Optimization of lactic acid production by a novel strain, Enterococcus faecalis KY072975 isolated from infants stool in Egypt

Abstract

Production of lactic acid using a novel strain of lactic acid bacteria isolated from infants stool was investigated in the present study. Out of ten isolates, a total of five bacterial isolates were found as positive in lactic acid production. The tested bacterial isolate W7 was observed as the potent strain in lactic acid production that exhibited a halo zone of 8 mm. The bacterial isolate W7 was identified phenotypically and genotypically as Enterococcus faecalis and was deposited in GenBank with accession number KY072975. The effect of different process parameters such as initial pH of the medium, incubation temperature, inoculum size and incubation time was also monitored to enhance lactic acid production and resulted in optimum lactic acid value of 0.72 mg/ml. The salted whey was the most applicable fermentation medium for production of lactic acid by Enterococcus faecalis KY072975 and recorded 2.07 ± 0.1 mg/ml. DOI: http://dx.doi.org/10.5281/zenodo.242164

Keywords

• Optimization
• Lactic acid
• Fermentation
• Skimmed milk
• Whey
• Enterococcus