tAn alkaline proteinase (STAP) was produced from strain TN650 isolated from a Tunisian off-shore oil fieldand assigned as Streptomyces koyangensis strain TN650 based on physiological and biochemical propertiesand 16S rRNA gene sequencing. Matrix assisted laser desorption ionization-time of flight mass spec-trometry (MALDI-TOF/MS) analysis revealed that the purified enzyme was a monomer with a molecularmass of 45125.17-Da. The enzyme had an NH2-terminal sequence of TQSNPPSWGLDRIDQTTAFTKACSIKY,thus sharing high homology with those of Streptomyces proteases. The results showed that this proteasewas completely inhibited by phenylmethanesulfonyl fluoride (PMSF), diiodopropyl fluorophosphates(DFP), and partially inhibited by 5,5-dithio-bis-(2-nitro benzoic acid) (DTNB), which strongly suggestedits belonging to the serine thiol protease family. Using casein as a substrate, the optimum pH and tem-perature values for protease activity were pH 10 and 70◦C, respectively. The protease was stable at pH7–10 and 30–60◦C for 24 h. STAP exhibited high catalytic efficiency, significant detergent stability, andelevated organic solvent resistance compared to the SG-XIV proteases from S. griseus and KERAB fromStreptomyces sp. AB1. The stap gene encoding STAP was isolated, and its DNA sequence was determined.These properties make STAP a potential candidate for future application in detergent formulations andnon-aqueous peptide biocatalysis.