Taxonomic and functional characterization of the microbiota from anaerobic reactors used for vinasse and biogas production

Abstract

From the perspective of environmental control and sustainability, new proposals for biotechnological solutions for wastewater treatment aiming to produce bioenergy have been brought forward. In this scenario, anaerobic technology should be mentioned, since provides not only a reduction in the pollutant load, but also, bioenergy generation. Vinasse, byproduct of the sugar and alcohol production process based on sugar cane, presents high organic and nutritional content and, therefore, high potential for anaerobic treatment. However, gaps such as the configuration, operation and stability of anaerobic reactors, as well as the limited knowledge of the microbiota involved in the process need to be overcome in order to allow the application of anaerobic technology using high-rate, compact and efficient reactors, that reach the maximum potential of organic matter removal and biogas production. Operational strategies are being investigated in pilot-scale anaerobic reactor by researchers in a company called Bioproj carrying out the PIPE-FAPESP project. The project present here aims to characterize the archaeal and bacterial microbiota of this bioreactor, as well as contribute to the knowledge of anaerobic processes and application of technology. The influence of the organic load rate on the structure and distribution of microbiota in the granules and biofilms will be monitored by by scanning electron microscopy. The change in composition and activity of the microbial community will be evaluated by the Illumina MiSeq sequencing technique, in parallel, from the genomic DNA and the transcriptome of cDNA libraries. Two operational conditions that result in better and poor biogas production will be analysed more in deep both taxonomically and functionally through shotgun sequencing. Functional genes of methanogenesis will be monitored by qPCR. Considering these strategies, the key factors for optimizing the anaerobic process of biogas production can be clarified. (AU)