IDENTIFICACIÓN DE MICROORGANISMOS FOTOSINTÉTICOS EN ENRIQUECIMIENTOS DE CINCO BIOFILMS PROVENIENTES DE LAS ZONAS GEOTERMALES DE DOMUYO Y CAVIAHUE ? COPAHUE, NEUQUÉN, ARGENTINA

SEGRETIN, ANA BELEN; DONATI, EDGARDO R.

Mar del Plata

Congreso; X Congreso de Microbiología General; 2014

Sociedad Argentina de Microbiología General

Photosynthetic microorganisms have gained a lot of attention in recent years because of their potential applications in biotechnology. They have been identified as a rich source of biologically active compounds and they have been considered as a very promising source of alternative energy. In addition to these applications, these microorganisms are also used in aquaculture, wastewater treatment, food, fertilizers and production of secondary metabolites including exopolysaccharides, vitamins, toxins, enzymes and pharmaceuticals. Microalgae and cyanobacteria play a major role in the nitrogen, carbon, and oxygen dynamics of a wide variety of aquatic environments. In particular, geothermal systems have shown to be a source of a variety of microorganisms with a great biotechnological potential. In this work the geothermal areas of Domuyo and Caviahue-Copahue have been selected for the research of photosynthetic microorganisms that could present distinctive properties useful for different biotechnological processes such as bioremediation and biofuel production. Three microbial mats in Las Máquinas spring placed in Copahue geothermal system, one from Domuyo spring and other from Caviahue area were chosen for microbial enrichment and identification. Temperature and pH values were measured in situ: (Biofilm A) 40ºC and pH 8; (Biofilm B) 50ºC and pH 7; (Biofilm C) 43ºC and pH 7; (Biofilm D) 40ºC an pH 7; (Biofilm E) 32ºC and pH 4. Enrichment cultures under autotrophic conditions were done from the five biofilms. Medium BG 11 at pH 7 was selected for this purpose and the cultures were grown under fluorescent lightning at 30ºC. The photosynthetic microorganism diversity of the samples was analyzed by cloning a 16S rRNA gene region using cyanobacterial specific probes (CYA359F ? CYA781Ra/CYA781Rb). The sequences obtained were compared with those in NCBI database using BLAST. Several photosynthetic microorganisms were identified including cyanobacteria and microalgae. Even though PCR dependent techniques are not quantitative, in Biofilm A the most abundant species seems to be Scenedesmus obliquus. This microalgae has been reported to be suitable for biodiesel production and wastewater treatment processes. Leptolyngbya sp. cyanobacteria was also identified in this sample. Enrichment cultures from Biofilm B and D had unique phototrophic species, Synechococcus elongatus and Synechocystis sp. respectively. These cyanobacteria, which belong to the Chroococcales order, are oxygenic phototrophs being the main source of primary production in oligotrophic aquatic environments and are able to grow at a wide range of light intensities. As regards biotechnological applications, both species have been used in the production of biofuel and different bioactive compounds. In enrichment corresponding to Biofilm C Scenedesmus obliquus and Synechococcus elongatus were found. Additionally, Chlorella sp. was identified in the culture but in a lower proportion. Finally in Biofilm E culture, three different sequences corresponding to uncultured species were found together with the already mentioned Synechococcus elongatus. Most photosynthetic microorganisms found are very versatile and have great biotechnological potential yet to be studied.