The feedstocks currently used by U.S.-based PLA manufacturer NatureWorks in the production of its Ingeo material are based on plant sugars that undergo a simple lactic acid fermentation process. The debate about ground use and the cultivation of feed and food crops for plastics continues, which has led the company to research the possibilities for feedstock diversification.
One of the alternatives currently being studied is the use of the greenhouse gas methane, in collaboration with a company called Calysta. Calysta is specialized in the development of proprietary organisms and biocatalysts to economically convert methane to the building blocks of higher-value, easily transportable fuels and chemicals. For NatureWorks, methane could be an additional feedstock several generations removed from the current crop-derived sugars used. The two companies NatureWorks and Calysta embarked on a multi-year development program that aims to sequester and use methane as a feedstock for NatureWorks' Ingeo biopolymers.