Are Antibacterial Peptides In Fermented Foods a Possible Source of New Antibiotics?

Abstract:

Goal:

This project sets out to screen fermented food products sold in Hong Kong for the presence of peptides with antibacterial activity.

Background:

The lack of new antibiotics is an increasingly worrying issue, where antibiotic resistance is mounting, causing infections to be difficult to treat. Previous studies have discovered a number of bioactive peptides in common foods, such as milk, seeds, fish, eggs and meat products. These compounds have been found to provide health benefits, as well as antimicrobials. Since there is a large range of traditional fermented foods in Hong Kong, including fermented tofu (fǔrǔ), soya sauce, as well as fermented shrimp paste (haam ha cheung), which might be expected to contain protein breakdown products, it is likely that some could contain antimicrobial peptides.

Method:

A typical preliminary test either uses the aqueous component of a food product or suspends a 1 g sample in 9 mL of (0.9%) saline. This extract is centrifuged (15,000 g, 5 minutes), syringe filtered (0.22 µm) and then assayed for antibacterial activity by disc diffusion against cultures of Gram positive and Gram negative bacteria on LB agar plates. Mixtures showing activity are separated using chromatography and the bioactive fraction(s) characterised using Liquid Chromatography - Electrospray Ionization - Quadrupole - Time of Flight Mass Spectrometer (LC-ESI-Q-TOF)*.