A Novel Low-Temperature Alkaline Lipase from Acinetobacter johnsonii LP28 Suitable for Detergent Formulation

A Novel Low-Temperature Alkaline Lipase from Acinetobacter johnsonii LP28 Suitable for Detergent Formulation

Hai Kuan Wang, Jing Shao, Yu Jie Wei, Jie Zhang and Wei Qi*

Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, PR China

Article history:
Received June 15, 2009
Accepted April 28, 2010

Key words:
Acinetobacter johnsonii, alkaline lipase, low-temperature lipase, detergent formulation

Summary:
A strain LP28 that produces alkaline and low-temperature lipase was isolated from the soil collected from the Bay of Bohai, PR China and identified as Acinetobacter johnsonii using 16S rDNA sequencing. The lipase was purified to homogeneity by centrifugation, followed by ammonium sulphate precipitation, dialysis, ion exchange chromatography on cellulose DE-52 and gel filtration chromatography on Sephadex G-75. The enzyme was purified about 34-fold with a final yield of 13 % and the relative molecular mass of the enzyme was determined to be 53 kDa by SDS-PAGE. The purified enzyme exhibited maximum activity at 30 °C and pH=9.0, and retained 94.53 % of its maximum activity at 20 °C. The enzyme was stable at 50 °C and retained 80.9 % of its original activity for 30 min. It was also highly stable in a pH range of 8.0–11.0. The enzyme hydrolyzed a wide range of oils and showed a high level of lipase activity in hydrolyzing tributyrin. The enzyme activity was promoted in the presence of Na⁺, Ca²⁺, K⁺, Mg²⁺ and sodium citrate. Ba²⁺, Mn²⁺, Cr³⁺ and Co²⁺ did not affect the enzyme activity, whereas the presence of Al³⁺, Cu²⁺, Fe²⁺, Fe³⁺, Zn²⁺ and EDTA reduced the enzyme activity. Regarding the stability of detergent process, the enzyme was highly stable in the presence of various oxidizing agents, some commercial detergents and alkaline protease, and its activity was also promoted by most of the surfactants, viz. Tween 20, Tween 80, sodium cholate, sodium taurocholate and saponin. For these characteristics, the lipase from Acinetobacter johnsonii LP28 showed good potential as an additive in laundry detergent formulation.

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