Center for Innovative Technology

James Madison University

Michigan State University

Douglas E Dennis

Steven C Slater

Henry E Valentin

Christopher R Somerville

Yves Poirier

Ho Gun Rhie

The PHA biosynthetic pathway is combined with a succinic semialdehyde metabolic pathway that metabolizes succinic semialdehyde via a 4-hydroxybutyryl-CoA intermediate in order to produce high levels of PHA comprising 4HB monomer units. This combination is particularly useful, in part, because the PHA biosynthetic pathway is well known and has been expressed to produce P(3HB) to levels as high as 70-80% of the cell dry weight, while the succinic semialdehyde metabolic pathway is also well known, and the combination of the two pathways means that production of PHAs comprising 4HB monomer units does not depend on immediate precursors of 4-hydroxybutyrate. Rather, the production of the PHAs comprising 4HB monomer units can occur simply from the extraction of succinate or succinyl-CoA from the citric acid cycle when the host cell is grown on an inexpensive carbon source such as glucose.

Methods of making polyhydroxyalkanoates comprising 4-hydroxybutyrate

The present invention provides methods for the production of poly-.beta.-hydroxyalkanoate copolymer comprising the steps of (a) introducing into a prokaryotic host cell a vector construct which directs the expression of a sequence which encodes a poly-.beta.-hydroxybutyrate biosynthetic pathway, (b) introducing into the host cell a vector construct which directs the expression of one or more proteins which regulate acetate and propionate metabolism, (c) culturing the host cell in medium containing propionate or a derivative thereof, and (d) isolating poly-.beta.-hydroxyalkanoate copolymer from the cultured host cell.

Method of production of poly-.beta.-hydroxyalkanoate copolymers

The present invention relates to transgenic plants which produce poly-beta-D-hydroxybutyric acid (PHB) and related polyhydroxyalkanoates (PHA). The production of PHB is accomplished by genetically transforming the plants with modified genes from microorganisms. The genes encode the enzymes required to synthesize PHB from acetyl-CoA or related metabolites. PHB is a very useful polymer which is biodegradable.

Transgenic plants producing polyhydroxyalkanoates

The present invention provides methods for the production of poly-.beta.-hydroxybutyrate, comprising the steps of (a) introducing into a prokaryotic host cell capable of metabolizing sucrose a vector construct which directs the expression of a sequence which encodes a poly-.beta.-hydroxybutyrate biosynthetic pathway, (b) culturing the host cell in medium containing sucrose, and (c) isolating poly-.beta.-hydroxybutyrate from the cultured host cell.

Production of poly-.beta.-hydroxybutyrate in prokaryotic host cells

Genes coding for poly-beta-hydroxybutyrate were removed from Alcaligenes eutrophus H16 and cloned into Escherichia coli. Some of the clones produced PHB to 90% of the cell weight.

Cloning and expression in Escherichia coli of the Alcaligenes eutrophus

Poly-.beta.-hydroxybutyrate is produced by providing a culture of Escherichia coli bacterial host cells transformed by a DNA sequence coding for the biosynthetic pathway of poly-.beta.-hydroxybutyrate and a DNA sequence coding for the lysozyme gene; growing the culture and obtaining expression of the poly-.beta.-hydroxybutyrate biosynthetic pathway and the lysozyme gene in each Escherichia coli bacterial host cell; lysing the Escherichia coli bacterial host cells and collecting the poly-.beta.-hydroxybutyrate. An Escherichia coli HMS174(p4A BstB!, pLysS) deposited with the American Type Culture Collection under Accession No. 69001, comprising a plasmid containing a biosynthetic pathway coding for poly-.beta.-hydroxybutyrate and a plasmid containing a lysozyme gene is disclosed.

Method for the improved production and recovery of

The invention related to recombinant deoxyribonucleic acid (DNA) technology and, more particularly, to a process whereby poly-beta-hydroxyalkanoate (PHA) copolymers can be synthesized in a recombinant host strain containing the poly-beta-hydroxybutyrate (PHB) biosynthetic genes of Alcaligenes eutrophus.

Method of production of poly-beta-hydroxyalkanoate copolymers

Methods are provided for enhancing the production of PHB from a transformed E. coli host which includes the genes coding for the PHB biosynthetic pathway. By inserting the genes coding for PHB into a host which includes a lactose utilization system, a low cost minimal medium including whey can be used as the fuel and carbon source for PHB production. A plasmid which codes for the PHB biosynthetic pathway plus four hundred extra bases on either side of the first and last genes in the pathway has been inserted into the host and has been shown to produce a larger amount of PHB accumulation in a shorter period of time than other plasmid constructs. CaCl.sub.2 has been shown to be an effective agglomerating agent for agglomerating PHB which has been produced in a transformed E. coli host.

Growing community of inventors

Weyers Cave, VA, United States of America

Douglas E Dennis