Butamax Advanced Biofuels LLC v. Gevo, Inc.

The definition in Butamax’s patent specification stating that the KARI polypeptide used a specific an electron donor did not mean that Butamax was acting as its own lexicographer and intending to limit the term to only cover use of the specific donor when both it and an alternate donor were within the ordinary meaning of the term at the time the patent was issued and where both the preferred embodiment and Enzyme Commission number listed in the patent permitted either electron donor to be used.

Opinion (Linn): Butamax Advanced Biofuels, LLC ("Butamax") sued Gevo, Inc. ("Gevo") alleging infringement of two of its patents (Nos. 7,993,889 and 7,851,188) that cover the use of microorganisms with a particular biosynthetic pathway in the production of isobutanol. Following claim construction, the district court denied Butamax’s motion for summary judgment of literal infringement, and granted Gevo’s motion for summary judgment of noninfringement under the doctrine of equivalents and Gevo’s motion for summary judgement that claims 12 and 13 of the ‘889 patent were invalid for lack of written enablement. Butamax appealed the district court's construction of a term in an independent claim found in both patents that covers the process of producing isobutanol where acetolactate is converted to 2,3-dihydroxyisovalerate, where “the polypeptide that catalyzes a substrate to product conversion of acetolactate to 2,3-dihydroxyisovalerate is acetohydroxy acid isomeroreductase.” Acetohydroxy acid isomeroreductase is also known as keto-acid reductoisomerase, or "KARI." The ‘188 patent clarifies that the KARI used in this step has the Enzyme Commission (EC) number 1.1.1.86, and in that patent’s specification the KARI is defined as “using NADPH (reduced nicotinamide adenine dinucleotide phosphate) as an electron donor.” Gevo’s process uses nicotinamide adenine dinucleotide (“NADH”). Due in part to the definition in the patent specification, the district court concluded that Butamax was acting as its own lexicographer and construed the KARI term to be NADPH dependent. Patent claims are normally given their ordinary and customary meaning unless the patentee specifies its own definition for the term or limits the scope of the term in the specification or during prosecution. The record established that the ordinary meaning of KARI at the time the patent was issued permitted the use of either NADH or NADPH. The Federal Circuit found that there was no evidence that Butamax intended “using NADPH” to mean only NADPH. It further found that the fact that both the preferred embodiment of the invention and the EC number specified in the ‘188 patent would permit the use of NADH suggested that Butamax did not intend to limit the term. Because there was no clear evidence that Butamax intended to limit the meaning of the KARI term to require NADPH dependence, the Federal Circuit construed the term according to its ordinary meaning and REMANDED the case.