IAL   21557
INSTITUTO DE AGROBIOTECNOLOGIA DEL LITORAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Metabolic adaptation to growing conditions of Chlorella spp.: a look centered in the metabolism of glyceraldehyde-3-phosphate
Autor/es:
PIATTONI, CLAUDIA VANESA; CORREGIDO, MARÍA CECILIA; IGLESIAS, ALBERTO ÁLVARO
Lugar:
PARANA
Reunión:
Congreso; 54 th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2018
Resumen:
Chlorella is a unicellular green alga with a great potential for application in biodiesel production, nutritional food for animals (including humans) and cosmetics treatment. One special characteristic of Chlorella is its ability to growth autotrophically through photosynthesis and also heterotrophically using organic carbon sources. When the organism switches from autotrophism to heterotrophism, the chloroplast is reduced and lipid bodies accumulating oil increase. Changes in the culture conditions are directly linked to cellular metabolic changes; however how carbon partition and metabolic pathways are modified is not completely understood. With focus on glyceraldehyde-3-phosphate (Ga3P), a key glycolytic precursor being partitioned inside the cell, we studied in this work the cytosolic (NAD+ dependent) Ga3P dehydrogenase (Ga3PDHase; EC 1.2.1.12) that catalyzes the reversible oxidation of Ga3P to 1,3 bisphosphoglycerate. The dynamics of carbon partition and Ga3PDHase activity was analyzed in different Chlorella species (Chlorella sp., C protothecoides and C. saccharophila) growing under variable trophic conditions. In these cells, oil and starch contents varied and Ga3PDHase protein and activity changed. Also, we heterologously expressed two genes coding for Ga3PDHase in Chlorella variabilis and characterized the kinetic properties of the purified recombinant enzymes. Results suggest that metabolism involving Ga3PDHase is of great plasticity in Chlorella and Ga3P oxidation is highly increased under heterotrophic growing conditions that promote high oil accumulation.