A UW-Madison researcher in collaboration with a researcher at Sandia National Laboratory has developed a simple, low-cost process for producing PHA (polyhydroxyalkanoate) co-polymers, a molecule that can be used to form biodegradable plastics, from two common lignin waste streams. The researchers recognized that the lignin waste streams from oxidative catalytic fractionation and base-catalyzed depolymerization, two different biomass treatment processes, resulted in a pH<5 and a pH>9 solution respectively. If they were combined, they might provide a more neutral, microbe-friendly lignin solution. They found that the resulting combined solution had a pH of 6-8. Adding microbial strains engineered to produce PHA co-polymers to the neutralized solution resulted in various PHA co-polymers being produced.