The ability of bacteria and other microorganisms to resist the effects of an antibiotic to which they were once sensitive, also known as antibiotic resistance, is a major concern all over the world. A new study conducted by the scientists at Council Of Scientific And Industrial Research–Central Food Technological Research Institute (CSIR–CFTRI) has sounded an alarm on the indiscriminate and rampant use of such ‘conventional antibiotics’ in the food industry.

The study revealed that new protein-based antimicrobials from Beneficial Microbes could be a better replacement for conventional antibiotics in the food industry. CSIR–CFTRI researchers have identified one from beneficial microbes, to demonstrate how it is better than antibiotics. The development of natural antimicrobials and their use in the food industry, researchers observed, is an emerging phenomenon.

“We were able to identify antimicrobial peptides from beneficial microbes. We checked their function in comparison with the other antimicrobials commercially available and ones developed in Europe and found that our antimicrobial agent was found much better as it could kill WHO prioritised Group-I, Group-II and Group-III organisms. The molecule works in very high temperatures, in harsh conditions such as acidic and alkaline,” says Professor Rajagopal Kammara, Head of Department of Protein Chemistry and Technology, CSIR-CFTRI, who was leading the study.

“It is highly suitable for the food industry because it works in the presence of metal salts, detergents and enzymes. It does not cause any harm after consumption, instead, it cleans up the harmful pathogens in the stomach, without harming the beneficial microbes,” adds Professor Kammara.

“Everywhere the conventional antibiotics are in rampant use, even in foods such as meat, vegetables, and one can find its traces even in water. There is huge contamination of antibiotics that is creating antibiotic-resistant organisms. This rampant use is creating a major problem in the environment, and the beneficial microbes are turning into antibiotic-resistant. Therefore, it is time for us to look for replacements for antibiotics. The best thing may be proteins or peptides from beneficial microbes,” observes Professor Kammara.

Apart from Professor Rajagopal Kammara, the research team included Shilja Choyam, and Priyanshi M Jain.

Their study began with the isolation of indigenous fermented foods, screening for bacteria producing various antimicrobials and characterising them. One of the best isolated ones was the Bug-Buster produced by Bacillus, and it was further characterised in comparison with Nisin, a polycyclic antibacterial peptide produced by the bacterium — Lactococcus lactis, which is used as a food preservative.

“A simple well diffusion antimicrobial assay was followed to check its ability to work in various conditions such as high temperature, pH, and presence of salts, physiological enzymes, and detergents. Antimicrobial agent Bug-Buster was purified from the organism, further characterised to know its sequence, as a protein. At the genome, we were able to find its sequence by whole genome sequencing approach. The purification technology of Bug-Buster has been patented and many well-known MNC’s have approached us for the technology transfer,” researchers noted in a release.

This indigenously developed antimicrobial agent can be stored at room temperature for three months. Having a wide activity spectrum and potential to control Salmonella, and Listeria bacteria, the Bug-Buster possesses commercially viable bioprocess with Hemolytic negative properties. Haemolytic negative properties are not only unique but also open doors for therapeutic use, Professor Kammara explains.

Probiotics are living organisms with ‘Generally Recognised as Safe’ (GRAS) status that several companies market as food or supplements, offering protection against diarrhoea and a host of other diseases. GRAS is a United States Food and Drug Administration (FDA) designation that means a chemical or substance added to food is considered safe by experts.

Researchers believe this development could bring the paradigm shift in making germ-free foods, food preservation and eradication of further rise of antibiotic-resistant organisms. The Bug-Buster stands globally, having the ability to kill ESKAPE organisms. ESKAPE is an acronym comprising the scientific names of six highly virulent and antibiotic-resistant bacterial pathogens including Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.

The study has been published in the Frontiers in Microbiology journal. (Article courtesy: India Science Wire)