Production and characterization of crude proteases from Halobacillus salinus strain DZ28 newly isolated from salt lake sediments in Algeria and their use as detergent bioadditives

Abstract

New Algerian Gram-positive, rod-shaped, endospore-forming, salt-philic bacteria (DZ28 strain) that overproduce extracellular alkaline proteases have been isolated from salt lake deposits in Lake Oubeira, El Taref. Strain DZ28 was assigned as Halobacillus salinus DZ28 on the basis of phenotypic properties and 16S rDNA gene sequencing (ripotyping). The maximum protease activity registered after 36 hours of incubation in optimized medium at 30 ° C was 19,000 U / ml in a shaking bottle culture at 160 rpm. The crude extract protease showed optimal activity at 60 ° C temperature and pH 12. It is actively inhibited by PMSF and DIFP, indicating that it belongs to the serine protease family. Interestingly, the crude extract protease was not only very stable to nonionic surfactants and oxidants, but also showed high stability and compatibility with some commercial detergents. It retaining more than 100% of its initial activity after pre-incubation for 1 h at 40°C with ISIS, followed by Pril (98%), Tide (95%) and Dixan (90%). More curiously, the wash overall performance evaluation discovered that it may dispose of blood-stains remove at 40°C for 1 h with low supplementation (500 U/mL). This is the first report of a protease from Halobacillus salinus and has potential as a promising candidate for future applications as a bioadditive for detergent formulations.