In a world with limited resources, the quest for sustainable energy is not just scientific—it's a necessity for our future.
Imagine a world where the inedible parts of plants—corn stalks, wheat straw, and special grasses—could power our cars, heat our homes, and fuel our society. This isn't science fiction; it's the pioneering work of Lee Lynd, a scientist who has dedicated his career to making biofuels from cellulose a practical reality. At a time when climate change and resource depletion pose existential threats, Lynd's work offers a visionary solution: living directly from nature's renewable income instead of depleting the earth's limited capital9 .
Why is turning plants into fuel so challenging? The answer lies in evolution. Plants appeared over 1.8 billion years ago, and they have evolved sophisticated cell walls specifically designed to be tough and resistant to decomposition. "Breaking down plant cell walls efficiently and inexpensively is a hard job," Lynd acknowledges. "We are at once trying to outwit nature and to take inspiration from her"9 .
This resistance, what scientists term "recalcitrance," has been the primary obstacle to affordable cellulosic biofuels7 . Traditional approaches involve expensive, energy-intensive processes using added chemicals, high temperatures, and enzymes produced in separate facilities. "This approach is inherently costly," says Lynd. "I think we can do better"9 .
Plant cell walls have evolved over billions of years to resist decomposition, making biofuel production challenging.
Conventional approaches use expensive, multi-step processes with high energy requirements and chemical inputs.
While the biofuel industry has largely relied on complex, multi-step processes, Lynd looked to nature for a more elegant solution. He observed that certain microorganisms in nature can break down plant cell walls and convert them to fuels in a single, integrated step. Three decades ago, he identified and named this strategy "consolidated bioprocessing" (CBP)9 .
CBP is widely considered the ultimate low-cost configuration for cellulosic biofuel production4 . Think of it as a microscopic factory where one community of microbes handles the entire job—from dismantling the tough plant structure to producing the final fuel product—eliminating the need for separate enzyme production and multiple processing steps1 4 .
"We now have—and this is recent—overwhelming evidence that some microorganisms and their enzymes are better at taking apart plant cell walls than the ones being used by industry today," Lynd explains9 .
CBP combines multiple steps into one integrated biological process
Specialized microbes handle both breakdown and fuel production
Eliminates need for separate enzyme production facilities
Despite the promise of CBP, Lynd and his team continued to encounter a persistent challenge: as they increased the amount of plant material in their fermentation tanks to commercially relevant levels, the microbes' ability to break down carbohydrates became less efficient3 . This performance barrier threatened the economic viability of the entire process.
Inspired by how cows alternately expose plant material to biological attack and mechanical chewing through rumination9 , the Lynd Lab developed an innovative solution called "cotreatment"—mechanical disruption of biomass during microbial fermentation.
Sugarcane bagasse, the fibrous residue left after sugar extraction, was selected as the cellulosic feedstock3 .
The bagasse was subjected to fermentation using two setups: monocultures of Clostridium thermocellum (specialized in breaking down cellulose) and cocultures that also included Thermoanaerobacterium thermosaccharolyticum (which can break down hemicellulose)3 4 .
During fermentation, the team introduced continuous mechanical milling using ball bearings to physically disrupt the liquefying plant material3 9 .
This process was applied across increasing solid loadings (from 10 to 80 grams per liter) to assess performance under more concentrated, industrially-relevant conditions3 .
Researchers meticulously measured the percentage of carbohydrates solubilized (broken down into usable form) in cotreated samples versus non-cotreated controls3 .
The experiments yielded compelling results. Cotreatment led to a 1.8-fold increase in total carbohydrate solubilization compared to fermentation without mechanical disruption3 . The mechanical milling was particularly effective at breaking down the hemicellulose fraction of the plant cell walls, which is often more challenging to access than cellulose3 .
Perhaps even more significantly, the coculture approach enhanced both solubilization and carbohydrate utilization compared to monocultures, regardless of the initial solids loading3 . This demonstrated the power of microbial teamwork in biofuel production.
The scientific importance of cotreatment lies in its potential to eliminate or reduce the need for thermochemical pretreatment, one of the most expensive and environmentally challenging steps in conventional cellulosic biofuel production4 . By combining biological and mechanical disruption in a single step, Lynd's approach could dramatically lower both the cost and energy footprint of advanced biofuels.
The work in the Lynd Lab relies on a sophisticated arsenal of biological and technical tools. Below are some of the essential components that enable their groundbreaking research.
A class of enzymes that can be engineered into microbes to shift their metabolic pathways, potentially increasing ethanol production by more than twofold3 .
Lynd's vision extends far beyond the laboratory. He is a serial entrepreneur who has co-founded companies like Mascoma Corp and Terragia to drive his technologies toward commercial reality1 6 . In 2024, Terragia secured $6 million in seed funding to advance its biology-based approach to converting cellulosic biomass into ethanol, with Lynd serving as Chief Technology Officer6 .
Double-cropped corn ethanol systems in Brazil can reduce greenhouse gas emissions6 .
Biofuel systems can save land while boosting regional income6 .
Advanced biofuel systems can improve food security6 .
Combining CBP with carbon capture could achieve large negative greenhouse gas emissions6 .
"Future generations will judge us appropriately as to whether we were paying attention to the depletion of resources, and also to poverty," he reflects. "So I think this is a big deal, to head for the high ground—to look for ways that bioenergy can be part of a solution to those problems"9 .
"The first step in realizing currently improbable futures is to show that they are possible"9 . Through decades of dedicated research, Lee Lynd has shown that a future powered by grass, stalks, and leaves is not just possible—but within reach.