Effectiveness of <i>Acetobacter aceti</i> bacteria from palm vinegar (<i>Arenga pinnata</i>) isolate on acid and bile salt resistance as a probiotic candidate

Abstract Palm vinegar ( Arenga pinnata ) is a natural product produced by fermentation of nira water. Palm vinegar contains acetic acid produced by Acetobacter aceti bacteria. This is a Gram-negative non-pathogenic to humans and animals. Acetobacter aceti can usually cause rotting and brownish discoloration of fruits. This study aims to provide information on the probiotic potential of acetic acid bacteria isolated from palm vinegar ( Arenga pinnata ) by in vitro testing, namely resistance to acidic pH conditions (pH 2, 3, and 4), bile salts with a concentration of 0.3% (b/v). This study used a descriptive experimental method. Acetobacter aceti were isolated from palm vinegar and then continued to test the acid resistance and bile salts. The isolation results obtained were acetic acid bacterial isolates which are members of the genus Acetobacter with morphological characteristics, namely white spherical colonies, ellipsoidal cell shapes, rods, single or chain and gram-negative and biochemical characters, namely motile and non-motile nature, positive catalase and negative oxidase, and oxidative carbohydrate metabolism. Acetobacter aceti as a result of isolation is able to live up to a bile salt concentration of 15%, resistant to acidic media up to pH 2. From the results of the study, it can be concluded that Acetobacter aceti , which is an isolate of palm vinegar ( Arenga pinnata ), has characteristics that have the potential to be used as probiotic microbes.