Two distinct pathways for the formation of hydroxy FA from linoleic acid by lactic acid bacteria

Twenty‐three of 86 strains of lactic acid bacteria transformed linoleic acid into hydroxy FA. Two distinct conversion pathways were in operation. Two strains of Lactobacillus acidophilus and a strain of Pediococcus pentosaceus produced 13( S )‐hydroxy‐9‐octadecenoic acid [13( S )‐OH 18∶1] and 10,13‐dihydroxyoctadecanoic acid (10,13‐OH 18∶0) as main and minor products, respectively, whereas 13 strains, including L. casei subsp. casei, L. paracasei subsp, paracasei, L. rhamnosus, L. lactis subsp. cremoris , and Streptococcus salivarius subsp. thermophilus produced 10‐hydroxy‐12‐octadecenoic acid (10‐OH 18∶1). Seven strains of L. plantanum converted linoleic acid to 10‐hydroxyoctadecanoic acid (10‐OH 18∶0) through 10‐OH 18∶1 Linoleic acid at 2 g/L was converted by L. acidophilus LFO13951 T to 1.3 g of 13( S )‐OH 18∶1 and 0.09 g of 10,13‐OH 18∶0 in 7 d. Lactobacillus paracasei subsp. paracasei JCM 1111 produced 10‐OH 18∶1 in 91% yield, and L. plantarum JCM 8341, 10‐OH 18∶0 in 59% yield from linoleic acid (2 g/L) under optimal conditions. To our knowledge, this is the first report on the production of 13( S )‐OH 18∶1 by lactic acid bacteria other than ruminal bacteria, and of 10,13‐OH 18∶0 by any bacteria.