Screening, purification and characterization of the thermoalkalophilic lipase produced by Bacillus thermoleovorans CCR11

• Published in: Enzyme and microbial technology 2005-11, Vol.37 (6), p.648-654
• Main Authors: Castro-Ochoa, Lelie D., Rodríguez-Gómez, Citlali, Valerio-Alfaro, Gerardo, Oliart Ros, Rosamaría
• Format: Article
• Language: English
• Subjects: Bacillus thermoleovorans; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; Enzyme characterization; Fundamental and applied biological sciences. Psychology; Lipase; Miscellaneous; Mission oriented research; Thermophile
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2005.06.003

Among eleven aerobic thermophilic Bacillus strains, isolated from “El Carrizal” hot springs in Veracruz, Mexico, Bacillus thermoleovorans CCR11 (EMBL # AJ536599) was selected for lipase characterization because of its high lipase specific activity. Lipase was purified by diafiltration (polyethersulfone ultrafiltration membrane co500,000), and preparative isoelectrofocusing. The lipase had a relative molecular mass of 11 kDa (the lowest M r reported), although it formed higher molecular weight aggregates in native form. The optimum catalytic conditions for Bacillus thermoleovorans CCR11 lipase were 60 °C and pH 9–10. Hg 2+, PMSF, SDS, Tween 80 and Tween 20 had an inhibitory effect on lipase activity, whereas Ca 2+ salts and Triton X-100 increased it. Lipase activity was compatible with the presence of organic solvents, except for butanol. Lipase showed a notable preference for C6–C10 p-nitrophenyl esters, with the highest activity toward p-nitrophenyl caproate (C10). Lipase stability in the presence of organic solvents, as well as in acidic and alkaline pHs and at high temperatures makes it a good candidate for its application in non-aqueous biocatalysis.