Chiral amines are prevalent in natural products, which often display potent biological activity. Such chiral amine motifs are also frequently found in pharmaceutical drug compounds and chemical building blocks meaning that the development of environmentally benign and sustainable routes to produce these important motifs is extremely desirable. Nature synthesizes these complex and valuable molecules through the action of highly specialized enzymes. These natural catalysts enable an extremely efficient biosynthesis from simple starting materials, installing functional groups with exceptional levels of selectivity. Chemical catalysts are frequently designed to mimic the action of enzymes and are often capable of achieving impressive selectivity. However, unlike enzymes, processes involving these catalysts usually involve high temperatures, sub-optimal pH, organic solvent and complex purification methods. Enzymes called omega-transaminases (TAs) catalyze the conversion of commercially available or easily accessible starting materials to high-value amines. These biocatalysts require an additional donor molecule to provide the amine functional group. This donor is ultimately converted to a by-product and the desired amine product is formed. However, the reaction is freely reversible and unless this by-product is removed from the reaction, low yields of the desired amine will be isolated, as the enzyme will more readily catalyse the reverse reaction to regenerate starting materials. A number of elegant approaches have been reported which remove this ketone by-product and allow access to appreciable quantities of the chiral amine. These strategies include the addition of expensive enzymes or the use of extremely large quantities of the amine donor in combination with the technically challenging removal of ketone by-products. One such approach, which relies on an extensively modified TA, is currently used for the industrial synthesis of the antidiabetic drug compound, sitagliptin. However, the approach is far from efficient and the development of this heavily modified TA biocatalyst was enormously challenging, highlighting an immediate need for more sustainable strategies for performing these biotransformations and for developing suitable enzyme catalysts. This research will build upon recent work reported in our laboratory that describes arguably the most efficient approach to date for performing biotransformations involving TAs. The success of the approach is due to spontaneous precipitation of the by-product, which cannot regenerate starting materials. This polymer is also highly colored and has allowed the development of an effective high-throughput screening strategy that enables the rapid identification of active enzymes. Our focus now is to optimize the process further and make it more suitable for industrial application. Specifically, low cost amine donor molecules will be used that are spontaneously removed from the reaction in a similar way to our previously reported method. We will also apply a simple high-throughput screening strategy to assist in the genetic engineering of natural enzymes in order to increase the scope of the reactions that they can catalyze and make them suitable for industrial scale synthesis. The enzymes developed in this study will enable cost-effective, sustainable and environmentally neutral methods for the small/medium and industrial scale production of one of the most important compound classes.