biostudies-literatureDai ADNatural Science Foundation of Zhejiang ProvinceNational Key R&amp;D Program of China50https://www.ebi.ac.uk/biostudies/studies/S-EPMC8795250biostudies-literatureUnknown12(2)2-chloronicotinic acid (2-CA) is a key precursor for the synthesis of a series of pesticides and pharmaceuticals. Nitrilase-catalyzed bioprocess is a promising method for 2-CA production from 2-chloronicotinonitrile (2-CN). In this study, a mutant of nitrilase from <i>Rhodococcus zopfii</i> (<i>Rz</i>NIT/W167G) was constitutively overexpressed with <i>Escherichia coli</i> as host, which exhibited a onefold increase in enzymatic activity compared with inducible expression. Biosynthesis of 2-CA using whole cells harboring nitrilase as biocatalysts were investigated and 318.5 mM 2-CA was produced, which was the highest level for 2-CA production catalyzed by nitrilase to date. 2-CA was recovered from the reaction mixture through a simple acidification step with a recovery yield of 90%. This st3 BiotechConstitutive expression of nitrilase from <i>Rhodococcus zopfii</i> for efficient biosynthesis of 2-chloronicotinic acid.PMC8795250LR19B0600012017YFE0129400Zheng YGDai ADZheng RCWu ZMfalseConstitutive expression of nitrilase from <i>Rhodococcus zopfii</i> for efficient biosynthesis of 2-chloronicotinic acid.2-chloronicotinic acid (2-CA) is a key precursor for the synthesis of a series of pesticides and pharmaceuticals. Nitrilase-catalyzed bioprocess is a promising method for 2-CA production from 2-chloronicotinonitrile (2-CN). In this study, a mutant of nitrilase from <i>Rhodococcus zopfii</i> (<i>Rz</i>NIT/W167G) was constitutively overexpressed with <i>Escherichia coli</i> as host, which exhibited a onefold increase in enzymatic activity compared with inducible expression. Biosynthesis of 2-CA using whole cells harboring nitrilase as biocatalysts were investigated and 318.5 mM 2-CA was produced, which was the highest level for 2-CA production catalyzed by nitrilase to date. 2-CA was recovered from the reaction mixture through a simple acidification step with a recovery yield of 90%. This st2022-01-01T00:00:00Z2022 Feb2025-04-19T17:58:49.858Z2025-04-19T17:58:49.858ZS-EPMC87952503512730510.1007/s13205-022-03119-0