This PhD aims to assess the diversity and prevalence of specialty carbohydrate enzymes in nature, and to build a specialty sugar enzyme portfolio ready to be implemented in microbial production systems. These specialty sugars have potential in human and animal welfare, yet they are largely unavailable. They are currently often discovered in plants and are little investigated regarding their microbial natural sources. Therefore, in this project, a metagenomics approach using advanced bioinformatics tools and a high-throughput screen based on functionality is followed to uncover microbial specialty sugar enzymes. Once discovered, they will be implemented in microbial production systems to create microbial cell factories.