Identification of superior lipid producing Lipomyces and Myxozyma yeasts

Abstract

Oleaginous yeasts are of interest for production of single cell oils from sugars. Eighteen members of the Lipomyces and Myxozyma clade were screened for lipid production when cultured on 10%w/v glucose. The highest ranking yeasts included L. tetrasporus (21 g/L), L. spencer-martinsiae (19.6 g/L), and L. lipofer (16.7 g/L). By contrast, Rhodosporidium toruloides, which was included as a positive control, produced 16.7 g/L. The L. tetrasporus and L. lipofer were further characterized for growth and lipid production on sugars present in biomass hydrolysates. These included L-arabinose, xylose, and an equal glucose and xylose mixture. L. tetrasporus had lipid titers of 16.3–20.8 g/L and L. lipofer 12.5–17.0 g/L. When both strains were grown on an equal mixture of glucose and xylose, xylose was consumed immediately following glucose. Lipid contents for the yeasts consisted primarily of C18:1 and C16:0, which makes them a promising source of lipids for fuel applications.