Department of Chemical Engineering, Toronto Metropolitan University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada.
Bioprocess Biosyst Eng. 2024 May;47(5):633-649. doi: 10.1007/s00449-024-02990-w. Epub 2024 Apr 1.
Fluid hydrodynamic stress has a deterministic effect on the morphology of filamentous fungi. Although the coaxial mixer has been recognized as a suitable gas dispersion system for minimizing inhomogeneities within a bioreactor, its performance for achieving enhanced oxygen transfer while operating at a reduced shear environment has not been investigated yet, specifically upon scale-up. Therefore, the influence of the impeller type, aeration rate, and central impeller retrofitting on the efficacy of an abiotic coaxial system containing a shear-thinning fluid was examined. The aim was to assess the hydrodynamic parameters, including stress, mass transfer, bubble size, and gas hold-up, upon conducting a scale-up study. The investigation was conducted through dynamic gassing-in, tomography, and computational fluid dynamics combined with population balance methods. It was observed that the coaxial bioreactor performance was strongly influenced by the agitator type. In addition, coaxial bioreactors are scalable in terms of shear environment and oxygen transfer rate.
流体力对丝状真菌的形态有确定性影响。虽然同轴混合器已被认为是一种合适的气体分散系统，可以最大限度地减少生物反应器内的不均匀性，但它在降低剪切环境下实现增强氧气传递的性能尚未得到研究，特别是在放大规模时。因此，考察了搅拌器类型、通气率和中央搅拌器改造对含有剪切稀化流体的非生物同轴系统效果的影响。目的是评估在进行放大研究时的流体动力学参数，包括应力、传质、气泡尺寸和气体持液量。这项研究通过动态通气、断层扫描和计算流体动力学与颗粒平衡方法相结合进行。结果表明，同轴生物反应器的性能受搅拌器类型的强烈影响。此外，同轴生物反应器在剪切环境和氧气传递速率方面具有可扩展性。
