SONG Hao1,3, ZHANG Yingxin1,2, XIN Jiaying1,2, XIA Chungu1*

(1.State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Lanzhou 730000, China; 2. Key Laboratory for Food Science and Engineering, Harbin University of Commerce, Harbin 150076, China; 3. Graduate University of the Chinese Academy of Sciences, Beijing 100039)

Abstract: Influencing factors on the molecular weight of poly-3-hydroxybutyrate (PHB) synthesized by methanotrophic bacteria were studied. The carbon sources, the concentration of NH₄⁺ , NO₃^-, HPO₄^2-, Mg²⁺ in the culture medium, key intermediate in TCA cycle and different purification methods, have important effects on the molecular weight of PHB accumulated in the cells. Moreover, it was suggested that each key enzyme have their unique effects on PHB synthesized pathway by the study on the key enzymes activities in PHB metabolism. The molecular weight of PHB depended mainly on the combined effect of PHB synthetase and PHB depolymerase.

Key words: Poly-3-hydroxybutyrate (PHB); molecular weight (Mw); methanotrophic bacteria

E-mail: cgxia@lzb.ac.cn

Journal of Molecular Catalysis, Vol. 26, Issue 1, 2012, 70-79