ISSN 2756-3413
African Journal of Virology Research ISSN 3421-7347 Vol. 5 (2), pp. 001-008, February, 2011. © International Scholars Journals
Full Length Research Paper
Poly-3-hydroxybutyrate production from methanol by Methylosinus trichosporium IMV3011 in the non-sterilized fed-batch fermentation
Hao Song1,3, Jiaying Xin1,2, Yingxin Zhang1,4, Weibao Kong1,3 and Chungu Xia1*
1State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
2Laboratory for Food Science and Engineering, Harbin University of Commerce, Harbin 150076, China.
3Graduate University of Chinese Academy of Sciences, Beijing 10039, China.
4Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
Accepted 19 November, 2010
Abstract
The methanotrophic bacteria have promising applications in the production of a biopolymer, poly-3-hydroxybutyrate (PHB). The fed-batch fermentation strategies were studied for PHB accumulation by methanol-grown Methylosinus trichosporium IMV3011 under the non-sterilized conditions. The biomass of 2.91 g dry wt/L and PHB accumulation of 47.6% (w/w) were reached in the fed-batch fermentation. In order to increase PHB content, some organic acids were added into the culture as inhibitors of tricarboxylic acid cycle (TCA). It was found that the malic acid should be optimum for PHB accumulation. The biomass and PHB yield would increase to 3.32 g dry wt/L and 58.5% (w/w), respectively by adding 0.2 g/L malic acid. Other key intermediates in the metabolism such as citric acid, succinic acid and acetyl-CoA, also influenced the cell growth and PHB accumulation to a certain extent. The PHB produced in the fermentation process was of steady quality with molecular weights up to 1.7 × 106 Da.
Key words: Biosynthesis, poly-3-hydroxybutyrate, methanotrophic bacteria, methanol, fed-batch fermentation.