Current Uses of Synthetic Biology
Creating Economic Advantage for a Commonly Used Chemical
Adipic acid is a valuable chemical intermediate used in production of nylon for well-established markets like automotive parts, footwear, and construction materials. The current market for adipic acid is approximately $5.2 billion. Current petrochemical processes for the production of adipic acid generate as much as 4.0 tons of CO2 equivalents per ton of adipic acid produced. A biobased process could reduce the production costs of adipic acid by 20 percent or more.
Verdezyne is developing a cost-advantaged, environmentally friendly fermentation process for adipic acid. The company’s proprietary metabolic pathway can utilize sugar, plant-based oils or alkanes, and the company has completed proof-of-concept testing for fatty acids and alkanes. The potential benefit of this feedstock flexible approach is the ability to maintain a sustainable economic advantage regardless of future energy volatility and to reduce the environmental footprint for producing adipic acid.
Adipic acid is not produced in nature. Verdezyne’s novel combinatorial approach to pathway engineering rapidly creates and harnesses genetic diversity to optimize a metabolic pathway. Rather than manipulating one pathway gene at a time, the company uses synthetic gene libraries to introduce diversity into a metabolic pathway. The company’s unique computational and synthetic biology toolbox allows effective design, synthesis and expression of synthesized genes in a heterologous recombinant yeast microorganism.
Producing Biofuels and Renewable Chemicals as Petroleum Alternatives
Diesel is the most widely used liquid fuel in the world. This energy dense fuel supports the transport of 70 percent of U.S. commercial goods and is in high demand in the developing world to support the heavy equipment (trucks, bulldozers, trains, etc) required for infrastructure development. Today there is no cost effective renewable alternative to diesel.
LS9 has developed a platform technology that leverages the natural efficiency of microbial fatty acid biosynthesis to produce a diversity of drop-in fuels and chemicals. Using synthetic biology, LS9 has developed microbial cells that can perform a one-step conversion of renewable carbohydrates (sugars) to two diesel alternatives, a fatty acid methyl ester (biodiesel ASTM 6751) and an alkane (ASTM D975).
The LS9 processes are unique in that all of the chemical conversions from carbohydrate to finished fuel are catalyzed in the cell, with the finished product secreted. The fuel forms an immiscible light organic phase that is non-toxic to the organism and is easily recovered from the broth through centrifugation. There is no need for further chemical conversion, and there is no requirement for hydrogen in the process. These simple processes enable the production of diesel from scalable renewable resources at a price competitive with petroleum (without subsidy).
Synthetic biology has been essential in engineering the LS9 microbial catalysts. The biosynthetic pathways to produce finished fuel products do not exist in the native E. coli host, and prior to our efforts alkane biosynthetic genes were unknown. LS9 designed the pathways, synthesized the genes encoding each enzyme in the pathway, and constructed multigene biosynthetic operons enabling production. To improve yield, productivity, and titer – the drivers of process economic efficiency – the biosynthetic pathways and host metabolism have required significant genetic optimization. LS9 developed capabilities for the computational design and automated parallel construction of gene, operon, and recombinant cell libraries that have enabled the rapid construction and evaluation of thousands of rationally engineered microorganisms. This capability in combination with state of the art screening, process development, and analytical methodologies has enabled LS9 in only a few years to advance from concept to a process slated for commercial-scale demonstration.
This same technology platform has been leveraged for the production of surfactants for use in consumer products in collaboration with Procter & Gamble. The ability to exchange biosynthetic parts and leverage the core host “chassis” has enabled the development of this chemical product line much faster, achieving in months what had taken years for the earlier products.
LS9 intends to continue to leverage the power of synthetic biology to further advance these and future products as quickly and cost effectively as possible. We feel strongly these technologies are essential to the goal of weaning our dependence on fossil feedstocks and the further development of a world leading industrial biotechnology industry.
Increasing Rates of Natural Fermentation for Polymers
Metabolix is bringing new, clean solutions to the plastics, chemicals and energy industries based on highly differentiated technology. For 20 years, Metabolix has focused on advancing its foundation in polyhydroxyalkanoates (PHA), a broad family of biopolymers. Through a microbial fermentation process, the base polymer PHA is produced within microbial cells and then harvested. Development work by Metabolix has led to industrial strains of the cells, which can efficiently transform natural sugars into PHA. The recovered polymer is made into pellets to produce Mirel™ Bioplastics by Telles products.
