Isolation and molecular identification of 16s rRNA of lactic acid bacteria with the most probiotics potential from ‘lawar ikan’, a traditional fermented typical food from East Nusa Tenggara

Abstract

‘Lawar ikan’ is a traditional fermented food typical of East Nusa Tenggara made from fresh anchovies. Fermented foods generally contain lots of lactic acid bacteria (LAB). This research aims to isolate lactic acid bacteria which have probiotic potential from ‘lawar ikan’. The research method used is the isolation of LAB by first making samples of ‘lawar ikan’, then carrying out serial dilutions, growing them in specific media, the colonies that grow will be selected for morphological and biochemical characterization. Furthermore, to determine whether the isolates produced have probiotic potential, resistance tests were carried out against low pH, bile salts and antibacterial tests against the pathogenic bacteria E. coli and S. aureus. The isolation results showed that 11 isolates had different characteristics, and were gram-positive bacilli and 1 isolate was a gram-positive cocci. The resulting isolate was heterofermentative and catalase negative. The results of the BAL resistance test to low pH, namely pH 2, were isolate L03 with a final viability percentage of 61.75%, at pH 3, namely isolate L04 with a final viability percentage of 51.75%. Testing for resistance to bile salts obtained isolates that were resistant at a concentration of 0.3%, namely isolates L07, L05 and L04. Testing against pathogenic bacteria found 2 potential isolates, namely L04 with an inhibitory zone diameter of 5 mm against E.coli and 13 mm against S. aureus, while isolate L11 with an inhibitory zone diameter of 1 mm against E.coli and equal to 21 mm against S. aureus. The best isolate was identified based on the 16S rRNA gene, the identification result of isolate L04 was Pediococcus pentosaceus with a similarity percentage of 100%.