Bactericidal Effects of Exiguobacterium sp GM010 Pigment Against Food-Borne Pathogens

Krishna-Prashanth Ramesh Mekala,Mohan A Dhale,Saritha G Pandit

doi:10.3389/fsufs.2020.00142

Abstract

Bacterium producing yellowish-orange pigment was identified (morphological, biochemical and 16S rRNA) as Exiguobacterium sp GM010. The UV-visible spectrum of Exiguobacterium sp GM010 extract showing λ max at 465nm revealed orange pigment characteristic. Pigment showed broad spectrum antibacterial action against gram positive and gram negative food-borne pathogens. The SYTO9 and propidium iodide (PI) staining revealed the cell membrane damage of food-borne pathogens under confocal laser scanning microscop (CLSM) indicating the bactericidal effect. This was evidenced by the fourier transform infrared (FTIR) spectrum, showing characteristic functional groups that mainly included hydroxyl, carbonyl and carboxylic groups causing a system of delocalized electrons leading to destabilization of membrane and decrease in membrane potential that resulted in bactericidal effect. The pigment of Exiguobacterium sp GM010 were nontoxic against Artemia franciscana and can be a promising source to control the food-borne pathogens in food industries.

Highlights

Food-borne diseases have become one of the most widespread public health problems
Since the selection of antagonistic strains was usually affected by the species and number of indicator microorganisms (Shnit-Orland and Kushmaro, 2009), all 43 strains were screened against both Gram positive and Gram negative food-borne pathogens (Data not shown)
Pigment of strain GM010 inhibited both Gram-positive and Gram-negative bacteria compared to broad spectrum antibiotics

Summary

Introduction

Food-borne diseases have become one of the most widespread public health problems. About two-thirds of all the outbreaks were due to consumption of microorganisms contaminated food and water. World Health Organization (WHO) estimates, unsafe food causes 600 million cases of food-borne diseases and 4,20,000 deaths annually, including children (Bajpai et al, 2013; Fukuda, 2015; World Health Organization, 2020). Food safety is a major concern for developing countries and for the developed countries. A study was conducted to characterize the prevalence and diversity of food-borne pathogens, recommended to minimize the risk of contamination in fields (Strawn et al, 2013). Recent reports have identified the prevalence of bacterial pathogens in quality export seafood (Bandekar, 2015) causes massive economic losses to the food industry

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Conclusion