The effect of some environmental conditions on planktonic growth and biofilm formation by some lactic acid bacteria isolated from a local cheese in Turkey.

Abstract

The purpose of this study was to determine the effect of some environmental conditions (different temperature degrees and pH values, different salt, glucose and lactose concentrations) on the planktonic growth and biofilm formation ability of the lactic acid bacteria (LAB) isolated from a local cheese in Turkey. It was determined that Enterococcus lactis EC61 and Enterococcus faecalis EC41 are the most resistant bacteria to the changing environmental conditions and they can stably maintain their planktonic growth in the pH values of 6.5, 7.0, 7.5, and 8.0; in the salt concentrations of 4% and 6.5%; in the glucose concentration of 0.5%; and in the lactose concentrations of 0.5%, 1.5%, and 2.5%. It was found that all strains had the biofilm formation ability and especially the biofilm formation of Enterococcus lactis EC61 and Enterococcus faecalis EC41 strains significantly increased in the acidic pH values and in the increasing glucose and lactose concentrations, and significantly decreased in the increasing salt concentration. When considered in terms of LAB potential as a starter culture, specifying the effect of some environmental conditions on the planktonic growth and biofilm formation ability is important for the food industry. As a conclusion, it was determined that lactic acid bacteria, which were previously determined to have some starter culture characteristics, had additional properties on the way to being an starter culture.