Of importance to the pharmaceutical, chemical, and industrial sectors, are the laccase-catalysed reactions providing means for the synthesis of dimeric phenolics showing biological activity, including antioxidant activity. This book investigates the production of value-added compounds, with biological activity, via laccase-catalysed oxidation reactions. A screening protocol, using criteria specifically suited to bioprocess development, was developed to investigate variables affecting the production of laccase by actinomycete native strains. The successful application of a Micromonospora strain in an airlift bioreactor specifically for the synthesis of laccase was demonstrated. This work reports on the isolation and structure determination of novel biocatalysis reaction products, showing that the dimeric derivatives of laccase-catalysed reactions with phenolic compounds have enhanced antioxidant capabilities. The biocatalysis products also showed antimicrobial activity against Mycobacterium aurum, a strain that displays a similar antibiotic susceptibility profile to Mycobacterium tuberculosis, the causative agent of the prevalent disease tuberculosis.