PHOTOSYNTHETIC MICROORGANISMS IN BIOFILM ENRICHMENT CULTURES FROM GEOTHERMAL DOMUYO AND CAVIAHUE?COPAHUE SYSTEMS, NEUQUÉN, ARGENTINA

SEGRETIN A.; DONATI E.R.

Congreso; SAMIGE 2014; 2014

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 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 (Biofilm A: 40ºC, pH 8; Biofilm B: 50ºC, pH 7; Biofilm C: 43ºC, pH 7) placed in Copahue geothermal system, one from Domuyo spring (Biofilm D: 40ºC, pH 7) and other from Caviahue area (Biofilm E: 32ºC, pH 4) were chosen for microbial enrichment and identification. 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 seemed to be Scenedesmus obliquus. This microalga has been reported for biodiesel production and wastewater treatment processes. Leptolyngbya sp. cyanobacterium 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, belonging to 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