Isolation and Identification of Lactic Acid Bacteria from Tempoyak for Making Yoghurt by Morphological and Biochemical Characterization

The selection of starter bacteria in yoghurt fermentation is important to produce yoghurt with good quality. The lactic acid bacteria (LAB) in “tempoyak” (local fermented durian pulp) have the potential to be starter bacteria for making yoghurt because the yoghurt fermentation process is the same as the tempoyak fermentation. This study aimed to isolate and identify morphological and biochemical characterization of LAB from tempoyak which will be used as starter bacteria. LAB selection was based on their ability to produce acid compounds and lactase. LAB isolates were identified based on morphological and biochemical tests. The results of the study obtained 23 isolates of the LAB with the same colony characteristics namely round shape, broken white color with convex elevation and smooth surface, and entire edge. Selection of acid-producing and lactase-producing LAB obtained six isolates (Tp-1, Tp-2, Tp-3, Tp-7, Tp-12, and Tp-19). The biochemical test showed six LABs were gram-positive bacteria, non-endospore, non- motile, and catalase-negative.