Cell growth and Trametes versicolor laccase production in transformed Pichia pastoris cultured by solid-state or submerged fermentations
✍ Scribed by Marcos López; Octavio Loera; Martha Guerrero-Olazarán; José M. Viader-Salvadó; Juan A. Gallegos-López; Francisco J. Fernández; Ernesto Favela-Torres; Gustavo Viniegra-González
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 2009
- Tongue
- English
- Weight
- 198 KB
- Volume
- 85
- Category
- Article
- ISSN
- 0268-2575
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✦ Synopsis
Abstract
BACKGROUND: Growth kinetics of Pichia pastoris and heterologous expression of Trametes versicolor laccase were compared. This is the first study of its kind between solid‐state yeast cultures done on polyurethane foam (PUF) and submerged liquid fermentations (SmF).
RESULTS: The maximum values of biomass were similar for SSF (solid‐state fermentation) and SmF experiments when the BOD (biochemical oxygen demand) was lower than 100 g L^−1^. For higher BOD levels, the maximum values of biomass were 55 g L^−1^ (SSF) and 35 g L^−1^ (SmF). Micrographs of PUF preparations showed yeast growing within liquid lamellae, thinner than 100 µm, forming large horizontal aggregates. Yeast aggregates were much smaller in SmF than in SSF experiments; however, laccase expression was lower in PUF than in SmF, unless the methanol concentration was increased to 63 g L^−1^, which was inhibitory only to the SmF system.
CONCLUSION: The results show that oxygen mass transfer is more efficient in SSF, which is related to the higher area/volume ratio compared with SmF. Induction differences may also be due to hindered diffusion of methanol within large yeast aggregates. Copyright © 2009 Society of Chemical Industry