Interaction of mechanical stresses and productivity of biological agglomerates in stirred fermenters

机械应力与搅拌发酵罐中生物团聚体生产率的相互作用

• 批准号: 315464571
• 负责人: Professor Dr.-Ing. Matthias Kraume
• 金额: --
• 依托单位: Fachgebiet Verfahrenstechnik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/315464571?language=en
• 关键词: Interaction; mechanical; stresses; productivity; biological

This project aims at investigating the mechanical stress acting on filamentous microorganisms in stirred fermenters. In the first funding period, the necessary methods to characterise mechanical stress were established. Based on the obtained results and developed methods, the goals set for the 2nd FP focus on three main topics:1. From cultivation broth to model solution and backIn the 1st FP, based on cultivation broths of Aspergillus niger, model systems were developed and used to quantify the particle stress in stirred tanks. The model systems will be further used. In the 2nd FP, to approach better to real cultivation broth while still ensuring good reproducibility, fragmentation experiments will be performed based on diluted broths. This experimental procedure can ensure that a larger number of broths with similar characteristics is produced. Moreover, it allows a controlled design of the properties of the system since the rheology of the broth can be set at a desired level, while the morphology of the bio-agglomerates can be easier characterised in the diluted broth. In the frame of several working packages, cultivations will be performed at the department and in cooperation with other groups of the SPP to broad the data base with results from investigations with other microorganisms, allowing a generalization of the conclusions.2. Fluid dynamic characterization of stirred tanks in diverse configurationsIn the 1st FP, during fundamental investigations of conventional and new stirrer types further influencing factors of specific importance for lab and larger scale fermenters were identified. Small changes in the configuration of the stirred system (e.g., baffle position) can influence the fluid dynamics in the tank. Such effects will be investigated with the methods established in the 1st FP. Conventional stirrer types will be optimized and the development of the novel stirrer geometries will be expanded to new radial flow stirrer types. Multiple stirrer configurations will also be part of the study.3. Analysis of the stress history of single bio-agglomerates in the stirred tankBesides the macroscopic investigation of global properties in the system, the numerical work in the 1st FP showed that local phenomena, as well as the investigation of single particle tracks within the reactor gives a deep insight and significant potential to interpret the impact of particle stress. The characterization of the stress experienced by a particle along its track and its residence time in a region of specific shear rates will be further developed in the 2nd FP. In a joined work with other groups, the results will be compared to different biological systems and apparatuses and further investigated down to molecular level.As outcome of the investigations a base for the choice of stirred tank configurations and stirrer types will be built, to allow a better defined and controlled operation of biotechnological processes in comparison to the current ones.

本计画旨在研究搅拌发酵罐中丝状微生物所受之机械应力。在第一个供资期间，建立了消除机械应力的必要方法。根据所获得的结果和开发的方法，为第二次FP设定的目标集中在三个主要主题：1。 从培养液到模型溶液再回到模型溶液在第一次FP中，基于尼日尔曲霉培养液，开发了模型系统，并用于定量搅拌槽中的颗粒应力。这些模型系统将得到进一步的应用。在第2次FP中，为了更好地接近真实的培养肉汤，同时仍确保良好的重现性，将基于稀释的肉汤进行裂解实验。该实验程序可以确保生产大量具有相似特性的肉汤。此外，它允许系统性质的受控设计，因为肉汤的流变学可以设定在期望的水平，而生物附聚物的形态可以在稀释的肉汤中更容易表征。在几个工作包的框架内，将在该部门进行培养，并与SPP的其他小组合作，以扩大数据库，包括其他微生物的调查结果，从而使结论得到概括。 在第一次FP中，在传统和新型搅拌器类型的基础研究过程中，确定了实验室和大型发酵罐的特殊重要性的进一步影响因素。搅拌系统配置的小变化（例如，挡板位置）可以影响罐中的流体动力学。将使用第1次FP中确定的方法研究这些影响。传统的搅拌器类型将得到优化，新型搅拌器几何形状的开发将扩展到新的径向流搅拌器类型。多个搅拌器配置也将是研究的一部分。 搅拌槽中单个生物聚集体的应力历史分析除了对系统中的全局性质进行宏观研究之外，第一FP中的数值工作表明，局部现象以及对反应器内单个颗粒轨迹的研究为解释颗粒应力的影响提供了深刻的见解和重要的潜力。颗粒沿着其轨迹所经历的应力及其在特定剪切速率区域中的停留时间的表征将在第二FP中进一步发展。在与其他研究小组的合作中，研究结果将与不同的生物系统和设备进行比较，并进一步研究到分子水平。作为研究结果，将为搅拌罐配置和搅拌器类型的选择奠定基础，以便与当前的生物技术过程相比，更好地定义和控制生物技术过程的操作。