NOVELTY - A Bacillus clausii I-52 strain (S1) capable of producing a protease, and deposited under Accession No. KCTC 10277BP, is new.    USE - Protease (I) or culture supernatant (IV) is useful as a detergent composition for a laundry detergent, a dish-washing detergent or a contact lens detergent, and for treating fibers or fabrics, and leather processing. (S1), (I), transformants (IIIa), (IIIb) or (IV) is useful for treating food or feed, decomposing organic wastes, and treating paper or pulp, and as a food or feed additive. (S1), (IIIa) or (IIIb) is useful for mass-production of (I). (All claimed). (S1), (IIIa), (IIIb), (IV) and/or (I) is useful for enhancing the freeness of pulp e.g. pulp made from secondary fiber, and in deinking processes. (I) or (IV) is useful for brewing (e.g. fermenting) beer. (I) is useful for cell isolation from tissue for cellular therapies, as antimicrobial agents, for therapeutically cleaving and destroying specific proteins such as toxin proteins e.g. Clostridium botulinum and ricin, and essential viral or cancer cell proteins, as disinfectants, for lipoma removal, wound debraidment and scar prevention and debriding chronic dermal ulcers and severely burned areas, and in sterile enzymatic debriding compositions, in dressings such as alginate dressings and antimicrobial barrier dressings. (I) is useful as protein restriction enzymes, and in proteomics. (I) or (IV) is useful for peptide synthesis, in hair removal, for waste management, in photography industry e.g. for silver recovery from the used X-ray film, in medical industry e.g. for dissolving blood clots by dissolving fibrin. (I) or (IV) is used as flavor enhancers in e.g. cheese and pet food, for increasing starch yield from corn wet milling, in biodefense (e.g. destruction of spores or bacteria), for decontamination of affected environment, in biofilm degradation, in biomass conversion to ethanol, and/or in personal care and cosmetic industry, for enhancing enantioselectivity.    ADVANTAGE - The microorganism is able to produce a protease retaining its activity under severe physical and chemical conditions.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a protease (I) separated from (S1);    (2) a gene (II) encoding (I);    (3) an expression vector (V1) containing (II);    (4) a transformant (IIIa) transfected with (V1);    (5) an expression vector (V2) containing (II), for the insertion into Bacillus genome;    (6) a transformant (IIIb) transfected with (V2);    (7) a culture supernatant (IV) obtained from the culture of (S1), (IIIa) or (IIIb); (8) purification of (I), involves recovering a culture supernatant by centrifugation after culturing the strain (S1), (IIIa) or (IIIb), eluting active fractions after absorbing a protease by adding a synthetic absorbent, eluting active fractions by loading the eluent onto chromatography, and isolating a 28 kDa protein having a protease activity;    (9) a detergent composition containing (I) or (IV);    (10) treating food or feed, involves treating food or feed with (S1), (I), (IIIa), (IIIb) or (IV);    (11) a food or feed additive, comprising (S1), (I), (IIIa), (IIIb) or (IV);    (12) treating fibers or fabrics, involves treating fibers of fabrics with (I) or (IV); (13) a composition for fibers or fabrics processing, comprising (I) or (IV);    (14) leather processing, involves treating leather with (I) or (IV);    (15) a composition for leather processing, comprising (I) or (IV);    (16) decomposing organic wastes, comprises treating organic wastes with (S1), (I), (IIIa), (IIIb) or (IV); (17) composition for organic waste decomposition, comprising (S1), (I), (IIIa), (IIIb) or (IV);    (18) treating paper or pulp, involves treating paper or pulp with (S1), (I), (IIIa), (IIIb) or (IV);    (19) a composition for paper or pulp processing, comprising (S1), (I), (IIIa), (IIIb) or (IV); and    (20) mass-producing the protease, involves culturing (S1), (IIIa) or (IIIb) in a medium with pH 7.0-12.0 containing one or more organic nitrogen sources (0.1-5%) chosen from casein, powdered skim milk, whey, soybean meal and peptone, one or more inorganic nitrogen sources (0.1-5%) chosen from ammonium sulfate and ammonium phosphate, and one or more carbon sources (0.1-5%) chosen from liquid maltose, maltose, honey potato starch, corn starch, wheat flour, sodium pyruvate, sodium citrate, sodium acetate, and sodium succinate, at 25-45degreesC with 150-1000 rpm for 20-96 hours under the air flow condition of 0.1-5 vvm.