Details of Transport Rates in Stirred Fermenters

该项目规定购买大型（200升） 发酵罐，以补充较小的发酵罐已经在 亚利桑那大学，以及支持初步探索 研究氧气运输。 发酵罐允许研究规模 在各种条件下对发酵罐操作的影响。 在 特别是，正在进行研究，以研究空间分布 在发酵罐中进行混合和运输， 发酵罐设计 多项研究表明， 氧气和营养基质的减少会降低细胞的生长速率， 所需产物，特别是蛋白质的产率。 为了实现 最佳的混合率，不破裂细胞，这是必要的 了解输送率（ka）、混合和剪切在 该容器在各种叶轮旋转速率下以及对于各种叶轮 的设计. 这将通过测量溶解的 氧气和氧气含量的气泡在相同的位置， 获得每个的空间分布。 液体和气体流量分布的详细测定将 然后用于计算各种操作下的局部ka分布， 条件和设计。 由于这项研究，规模扩大将 变得更加准确，因为ka值的分布以及它们如何 不同的规模将提供。

This project provides for the purchase of a large (200 liter) fermenter to complement smaller fermenters already available at the University of Arizona, as well as support for an initial exploratory study of oxygen transport. The fermenter allows studies of scale effects in fermenter operation under various conditions. In particular, research is underway to study the spatial distribution of mixing and transport in fermenters leading to a sound foundation for fermenter design. Several studies have shown that poor distribution of oxygen and nutrient substrates can reduce cell growth rate and yield of desired product, particularly proteins. In order to achieve optimum mixing rates which do not rupture the cells, it is necessary to know how transport rates (ka), mixing and shear are distributed in the vessel at various impeller rotation rates and for various impeller designs. This will be achieved by measuring local values of dissolved oxygen and oxygen content of gas bubbles at the same locations to obtain a spatial distribution of each. Detailed determinations of flow distributions of liquid and gas will then be used to compute local ka distributions under various operating conditions and designs. As a result of this research, scale-up will become more accurate, since distributions of ka values and how they vary with scale will be available.