Abstract

Three yeast strains were isolated from decaying wood of Chilean Valdivian forest and identified asMeyerozyma guilliermondii,Scheffersomyces coipomensis, andSugiyamaella paludigena. These strains were able to efficiently grow on the major monomers contained inPinusspp. andEucalyptusspp. wood that includes glucose (Glc), xylose (Xyl), and mannose (Man), showing at 28 degrees C higher uptake rates forMan, and in some cases forGlc, than forXyl, used as single carbon sources. Nevertheless, in cultures performed on sugar mixtures, the strains displayed a notable preference forGlc. Additionally, in sugar mixtures, the absence of regulatory mechanisms in sugar assimilation (e.g., catabolic repression) was observed and documented when the activities of several enzymes involved in sugar assimilation (i.e., phosphoglucose isomerase, phosphomannose isomerase, and xylulokinase) were determined. The activity of the key enzymes involved in the onset of lipid accumulation (i.e., NAD(+)-ICDH) and in fatty acid (FA) biosynthesis (i.e.,ATP:CL) indicated a significant accumulation of storage lipids (i.e., up to 24%, w/w) containing oleic and palmitic acids as the major components. The present paper is the first report on the potential ofM. guilliermondii,S. coipomensis, andS. paludigenaas oleaginous yeasts. We conclude that the new isolates, being able to simultaneously assimilate the major lignocellulosic sugars and efficiently convert them into oily biomass, present a biotechnological potential which deserve further investigation.