Abstract—α-Linolenic Acid (ALA, C18:3) that is an essential Polyunsaturated Fatty Acid (PUFA) plays a vital role in many metabolic processes. The oleaginous yeast Rhodosporidium toruloides has generally been used for triacylglycerol production, including PUFAs. In this work, α-linolenic acid, not its γ- isomer, is firstly identified to be synthesized by R. toruloides and the mutant M18 that was obtained through plasma mutagenesis in the previous studies. The effects of five different nitrogen sources and four C/N ratios on the biomass, total lipid and ALA production from R. toruloides and M18 were studied. It was found that the highest biomass and lipid production were achieved when tryptone used as nitrogen with C/N ratio 100:1. In fed-batch cultivation, M18 has the highest ALA accumulation of 5.33% of total lipid, compared to 3.67% in the wild type strain. M18 has a promising potential in ALA production and commercial application of microbial PUFAs.

 

Index Terms—α-Linolenic Acid (ALA), C/N ratio, nitrogen sources, R. toruloides

Cite: F. Qi, L. Sun, M. L. Zhang, X. Z. Jiang, X. Cao, and J. Z. Huang, "Alpha-Linolenic Acid Production by the Mutant Rhodosporidium toruloides," International Journal of Food Engineering, Vol. 2, No. 2, pp. 140-146, December 2016. doi: 10.18178/ijfe.2.2.140-146