Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
The development of robust biocatalysts with enhanced resistance to the inhibitors is one of the key elements for commercial biofuel production. Zymomonas mobilis is an ethanologenic bacterium with high productivity and high ethanol tolerance that we have engineered to use both glucose and xylose. In this study, the molecular response of the xylose-fermenting strain Z. mobilis 8b to furfural (a strong inhibitor) was investigated using transcriptomic approaches of both chip-based microarray and next-generation sequencing (NGS)-based strand specific RNA-Seq (ssRNA-Seq). Time course experiments with furfural shock were carried out to study the short and long-term effect of furfural on physiological and transcriptional profiles of 8b. Furfural, added at the beginning of fermentation and later during exponential phase, inhibited growth in terms of final biomass and the fermentation time. Transcriptomic studies indicated that the response of 8b to furfural is dynamic, complex and differences exist between short-term shock and long-term stress responses. However, the gene function categories affected by both treatments were similar with the most regulated genes falling into common categories. Our comparison of microarray and ssRNA-Seq platforms indicated that the ssRNA-Seq data provided valuable insights, not only in gene expression profiling, but also in transcriptional architecture, which will expand our scientific understanding and directly help strain improvement efforts.