Using a flexible shaft agitator to enhance the rheology of a complex fungal fermentation culture
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The rheology behavior of biological fluids particularly when the viscosity is high and rheology is complex, is an important issue to understand, particularly for studies in mass-transfer and for solving technical problems with mixing in stirred bioreactors. In this paper, the use of a Swingstir® impeller during the fermentation of Aspergillus oryzae resulted in decreases from the parameters of a power-law model, in viscosity and in the thixotropic behavior of a cultivation broth. The results showed that both the K L a and the alpha amylase activity were improved when using the Swingstir® in comparison with Fullzone® impeller (FZ) at the same level of energy consumption. Increasing the pellet porosity during mixing via the Swingstir® resulted in increases in oxygen mass transfer and the average shear stress.
KeywordsFermentation Rheology Swingstir® Fullzone Aspergillus oryzae
This work was supported by Special Coordination Funds for Promoting Science and Technology, the Creation of Innovation Centers for Advanced Interdisciplinary Research Areas (Innovative Bioproduction Kobe) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.
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Conflict of interest
The authors declare that they have no conflicts of interest.
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