Levaduras Oleaginosas

Appl Microbiol Biotechnol (2011) 90:1219–1227
DOI 10.1007/s00253-011-3200-z

MINI-REVIEW

Oily yeasts as oleaginous cell factories
Jose Manuel Ageitos & Juan Andres Vallejo &
Patricia Veiga-Crespo & Tomas G. Villa

Received: 22 December 2010 / Revised: 8 February 2011 / Accepted: 9 February 2011 / Published online: 5 April 2011
# Springer-Verlag 2011

Abstract Oily yeasts have beendescribed to be able to
accumulate lipids up to 20% of their cellular dry weight.
These yeasts represent a minor proportion of the total yeast
population, and only 5% of them have been reported as able to
accumulate more than 25% of lipids. The oily yeast genera
include Yarrowia, Candida, Rhodotorula, Rhodosporidium,
Cryptococcus, Trichosporon, and Lipomyces. More specifically, examples ofoleaginous yeasts include the species:
Lipomyces starkeyi, Rhodosporidium toruloides, Rhodotorula glutinis, and Yarrowia lipolytica. Yeast do exhibit
advantages for lipid production over other microbial sources,
namely, their duplication times are usually lower than 1 h,
are much less affected than plants by season or climate
conditions, and their cultures are more easily scaled up than
thoseof microalgae. Additionally, some oily yeasts have
been reported to accumulate oil up to 80% of their dry
weight and can indeed generate different lipids from
different carbon sources or from lipids present in the culture
media. Thus, they can vary their lipid composition by
replacing the fatty acids present in their triglycerides. Due to
the diversity of microorganisms and growth conditions,oily
yeasts can be useful for the production of triglycerides,
surfactants, or polyunsaturated fatty acids.
Keywords Oleaginous . Yeast . Cryptococcus .
Rhodotorula . Rodosporidum . Candida . Lipids .
Triglycerides

Jose Manuel Ageitos and Juan Andres Vallejo are equal contributors.
J. M. Ageitos : J. A. Vallejo : P. Veiga-Crespo : T. G. Villa (*)
Department of Microbiology andParasitology, Faculty of
Pharmacy, University of Santiago de Compostela,
Campus Sur,
15782 Santiago de Compostela, Spain
e-mail: tomas.gonzalez@usc.es

Introduction
The ability of certain microorganisms to accumulate high
amounts of lipids has been known for years, but only in the
last decades, real efforts have been made to unravel the
underlying biochemical pathways (Beopoulos et al. 2009).Some oily yeasts (OY) described are able to accumulate
lipids to levels greater than 20% of their cellular dry
weight. The typical OY genera so far indentified include
Yarrowia, Candida, Rhodotorula, Rhodosporidium, Cryptococcus, Trichosporon, and Lipomyces. Also, the possibility
of lipid production on an industrial basis, using OY, has been
previously considered (Angerbauer et al. 2008; Jacob1992b;
Li et al. 2008; Ratledge 2004; Turcotte and Kosaric 1989).
Basically, lipids are accumulated in OY as discrete fat
globular deposits and can also be associated (less than 5%)
with different cell organelles. Microbial lipid compounds,
known as single cell oils (SCO), have industrial interest
due to their particular and precise biochemical and
physicochemical properties. Additionally,OY accumulate
lipids as triglycerides rich in polyunsaturated fatty acids
(Papanikolaou et al. 2001). These microorganisms can
accumulate oil up to 80% of their dry weight, and the
technology for growing OY with high oil content is well
developed (Picataggio and Smittle 1979; Boulton and
Ratledge 1984; Pan et al. 2009).
Yeasts can generate lipids from different carbon sources,
even fromlipids present in the culture media. They can, in
fact, vary their lipid composition by replacing the fatty
acids in the triglycerides with those present in the culture
medium (Iassonova et al. 2008).
The economic feasibility of the fermentation process to
produce microbial lipids is determined by the cost of the
raw materials plus the fermentation processes themselves.
The cost of the raw...