(238a) Metabolic Engineering for Lignocellulosic Biopolymer Production.

Microorganisms inherently produce biopolymers with diverse applications, from 3D-printed materials to pharmaceutical scaffolds. While these microbes offer a sustainable alternative to conventional polymer manufacturing, scaling production remains economically challenging due to constraints in substrate utilization, metabolic robustness, and yield optimization. A critical opportunity lies in engineering microbial platforms that efficiently convert lignocellulose-derived sugars into high-value biopolymers. This presentation explores two engineered systems: polyhydroxyalkanoate (PHA) and bacterial cellulose (BC) production.

First, development of next-generation Cupriavidus necator whole-cell biocatalysts will be discussed. Traditionally, tailoring metabolism of C. necator for application-specific PHA production has been hindered by slow, laborious strain development. To overcome this, we engineered a novel platform strain with chromosomally integrated CRISPR-Cas9, enabling rapid genetic optimization. We demonstrate how this system identifies genetic and environmental drivers of PHA molecular weight and copolymer composition.

Next, metabolic engineering of Komagataeibacter xylinus for lignocellulosic BC production will be discussed. By systematically evaluating growth and production metrics, we identified a superior host strain for metabolic enhancement. Through targeted pathway engineering, we achieved significant improvements in cell growth and BC production rates, which are two critical bottlenecks in industrial scaling. Additionally, we engineered a fermentation process that controls BC particle size while boosting titers, paving the way for customizable biomaterials.