Microbiomes for bio-based innovation and environmental applications Microbiomes is the term given to the collective genomes of mixed nature-based microorganism populations. In recent years, scientific-technological progress in genome sequencing and other -omics technologies and in the bioinformatic analysis and interpretation of the data has opened up the opportunity to better understand the composition of (often difficult to cultivate with existing approaches) microbial communities, the functions and interaction of their members, and their interaction with their environment (e.g. soil) or hosts (humans, animals, plants). The scope includes developing the methods for molecular cartography, the quantitative determination of genes and metabolites and establishing the R&D resources (e.g. inventories, catalogues, “reference microbiomes”, databases etc.). Marine microbiomes are excluded from the scope, in order to avoid overlaps with the parallel topic[[HORIZON-CL6-2022-CIRCBIO-01-07: Marine microbiome for a healthy ocean and a sustainable blue bioeconomy]].International cooperation is encouraged, as it can contribute to European competitiveness and resilience. Proposals should: Develop and apply a toolbox of technologies to identify, characterise and sustainably exploit (including isolation and cultivation aspects) the microbiomes and their genetic and metabolic diversity relevant for the bio-based sectors. Develop the related microbiome-based bioprocesses, e.g. to enable industrial manufacturing of high-value bio-based substances or materials (excluding biofuels/bioenergy applications), at sufficiently large scale, or for the environmental protection applications (e.g. decomposition of persistent and hazardous contaminants or industrial, municipal waste and residues). Identify and characterise the key environmental and safety aspects, and potential impacts, while adhering to the binding EU and international regulatory framework. Outline the scale-up production processes for novel bio-based innovations that are necessary to reach a critical mass for a given application, to achieve economies of scale, address different market segments and potential applications, etc. This includes addressing process and product safety, including occupational and consumer safety aspects, taking into account best international practice and initiatives.Ensure the transparent and inclusive engagement of all actors, including industry and SMEs, the scientific community, regulatory institutions, and broader civil society, including NGOs, to ensure the necessary impact and awareness. Where relevant, proposals should seek links with and capitalise on the results of past and ongoing research projects, including on food systems, health and industrial value chains, as related to microbiomes. For this topic, it is not mandatory to integrate the gender dimension (sex and gender analysis) into research and innovation.