Manuel Porcar.

Scientists of the European research project Micro4Biogas, coordinated by the University of Valencia professor Manuel Porcar, have discovered and characterized a new taxonomic order of bacteria specialized in the decomposition of organic matter and that could be key to improving biogas production. The group, which they have called Darwinibacteriales, is one of the most abundant in biogas production reactors, but had never been characterized in depth. Dutch and Spanish. The latter belong to the Institute of Integrative Systems Biology of the University of Valencia and the company Darwin Bioprospecting Excellence, the two institutions located in the Science Park of the University of València. They took 80 samples of decomposing organic matter from 45 large-scale biogas production plants (in Germany, the Netherlands and Austria) and sequenced their DNA to study their microbial composition. Surprisingly, members of Darwinibacteriales were present in all 80 samples, despite the differences and distance between these plants. in their study of the main microbial actors in the process known as anaerobic digestion, by which organic matter is degraded and then transformed into a gas with high energy value that is useful as fuel. This process is considered a 'black box', since the metabolic pathways carried out by most of the microorganisms involved are unknown. Biogas production would constitute a paradigm shift in the energy industry, since it would reduce dependence on fossil fuels and imported energy. But the lack of microbiological research has slowed down the sector. Manuel Porcar,scientific coordinator of the Micro4Biogas project and co-author of the articles. "Our work shows the tip of a microbial iceberg that is most likely key to biogas production, but that has never been characterized at the genomic level." style="tab-stops:167.4pt">Thanks to this discovery, the next step for the Micro4Biogas team will be to create optimized and highly efficient communities of biogas-producing microorganisms. Its objective is to ensure that biogas plants have more robust procedures and these facilities are less dependent on subsidies to operate competitively, which would boost renewable energy around the world. microorganisms ignored

To understand the composition and diversity of the microbial communities present in all the collected samples, a taxonomic analysis was performed, sequencing a specific gene (the 16S rRNA gene) in the entire sample. The results were compared to reference databases to determine which species or taxa were present and their relative abundance. like a group of bacteria not grown in the laboratory, but no one had paid much attention to it. "[This group] was generally detected when analyzing microbiomes through 16s rRNA gene sequencing," explains Adriel Latorre, director of the Genomics Department at Darwin Bioprospecting and lead author of the study. style="tab-stops:167.4pt">To further investigate this unknown group, 30 samples in which MBA03 abundance had been confirmed were completely sequenced. "But, surprisingly, when we analyzed the complete metagenomes of the 30 samples, we did not detect MBA03 in any of them. This revealed a technical limitation: the genome of this taxon was not available in the databases. From that moment on, our objective was clear: we had to isolate the MBA03 genome and describe it in depth," says Latorre.

Using the Micro4Biogas data set, phylogenetic and phylogenomic reconstructions corroborated that MBA03 constitutes a new order, that is, the taxonomic group above family, genus and species. The new order has been named Darwinibacteriales. Scientists suspect that one particular family within this new order, the Darwinibacteriaceae, works in mutualistic collaboration with archaea, another type of microorganisms involved in anaerobic digestion. Bacteria produce metabolic compounds that archaea use to generate methane gas. If this relationship is confirmed, these bacteria will be the main target to develop strategies to increase and improve biogas production. Micro4Biogas

Micro4Biogas is an EU funded project (H2020, grant agreement number 101000470) working on consortia development customized microbials to increase biogas production.

Bringing together 15 institutions from 6 countries (including universities, companies and the local government of a Spanish city where a state-of-the-art biogas plant will be built), the project aims to increase the performance, speed, quality and reproducibility of biogas production, consolidating this renewable energy as a viable option from an environmental, political and economic point of view.

Scientific publications

Link list:

• Project website