Introduction
Acetic acid bacteria are classified into the group of α-proteobacteria, rod shape and obligate aerobe. Among 12 genera currently classified, genus Acetobacter and Gluconacetobacter aer characterized on their strong ability for ethanol oxidation and resistant to acetic acid (1.) Exposure on ethanol, acetic acid and temperature during vinegar fermentation could be resulted in a decline of cell viability. Therefore, the cost expense would be more concerned for the optimal fermentation, particularly cooling Several reports had been described on the identification of the alternative AAB could grow at higher temperature than that of the mesophillic so called, thermotolerant. Various thermotolerant AAB isolated from tropical area had been reported and examined on their growth and ethanol oxidation at high temperature (1-3). Even several isolated AAB could be grown at 42°C however the effective fermentation still achieved at around 37-39°C (4). Recently, it had been reported that thermotolerant mechanism is inheritable by adaptation under sub-lethal stress resulting in several mutation (4). With the gradually increasing of global temperature, we expected that a lot of AAB in various natural habitats would be adapted themselves for surviving, thus become a started collecting the samples including fruits and flowers in Nong Khai for AAB isolation. After confirmation of AAB, the growth and acetic acid fermentation was then examined in these strains.