文献类型：期刊文献

英文题名：Improvement of glucoamylase production using axial impellers with low power consumption and homogeneous mass transfer

作者：Tang, Wenjun[1];Pan, Ao[1];Lu, Hongzhong[1];Xia, Jianye[1];Zhuang, Yingping[1];Zhang, Siliang[1];Chu, Ju[1];Noorman, Henk[2]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]DSM Biotechnol Ctr, NL-2600 MA Delft, Netherlands

年份：2015

卷号：99

起止页码：167

外文期刊名：BIOCHEMICAL ENGINEERING JOURNAL

收录：;EI(收录号：20151500730339);WOS:【SCI-EXPANDED(收录号:WOS:000355349900020)】；

基金：This work was financially supported by Royal DSM (Delft, the Netherlands) and partially supported by NWO-MoST Joint Program (2013DFG32630). Experimental strain (A. niger CBS513.88) was kindly donated by Royal DSM (Delft, the Netherlands). We especially would like to thank Reinhard Karge, Qing Yuan Yin Noel van Peij, Sybe Hartmans and Rogier Meulenberg for their kind concern on this project, and Sef Heijnen (TU Delft) for helpful comments to the manuscript.

语种：英文

外文关键词：Glucoamylase; Impeller type; Aspergillus niger; Morphology analysis; CFD

摘要：Significantly influenced by complex cell morphology, glucoamylase fermentation using Aspergillus niger is characterized by high apparent viscosity and shear-thinning rheology. In this study, the influence of liquid flow field patterns on morphology, broth rheology, mass transfer and glucoamylase production was investigated by applying two different configurations with radial (Ruston Turbine, RT) and axial (Wide-blade hydrofoil upward-pumping, WHu) flow impellers. It was found that empirical correlations for averaged quantities, such as the mass transfer coefficient and viscosity, cannot reasonably explain the observations. Therefore, numerical simulation was carried out to study the detailed characteristics of local field in lab-scale bioreactors. The results showed, under similar glucose and oxygen uptake rates, that the WHu configuration formed relatively homogeneous viscosity and mass transfer fields, while the RT configuration was accompanied with significant heterogeneities. Under these conditions, the fraction of active mycelia in pellets could be highly correlated with enzyme production, and a novel parameter (Active Part Percentage, APP) was defined to introduce the effects of flow field on pelletized morphology. The WHu impellers facilitated the formation of pellets and hairy structures, with a higher APP of the pellets. As a result, the culture with the axial flow impeller configuration exhibited a larger glucoamylase production rate (+25%) and product yield on sugar (+23%) and yield on energy (+60%) in comparison to the radial flow impeller. Computational fluid models were proposed to in-depth understand such results based on local mass transfer and viscosity values, since the average values are similar over the entire fermentation processes. (C) 2015 Elsevier B.V. All rights reserved.