Adaptation of a plant-fermenting bacterium to resist lignin phenolics. BNB-BSM

Here we explore how Clostridium phytofermentans, a model for fermentation of lignocellulosic biomass, adapts to short and long-term stress from biomass-derived inhibitors by focusing on the lignin-derived phenolic, ferulic acid. We measure mRNA expression changes in response to abrupt ferulate stress at two time points after ferulate addition: t=30 min and t=4h. We apply long-term growth selection in a GM3 automat to isolate clones with progressively higher ferulate resistance. Ultimately, clones grow robustly at the solubility limit of ferulate, which previously permitted no growth. We sequence the genomes of GM3 isolates to identify positively-selected DNA variants.