(399g) Transcriptional Response of Lactobacillus Brevis to Sudden Ferulic Acid Stress

There is great interest in the use of waste biomass to reduce the environmental footprint and cost of biological processes. Preparing the biomass by acid hydrolysis generates toxic phenolic acids such as the model compound ferulic acid, however, that must be removed prior to further downstream processing. Lactobacillus brevis, a poorly characterized heterofermentative lactic acid bacterium, exhibits high tolerances of ferulic acid and other phenolic acids that are common in hydrolyzed biomass. A better understanding the genetic basis for this complex phenotype can guide efforts to engineer other bacterial strains. Here we examine the transcriptional response of L. brevis to sudden ferulic acid stress to achieve that end. We find evidence to suggest that L. brevis undertakes a variety of ameloriative actions, including specific membrane modifications, phenolic acid decarboxylase expression, and others in response to ferulic acid in situ. These results will aid in the creation of phenolic-tolerant strains necessary for the utilization of untreated biomass hydrolysates.