Catalyzes the sulfur transfer reaction from thiosulfate to cyanide, thus converting cyanide to the less toxic thiocyanate (PubMed:15522204). Contributes to P.aeruginosa survival under cyanogenic conditions, and thus provides the bacterium with a defense mechanism against endogenous cyanide toxicity (PubMed:17098912). Is the main cytoplasmic rhodanese in P.aeruginosa, accounting for 90% of total rhodanese activity (PubMed:17098912). hydrogen cyanide + thiosulfate = 2 H(+) + sulfite + thiocyanate Optimum temperature is 20-32 degrees Celsius. Is constitutively expressed during the entire growth cycle. Expression increases during exponential growth to attain a maximum level at the onset of the stationary phase, slightly decreasing thereafter. The growth of a rhdA-deletion mutant is impaired under cyanogenic conditions and fully restored upon complementation with rhdA. When P.aeruginosa cultures are treated with exogenous cyanide, only minor differences in viability between the rhdA-deletion mutant and the wild-type are observed. Microbial rhodaneses may contribute to cyanide detoxification in natural environments.