Da degradação da quitina aos produtos naturais: alavancando o microbioma do mar para uma bioeconomia azul circular

Chitin and chitin-degrading enzymes find biotechnological applications in the medical, food and agriculture sectors and chitinous seafood waste can be used as a carbon source in microbial fermentations [19]. Shellfish waste constitutes a growing environmental concern and the development of environmentally friendly, inexpensive processes, which turn chitin into biotechnologically versatile chito-oligosaccharides (COS) and chitosan hold promise in tackling this problem [20]. This project aims to assess the diversity and taxonomic origin of marine chitinases across cultured and uncultured bacterial and archaeal lineages in the global ocean by exploring large public genomic and metagenomic datasets. Indeed, we still know little about the phylogenetic and functional diversity of marine chitinases. To fill this knowledge gap, this project employs a Big Data analysis strategy in close collaboration with the Microbial Systems Data Science Lab led by Dr Ulisses Nunes da Rocha at the Helmholtz Centre for Environmental Research (UFZ) in Leipzig, Germany. With the advent of next-generation sequencing technologies and global initiatives such as the TaraOceans Expeditions and OceanSamplingDay (OSD), the number of marine metagenomes and genomes is rising steadily. Several databases and catalogues were created to capitalize on this vast amount of data for meta-analyses. These include the MarineMetagenomeDB [1], a database of marine metagenomes with curated metadata, created by the UFZ collaborators with help from the PI of this proposal, The OceanDNA MAG catalog, comprising over 50,000 prokaryotic genomes from various marine environments [2] and the Genomic Catalog of Earth’s microbiomes (GEM) containing over 52,000 MAGs from diverse microbiomes to capture Earth’s microbial metabolic potential [3]. High-performance computational resources and bioinformatics pipelines such as Melange [4], developed by the Portuguese team together with the UFZ team, allow the simultaneous annotation of thousands of genomes and MAGs, and will be employed here to assess the provenance, biogeography, and phylogenetic diversity of marine microbial chitinases at a global scale. Simultaneously, this project aims to zoom into one culturable, chitin-degrading bacterial taxon that is a key player in the oceans’ carbon and nitrogen cycling. It aims to discover, express, and characterise novel chitinases from the marine bacterial genus Aquimarina with potential to outperform or widen the supply spectrum of current commercial enzymes, thus fostering the development of blue biotechnology for chitin waste to promote a circular bioeconomy. Moreover, this project aims to provide a deep understanding of the co-regulation of chitin degradation and secondary metabolite biosynthesis in the emerging opportunistic pathogen Aquimarina, which is of relevance to seafood farming. This will sharpen our view on the ecological role and regulatory mechanisms of secondary metabolism in Aquimarina and marine pathogen-host interactions at large. Finally, this project aims to determine whether growth on chitin-rich seafood waste enhances production of bioactive compounds in this genus. It thus bears promise for finding strategies to stimulate the production - not only of novel chitinases - but also novel natural products with biocidal and/or antimicrobial activities.