The Scientist of IPB: the Production of Antibacterial Compound of Siamese gourami (Trichogaster sp.) Bekasam
Bekasam is an Indonesian fermented fish product that tastes sour and mostly contains lactic acid bacteria (LAB). Bekasam is a popular food in Central Java, South Sumatra and South Kalimantan, and other places of Indonesia. Generally the production of bekasam involves a spontaneous, fermentation process of freshwater fish, supplemented by salt, and rice or fermented cassava. This product is made by mixing fish, rice, and salt in a closed container and then fermentation process is done at room temperature between 5 to 7 days. Lactic acid bacteria LAB is the dominant microorganism found in fermented fish. Lactic acid bacteria has been used as biopreservatives because it produce safe number of antibacterial substances and has inhibitory activity against enteropatogenic bacteria.
Lactobacillales or lactic acid bacteria (LAB) are an order of Gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod- or coccus-shaped bacteria that share common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants and milk products, produce lactic acid as the major metabolic end product of carbohydrate fermentation. One of the most important characteristics of LAB is its ability to produce diverse metabolites with antibacterial properties. Among other lactic acids, acetic acid, ethanol, diasetil, CO2, H2O2, reuterin, and bacteriocin. The potential of LAB from bekasam has been studied as antibacterial, probiotic agent and biopreservatives. Antibacterial compounds produced by LAB can be used as a preservative in food.
This is reason why Inayati Rahmi, Student of the Department of Aquatic Product Technology, of the Faculty of Fishery and Marine Sciences of Bogor Agricultural University (IPB) to implement her research program on Lactic acid bacteria (BAL) of bekasam. The title of her research is the Characterization and Production of Antibacterial Compound of Pediococcus pentosaceus BP (8) from Siamese gourami (Trichogaster sp.) of Bekasam. This study was conducted under the supervision of Dr. Desniar and Dra. Ella Salamah MSi.
"Lactic acid bacteria can be used as natural preservatives in food, because the secondary metabolites they produce tend to be harmless and have an inhibitor effect on pathogenic bacteria," Ina said.
According to Ina, isolates of Pediococcus pentosaceus BP(8) produces antibacterial compounds against pathogenic bacteria Escherichia coli, Salmonella typhimurium, and Listeria monocytogenes. "The resulting antibacterial compounds are presumably derived from organic acids, antifungal compounds, and bacteriocins," she explained.
The research was devided into three steps: (1) Refreshing the isolates and P. pentosaceus BP(8) verification, (2) Screening of antibacterial compounds from P. pentosaceus BP(8) was given four treatments adjusting the pH 5-7, (3) Production of antibacterial compound of P. pentosaceus BP(8) during 24 hours incubation.
The results showed that the production of the antibacterial compounds were produced at 6 hours of incubation until the end of incubation. The antibacterial activity produced by P. pentosaceus BP(8) against E. coli, B. cereus, and S. aureus was due to organic acids compound. Antibacterial activity continued to increase until at 18 hour of incubation. The antibacterial activity produced by P. pentosaceus BP (8) against S. aureus, E. coli, and B. cereus bacteria was suspected from organic acid compounds. The antibacterial activity against E. coli is stronger than S. aureus and B. cereus. The antibacterial activity was also increased simultaneously with the increased acid and decreases of pH value during growth of S. aureus and B. cereus bacteria.
Ina expected that her research results will provide scientific and accurate information on the production of antibacterial compounds of P. pentosaceus BP(8). "I also hope that this research can be applicable as biopreservatives, pharmaceutical, and nutraseutical," she concluded. (Wied)
