Genomics initiatives have uncovered the critical importance of microbial enzymes to expand-ing the range of products that can be made from plant biomass (i.e., lignocellulose). So far, most applications of such enzymes focus on the deconstruction of lignocellulose to mono-saccharides and monolignols for subsequent fermentation to fuels and target chemicals. While necessary for capturing the full potential of renewable plant biomass, this approach inevitably foregoes the benefit of upgrading the energy and carbon already fixed in structures. In this presentation, I will describe our efforts to discover and develop enzymes and enzyme systems that introduce new chemical and physical functionality to underused lignocellulose fractions, leading to lignocellulosic building blocks primed for use in value-added applications, including use as crosslinkers and plant-based polyamines. In particular, this presentation will describe our characterization and application of carbohydrate oxidoreductases oxidases [1-3], carbohydrate-active transaminases [4], and microbial expansin-related proteins [5].