Modified photosynthetic microorganisms for producing triglycerides
Inventors
Roberts, James • Cross, Fred • Warrener, Paul • Munoz, Ernesto Javier • Lee, Martin Henry • Romari, Khadidja • Kotovic, Kimberly Marie • Hickman, Jason W.
Assignees
Matrix Genetrics LLC • Lumen Bioscience Inc
Publication Number
US-8394621-B2
Publication Date
2013-03-12
Expiration Date
2029-10-23
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
This disclosure describes genetically modified photosynthetic microorganisms, including Cyanobacteria, that contain one or more exogenous genes encoding a diacylglycerol acyltransferase, a phosphatidate phosphatase, and/or an acetyl-CoA carboxylase, and which are capable of producing increased amounts of fatty acids and/or synthesizing triglycerides.
Core Innovation
The invention describes genetically modified photosynthetic microorganisms, specifically Cyanobacteria, that contain one or more exogenous genes encoding enzymes such as diacylglycerol acyltransferase (DGAT), phosphatidate phosphatase, and/or acetyl-CoA carboxylase (ACCase). These modified microorganisms are capable of producing increased amounts of fatty acids and synthesizing triglycerides, which they do not naturally produce in significant quantities.
This innovation addresses the problem that wild-type Cyanobacteria, although genetically manipulable and similar to algae in terms of photosynthesis, lack the enzymes necessary for triglyceride synthesis and consequently cannot produce triglycerides to serve as energy storage molecules. This limits their utility as a feedstock for producing biofuels and other specialty chemicals, especially when compared to naturally triglyceride-producing organisms like algae, which present challenges in genetic manipulation and industrial oil yield.
The core of the invention lies in engineering Cyanobacteria by introducing exogenous polynucleotides encoding enzymes catalyzing key steps in triglyceride biosynthesis and fatty acid synthesis. By doing so, Cyanobacteria are rendered capable of converting their naturally occurring fatty acids into triglyceride energy storage molecules and/or increasing overall fatty acid production. Codon-optimized genes and suitable expression constructs, including inducible and constitutive promoters, are utilized to ensure high-level and regulated gene expression in photosynthetic microorganisms.
Claims Coverage
There are two independent claims, each defining a principal inventive feature of the patent.
Modified cyanobacterium with exogenous prokaryotic diacylglycerol acyltransferase (DGAT)
A modified Cyanobacterium comprising an exogenous polynucleotide encoding a prokaryotic diacylglycerol acyltransferase (DGAT), wherein the modified Cyanobacterium produces a triglyceride, a wax ester, or both. The claim is not limited to a particular DGAT source, but dependent claims specify DGATs from Acinetobacter, Streptomyces, or Alcanivorax, including Acinetobacter baylii ADP1 diacylglycerol acyltransferase (AtfA), Streptomyces coelicolor DGAT, and Alcanivorax borkumensis DGAT. The exogenous polynucleotide may be codon-optimized for expression and present in an expression construct with a constitutive or inducible promoter.
Modified cyanobacterium with DGAT utilizing acyl-ACP as a substrate
A modified Cyanobacterium comprising an exogenous polynucleotide encoding a prokaryotic diacylglycerol acyltransferase (DGAT) that uses acyl-ACP as a substrate, wherein the modified Cyanobacterium produces a triglyceride, a wax ester, or both.
The claims cover modified Cyanobacteria expressing exogenous, especially prokaryotic, DGAT enzymes to confer the ability to produce triglycerides and/or wax esters, including DGATs that utilize acyl-ACP as a substrate and various optimizations for gene expression.
Stated Advantages
The modified photosynthetic microorganisms can produce large amounts of triglycerides from minimal energy and nutrient input, making them a readily manageable and efficient source of feedstock for biofuel and specialty chemical production.
Cyanobacteria are genetically manipulable in contrast to algae, allowing tailored engineering for specific production characteristics and improved yields under controlled culture conditions.
Certain modified Cyanobacteria can be grown in salt or brackish water, reducing reliance on freshwater resources and potentially lowering production costs.
Documented Applications
Production of triglycerides to be used as feedstock for biofuels, such as biodiesel.
Production of specialty chemicals, including glycerin for pharmaceutical and cosmetic industries.
Interested in licensing this patent?