Pseudomonas aeruginosa β-carbonic anhydrase, psCA1, is required for calcium deposition and contributes to virulence.

•This is the first evidence that a β-class carbonic anhydrase (CA), psCA1, plays a major role in the formation of calcium deposits in a human pathogen Pseudomonas aeruginosa.•The expression of psCA1 is increased in the presence of elevated calcium levels. The deletion of psCA1 impaired virulence of the pathogen.•In-silico modeling of three PAO1 β-class CAs identified four amino acids that differ in psCA1 compared to psCA2, and psCA3, and these differences may play a role in catalytic rate and thus calcium deposition.•Among a series of inhibitors tested against the recombinant psCA1, aminobenzene sulfonamide (ABS) and acetazolamide (AAZ) inhibited the enzyme at nano-molar levels. Their addition significantly reduced calcium deposition.•Overall, this is the first report that inhibiting the CA activity in P. aeruginosa significantly reduces its ability to deposit calcium, which may be used to control virulence of the pathogen.