title: Purification and partial characterization of a detergent and oxidizing agent stable alkaline protease from a newly isolated Bacillus subtilis VSG-4 of tropical soil.
abstract: An extracellular detergent tolerant protease producing strain VSG-4 was isolated from tropical soil sample and identified as Bacillus subtilis based on morphological, biochemical characteristics as well as 16S-rRNA gene sequencing. The VSG-4 protease was purified to homogeneity using ammonium sulphate precipitation, dialysis and sephadex G-200 gel permeation chromatography with a 17.4 purification fold. The purified enzyme was active and stable over a broad range of pH (8.0-11.0, optimum at 9.0) and temperature (40°C to 60°C, optimum at 50°C). The thermostability of the enzyme was significantly increased by the addition CaCl(2). This enzyme was strongly inhibited by PMSF and DFP, suggesting that it belongs to the serine protease superfamily. The purified VSG-4 alkaline protease showed remarkable stability in anionic (5 mM SDS) and ionic (1% Trion X-100 and 1% Tween 80) detergents. It retained 97±2% and 83.6±1.1% of its initial activity after 1 h preincubation in the presence of 1 % H(2)O(2) and 1 % sodium perborate, respectively. Furthermore, the purified enzyme showed excellent stability and compatibility with some commercial laundry detergents besides its stain removal capacity. Considering these promising properties, VSG-4 protease may find tremendous application in laundry detergent formulations.
authors: Department of Biotechnology, Periyar Maniammai University, Thanjavur, 613403, Tamilnadu, India. sibsankar_2008@rediffmail.com
authors: Sib Sankar
authors: SS
authors: Giri
authors: V
authors: V
authors: Sukumaran
authors: Shib Sankar
authors: SS
authors: Sen
authors: M
authors: M
authors: Oviya
authors: B Nazeema
authors: BN
authors: Banu
authors: Prasant Kumar
authors: PK
authors: Jena
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D003902:Detergents / Q000494:pharmacology*; D010450:Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D016877:Oxidants / Q000494:pharmacology*; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013696:Temperature; D014329:Tropical Climate
chemical_list: D001426:Bacterial Proteins; D003902:Detergents; D016877:Oxidants; D010450:Endopeptidases; C087822:alkaline protease