EBI Personnel Directory Zhang, Wenjun


Biofuels Production

Wenjun Zhang

wjzhang@berkeley.edu

 

 

Project(s)

Microbial Production of 1-Undecene and Related Fuel-like Molecules

Bacterial volatiles represent a source for new biofuel compounds in addition to the traditional bioethanol and plant oil-derived biodiesel. The identified relevant volatile compounds include various short- to mediun-chain alkanes, alkenes, alcohols and isoprenoids, which have great potential to replace or supplement petroleum-derived fuels. For example, butanol, isopentanol, undecene and undecane are routinely observed in Pseudomonas cultures. l-Undecene is particularly intriguing attributed to its superior physical properties, which may have direct applications as both a fuel and an industrial chemical. However, little is known about the enzymatic logic for biosynthesis of many volatile organic compounds (VOCs) produced by various bacterial cultures. This project seeks to understand the biosynthetic machinery and to engineer the biosynthesis of l-undecene and related fuel-like molecules. The results will expand our molecular toolbox for hydrocarbon biosynthesis and facilitate the production of new microbial fuels.
 


Improving Clostridial Fermentation Performance by Signaling Molecules

Extracellular signaling small molecules (SSMs) are commonly used by bacteria to access information about both the intracellular physiological status and extracellular environment. These small molecules are critical in controlling complex biological processes including morphological differentiation, multicellularity, biofilm formation, virulence, motility, stress response, substrate usage, and secondary metabolite production. Despite the importance of SSMs In bacterial physiology and behavior, little is known about SSMs in clostridia. Although genomic analysis indicates the presence of SSMs in this genus, little work has been done to experimentally investigate these molecules. In order to improve the performance of clostridial ABE fermentation, it is crucial to unveil the identity and function of hidden SSMs in relevant Clostridium species. The governing hypothesis of this proposal is that SSMs can be used to manipulate clostridial fermentations by controlling cell density, cellular development, substrate usage, solvent production, and solvent tolerance. This project will use comprehensive approaches: activity-based profiling and targeted genome mining to unveil SSMs of clostridia, with the goal of improving ABE fermentation performance. In addition, common bacterial pheromones, especially those involved in morphological differentiation and the initiation of secondary metabolite production, will be applied to clostridial cultures to probe the possible beneficial effects of heterogenous SSMs on ABE fermentation.