Brown A K, Kaul A, Varley J
Biotechnology and Biochemical Engineering Group, Food Science and Technology Department, The University of Reading, Whiteknights, PO Box 226, Reading, RG6 6AP, United Kingdom.
Biotechnol Bioeng. 1999 Feb 5;62(3):278-90. doi: 10.1002/(sici)1097-0290(19990205)62:3<278::aid-bit4>3.0.co;2-d.
Foam separation is known to have potential for separation of biological molecules with a range of surface activities. A statistical study (factorial design) was carried out to establish the optimum operating conditions for the continuous foam separation of beta-casein. Maximum values of enrichment of beta-casein into the foam phase were found for low levels of initial feed protein concentration, gas flow rate, feed-flow rate, and high foam heights. Maximum values of protein recovery, were generally found at high levels of initial feed protein concentration, gas-flow rate, feed-flow rate, and low foam heights. The highest values obtained for enrichment and separation ratio were 54.7 and 181.3, respectively, with a simultaneous protein recovery of 62%; thus, illustrating the potential effectiveness of this technique. The effect of foaming on protein conformation is also important, and in this study protein structure was analyzed before and after foam separation experiments. Techniques used were: native polyacrylamide gel electrophoresis (PAGE), UV absorbance spectroscopy, circular dichroism, and fluorescence. Native PAGE showed no detectable changes in protein structure. However, absorbance scanning, fluorimetry, and circular dichroism revealed some conformational changes over a range of concentration effects.
众所周知，泡沫分离对于分离具有一系列表面活性的生物分子具有潜力。开展了一项统计研究（析因设计），以确定β-酪蛋白连续泡沫分离的最佳操作条件。在低初始进料蛋白质浓度、气体流速、进料流速和高泡沫高度的情况下，发现β-酪蛋白在泡沫相中的富集值最大。蛋白质回收率的最大值通常在高初始进料蛋白质浓度、气体流速、进料流速和低泡沫高度时出现。富集和分离比的最高值分别为54.7和181.3，同时蛋白质回收率为62%；因此，说明了该技术的潜在有效性。发泡对蛋白质构象的影响也很重要，在本研究中，在泡沫分离实验前后对蛋白质结构进行了分析。使用的技术有：天然聚丙烯酰胺凝胶电泳（PAGE）、紫外吸收光谱、圆二色性和荧光。天然PAGE显示蛋白质结构没有可检测到的变化。然而，吸光度扫描、荧光测定法和圆二色性显示在一系列浓度效应范围内存在一些构象变化。
