INVESTIGADORES
GRAMAJO Hugo Cesar
artículos
Título:
Overexpression of a phosphatidic acid phosphatase type 2 leads to an increase in triacylglycerol production in oleaginous Rhodococcus strains
Autor/es:
COMBA, S; ARABOLAZA, A. AND GRAMAJO, H.; HERNÁNDEZ MA, ALVAREZ HM
Revista:
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2015
ISSN:
0175-7598
Resumen:
Abstract Oleaginous Rhodococcus strains are able to accumulate
large amounts of triacylglycerol (TAG). Phosphatidic
acid phosphatase (PAP) enzyme catalyzes the dephosphorylation
of phosphatidic acid (PA) to yield diacylglycerol (DAG),
a key precursor for TAG biosynthesis. Studies to establish its
role in lipid metabolism have been mainly focused in eukaryotes
but not in bacteria. In this work, we identified and
characterized a putative PAP type 2 (PAP2) encoded by the
ro00075 gene in Rhodococcus jostii RHA1. Heterologous
expression of ro00075 in Escherichia coli resulted in a fourfold
increase in PAP activity and twofold inDAG content. The
conditional deletion of ro00075 in RHA1 led to a decrease in
the content of DAG and TAG, whereas its overexpression in
both RHA1 and Rhodococcus opacus PD630 promoted an
increase up to 10 to 15 % by cellular dry weight in TAG
content. On the other hand, expression of ro00075 in the nonoleaginous
strain Rhodococcus fascians F7 promoted an increase
in total fatty acid content up to 7 % at the expense of
free fatty acid (FFA), DAG, and TAG fractions. Moreover, coexpression
of ro00075/atf2 genes resulted in a fourfold increase
in total fatty acid content by a further increase of the
FFA and TAG fractions. The results of this study suggest that
ro00075 encodes for a PAP2 enzyme actively involved in
TAG biosynthesis. Overexpression of this gene, as single
one or with an atf gene, provides an alternative approach to
increase the biosynthesis and accumulation of bacterial oils as
a potential source of raw material for biofuel production.