The combination of algae and fermented products rich in lactic acid bacteria brings many health benefits and makes it possible to design a brand new segment of fermented food. One of the effective food preservation methods is the use of osmotic dehydration process consisting in adding a substance (e.g. sodium chloride) to reduce water activity in the product. The objective of this research study was to determine the effect of Chlorella vulgaris on the survival of Lactobacillus brevis under adverse environmental conditions (high concentrations of sodium chloride) using a plate and turbidimetric method. The content of 5 and 10 % sodium chloride in the bacterial growth environment significantly reduced the count of lactic acid bacteria tested. However, adding the Chlorella vulgaris algae caused the tested Lactobacillus brevis strains to be protected from dying. Moreover, in the case of Lactobacillus brevis ŁOCK 0944 and ŁOCK 0992 no statistically significant differences were reported between the control sample containing bacteria plus Chlorella vulgaris and the tested sample with bacteria, algae and 10 % sodium chloride added in the 48th hour of incubation. Therefore, the algae introduced into the growth environment of lactic acid bacteria reduced the adverse effect of 10 % sodium chloride. It was found that the survival of all the tested Lactobacillus brevis strains cultured in the presence of Chlorella vulgaris after 48 h of incubation was higher in the presence of 10 % sodium chloride than in the case of 5 % NaCl. Using a scanning electron microscopy (SEM), it was found that this was probably owing to the release of additional content of algae cells.
Chlorella vulgaris, Lactobacillus brevis, adverse environmental conditions, sodium chloride