Abstract A leucine dehydrogenase from Exiguobacterium sibiricum (EsLeuDH) was discovered by genome mining approach. The EsLeuDH was overexpressed in Escherichia coli BL21, purified to homogeneity and characterized. This enzyme showed good thermostability with a half-life of 3.1 h at 60 C. Furthermore, EsLeuDH has a broad spectrum of substrate specificity, showing activities toward many aliphatic α-keto acids and L-amino ...