INVESTIGADORES
ALVAREZ Hector Manuel
congresos y reuniones científicas
Título:
Study of two dgat genes involved in triacylglycerols biosynthesis in Rhodococcus opacus PD630
Autor/es:
HERNANDEZ MA; ARABOLAZA A,; GRAMAJO H,; RODRIGUEZ E; ALVAREZ, HÉCTOR M
Lugar:
PUERTO MADRYN
Reunión:
Congreso; XLVI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2010
Institución organizadora:
SAIB
Resumen:
R. opacus PD630 is an oleaginous bacterium able to accumulate significant amounts of triacylglycerols (TAG) (up to 60% of CDW) after growth on different carbon sources. The last step of TAG biosynthesis is catalyzed by diacylglycerol acyltransferases enzymes (DGAT). Strain PD630 possesses 10 atf genes encoding for DGAT isoenzymes. We studied two DGAT genes (atf1 and atf2), which exhibited higher acyltransferase activity when expressed in E.coli, by means of gene disruption and over-expression procedures. The disruption of both genes caused a decrease of cellular TAG content in comparison with the wild type (WT) strain. Whereas the WT accumulated 41.03% (CDW) of TAG after cultivation in MSM0.1 medium with gluconate during 24 h at 28ºC, atf1 and atf2 mutants produced 26.70% and 28.65% of TAG, respectively. The fatty acid profiles of the mutants obtained after preparative TLC of TAG fraction was similar to that of the WT strain. On the other hand, over-expression of the genes cloned under a strong acetamide promotor of pJAM2 vector in the strain PD630 caused an increase of TAG content in comparison with the WT after cultivation on glucose as sole carbon source. The results indicate that atf1 and atf2genes are involved in TAG biosynthesis in strain PD630 and their overproduction increase TAG contents in cells.