In this study, a simple sugaring-out supported by liquid biphasic flotation technique combined with ultrasonication was introduced for the extraction of proteins from microalgae. Sugaring-out as a phase separation method is novel and has been used in the extraction of metal ions, biomolecules and drugs. But, its functioning in protein separation from microalgae is still unknown. In this work, the feasibility of sugaring-out coupled with ultrasound for the extraction of protein was investigated. Primary studies were carried out to examine the effect of sonication on the microalgae cell as well as the separation efficiency of the integrated method. Effect of various operating parameters such as the concentration of microalgae biomass, the location of sonication probe, sonication time, ultrasonic pulse mode (includes varying ON and OFF duration of sonication), concentration of glucose, types of sugar, concentration of acetonitrile and the flow rate in the flotation system for achieving a higher separation efficiency and yield of protein were assessed. Besides, a large-scale study of the integration method was conducted to verify the consistency of the followed technique. A maximum efficiency (86.38%) and yield (93.33%) were attained at the following optimised conditions: 0.6% biomass concentration, 200 g/L of glucose concentration, 100% acetonitrile concentration with 5 min of 5s ON/10s OFF pulse mode and at a flow rate of 100 cc/min. The results obtained for large scale were 85.25% and 92.24% for efficiency and yield respectively. The proposed liquid biphasic flotation assisted with ultrasound for protein separation employing sugaring-out demonstrates a high production and separation efficiency and is a cost-effective solution. More importantly, this method provides the possibility of extending its application for the extraction of other important biomolecules.

在这项研究中，介绍了一种通过液体双相浮选技术结合超声处理的简单糖化工艺，用于从微藻中提取蛋白质。加糖作为一种相分离方法是新颖的，已用于金属离子，生物分子和药物的提取。但是，其在从微藻类分离蛋白质中的功能仍是未知的。在这项工作中，研究了加糖结合超声提取蛋白质的可行性。进行了初步研究，以研究超声处理对微藻细胞的影响以及集成方法的分离效率。各种操作参数的影响，例如微藻生物质的浓度，超声处理探头的位置，超声处理时间，为了达到更高的分离效率和蛋白质产量，评估了超声脉冲模式（包括改变超声的打开和关闭持续时间），葡萄糖的浓度，糖的类型，乙腈的浓度以及浮选系统中的流速。此外，对集成方法进行了大规模研究，以验证所遵循技术的一致性。在以下优化条件下获得了最高效率（86.38％）和产率（93.33％）：生物量浓度为0.6％，葡萄糖浓度为200 g / L，乙腈浓度为100％，并且5s ON / s为5s OFF脉冲模式下5min。流速为100 cc / min。大规模获得的效率和产率分别为85.25％和92.24％。拟议的液体双相浮选，辅以超声，通过糖析分离蛋白质，证明了高生产和分离效率，是一种经济高效的解决方案。更重要的是，该方法提供了扩展其在提取其他重要生物分子中的应用的可能性。