Abstract:
The aim of this study was to produce vinegar without using a high cost
submerged fermentor which is used in mass scale industries, by isolating
and identifying Acetic Acid Bacterial (AAB) species from toddy that yield a
high acetic acid concentration to produce vinegar. In the experiment, from
coconut toddy samples AAB were isolated using Carr’s Ethanol medium.
From the preliminary screening, 06 Gram negative bacterial isolates
produced yellow colorization around the colonies that indicated the acetic
acid production. Motility and endospore staining also were carried out.
Furthermore, biochemical characterization of the 06 bacterial isolates
resulted Acetobacter aceti, Acetobacter xylinus, Gluconobacter hansenii
and Gluconobacter liquefaciens. Two isolates were identified as A. aceti
strains. Isolates were tested for acetic acid productivity, ethanol tolerance,
temperature tolerance and acetic acid tolerance. Isolate 05 (Acetobacter
aceti) was the most potent strain. 5ml of ethanol-yeast extract medium
(ethanol 5%) fermented by isolate 05 was titrated against NaOH in 2 day
intervals resulted an acetic acid concentration starting from 0.72% and
increased up to 5.62% within 14 days of shaking incubation. It was able to
grow at temperatures of 30ºC, 37ºC, 40ºC, was able to tolerate ethanol
concentrations of 4-10% and remained viable at acetic acid concentrations
of 2-4%. This organism was able to produce vinegar of 5.62% acetic acid
concentration under low cost conditions without the fermentor which can be
modified in to a mass scale vinegar producer.
