Francisco B. Elegado

Rapid purification, partial characterization, and antimicrobial spectrum of the bacteriocin, Pediocin AcM, from Pediococcus acidilactici M

The bacteriocin from Pediococcus acidilactici M, designated as Pediocin AcM, was rapidly purified to homogeneity by the pH mediated cell adsorption-desorption method and semi-preparative reversed-phase HPLC. The purification yield was 40.4% and the specific activity was increased by 2450-fold. It gave a single band and a single peak on SDS-PAGE and HPLC analysis, respectively. When subjected to electrospray LC-MS analysis, the protein was found to be highly pure and the molecular weight was determined as 4,618 Da. High concentration of the bacteriocin (> 50 micrograms/ml) showed good resistance to extremes of pH (1-12) and temperature (121 degrees C). Pediocin AcM was deduced to be a monomer with an intra-peptide disulfide bond from the results of reversed-phase analytical HPLC analyses after reduction, oxidation and trypsin digestion. P. acidilactici M inhibited a large number of bacteria, including Staphylococcus aureus, Listeria monocytogenes, Clostridium perfringens, Bacillus coagulans, B. cereus, and Aeromonas hydrophila.

Bacteriocins from Lactic Acid Bacteria: A Review of Biosynthesis, Mode of Action, Fermentative Production, Uses, and Prospects

Bacteriocins are antimicrobial peptides that help bacteria fight competing bacteria in microecological systems. Bacteriocins of lactic acid bacteria (LAB) have attracted much interest in recent years because of their properties that make them suitable as natural food preservatives against specific food pathogens, and as possible supplement to antibiotics against drug resistant bacterial strains. LAB bacteriocins are generally classified into the lantibiotics and non-lantibiotics, the latter divided into four subgroups. To date, only nisin and to a lesser extent, pediocin are the commercially applied bacteriocins for food use. Clinical applications are still limited to animal health. One of the more exciting prospects on the use of bacteriocins is the possibility of subjecting them to bioengineering to either increase antimicrobial activity or further specify their target microorganism. The latter would make it less damaging to the natural gut microflora, which is a common drawback of conventional antibiotic therapy. This paper focuses on the nature, biology, and applications of bacteriocins based on knowledge gained abroad and in the Philippines during the last two decades. Keywords—lactic acid bacteria, antimicrobial peptides, bacteriocin, bacteriocin application, bacteriocin biosynthesis, bacteriocin prospects

Lactic Acid Bacteria in Philippine Traditional Fermented Foods

The Philippine archipelago is home to a diverse array of ecosystems, organisms, peoples, and cultures. Filipino cuisine is no exception as distinct regional flavors stem from the unique food preparation techniques and culinary traditions of each region. Although Philippine indigenous foods are reminiscent of various foreign influences, local processes are adapted to indigenous ingredients and in accordance with local tastes. Pervasive throughout the numerous islands of the Philippines is the use of fermentation to enhance the organoleptic qualities as well as extend the shelf-life of food.

Ethnic Fermented Foods of the Philippines with Reference to Lactic Acid Bacteria and Yeasts

The Philippines with its large ethnic diversity has regional varieties of fermented foods, generally produced in households or small-scale industry, depending on the availability of raw materials and traditional food preferences. The major documented Philippine fermented foods are basically made from rice, seafood, sugarcane, coconut, nipa palm, and selected fruits and vegetables. These fermented foods are prepared for preservative and organoleptic (condiments) usage and in some instances for folkloric purposes. Urbanization has remarkably affected the diet in developing countries like the Philippines. There are the dramatic increase in food variety and influences of international cuisine. The recent trends in enhanced consumer preference for functional foods create added economic opportunity for fermented foods, specifically probiotic foods and drinks. The identification and characterization of lactic acid bacteria and yeast flora of fermented foods from Central Luzon, Philippines, and the muscovado sugar-based kefir from Leyte, Philippines, with particular emphasis on their antimicrobial activities, are discussed here. These are additional contributions to the continuing research on probiotic and functionalities of Asian fermented foods.