus strain. Lactobacillus brevis FJ476121.1 and Pediococcus acidilactici  CP053421.1 were the most alkaliphilic tolerant bacteria detected with OD of 0.285±0.04 and 0.198±0.04 respectively. Different metal ions  significantly influenced the growth of isolates in this study. The results in this study indicate potential applicability of the detected  bacteria for industrial processes.