fungal biofilm reactor based on metal structured packing improves the quality of a Gla::GFP fusion protein produced by Aspergillus oryzae

• Published in: Applied microbiology and biotechnology Vol. 99; no. 15; pp. 6241 - 6254
• Main Authors: Zune, Q, Delepierre, A, Gofflot, S, Bauwens, J, Twizere, J. C, Punt, P. J, Francis, F, Toye, D, Bawin, T, Delvigne, F
• Format: Journal Article Web Resource
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-08-2015; Springer; Springer Nature B.V; Springer Verlag
• Subjects: Analysis; Antibiotics; Aspergillus oryzae; Aspergillus oryzae - growth & development; Aspergillus oryzae - metabolism; Aspergillus oryzae - physiology; autolysis; biofilm; Biofilms; Biofilms - growth & development; Biomass; Biomedical and Life Sciences; Bioreactor; Bioreactors; Bioreactors - microbiology; Biotechnological Products and Process Engineering; Biotechnologie; Biotechnology; Design; Enzymes; excretion; Fermentation; Fluorescence; fluorescent proteins; Fungal biofilm; Fungi; Gene Expression; Genetic recombination; Glucan 1,4-alpha-Glucosidase - genetics; Glucan 1,4-alpha-Glucosidase - metabolism; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Life Sciences; Membrane reactors; Metabolites; microbial biomass; Microbial Genetics and Genomics; Microbiology; Microscopy; Physiology; Plant metabolites; Promoter Regions, Genetic; Proteins; Reactors; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Scale-up; Sciences du vivant; Secondary metabolites; Shear stress; solid state fermentation; Studies; submerged fermentation; two-dimensional gel electrophoresis; Bioreactor; Fungal biofilm; Recombinant protein; Scale-up
• ISSN: 0175-7598; 1432-0614; 1432-0614
• DOI: 10.1007/s00253-015-6608-z

Fungal biofilm is known to promote the excretion of secondary metabolites in accordance with solid-state-related physiological mechanisms. This work is based on the comparative analysis of classical submerged fermentation with a fungal biofilm reactor for the production of a Gla::green fluorescent protein (GFP) fusion protein by Aspergillus oryzae. The biofilm reactor comprises a metal structured packing allowing the attachment of the fungal biomass. Since the production of the target protein is under the control of the promoter glaB, specifically induced in solid-state fermentation, the biofilm mode of culture is expected to enhance the global productivity. Although production of the target protein was enhanced by using the biofilm mode of culture, we also found that fusion protein production is also significant when the submerged mode of culture is used. This result is related to high shear stress leading to biomass autolysis and leakage of intracellular fusion protein into the extracellular medium. Moreover, 2-D gel electrophoresis highlights the preservation of fusion protein integrity produced in biofilm conditions. Two fungal biofilm reactor designs were then investigated further, i.e. with full immersion of the packing or with medium recirculation on the packing, and the scale-up potentialities were evaluated. In this context, it has been shown that full immersion of the metal packing in the liquid medium during cultivation allows for a uniform colonization of the packing by the fungal biomass and leads to a better quality of the fusion protein.