The exponential increase in microbial genome and metagenome sequencing throughput has widened the gap between sequence and functional understanding. A clear picture of metabolic processes across the spectrum of bacterial species is essential to enable the exploitation of microbial genomics for the purposes of environmental biotechnology. The Microme project endeavors to extend the scope of microbial genome annotation from functional assignment at the gene level to the systematic generation of pathway assemblies and genome-scale metabolic models. A few key ideas and design principles will enable the Microme reconstruction pipeline to achieve this ambitious goal.A clear definition of a metabolic pathway as a collection of reaction sets, each of which convert the same defined inputs into the same outputs, will allow species-specific pathway variants to be identified, assembled into networks, compared across species, and used for downstream computations. A unique pathways projection, curation and assembly cycle, feeding directly into the flow of newly sequenced genomes, will allow a qualitative increase in the speed and reliability of the pathway generation process. Pathways and models produced the pipeline will be accessible to the scientific community as an integrated resource via the Microme portal. Finally, taking advantage of the availability of pathway assemblies from a large sample of genomes, methods for comparative and phylogenetic analyses and novel metabolic engineering strategies for environmental biotechnology goals will be developed, applied to proof-of-concept studies, and integrated to the resource as an analytical tool layer. Microme will be supported by a robust bioinformatics infrastructure, developed by integrating a set of established European databases and tools, integrated with reference protein annotation, metabolites and reactions databases, and interfaced with the annotation pipelines of the two main European sequencing centers.