Production of salts of 4-hydroxybutyrate using biobased raw materials

A method for producing a sample from an approved source, said method comprising:

• fermenting engineered microbes which produce poly(4-hydroxybutyrate) (P4HB) polymer with a growth medium comprising D2O with deuterated glucose or without deuterated glucose to produce a deuterated P4HB;
• reacting the deuterated P4HB for obtaining a deuterated gamma-butyrolactone, a deuterated 4-hydroxybutyrate, an oligomer of deuterated 4-hydroxybutyrate, or a combination thereof;
• and
• mixing the reacted deuterated P4HB with a gamma-butyrolactone prepared from petroleum-based starting materials, a 4-hydroxybutyrate prepared from petroleum-based starting materials, an oligomer of 4-hydroxybutyrate prepared from petroleum-based starting materials, or a combination thereof to prepare a mixture of GBL, a mixture of GHB, a mixture of oligomers of 4-hydroxybutyrate, or a mixture comprising a combination thereof, wherein the mixture has a chosen percent modern carbon range,
• wherein the growth medium comprises a selected mixture of a biobased material and a petroleum-based material to yield a desired percent modern carbon, wherein a percentage of the carbon in the deuterated P4HB is modern carbon and the remaining percentage of carbon is fossil-carbon, wherein the chosen percent modern carbon range is controlled to provide a unique carbon footprint, and wherein the chosen percent modern carbon range corresponds to a defined range of the approved source,
• wherein the growth medium comprises a concentration of D2O above the natural abundance in water, and
• wherein the deuterated P4HB produced by fermenting is 27% to 80% deuterated.