Biocatalysis is considered a green and environmentally friendly technology. Therefore, novel enzymes and enzymatic systems, together with cascades and protein engineering approaches, are in high demand. Here, three very different biocatalytic approaches have been studied. First, the richness of enzymes in the Red Sea brine pools has been assessed, and the discovery and characterization of a novel halophilic γ-carbonic anhydrase is described, together with the protein engineering approach, which boosted the initial catalytic activity of the γ- carbonic anhydrase. The understanding of polyextremophilicity principles from enzymes from the Red Sea brine pool, contributes to the bioengineering effort of turning mesophilic enzymes into more stable variants. Next, focus is given to the use of amine-transaminases in cascades for chiral amine synthesis. This resulted in the development of a self-sufficient sustainable cascade for chiral and non-chiral amine synthesis. This cascade was achieved by combining a lysine decarboxylase with an amine-transaminase to generate a cheap amino donor source for a more sustainable reaction economy. Finally, gas vesicle nanoparticles are functionalized by various engineering principles to create floating platforms for the immobilization of enzymes. The proof-of-concept was achieved by anchoring a phytase via anchoring peptides on the gas vesicle nanoparticles surface. These bioengineering approaches contributed to the effort of generating first principles for protein engineering.