Growth and Cell Properties of Modified Lactobacillus plantarum CICC21001 with Supplementing C18-FFAs to Growth Medium in vitro

Abstract

Fatty acids (FAs) are one of the important factors that can influence cell growth and membrane composition. The aim of this study was to investigate the influence of supplementing MLM growth medium with C18 free fatty acids (C-FFAs), including stearic (C18:0), oleic (C18:1), linoleic (C18:2), and linolenic (C18:3) acid, on the growth of Lactobacillus plantarum CICC21001 by forming ion pairs with lysine to increase the solubility of FAs in liquid medium. The utilization of C-FFAs was further confirmed by GC-FID. The investigation of cell properties, including cell surface hydrophobicity and zeta potential, was carried out for the modified L. plantarum and control group (non-supplementation). Furthermore, cell survival was measured in real time under heat (at 55 and 62 °C for 5 min), acid (pH 2.2), and bile salt stress. Our results indicated that the action of L. plantarum was modulated by assimilating C-FFAs. This study suggested that C-FFAs altered the life cycles and physiochemical properties of L. plantarum, which provided a guideline for probiotics production and their medical application.