The synthetic biology company Kalion Inc. (Milton, Mass.; www.kalioninc.com) recently completed its first commercial-scale production run of high-purity (98–99%) glucaric acid via fermentation of glucose at a custom-manufacturing facility owned by Evonik Industries AG (Essen, Germany; www.evonik.com).
The high purities achieved by Kalion’s advanced fermentation process far outstrip those achieved by existing bio-based glucaric acid processes at lower cost, widening the range of possible applications.
Combined with standard unit operations, the Kalion fermentation process uses proprietary synthetic biology techniques developed in the laboratory of Kristala Prather at Massachusetts Institute of Technology (MIT; Cambridge, Mass.; www.mit.edu) to engineer the metabolic pathways of Escherichia coli bacteria and induce efficient and low-cost production of glucaric acid.
The initial manufacturing produced material to meet existing customer commitments for high-purity glucaric acid. Among the customer applications is using glucaric acid as a corrosion inhibitor in cooling-water treatment. Glucaric acid obviates the need for phosphate-based inhibitors, which can have damaging effects when allowed to run off into coastal waters.
Darcy Prather, Kalion president and co-founder (along with his MIT-professor wife) points out that Kalion’s glucaric acid would not be subject to the effluent restrictions now common to phosphate-based solutions, and production reduces greenhouse gas emissions by roughly 50% when compared with those alternatives.
“Use of high-purity glucaric acid expands the operating pH range in cooling water treatment,” Prather says, and when used for corrosion inhibition in hard-water and high-temperature scenarios common at petroleum refineries, “glucaric acid does not cause the precipitate fouling with calcium that is observed with phosphate-based chemicals.” The absence of precipitate preserves heat-transfer efficiency in heat exchangers and cooling systems.
While the water treatment market is Kalion’s initial target, high-purity glucaric acid and related compounds can also enhance sustainability and improve performance as a polymer additive in textiles and coatings applications, as well as in detergents and pharmaceuticals. In textiles, for example, glucaric acid has been shown to increase modulus and tensile strength — by 50% to nearly an order of magnitude — for fibers such as polyvinyl alcohol, polyacrylic nitrile, recycled cotton and viscose (rayon) fibers, Prather says. Kalion is further developing these advantages in collaborations with fiber producers.