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Pulsed addition of limiting‐carbon during Aspergillus oryzae fermentation leads to improved productivity of a recombinant enzyme
Author(s) -
Bhargava Swapnil,
Wenger Kevin S.,
Marten Mark R.
Publication year - 2003
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.10548
Subject(s) - aspergillus oryzae , fermentation , carbon fibers , bioprocess , chemistry , food science , limiting , pulp and paper industry , biology , materials science , composite number , mechanical engineering , paleontology , engineering , composite material
Fungal morphology in many filamentous fungal fermentations leads to high broth viscosity which limits oxygen mass transfer, and often results in reduced productivity. The objective in this study was to determine if a simple, fed‐batch, process strategy—pulsed addition of limiting‐carbon source—could be used to reduce fungal broth viscosity, and increase productivity of an industrially relevant recombinant enzyme (glucoamylase). As a control, three Aspergillus oryzae fed‐batch fermentations were carried out with continuous addition of limiting‐carbon. To determine the effect of pulse‐feeding, three additional fermentations were carried out with limiting‐carbon added in 90‐second pulses, during repeated five‐minute cycles. In both cases, overall carbon feed‐rate was used to control dissolved oxygen concentration, such that increased oxygen availability led to increased addition of limiting‐carbon. Pulse‐fed fermentations were found to have smaller fungal mycelia, lower broth viscosity, and improved oxygen mass transfer. As a result, more carbon was added to pulse‐fed fermentations that led to increased enzyme productivity by as much as 75%. This finding has significant implications for the bioprocessing industry, as a simple process modification which is likely to cost very little to implement in most production facilities, has the potential to substantially increase productivity. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 111–117, 2003.