More of the Fuel, Twice the Food: Microbiogen’s Yeast Breakthrough

by Jim Lane (Biofuels Digest) For years, it’s been ‘food vs fuel,” a claim that has plagued ethanol producers, that somehow producing fuel from crops would lead to less food production, and anti-ethanol forces painted pictures of mass starvation and land degradation. It was mostly a canard, but an effective one — generally, when fuel is introduced into the equation, farmers respond not by clearing land to make room for fuel crops, but by increasing the yield from the lands they already control. But, it’s been a nuanced argument.

No more, bioeconomy fans. Microbiogen and its global partner Novozymes have come up with a circular technology breakthrough that completely blows up, and blows away, the food vs fuel debate.

They now have a production yeast organism that produces lots of fuel, and now the yeast have been evolved to recapture their own glycerol waste stream and produce a single cell protein than can be used as animal feed.

Let’s put this in context. If you go to Brazil and utilize this process with the bagasse streams that are the waste product of sugarcane production, you get something special. With every acre you put into sugar production, you take away 2.4 hectares of land needed to grow food for cattle production.

Less land for the cattle means less stress on land demand, and less pressure to clear Amazonian forest for cattle production. You solve the Amazonian problem not by avoiding ethanol production, but by embracing it.

It’s been a 15-year journey to commercialize technology ideas that MicroBiogen CEO Geoff Bell first developed with his year in the late 2000s.

On the Balance Beam: managing heat and other problems

Yeast fermentation is exothermic, you produce heat when you do it, and the faster you run the fermentation, it’s like a car, it heats up, it can stress out and overheat.

So, that’s another aspect in making that ‘complete yeast package’ — it’s more than just producing strains, it’s making them all work in harness with each other.

“One of the ways you add value,” Bell told The Digest, “is how you think about the waste product. One way to think about it is simply to accept that after all the work you do in hydrolysis and fermentation and clean up, that you’ll have a lot of black stuff out the back which you’ll feed to the anaerobic digesters to make biopower. The other way is to attack that problem and develop the ability of yeast to grow on its own waste streams, so that you have more opportunity to recycle that wastewater. We have the yeast producing a single-cell protein, and it’s much more circular. We had that concept 15 years ago but it took 10 years to develop a yeast that grows efficiently on yeast, they can do it, but they aren’t good at it.”

ARENA steps in as a partner

After years of development in the lab, MicroBioGen’s $8 million project formally commenced in 2017 with the intention of optimizing yeast genetics to reduce the cost of 2G biofuel production and boost its performance on key sustainability metrics. The Australian Renewable Energy Agency (ARENA) stepped in with $4 million in support.

Geoff Bell puts it more directly. “For the first time ever, a single yeast strain – optimized using our proprietary technology – can produce both clean fuel and food from non-food biomass”.