Ren T J, Frank J F, Christen G L
Department of Food Science and Technology, University of Georgia, Athens 30602.
J Dairy Sci. 1988 Jun;71(6):1432-8. doi: 10.3168/jds.S0022-0302(88)79705-2.
The objectives of this research were to isolate lipase from Pseudomonas fluorescens 27, to compare the purity of the partially purified lipase preparation with crude extract, and to determine if bands of lipase activity revealed by disc gel electrophoresis liberated different free fatty acids from milk fat. Lipases were isolated from a shaken skim milk culture of P. fluorescens 27 by using ion-exchange chromatography on DEAE cellulose (Whatman DE 32) and gel filtration on Sephadex G-150. The principal lipase-rich fractions from gel filtration represented 6.2% of total lipolytic activity. Disc gel electrophoresis of partially purified enzyme revealed two protein bands. These protein bands were cut from disc electrophoresis gels and used as an enzyme source for reaction with butter oil. Free fatty acids were isolated from the assay mixture, separated, and quantified by gas chromatography. Data from gas chromatographic analysis indicated that P. fluorescens 27 produces at least two different lipases.
本研究的目的是从荧光假单胞菌27中分离脂肪酶,比较部分纯化的脂肪酶制剂与粗提物的纯度,并确定圆盘凝胶电泳显示的脂肪酶活性条带是否能从乳脂中释放出不同的游离脂肪酸。通过在DEAE纤维素(Whatman DE 32)上进行离子交换色谱和在Sephadex G - 150上进行凝胶过滤,从荧光假单胞菌27的摇瓶脱脂乳培养物中分离脂肪酶。凝胶过滤得到的主要富含脂肪酶的组分占总脂肪分解活性的6.2%。部分纯化酶的圆盘凝胶电泳显示出两条蛋白带。将这些蛋白带从圆盘电泳凝胶上切下,用作与黄油反应的酶源。从测定混合物中分离出游离脂肪酸,进行分离并通过气相色谱法定量。气相色谱分析数据表明,荧光假单胞菌27至少产生两种不同的脂肪酶。