Changes in membrane fatty acids of Lactobacillus helveticus during vacuum drying with sorbitol

Aims: To examine changes in membrane fatty acid profile attributed to the physiological adaptation of Lactobacillus helveticus during vacuum drying. Methods and Results: The viability and membrane integrity of the cells after vacuum drying were measured by plate counts and DNA fluorescence dyes. The physiological adaptation of cells dried in the presence of sorbitol was observed by determining changes in membrane fatty acid composition using gas chromatography. Results showed that viability and membrane integrity of Lact. helveticus cells increased when drying in the presence of sorbitol. The occurrence of the very low melting point polyunsaturated fatty acids linoleic and arachidonic acid was observed in cells dried in the presence of sorbitol. Conclusions: The physiological adaptation of cells occurred with cell membrane of Lact. helveticus during vacuum drying of cells in the presence of sorbitol. Significance and Impact of the Study: The study showed that physiological adaptation with membrane of the cells occurred during the drying process. The insight implies that instead of viability improvement of dried cells by the conventional stress induction during cultivation, the induction may be exercised thereafter without compromising growth of the cells.