Lipase production from a novel thermo-tolerant and extreme acidophile Bacillus pumilus using palm oil as the substrate and treatment of palm oil-containing wastewater

• Published in: Environmental science and pollution research international 2014-03, Vol.21 (5), p.3907-3919
• Main Authors: Saranya, P., Sukanya Kumari, H., Prasad Rao, B., Sekaran, G.
• Format: Article
• Language: English
• Subjects: Acidic soils; Amino acids; Amino Acids - analysis; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacillus - genetics; Bacillus - isolation & purification; Bacillus - metabolism; Bacillus pumilus; Bacterial Proteins; Base Sequence; Benzene; DNA, Bacterial - genetics; DNA, Ribosomal - genetics; Earth and Environmental Science; Ecotoxicology; Efficiency; Environment; Environmental Chemistry; Environmental Health; Environmental studies; Enzyme kinetics; Fermentation; Fourier transforms; Hydrogen-Ion Concentration; Hydrolysis; Industrial research; Infrared spectroscopy; Kinetics; Lipase; Lipase - chemistry; Lipase - metabolism; Lipids; Microorganisms; Molecular Sequence Data; Molecular weight; Oils & fats; Palm Oil; Phylogenetics; Plant Oils - metabolism; Protein folding; Protein purification; Research Article; Ribosomal DNA; Soil contamination; Soil microorganisms; Statistical analysis; Temperature; Variance analysis; Vegetable oils; Viscosity; Waste Disposal, Fluid - methods; Waste materials; Waste Water; Waste Water Technology; Water Management; Water Pollutants, Chemical - metabolism; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-013-2354-x

The thermo-tolerant and extreme acidophilic microorganism Bacillus pumilus was isolated from the soil collected from a commercial edible-oil extraction industry. Optimisation of conditions for the lipase production was conducted using response surface methodology. The optimum conditions for obtaining the maximum activity (1,100 U/mL) of extremely acidic thermostable lipase were fermentation time, 96 h; pH, 1; temperature, 50 °C; and concentration of palm oil, 50 g/L. After purification, a 7.1-fold purity of lipase with specific activity of 5,173 U/mg protein was obtained. The molecular weight of the thermo-tolerant acidophilic lipase (TAL) was 55 kDa. The predominant amino acid in the TAL was glycine. The functional groups of lipase were determined by Fourier transform infrared spectroscopy. TAL exhibited enhanced activity (114 %) with dimethyl sulphoxide (20 %, v / v ), and it showed a moderate activity with methanol, hexane and benzene. The optimum conditions for the treatment of palm oil in wastewater using the TAL were found to be time, 3 h; pH, 1; temperature, 50 °C with pseudo second-order kinetic constant of 1.88 × 10 −3  L mol −1  min −1 . The Michaelis–Menten enzyme kinetic model and the nonlinear kinetic model were evaluated for the TAL. TAL established hydrolysis efficiency of 96 % for palm oil in wastewater at 50 °C.