Abstract:
Probiotic lactic acid bacteria are “live microorganisms which, when
administered in adequate amounts, confer a health benefit on the host”. Therefore, the
purpose of the study was to isolate the lactic acid bacteria from papaya fruit, banana
fruits, fermented papaya fruit, fermented banana fruit and fermented red raw rice batter
to screen the probiotic potential of isolated strains. The gram staining and catalase
tests were performed to identify the presumptive lactic acid bacteria. Further, the
isolated strains were subjected to diverse biochemical and physiological tests, such as
different carbohydrate fermentation test, gas production from fructose and glucose and
ability to survive under different temperature, pH concentration, bile salt concentration
and sodium chloride concentration. The antimicrobial test was done for all selected
isolated bacterial strains against E. coli, Pseudomonas aeruginosa and
Staphylococcus aureus. Eight bacterial strains were isolated, and all isolated bacteria
strains were gram positive, catalase negative, non-spore forming and non-motility
strains. Based on the antimicrobial activity, the R2 isolated from fermented red raw rice
batter and FB1 and FB2 isolated from fermented banana fruit bacterial strains have
ability to control E. coli, Pseudomonas aeruginosa and Staphylococcus aureus than
other bacterial strains. Therefore, the R2, FB1 and FB2 bacterial strains identified as
probiotic lactic bacterial strains due to antimicrobial activity. Based on the biochemical
and physiological tests indicated that R2 can survive at low pH (1.5 to 4), high
temperature (470C), different bile salt concentrations (0.3%, 0.8% and 1.0%) and
different sodium chloride concentrations (2% ,6% and 10%). Therefore, this study
concluded that R2 isolated from fermented red raw rice batter considered as potential
probiotic lactic acid bacteria. Further study could be performed to confirm its probiotic
potential and identify strain based on molecular techniques.
