A research team led by the Oak Ridge Bioengineering Laboratory (ORNL) has grown a bacterium that efficiently converts waste into itaconic acid. It is an industrial chemical used in plastics and paints.
Itaconic acid, or methyl succinic acid, is a valuable chemical used in the polymer industry, wastewater treatment, and ion exchange chromatography. It can be turned into a chemical that burns better than gasoline. The industrial production of itaconic acid involves the fungi Aspergillus terreus.
The problem is that they eat relatively pure sugars. Their use makes the process too expensive. In their work, ORNL scientists used lignin – waste from biorefineries and paper mills – to grow the bacterium Pseudomonas putida to potentially produce itaconic acid at a lower cost.
Biologists have created a dynamic control method that separates the growth and production phases of bacteria using a special biosensor to increase the efficiency and yield of acid. It starts the metabolic pathway for the production of itaconic acid only after the bacteria have consumed all the nitrogen that feeds their growth.
“The technology will add value to biorefineries by converting lignin into a valuable chemical,” says ORNL’s Adam Gass. – One strain has reached almost 90% of the theoretical yield at the production stage and can still be optimized. The new method is applicable to other wastes as well.”