In the course of a project devoted to the stereoselective synthesis of non-proteinogenic alpha-amino acids using alpha-transaminases (alpha-TA), we report the design and optimization of generic high-throughput continuous assays for the screening of alpha-TA libraries. These assays are based on the use of l- or d-cysteine sulfinic acid (CSA) as irreversible amino donor and subsequent sulfite titration by colorimetry. The assays' quality was assessed under screening conditions. Hit selection thresholds were accurately determined for every couple of substrates and a library of 232 putative transaminases expressed in Escherichia coli host cells was screened. The reported high throughput screening assays proved very sensitive allowing the detection with high confidence of activities as low as 10 mu U (i.e., 0.01 nmol substrate converted per min). The assays were also evidenced to be stereochemically discriminant since l-CSA and d-CSA allowed the exclusive detection of l-TA and d-TA, respectively. These generic assays thus allow testing the stereoselective conversion of a wide range of alpha-keto acids into alpha-amino acids of interest. As a proof of principle, the use of 2-oxo-4-phenylbutyric acid as acceptor substrate led to the identification of 54 new alpha-TA offering an access to valuable l- or d-homophenylalanine.