Around 85% of brewery waste is spent grain, which spoils rapidly and is difficult to compost.
As a result, breweries often have little choice but to sell it cheaply as animal feed or send it to landfill, where it contributes to carbon emissions.
Around 85% of brewery waste is spent grain. Photo / 123rf
“Brewers have to organise farmers to come and pick up the waste on the same day that they do the brewing, and if it’s not that same day, then it’s gone off, and it can’t be fed to animals,” third-year biochemistry student Jade Wilson said.
She explained that nanocellulose is a tiny, high-performance fibre with a global market value in the billions of dollars, thanks to its diverse applications.
“It’s one of those new, really exciting materials, so it’s being explored in a range of applications,” she said.
A UC spokesperson said design researchers were already developing products from nanocellulose, including wound dressings, oil remediation, cosmetic formulations, and potentially also plastic substitutes.
Wilson said that the opportunity for the brewing industry was “significant” and would transform their largest waste stream into a “valuable commodity, potentially creating packaging or containers from their own byproducts”.
The Nanobrew team of 10 student biochemists, biologists and engineers is working with local and national breweries and brewing industry-focused organisations to test their concept.
“The students’ approach combines cutting-edge synthetic biology with practical engineering. They plan to use two specialised enzymes to break down the complex plant structures surrounding cellulose fibres in barley grain, then further process those fibres into nano-scale particles,” a UC spokesperson said.
If successful, Nanobrew could offer New Zealand breweries an opportunity to lead globally in sustainability while tapping into a billion-dollar material market. Photo / Supplied / 123RF
“One enzyme is particularly innovative: an ancestral endoglucanase reconstructed from computer analysis of proteins across different species throughout evolutionary time. This hypothetical enzyme, which never actually existed in nature but represents the theoretical ancestor of modern enzymes, has been shown to be more thermally stable and resistant to different conditions than naturally occurring versions.
“The goal is to design a bioreactor, which is essentially a large vat where bacteria produce the enzymes that break down the spent grain, yielding nanocellulose at the other end.
“If successful, Nanobrew could offer New Zealand breweries an opportunity to lead globally in sustainability while tapping into a billion-dollar material market — all from what they currently throw away.”
Nanobrew’s research will be completed by October and judged as part of the international Genetically Engineered Machine (iGEM) synthetic biology competition.
They plan to share their findings publicly in December.