Polyhydroxyalkanoate production methods and systems for same

A multi-phase method for producing a polyhydroxyalkanoate (PHA) in a culture of methanotrophic microorganisms, the method comprising:

• providing a gas comprising methane and one or more non-methane substances;
• providing a culture of methanotrophic microorganisms capable of expressing particulate methane monooxygenase (pMMO) and/or soluble methane monooxygenase (sMMO);
• providing a culture medium comprising at least nitrogen;
• in a first phase, culturing the culture of methanotrophic microorganisms in the culture medium and exposing the culture of methanotrophic microorganisms to the gas,
• wherein the culture of methanotrophic microorganisms is initially overfed based on the concentration of the gas followed by being underfed based on the same concentration of gas and growth of the culture;
• in a second phase, culturing the culture of methanotrophic microorganisms in the culture medium and exposing the culture of methanotrophic microorganisms to the gas in a manner allowing the culture of methanotrophic microorganisms to deplete the nitrogen from the media to create an underfeeding condition, thereby stimulating the culture of methanotrophic microorganisms to synthesize PHA via pMMO and/or sMMO.

A method for producing a polyhydroxyalkanoate (PHA) in a culture of methanotrophic microorganisms, the method comprising:

• culturing a population of methanotrophic microorganisms capable of expressing particulate methane monooxygenase (pMMO) and/or soluble methane monooxygenase (sMMO) in a culture medium comprising at least nitrogen;
• exposing the population of methanotrophic microorganisms in the media to a gas comprising methane and one or more non-methane substances for a first period of time,
• wherein the population of methanotrophic microorganisms is initially overfed based on the concentration of methane followed by being underfed based on the same concentration of methane and growth of the population of methanotrophic microorganisms;
• and
• culturing, for a second period of time, the population of methanotrophic microorganisms in the media under conditions that allow the population of methanotrophic microorganisms to deplete the nitrogen from the media to create a nitrogen-underfeeding condition,
• thereby stimulating the population of methanotrophic microorganisms to utilize the carbon from the methane to produce PHA.

A method for producing a polyhydroxyalkanoate (PHA) in a culture of methanotrophic microorganisms, the method comprising:

• culturing a population of methanotrophic microorganisms in a culture medium comprising at least nitrogen;
• exposing the population of methanotrophic microorganisms in the media to a gas comprising methane and one or more non-methane substances for a first period of time,
• wherein, during the first period of time, the population of methanotrophic microorganisms is initially overfed based on the concentration of methane followed by being underfed based on the same concentration of methane and concurrent increase in the size of the population of methanotrophic microorganisms;
• and
• culturing, for a second period of time, the population of methanotrophic microorganisms in the media without additional nitrogen, resulting in the population of methanotrophic microorganisms depleting the nitrogen from the media to create a nitrogen-underfeeding condition,
• thereby stimulating the population of methanotrophic microorganisms to utilize the carbon from the methane to produce PHA.