Identification and antimicrobial activity of lactic acid bacteria from the digestive tract of eels (Monopterus albus)

Abstract. Ridwan, Retnaningrum E, Ilmi M, Daryono BS. 2019. Identification and antimicrobial activity of lactic acid bacteria from the digestive tract of eels (Monopterus albus). Bioteknologi 16: 5-10. This study aims to identify the species of lactic acid bacteria from the digestive tract of eels (Monopterus albus) which have inhibitory activity against pathogenic bacteria. The eel used in this study was obtained from the eel cultivation site in Yogyakarta. The isolation results obtained thirteen isolates; the isolated bacteria were then phenotypically characterized to select lactic acid bacteria. The results of phenotypic characterization obtained seven isolates that were in accordance with the character of lactic acid bacteria. Seven lactic acid bacterial isolates were then screened to select the three best isolates in inhibiting the growth of pathogenic bacteria (Aeromonas hydrophila, Staphylococcus aureus, and Vibrio harveyi). The results showed that seven isolates of lactic acid bacteria had antimicrobial activity, which were able to inhibit the growth of pathogenic bacteria. Three of the best isolates were selected to be used for molecular identification and monitoring of antimicrobial activity. The results showed that the three selected isolates produced an antimicrobial extract which was able to inhibit the growth of pathogenic bacteria. Furthermore, the results of the molecular identification showed that the three selected isolates were Lactococcus lactis species.