[Objective] The aim of this study was to identify a novel L-cysteine sulfinate decarboxylase from alkaline polluted soil metagenome and to use non-rational design method to improve the enzyme. [Methods] L-cysteine sulfinate decarboxylase gene undec1 A was cloned into p ETBlue-2 vector and expressed in Escherichia coli Tuner(DE3) p Lac?. The recombinant Undec1 A protein was purified to homogeneity. The original Undec1 A protein was characterized and a mutagenesis library was constructed with sequential error...