Selection of Thermotolerant and Non Overoxydative Acetic Acid Strains for Cost Effective Vinegar Production

The aim of this study was to select thermotolerant acetic acid bacteria with no overoxidation ability that would be useful for low-cost vinegar production. Acetic bacteria were isolated from palm wine and mango pulp after 3 to 5 days of fermentation. The isolates were first characterized by biochemical tests and were identified by sequencing of the rRNA 16 S gene. From the substrates collected, a total of 48 acetic acid bacteria were isolated. Among them, 8 strains showing inability to oxidate acetate to CO2 and H2O. Three strains of these 8 isolates belonging to Gluconobacter oxydans (Ski1) and to Acetobacter ghanensis (Fke 22 and Fk5) were able to grow and produce acetic acid at 37°C and in culture medium containing 5% of ethanol and until 10% of acetic acid. This study allows to select three thermotolerant acetic acid bacteria strains with high amount of acetic acid production capacity but with no-overoxydation ability. These strains could then be useful as starters for low-cost vinegar production.