The new fermentation process uses E. coli to convert glycerin into high-value chemicals such as succinate, which is used as a flavoring agent in food and beverages.
Most of the waste glycerin comes from the production of biodiesel, which is converted from a variety of oils, including rapeseed and soybean oils, mustard, flax, sunflower, and palm oil, waste vegetable oil, animal fat oil, and algae.
Glycerin is cheap and abundant but although there are many potential uses for the substance, it has been difficult to break it down into products with greater economic value.
Succinate and its derivatives have an annual domestic market of more than $1.3bn. It is used in a variety of products as a flavoring agent, as well as an intermediate compound for dyes and perfumes, and medical applications.
Formate, another product from the process developed with funding from US Department of Agriculture’s Cooperative State Research, Education, and Extension Service, is principally used as a preservative and antibacterial agent in livestock feed.
Ramon Gonzalez, the William W Akers Assistant Professor in Chemical and Biomolecular Engineering at Rice University, who developed the new process, said: “Biodiesel producers used to sell their leftover glycerin, but the rapid increase in biodiesel production has left them paying to get rid of it.
“The new metabolic pathways we have uncovered pave the way for the development of new technologies to convert this waste product into high-value chemicals.”
Making good use of waste products is also a big issue in the food industry, along with biofuels policy, as crops such as corn are diverted to ethanol production.
Recently chairman and CEO of Kraft Foods, Irene Rosenfeld, said the US biofuels policy is resulting in soaring global food prices, along with unprecedented high input costs for the food industry, and needs to be changed.
Similarly, as biofuel production increases, the market is being flooded with its waste byproducts, specifically glycerin, or glycerol.
Technologies based on Gonzalez's work have been licensed to Glycos Biotechnologies Inc., a Houston-based startup company that plans to open its first demonstration facility within the next 12 months.
Biofuel policy
Kraft, along with other member companies of the Grocery Manufacturers Association, is working to raise awareness and petition lawmakers and regulators to adjust the current biofuels policy so it is more in line with market forces.
The US is spearheading research into second generation biofuels, which would draw on waste cellulose material instead of diverting grain supplies from food.
Similarly food companies are taking another look at waste, as by-products from production are a major problem to industry. Disposal can be costly and if a firm must pay for the whole fruit, they may as well find a way to use it all.