Investigation of lipid production by Methylomicrobium buryatense using CH4 as the carbon source

The objective of this study is to optimize the fermentation process for lipid production by Methylomicrobium buryatense to reach a high lipid production in a high cell density culture. In order to meet the targets, the quantitative effects of the initial concentrations of nitrogen source, phosphate solution, and trace element solution in nitrate minimal salt medium as well as the total gas flow rate on cell growth and lipid production were investigated in this study. The results indicate that M. buryatense is able to grow well in batch culture with higher concentrations of nitrogen phosphate, and trace solution to avoid nutrient limitations. To have a better mass transfer rate and gas sparging system, we replaced the spinner bottles with commercial bench scale fermenters to use as continuous stirred tank reactors to achieve a higher growth rate, cell density, lipid content, and productivities in batch cultivations.