Objectives: 1) To isolate acetic acid bacteria (AAB) from promising sources of thermotolerant AAB in Mekong Delta, Vietnam. 2)To investigate the conditions for acetic acid and acerola vinegar fermentation at high temperatures of selected AAB strains; and 3) To study the conditions for biocellulose production. A collection of 178 acetic acid bacteria was achieved from many different kinds of raw materials in the Mekong Delta, Vietnam; such as fruits, flowers, cocoa, fermented products, alcoholic rice starters, sugarcane, molasses, agricultural by-products and soil samples. The results of thermotolerant characterization showed that 88.0% of the isolates could grow at 39ºC. The percentage of strains able to grow decreased to 66.2% and 32.6% when the incubation temperatures increased to 41ºC and 43ºC, respectively. A half of tested isolates could grow in the media supplemented with 1.0% (v/v) of acetic acid and it was decreased to 20.4%, 9.86%, 2.82% and 2.11% of the isolates in the medium containing 1.5%, 2.0%, 2.5% and 3.0% (v/v) of acetic acid, respectively. Twenty AAB isolates which could grow at 43ºC and produce 2.72-3.04% (w/v) of acetic acid concentrations in YPGD (containing 4% (v/v) ethanol) at 37ºC after 5 days of fermentation were selected for identification and futher study. Based on the 16S rDNA analysis (Fig. 1), it was shown that AAB isolates (A3, A19, A22, A23, A31, A47, A49, A50) were belong to A. tropicalis; 5 isolates (A1, A16, A24, A52, A55) were recognized as A. pasteurianus; while A8, A11 and A29 were A. orientalis. Isolates A13, A18, A28, and A46 were identified as A. aceti, A. sicerae, A. senegalenesis, and A. indonesiensis, respectively. Thus, total 7 Actobacter species were identified.