Screening of Acetic Acid Producing Microorganisms from Decomposed Fruits for Vinegar Production

Abstract

Acetic acid bacteria capable of growing at 30˚C -37˚C were collected from various decomposed fruits available in Bangladeshi local markets in order to assess their suitability for vinegar production. Initially, 42 microorganisms were isolated from decomposed fruits like grapes, mangoes, pineapples, oranges, safeda etc. during summer when temperature reaches up to 37˚C. Then their growths were checked in YPG medium containing various ethanol concentrations at different time point at 37˚C. From the preliminary screening, 15 Gram negative bacterial isolates have produced halos or yellow zone around the colonies on YPG agar plate at 37˚C which indicated acetic acid production capability by those bacteria. Furthermore, acetic acid production rates were determined by titration method and about 3 -6.9 gm/100ml acetic acid were estimated by using 4% ethanol at 37˚C by shaking culture for 3 days. Several biochemical analysis revealed that our collection contained huge amount of acetic acid producing bacteria and some of them could be potential candidates for vinegar production.

Optimization of Acetic Acid Production Rate by Thermotolerant <i>Acetobacter</i> spp.

“…Previously isolated strains, F-1, F-3 and F-10 were selected for this work because; they were found to be the most potent ones for acetic acid production among the 15-isolates [7]. Here, they were further characterized phylogenetically based on their 16s rRNA sequence.…”

“…We have isolated several strains from the natural decomposed fruit materials, which could produce acetic acid under high temperature fermentation process [7]. In this study, our main target was to optimize acetic acid production rate by stress tolerant as well as thermotolerant Acetobacter spp.…”

“…Here, we have selected 3-strains from our 15 isolated strains for genetic analysis, because these were previously found to be the most efficient ones for acetic acid production [1]. After BLAST search, all three isolates (F-1, F-3 and F-10) showed maximum identity of 99% with the reference strains [7]. Based on phylogenetic tree designed here, F1, F3 and F10 closely resembled Staphyococcus, Bacillus and Acetobacter spp., respectively, and are closely related to each other with acetic acid producing strains as shown in Figure 1 [10] [11].…”

“…Fifteen isolates from decomposed fruits materials were collected for acetic acid production previously and their preliminary characterization were reported [7]. Among these, three isolates (F-1, F-3, F-10) were selected for further analysis to observe their potentiality for acetic acid production under various physiological conditions.…”

“…Utilization of this molasses for production of ethanol and then microbial oxidation to acetic acid by indigenous potential bacteria has render attention in recent years. We have identified some strains those could produce acetic acid at high temperature [7]. Among those isolates, for this study we have chosen F-1, F-3, and F-10 strains, as they were the most potent ones according to our previous observation.…”