Trash to beauty: Scientists turn waste into cosmetics chemicals with bacteria

Researchers at the University of Toronto have identified how certain bacteria can be guided to turn waste into valuable industrial chemicals now largely sourced from palm oil. The discovery could help create a more sustainable route to making medium-chain carboxylic acids, or MCCAs, a family of molecules used in cosmetics, cleaning products, agricultural feed, antimicrobials, and nutritional supplements. Today, many of these chemicals come from palm kernel oil. Palm oil production has long faced criticism over links to deforestation, biodiversity loss, and weak supply-chain traceability. The team says bacterial fermentation could offer an alternative by converting food waste and agricultural byproducts into high-value chemicals instead of relying on crops. Waste into value “The chemicals we are targeting here are known as medium-chain carboxylic acids (MCCAs) or medium-chain fatty acids (MCFAs),” said Professor Chris Lawson, who led the study. “They are six to twelve carbon atoms long, and they are used in all kinds of things: agricultural feeds, cosmetics, antimicrobials, surfactants and much more. The global market for them is on the order of $3 billion.” The researchers focused on chain-elongating bacteria, or CEBs. These microbes live without oxygen and can naturally convert organic material into useful acids through fermentation, a process similar to how yeast produces alcohol. Because the bacteria can feed on waste streams rather than refined sugars, they may lower costs while reducing food-based inputs used in conventional bio-manufacturing. Examples being explored include municipal food waste, such as material collected through Toronto’s Green Bin program, and byproducts from dairy processing. But the microbes have one major drawback: they do not always make the most valuable product. “What we want them to produce is octanoic acid, which is eight carbons long and one of the most high-value MCFAs, especially because palm kernel oil doesn’t contain that much …