W. J. Jang1, S. W. Hyung1, C. W. Park1, S. J. Kim1, Y. S. Kim1, M. S. Kim1, R. M. Cerbo1, J. O. Kim2, and Y. L. HA1. (1) Division of Applied Life Science (BK21), Graduate School, Gyeongsang National University, Jinju, 660-701, South Korea, (2) HK Biotech CO., Ltd., Jinju, 660-902, South Korea
Conjugated linoleic acid (CLA) exhibits several biological activities in animal models and also reduces body fats in human trials. CLA has various isomers including c9,t11 and t10,c12 CLA isomers. A mixture of these two isomers were simply produced from linoleic acid isomerization at high temperature; however c9,t11 CLA isomer was usually produced by bacterial fermentation, especially, B. fibrisolvens and L. reuteri sp. It is of significance to find other sources of microorganisms producing c9,t11 CLA. Preliminary our results showed that a mushroom stain, Agaricus blazei (AB), produced a substantial amount of c9,t11 CLA.
Our objective was to optimize the cultural condition for the production of c9,t11 CLA using AB.
AB was cultured in the medium (4% soybean flak + 4% yellow sugar, 0.12% MgSO4, 0.12% KH2PO4), containing safflower oil (SO; 0, 0.2, 0.4, 0.6 or 0.8%), in a fermenter jar (25oC, airation rate 1.0 v/v/m). Three days later, mycelia was separated from the cultured medium by filtration. CLA was extracted from medium, mycelial surface and mycelia (homogenized) with hexane, and analyzed by GC.
As compared to control the growth of AB was stimulated by 0.4% SO addition, but inhibited by greater than 0.6% SO addition. Total CLA content in whole media (L) containing 0, 0.2, and 0.4% SO was 2.5, 6.9 and 13.9 mg, respectively, which was equal to 0.6, 1.7, and 3.4 mg/g lipid. In the case of 0.4% SO containing medium, CLA was distributed to medium (1.2%), mycelial surface (23.5%) and mycelial inside (75.3%).
These results indicate that 0.4% SO addition to the medium was suitable for the production of c9,t11 CLA by AB, resulting in 10.2 mg/L equivalent to 2.5 mg/g lipids, and also suggest that AB possesses linoleate isomerase with substantial activity.
Session 33G, Nutraceuticals & Functional Foods: Lipid and probiotic functional foods