Microbial Conversion of Lignin into Biodegradable Plastics
This project investigates the growth of anaerobic bacteria capable of coupling the breakdown of the recalcitrant lignin biopolymer with the production of sustainable bioplastics such as polyhydroxyalkanoates (PHA). This turns a waste stream from biofuel or paper industries into a valuable product. Our main goal is to cultivate microbial communities that can simultaneously break down lignin and produce PHA. To achieve this, we will use enrichment cultures as well as genetically engineered lignin-degrading strains that have been modified to express PHA biosynthesis genes.
The student will assist with culturing these strains and monitoring their growth and PHA production using absorbance measurements, direct fluorescent microscopic counts, and nitrate reduction assays. There may also be opportunities to characterize the enrichment cultures through metagenomic sequencing and assembly. Through this project, the student will gain hands-on experience in anaerobic culturing techniques, fluorescence microscopy, molecular biology, and potentially bioinformatics.
Essay prompt: Why are you interested in studying the microbial conversion of lignin into bioplastics, and how do you think this research experience will help you achieve your future goals after graduating from UMass Amherst?
Plastic pollution and dependence on petroleum-based plastics are major global challenges. Bioplastics such as polyhydroxyalkanoates (PHA) offer biodegradable alternatives, and in this project, we link PHA production to the degradation of lignin, an abundant industrial byproduct from the paper and biofuel industries. This integrated approach addresses both waste reduction and renewable materials development in a single system. Additionally, little is known about anaerobic lignin degradation coupled to PHA synthesis, giving students the opportunity to participate in the discovery of new microbial pathways and cooperative consortia.
The project’s interdisciplinary nature blends microbial physiology, molecular biology, and bioengineering, allowing students to see how these disciplines converge to solve complex, systems-level problems. Participants will develop skills in anaerobic culturing (applicable to wastewater treatment, biogas research, and environmental microbiology), fluorescence microscopy and cell quantification (relevant to cell biology, biomedical, and bioprocessing labs), and assays for nitrate, ammonia, and lignin degradation (transferrable analytical skills). Students may also gain experience in metagenomic sequencing and bioinformatics, which are highly sought-after skills in microbiome and environmental microbiology research.
Experiences gained from participation in this project will also prepare students for graduate studies in microbiology, bioengineering, environmental science, or biochemistry, as well as for careers in industrial biotechnology (bioplastics, fermentation, waste valorization), and wastewater treatment.