Isolation, characterisation and identification of Probiotics Lactobacillus species in Belacan (Shrimp Paste)

The genus of Lactobacillus in fermented foods is commonly associated with probiotic properties. Belacan is one of the popular Malaysian fermented foods and it is believed to have varieties of probiotic Lactobacillus species. Therefore, this study was conducted to identify several probiotics Lactobacillus species in belacan. Of the 154 bacterial isolates on MRS agar, 18 isolates were identified as Lactobacillus through Gram-staining morphology and catalase test. All the genera was tested for probiotic properties using method of acid tolerance,bile salts tolerance, and antimicrobial activities against three pathogenic bacteria which were Staphylococcus aureus 25923, Staphlococcus epiderdemidis 12228, and Salmonella typhimurium 13311. In acid tolerance test, result showed that all 18 genera of Laactobacillus grew well at pH(control), 50% of the genus Lactobacillus grew well at pH 3 with a colony count less than 2 log cfu/mL compared with control pH. At pH 2.5, 44.4% of the genus of Lactobacillus was able to grow with colony count between 9 and 11 log cfu/mL. Of these 18 genera of Lactobacillus studied, only sic genera which were LT19,LT28, LT31,LT37, LT38(isolates from belacan sample of Papar,Sabah), and MY45(isolate from belacan sample of Sabak Bernam,Selangor) were tolerant to bile salts, in which 75% was tolerant to porcine bile salt, and 100% was tolerant to bovine bile salt. All the six genera of Lactobacillus showed inhibitory activity against selected pathogens by exhibiting inhibition zone diameter worth 33mm, 30mm, and 31mm for S.aureus 25923,S.epidermidis 12228, and S.typhimurium 13311,respectively. The six genera of Lactobacillus species were identified using API CHL kits. The species of Lactobacillus were identified as L.plantarum 1 and L.rhamnosus. According to these results, it showed that belacan coontains probiotic Lactobacillus species and these may be potential candidates for commercialization in the production of fermented foods.