A Bioreactor and Process for Forming Polyhydroxybutyrate Directly from Depolymerized Polyhydroxybutyrate
AssigneeKimberly-Clark Worldwide, Inc.
InventorStephen Quirk
Life of this patent
Estimating the term…
Abstract
A bioreactor and process are disclosed for forming polyhydroxybutyrate directly from depolymerized polyhydroxybutyrate. In two bioreactor vessels, a microorganism product, such as one or more enzymes, are combined with the polyhydroxybutyrate-containing post-consumer product materials. The microorganism can naturally secrete the one or more enzymes or can be genetically modified to secrete the enzyme. The combination of enzymes is designed to facilitate a metabolic pathway that can depolymerize PHB, convert the resulting hydroxybutyrate to hydroxybutyryl-CoA, and in turn polymerize it into PHB. Namely, a solution for the recycling of polyhydroxybutyrate to hydroxybutyrate and back to polyhydroxybutyrate.
Claims20
A process for recycling biopolymers in polyhydroxyalkanoate family from a polyhydroxyalkanoate-containing post-consumer product comprising:
- within a first vessel, contacting a post-consumer product with an extremophilic microorganism suspension or an extremophilic depolymerase enzyme to supply a hydroxyalkanoate monomer;
- pumping the monomer through a filter to a second bioreactor vessel;
- and
- within the second vessel, contacting the monomer with an enzyme, producing a recycled polyhydroxyalkanoate.
A polyhydroxybutyrate produced from hydroxybutyrate liberated by the depolymerization of polyhydroxybutyrate in a multi-step enzymatic reaction comprising:
- in a first bioreactor vessel, contacting polyhydroxybutyrate with a depolymerase enzyme or depolymerase exhibit microorganism to supply a hydroxybutyrate monomer;
- and
- in a second bioreactor vessel, converting the hydroxybutyrate monomer to acetoacetate with a hydroxybutyrate dehydrogenase enzyme, converting acetoacetate to acetoacetate-CoA with an Acetoacetyl-CoA synthetase enzyme, reducing acetocetyl-CoA to hydroxybutyrl-CoA with an acetoacetyl-CoA reductase, and polymerizing hydroxybutyryl-CoA with a hydroxybutyrate polymerase to form polyhydroxybutyrate.
A process for recycling polyhydroxybutyrate from a polyhydroxybutyrate-containing post-consumer product comprising:
- within a first bioreactor vessel, contacting a post-consumer product with a thermophilic or halophilic bacteria suspension or a thermophilic or halophilic depolymerase enzyme to supply a hydroxybutyrate monomer;
- pumping the hydroxybutyrate monomer through a molecular weight cutoff filter, optionally followed by an ion exchange bed, to a second bioreactor vessel;
- and
- within the second bioreactor vessel, contacting the hydroxybutyrate monomer with one or more enzymes and a cofactor feed, thereby producing a recycled polyhydroxybutyrate.
Dependencies are inferred from the claim text.