title: Dependence of fungal characteristics on seed morphology and shear stress in bioreactors.
abstract: The fungal morphology during submerged cultivations has a profound influence on the overall performance of bioreactors. In this research, glucoamylase production by Aspergillus niger has been taken as a model to improve more insights. The morphology engineering could be conducted effectively by changing the seed morphology, as well as specific power input. During the fed-batch cultivations, pellet formation under milder shear stress field helped to reduce the broth viscosity, thus relieving oxygen limitation and promoting the enzyme production. Furthermore, we found that the relation between the shear stress field, which was characterized by energy dissipation rate/circulation function (EDCF), and enzyme activity was consistent with quadratic parabola, which threw light on the process optimization and scale-up for industrial enzyme production.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, P.O. Box 329#, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
authors.forename: Hongzhong
authors.initials: H
authors.lastname: Lu
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Wenjun
authors.initials: W
authors.lastname: Tang
authors.forename: Zejian
authors.initials: Z
authors.lastname: Wang
authors.forename: Jianye
authors.initials: J
authors.lastname: Xia
authors.forename: Siliang
authors.initials: S
authors.lastname: Zhang
authors.forename: Yingping
authors.initials: Y
authors.lastname: Zhuang
authors.forename: Ju
authors.initials: J
authors.lastname: Chu
authors.forename: Henk
authors.initials: H
authors.lastname: Noorman
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology*; D018533:Biomass; D019149:Bioreactors; D004798:Enzymes / Q000737:chemistry; D005285:Fermentation; D005087:Glucan 1,4-alpha-Glucosidase / Q000096:biosynthesis; D007218:Industrial Microbiology; D007700:Kinetics; D010100:Oxygen / Q000737:chemistry; D015202:Protein Engineering; D012212:Rheology; D033081:Shear Strength; D013314:Stress, Mechanical; D014783:Viscosity
chemical_list: D004798:Enzymes; D005087:Glucan 1,4-alpha-Glucosidase; D010100:Oxygen