The Role of Copper in the Growth of Methylosinus trichosporium IMV 3011 and Poly-β-Hydroxybutyrate Biosynthesis

Methanotrophs are aerobic microorganisms that utilize methane as substrates for growth and PHB Biosynthesis. Copper plays an important role in cell growth and PHB biosynthesis. The effect of initial copper concentration on cultivation of M. trichosporium IMV 3011 on methane was investigated. With the addition of 30μmol/L CuSO4•5H2O, PMMO activity improved to 4 times of that without copper addition. The highest density of cultivated cells is 0.48g dry wtL-1, which is 2 times of that without copper addition. The lag time shortened to 15.87h, and the growth rate increased to 0.082h-1.The PHB content increased to 8.3%. It is found that certain initial copper concentration is beneficial to expression of high particulate methane monooxygenase activity, which may contribute to the synthesis of PHB in the cell.