Isolation and identification of a novel strain of Acetobacter ghanensis KBMNS-IAUF-6 from banana fruit, resistant to high temperature and ethanol concentration

Abstract

Background and Aims: The use of ethanol-temperature-resistant Acetobacter strains to produce vinegar on an industrial scale is important due to their sensitivity to high ethanol concentration as substrate and high energy consumption for acetator cooling. The aims of this study were to isolate and identify high temperature and ethanol resistant Acetobacter strains as starter for production of vinegar. Materials and Methods: The banana alcoholic extract was transferred to the fermenter medium and after 24 h incubation at 30°C, colonies with transparent zone were purified as acetic acid bacteria and examined macroscopically and microscopically. The resistance to high temperature in constant ethanol and time as well as resistance to high ethanol in constant temperature and time were investigated. Results: The studies of AAB isolate grown in the Carr medium showed that it was a Acetobacter strain. According to the single-factor optimization, this species was able to grow in a Carr medium containing 9% ethanol at 40°C after 72 h. Conclusion: This is the first report of an AAB isolation from banana in Iran. This bacterium, as a new resistant strain to high levels of ethanol and temperature, was identified as Acetobacter ghanensis KBMNS-IAUF-6 and its 16S-rDNA sequence was deposited in GenBank, NCBI, under the accession number of MK968570. This new strain can be suggested as a high temperature and ethanol resistant strain for producing banana vinegar on a semi-industrial and industrial scale