关键词: 生物转化, 性质, 分离, 脂肪酶, 莱茵海默氏菌

Abstract: An effective lipase-producing bacterium was isolated from soil samples of farmland in Lanzhou China, using Tween 80 agar plates. It was identified to belong to Rheinheimera sp. based on morphological and biochemical tests and 16S rDNA sequence analysis and was designated as Rheinheimera sp. NT-1. The cultivating conduction for the lipase production of Rheinheimera sp. NT-1 was studied in this paper. The optimum temperature, pH, salinity, liquid volume and incubation time for lipase production was 20℃, pH 8.0, 8.1%(m/v), 30 mL and 24 h, respectively. A Box-Behnken experimental design was used to optimize the lipase production. The optimization process parameters were pH 8.8 and salinity of 0.78% (m/v) at 32℃ through factorial design and RSM analysis. The highest lipase production was 780±4.5 U/mL. The optimum temperature of the lipase was 60℃. The lipase showed relatively high specific activity at the range of 20~70℃ and pH 7~10. It might be a thermo stable and alkaline lipase. The enzyme could catalyze the synthesis of fatty acid ethyl esters such as ethyl oleate, ethyl palmitate and ethyl linoleate, which had potential applications in the biotransformation.