Chiang Mai Journal of Science

In the present study, we aimed to clarify the potential roles, the effect of groEL gene disruption and the induction of groESL gene expression in the thermotolerant acetic acid bacterium, Acetobacter pasteurianus SKU1108. The growth of the groEL gene disruptant decreased and the disruptant exhibited a complete loss of toleration ability to stressors compared with a wild type. Complementation of the A. pasteurianus SKU1108 groESL gene in a groEL gene disruptant restored significant toleration ability to stressors. The heat shock promoter was induced by stressors for groESL gene expression as shown by a steady increase in the transcription level of the groESL gene with elevated temperature, acetic acid and ethanol concentration. Moreover, a CIRCE element found in the upstream region was examined and compared in all known genome sequences of acetic acid bacteria. The results revealed that these consensus sequences of all strains are highly conserved and have evolved phylogenetically.