Enzyme leader Novozymes and Terranol, a Denmark-based biotechnology company specialized in yeast, announced an agreement that will ensure the final optimization of the Terranol C5 yeast strain and give Novozymes the rights to register and market Terranol’s C5 yeast technology. Terranol A/S is a research and development company dedicated to developing and commercializing C6/C5 fermenting yeasts for cellulosic ethanol production.
“A yeast that ferments C5 sugars is essential to cost-efficient production of cellulosic ethanol. Our C5 yeast is among the furthest developed in the industry and by leveraging Novozymes’ global marketing muscle we can speed up its commercialization,” said Birgitte Rønnow, CEO of Terranol.
The manufacturing process for cellulosic ethanol via fermentation involves pretreatment of biomass such as corn stover and wheat straw; enzymatic hydrolysis to release the sugars; fermentation of the sugars; and distillation. Biomass contains C6 sugars, primarily from cellulose, and C5 sugars from the hemicellulose part of the plant material. While yeasts naturally ferment C6 sugars to ethanol, C5 sugars are not fermented to ethanol by any natural microorganism in sufficiently high concentrations.
To obtain optimal yields it is important to ferment not only the easily accessible C6 sugars (glucose), but also the more difficult C5 sugars (xylose and arabinose).
Terranol A/S, formed in 2007 and based at the Technical University of Denmark, has designed and demonstrated genetically optimized yeasts to fulfill the requirements in industrial settings with respect to robustness, performance and productivity, enabling increased yields of ethanol production.
Terranol developed an industrial S. cerevisiae strain for fermentation of xylose at increase rates. The company identified a xylose isomerase of bacterial origin that is highly active when expressed in yeast. To assist the xylose isomerase in its strains, Terranol also inserted an aldose 1-epimerase that catalyzes an otherwise slow conversion between the β- and α-anomers of D-xylose, of which only the α-anomer is a substrate of the xylose isomerase. (An anomer is a special type of epimer, which in turn is a type of isomer—compounds with the same molecular formula but different structural formulas.)
All inserted genes are stably integrated into the genome of the yeast, and the strain has undergone extensive adaptation by evolutionary engineering. Terranol says that the resultant strain has high resistance towards biomass derived inhibitors, low formation of the byproduct xylitol. Terranol says that its strain V1 is ready for commercial ethanol production and can ferment xylose and glucose in lignocellulosic hydrolysates with a resulting ethanol yield above 90% of total sugars and a final ethanol titer above 5% (w/w) in as little as 48 h.
The partnership will allow Novozymes to speed up global rollout of Terranol’s yeast to customers in the cellulosic ethanol industry. Wide availability of a high-performing and cost-efficient yeast will enable the nascent industry to accelerate the transition from demonstration-scale production to large-scale commercialization.
We want to make sure there are no biotech-related hurdles to the creation of a cellulosic ethanol industry. Terranol’s C5 yeast is currently one of the best strains developed, and by getting it registered and marketed around the world, we can help make it available to the biofuel industry. This will provide a higher degree of certainty in the commercialization of cellulosic ethanol—Poul Ruben Andersen, Vice President Bioenergy at Novozymes
With our combined R&D capabilities we can ensure the final optimization of the strain in order to achieve maximum economic performance for our cellulosic ethanol customers.—Claus Crone Fuglsang, Vice President R&D at Novozymes
In February, Novozymes launched Novozymes Cellic CTec3, the best-performing enzyme in the market for production of cellulosic ethanol. (Earlier post.)The first commercial-scale cellulosic ethanol plants are scheduled to open later this year.
Terranol’s work is supported by Danish Energy Authority’s Programme for Energy Technology Development and Demonstration (EUDP).