Bioprocess development for the production of sonorensin by Bacillus sonorensis MT93 and its application as a food preservative

• Optimization of sonorensin production by RSM led to 15-fold increase in its yield.
• Sonorensin production in a bioreactor validated optimized medium composition.
• Sonorensin production was influenced by medium composition and process parameters.
• Sonorensin showed its potential as a biopreservative.

Media composition and environmental conditions were optimized using statistical tools, Plackett Burman design and response surface methodology, to maximize the yield of a bacteriocin, named as sonorensin, from a new marine isolate Bacillus sonorensis MT93 showing broad spectrum of antimicrobial activity. Under optimized conditions, MT93 produced 15-fold higher yield of sonorensin compared to that under initial fermentation conditions. As oxygen supply is a critical parameter controlling growth and product formation in aerobic bioprocesses and used as a parameter for bioprocess scale up, the effects of oxygen transfer, in terms of volumetric oxygen transfer coefficient (kLa), on production of sonorensin was investigated using optimized medium composition in a bioreactor. Studies on effectiveness of sonorensin against Staphylococcus aureus and Listeria monocytogenes in fruit juice and as a preservative in pasteurized milk demonstrated its potential as a biopreservative in fruit products and shelf life extender of the pasteurized milk.