A new generation of Agrivida’s proprietary trait technology— proteins genetically engineered into the cell walls
of waste corn stover and “energy crops” such as sorghum and switchgrass – increases cell wall degradation by up
to 100 percent compared to non-engineered plants, while significantly decreasing enzyme loadings, following a
mild pretreatment and heat activation, according to studies presented by Agrivida scientists at the World
Congress on Industrial Biotechnology and Bioprocessing in Washington, DC. The meeting is sponsored by the
Biotechnology Industry Organization (BIO).
The study presented at the meeting determined that embedding Agrivida’s engineered enzymes in the cell
walls of the crops was an effective strategy for improving the biofuels processing characteristics of the plants
and dramatically decreasing external enzyme loadings, while still protecting the plants’ development and growth
the scientists said. The study compared the appearance, processing characteristics, and other parameters of the
intein-modified plants with non-engineered, native plants.
“Agrivida transgenic corn stover was demonstrated in this study to have a conversion of more than 60 percent
of cellulose to glucose, compared to approximately 30 percent seen with the control plants,” following a
proprietary low-cost pretreatment with heat and at reduced enzyme loadings, according to Michael Raab, Ph.D.,
President of Agrivida. “Further, the enzyme loadings used with Agrivida’s engineered plants can be reduced well
over 50 percent and still provide improved performance relative to the full enzyme loadings on non-engineered
plants, thereby significantly lowering external enzyme requirements. Our new data provide additional proof that
Agrivida transgenic crops can facilitate cellulose degradation in a way that greatly reduces the need for
hydrolytic enzymes and expensive pretreatment processes.
This capability suggests that cellulosic ethanol production can be greatly expanded at lower costs and with
fewer emissions, chemicals, and other downstream requirements.” According to Raab, the ability to reduce
external enzyme requirements is a critical development that should help enable the growth of the cellulosic
biofuels industry. In the absence of such technology, the external enzyme production capacity build-out
required to meet the U.S. Renewable Fuels Standard would exceed a cost of $5B. Agrivida’s plant traits aim to
eliminate those enzyme production costs for producers.
In earlier studies, Agrivida had reported that embedding CWD enzymes in plant material during the growth
phase enables more efficient processing of biomass by initiating hydrolysis of plant polysaccharides from within
the plant. Agrivida’s enzymes are only activated only after harvest, decoupling enzyme production from
hydrolysis. This enables even higher levels of expression in selected energy crops, according to Raab.
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