Study of mitochondrial gamma carbonic anhydrases in the diatom Halamphora coffeaeformis str. Bahía Blanca Estuary

CAINZOS MAXIMILIANO; CORDOBA J.; POPOVICH CECILIA; LEONARDI, PATRICIA; PAGNUSSAT G.; ZABALETTA EDUARDO

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

SAIB

Diatoms areresponsible for 20?25% of totalterrestrial primary production and approximately 40% of annual marine biomassproduction, which make the most dominant group of organisms sequestering carbonfrom the atmosphere. It has been proposed that the high photosyntheticefficiency of diatoms is mainly based on the close relationship between theirmitochondria and chloroplasts. In previous studies in our laboratory, we haveshown that the mitochondrial gamma carbonic anhydrases (CA's) forming the CAdomain of the mitochondrial complex I are important components involved in complexI assembly, in development and in the basal carbon concentrating mechanism inplants. Now we are studying the role of the gammaCA's in diatoms. In allsequenced genomes of diatoms, we found at least three gammaCAs predicted to bein mitochondria as in plants. We cloned partial sequences of gammaCA's andother genes from a highly oil productive strain (Bahía Blanca Estuary, 38° 45'S, 62| 22' W) of H. coffeaeformis. This strain has around 80% nucleotideidentity with a north-american H. coffeaeformis strain (SRX691230) forwhich a RNA-seq experiment has been performed. We then proposed that both are bothdifferent strains of H. coffeaeformis.We found that the enriched CO2 atmosphere has a direct positiveimpact in the growth of H.coffeaeformis. In this context, we arestudying, by silencing strategies, the role of the mitochondrial gammaCA's inthe growth and development of south American H. coffeaeformis strain.