Abstract
Microbial metabolism has been deeply studied over decades and it is considered to be understood to a great extent. Annotated genome sequences of many microbial species have contributed a lot to generating biochemical knowledge on metabolism. However, researchers still discover novel pathways, unforeseen reactions or unexpected metabolites which contradict to the expected canon of biochemical reactions in living organisms. Here, we highlight a few examples of such non-canonical pathways, how they were found, and what their importance in microbial biotechnology may be. The predictive power of metabolic modelling, well-founded on biochemical knowledge and genomic information is discussed in the light of both discovery of yet unknown existing metabolic routes and the prediction of others, new to Nature.