Lactobacillusgrowth and membrane composition in the presence of linoleic or conjugated linoleic acid

Abstract

Five Lactobacillus strains of intestinal and food origins were grown in MRS broth or milk containing various concentrations of linoleic acid or conjugated linoleic acid (CLA). The fatty acids had bacteriostatic, bacteriocidal, or no effect depending on bacterial strain, fatty acid concentration, fatty acid type, and growth medium. Both fatty acids displayed dose-dependent inhibition. All strains were inhibited to a greater extent by the fatty acids in broth than in milk. The CLA isomer mixture was less inhibitory than linoleic acid. Lactobacillus reuteri ATCC 55739, a strain capable of isomerizing linoleic acid to CLA, was the most inhibited strain by the presence of linoleic acid in broth or milk. In contrast, a member of the same species, L. reuteri ATCC 23272, was the least inhibited strain by linoleic acid and CLA. All strains increased membrane linoleic acid or CLA levels when grown with exogenous fatty acid. Lactobacillus reuteri ATCC 55739 had substantial CLA in the membrane when the growth medium was supplemented with linoleic acid. No association between level of fatty acid incorporation into the membrane and inhibition by that fatty acid was observed.

Trans fatty acids promote the growth of some Lactobacillus strains

“…They also reported that dodecanoic acid inhibited the growth of L. delbrueckii. Jenkins and Courtney (2003) observed that linoleic acid inhibited the Lactobacillus growth but not conjugated linoleic acid. Kankaanpaa et al (2004) reported that the addition of polyunsaturated FAs such as linoleic, a-linolenic, arachidonic and docosahexaenoic acids to the growth medium affected the FAs composition of total lipids in Lactobacillus rhamnosus, L. casei and L. delbrueckii.…”

Sweet Potatoes as a Basic Component in Developing a Medium for the Cultivation of Lactobacilli

“…Sweet potatoes also contain other minor nutrients including antioxidants, triglycerides, linoleic acid, and palmitic acid. 18,19) Oleic acid is known as an essential growth factor for Lactobacillus strains, 20) whereas antioxidants can stimulate the growth of Lactobacillus. 21) In addition, the state of North Carolina y To whom correspondence should be addressed.…”

Modification of the Technical Properties of Lactobacillus johnsonii NCC 533 by Supplementing the Growth Medium with Unsaturated Fatty Acids

“…Membrane fluidity can be altered by changing the ratio of saturated to unsaturated fatty acids in the membrane, with the double bond in unsaturated fatty acids preventing lipids from being closely packed and thus increasing fluidity. Bacteria can alter the composition of the membrane fatty acids by a number of processes, including cyclopropanation, cis-trans isomerization, (de)saturation, or the incorporation of free exogenous fatty acids into the membrane (7,9,18,21). It has been reported that bacterial membrane composition changes during acid shock (5,23), osmolarity fluctuations (46), freeze-drying (31), and exposure to suboptimal growth temperatures (16).…”