Pyocin QDD1: A highly thermostable bacteriocin produced by Pseudomonas aeruginosa QDD1 for the biocontrol of foodborne pathogens Staphylococcus aureus and Bacillus cereus

Abstract

This study was designed to explore alternative antibacterial bioresource products, bacteriocins produced by local strain of Pseudomonas aeruginosa QDD1. This bacteriocin (termed as Pyocin) has high inhibitory activity against Gram-positive bacteria including S. aureus, B. cereus, B. thuringiensis and B. subtilis. QDD1 Pyocin production was constitutive, auto-regulated and reached an activity level of 110 AU/mL. It affects 40 % of sensitive cells starting from the 1 st hour. Pyocin QDD1 activity was not affected by Proteinase K, α-amylase, β-mercaptoethanol and 8 M urea. It displayed broad pH stability (pH 3–9) and significant thermostability (121 °C). Considering that the spores produced by Bacillus cereus are highly resistant to cooking temperatures and cause food poisoning upon germination in gastrointestinal tract, Pyocin QDD1's ability to withstand high temperatures can help control Bacillus cereus populations in contaminated food products. Thus, Pyocin QDD1 can be considered as an important bioresource product of industrial applications.