PCASTRD supports R&D on bacteriocins

By Framelia V. Anonas
MediaCore, PCASTRD

To many, bacteriocins may sound like rare acrid-tasting medicine.  But to health scientists, bacteriocins are substances produced by lactic acid bacteria that torment bad bacteria, ferment food, and defend human health.

The intestinal tracts of humans and animals are the natural home for bacteriocins, more popularly known as lactobacilli.  

When you are down with diarrhea, ulcer, and abdominal cramps, chances are you ingested food that may have been infected with bad bacteria such as E. coli, Salmonella, and H. pylori.  These bad bacteria, called pathogens, weaken man's defenses and cause infections and disease.  They generally freeload on various foods through infected eggs, meat, and food handlers' unwashed hands.

When contaminated food washes down the intestinal tract, bad bacteria are immediately swamped by bacteriocins, which are the body's first line of defense. Bacteriocins commonly attack opponents by pricking holes in the cell membrane so that small molecules leak out.  When the bad bacteria's cell can no longer maintain its energy metabolism, it dies.

Compared to man-made antibiotics, bacteriocins tend to be specialized.  They have a narrow spectrum of activity and only inhibit one or two other organisms and leave other Lactobacilli and human cells unharmed.

Bacteriocins were first discovered by the dairy processing industry, which noticed that some bacteria used in food fermentation such as in making sour cream are better than others in preventing food spoilage.   But that is something that happens for the last 4000 years.

Ancient food makers used bacteriocins to produce and preserve cultured foods with improved preservation properties and with characteristic flavors and textures different from the original food.  A good combination of bacteriocins and other variables such as temperature and composition of food being fermented contribute to the features of different products.  These include slightly tart taste of fermented milk, unique aroma of yoghurt, cheese, buttermilk and others.  As such, bacteriocins  are also used in pickling of vegetables, baking, winemaking, curing fish, meats, and sausages.

 Recently there is renewed interest in bacteriocins sparked by continuing food spoilage everywhere.  Chemical preservatives are slowly being eased out of the market as these are found hazardous to human health.

As a result, food researchers now focus on bio-preservation system where good bacteria are allowed to produce bacteriocins in food where they naturally grow or cultured.  Bacteriocins are then purified and used as pure, natural food preservatives.

Meanwhile, studies on bacteriocins funded by the Philippine Council for Advanced Science and Technology Research and Development are ongoing at the University of the Philippines Los Baños, and Leyte State University under its R&D support program.

Scientists involved in the studies look into the structure of bacteriocin at the molecular level to determine the substance's other possible commercial applications. They are also in the process of screening several locally available root crops for bacteriocin-producing microorganisms, the kinds of bacteriocins they synthesize along with specific enemy organisms.

PCASTRD also supports R&D projects on biotechnology including molecular markers, gene mapping and sequencing, and production of enzymes. 

A planning council of the Department of Science and Technology, PCASTRD's mandate is to develop the advanced S&T sector that includes biotechnology.   The agency encourages and supports biotech R&D projects that will help strengthen the country's capability in producing more precise, time-saving and cost-effective new strains of improved crops.

[For details on PCASTRD's R&D Support Program, log on tohttp://www.pcastrd.dost.gov.ph, or call tel. no. 837-2071 local 2106, or send e-mail to pcastrd@dost.gov.ph]