A team of UBC researchers has discovered a new bacterium that enhances the conversion of food waste into renewable natural gas, providing a significant breakthrough in waste management and renewable energy production.
In a new study, researchers at the University of British Columbia (UBC) have identified a previously unknown bacterium that plays a pivotal role in transforming food waste into renewable natural gas (RNG). This discovery, published in Nature Microbiology, underscores the potential for more efficient waste-to-energy processes and bolsters the promise of sustainable energy solutions.
Each year, the Surrey Biofuel Facility processes 115,000 tonnes of food waste. This waste, which includes everything from banana peels to leftover pizza, undergoes a transformation thanks to billions of microbes. These microorganisms break down the organic matter to produce RNG, a cleaner alternative to fossil fuels.
Ryan Ziels, an associate professor in UBC’s department of civil engineering, led the study. He was intrigued when he observed that ordinary microbial activity had ceased, yet methane production continued unabated.
“We were studying microbial energy production in the Surrey Biofuel Facility when we noticed something odd: the microbes that usually consume acetic acid had vanished, yet the methane kept flowing,” Ziels said in a news release. “Traditional methods couldn’t identify the organisms doing the heavy lifting.”
The phenomenon was particularly perplexing because methane production is a multi-step process involving various microbial interactions. Initially, bacteria decompose the food scraps into simple compounds like fatty acids, amino acids and sugars, which then transform into organic acids such as acetic acid. Methane-producing microbes feed on these acids to produce methane.
The new bacterium belongs to the Natronincolaceae family and thrives in conditions where traditional methane producers would fail.
“Converting waste to methane is a cooperative process involving multiple interacting microbes,” added co-author Steven Hallam, a professor in UBC’s department of microbiology and immunology. “This newly identified bacterium is one of the key players making it happen.”
One of the critical findings of Ziels and his team’s research is that the new bacterium can withstand high levels of ammonia — a common byproduct of protein-rich food waste.
Excessive ammonia typically disrupts methane production by causing acetic acid to accumulate, turning the waste tanks acidic and unproductive. The hardy nature of this bacterium helps keep the system operational even under these challenging conditions.
“Municipal facilities owe a lot to these organisms,” Ziels added. “If acetic acid builds up, tanks have to be dumped and restarted — an expensive, messy process.”
The implications of this discovery are far-reaching. Insights from this study could significantly improve the design and efficiency of anaerobic digesters, making it possible to produce more RNG from the same amount of organic waste.
It also presents a model for better managing waste and energy production, crucial at a time when cities are grappling with waste management and climate change.
Ziels and his colleagues are now expanding their research to explore microbial communities that break down microplastics in the ocean, potentially opening up new frontiers in environmental remediation.
“Next time you toss your scraps in the compost bin, remember: you’re not just composting. You’re feeding microscopic powerhouses that help produce cleaner energy,” added Ziels.