title: Thermostable, alkaline and detergent-tolerant lipase from a newly isolated thermophilic Bacillus stearothermophilus.
abstract: Lipases are the enzymes of choice for laundry detergent industries, owing to their triglyceride removing ability from the soiled fabric, which eventually reduces the usage of phosphate-based chemical cleansers in the detergent formulation. In this study, a novel thermo-alkaline lipase-producing strain identified as Bacillus stearothermophilus was isolated from the soil samples of olive oil mill. Enhanced lipase production was observed at 55 degrees C, pH 11 and after 48 h of incubation. Among the substrates tested, xylose (a carbon source), peptone (a nitrogen source) and olive oil at a concentration of 1% were suitable substrates for enhancing lipase production. MgSO4 and Tween-80 were suitable substrates for maximizing lipase production. The enzyme was purified to homogeneity by a single CM-Sephadex column chromatography and revealed molecular mass of 67 kDa. The enzyme (BL1) was active over a wide range of pH from 9.0 to 13.0, with an optimum at pH 11.0, exhibited maximal activity at 55 degreesC and retained more than 70% of its activity after incubation at 70 degrees C or pH 13 for 0.5 h or 24 h, respectively. The enzyme hydrolyzed both short and long-chain triacylglycerols at comparable rates. BL1 was studied in a preliminary evaluation for use in detergent formulation solutions. This novel lipase showed extreme stability towards non-ionic and anionic surfactants after pre-incubation for 1 h at 40 degrees C, and good stability towards oxidizing agents. Additionally, the enzyme showed excellent stability and compatibility with various commercial detergents, suggesting its potential as an additive in detergent formulations.
authors.forename: Abir
authors.initials: A
authors.lastname: Ben Bacha
authors.forename: Nadine M S
authors.initials: NM
authors.lastname: Moubayed
authors.forename: Islam
authors.initials: I
authors.lastname: Abid
mesh_terms: D000468:Alkalies / Q000378:metabolism*; D003902:Detergents / Q000378:metabolism*; D004795:Enzyme Stability; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D008049:Lipase / Q000378:metabolism*
chemical_list: D000468:Alkalies; D003902:Detergents; D008049:Lipase