Experimental and numerical investigations on the effects of cavitation and flow-related collisions on aggregate formation and loss of activity after cell disruption in the high-pressure homogeniser using the model systems lipase or beta-lactoglobulin as e

通过生物技术从植物源获得的酶或分离蛋白通常是通过破坏细胞获得的。高压均质机用于此目的。在高压均质中，介质的极端加速会产生应力，这是导致细胞高崩解率的原因。其副作用通常是空化，产生气/液（气泡）和/或固体/液体（磨损颗粒）界面。这项研究计划集中于酶活性的丧失和蛋白质的变性和聚集，根据文献，边界和/或剪切诱导的三维结构的展开随后在流动中聚集是负责的。本项目的基本工作假设是，如果能在很大程度上避免高压均质机破坏单元的空化，有效降低出流室的碰撞频率，就能减少酶或蛋白质活性的结构损失。实现这一目标的方法是应用背压并将稀释的混合流直接送入最窄横截面后面的流出室，这样可以在局部实现高混合效率。在该提案中，将进行这种新型同步均质和混合（SHM）单元的数值流动模拟，并将开发预测空化和碰撞率作为几何和工艺参数的函数的评估方法，并通过伴随的实验进行验证。与SPP中的其他子项目伙伴合作，预测应力历史和预期的聚集率。这导致设计策略，以保存在高压均质器中细胞破坏获得的酶和蛋白质的功能。

Biotechnologically obtained enzymes or protein isolates from plant sources are often obtained by cell disruption. High pressure homogenisers are used for this purpose. In high-pressure homogenization, an extreme acceleration of the medium generates stresses, which are responsible for high cell disintegration rates. A side effect is often cavitation, which creates gas/liquid (bubbles) and/or solid/liquid (abrasion particles) interfaces. This research proposal concentrates on the loss of enzyme activity and the denaturation and aggregation of proteins, for which according to literature a boundary and/or shear-induced unfolding of the three-dimensional structure followed by aggregation in the flow is held responsible. The basic working hypothesis of this project is the assumption that structural losses of enzyme or protein activity can be reduced if cavitation in disruption units of high-pressure homogenisers is largely avoided and the collision frequency in the out-flow chamber is efficiently reduced. Methods for this are the application of back pressure and feeding of a diluting mixed stream directly into the outflow chamber behind the narrowest cross-section, so that high mixing efficiencies can be achieved locally. In the proposal, numerical flow simulations of such novel simultaneous homogenizing and mixing (SHM) units will be performed and evaluation methods for predicting cavitation and collision rates as a function of geometry and process parameters will be developed and verified by accompanying experiments. In cooperation with other subproject partners in the SPP, stress histories and expected aggregation rates are predicted. This leads to design strategies for the preservation of functionality of enzymes and proteins obtained by cell disruption in a high-pressure homogeniser.