Response surface optimization of the nitrogen source for pullulan production by Aureobasidium pullulans CGMCC3945 with corn steep liquor

DOI

10.2991/ifeesd-16.2016.153How to use a DOI?

Keywords

Pullulan, Response Surface Methods, Corn Steep Liquor, Fermentation Medium

Abstract

Pullulan is a linear homopolymer composed of maltotriose subunits interconnected with a-1, 6 glucosidic linkages and one of such commercially emerging biopolymers and synthesized by a yeast-like fungus A. pullulans. Pullulan's solubility can be controlled or provided with reactive groups by chemical derivatization. It is moldable and spinnable, being a good adhesive and binder. It is also non-toxic, edible, and biodegradable. Consequently, pullulan and its derivatives have numerous potential for food, pharmaceutical and other industrial applications. The major constraint prevailing on the use of pullulan is its higher cost. In order to realize large-scale pullulan production by A. pullulans, an attempt was made to optimize medium components for maximizing the production of the strain from corn steep liquor. Methods The optimal condition based on the single factor experiment was made in fermentation medium. We aimed to research effect of the ingredient of medium on growth and production of A. pullulans. Corn steep liquor (CSL), NH4NO3 and K2HPO4 which were identified to significantly affect pullulan production by Plackett-Burman design were further optimized using response surface methodology of central composite design (CCD). Results An inexpensive medium for pullulan production was achieved in shake flasks. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis. By solving the regression equation and analyzing the response surface contour plots, the optimum variables that supported maximum pullulan production were 0.72 g/L NH4NO3, 1.38 g/L K2HPO4 and 0.70g/L CSL. The average productivity of pullulan is 23.22g/L under the desired fermentation conditions. Conclusion CSL is an inexpensive and abundantly available raw material in comparison with yeast extract, and the cost of yeast extract is many times higher than that of CSL. It has further scope for improving pullulan production by optimizing the most significant variables and culture conditions from the present analysis. It was verified that CSL supplemented with yeast extract appeared to be an economical alternative to yeast extract alone.

Copyright

© 2016, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Yuhua Wang
AU  - Jiaqi Wen
AU  - Dongmei Jia
AU  - Chunhong Piao
AU  - Junmei Liu
AU  - Hansong Yu
AU  - Jingsheng Liu
PY  - 2016/05
DA  - 2016/05
TI  - Response surface optimization of the nitrogen source for pullulan production by Aureobasidium pullulans CGMCC3945 with corn steep liquor
BT  - Proceedings of the 2016 International Forum on Energy, Environment and Sustainable Development
PB  - Atlantis Press
SP  - 844
EP  - 850
SN  - 2352-5401
UR  - https://doi.org/10.2991/ifeesd-16.2016.153
DO  - 10.2991/ifeesd-16.2016.153
ID  - Wang2016/05
ER  -