Fueling Sustainability: Engineering Anaerobic Gut Fungi for Biomass Breakdown

McDonnell Douglas Engineering Auditorium

ChEMS Seminar

Prof. Michelle A. O'Malley

Chemical Engineering Department

University of California, Santa Barbara



Renewable biofuels derived from plant biomass (stems, stocks, and leaves, mainly composed of cellulose and lignin) are attractive alternatives to petroleum-based fuels. To produce biofuels, enzymes are used to break down cellulose into simple sugars, which are later fermented into fuels such as ethanol and butanol. However, because the structure of cellulose is a tightly bound network of crystalline cellulosic fibers and lignin, existing biomass degrading enzymes are not very efficient. To develop new technologies to break down plant material into sugar, much can be learned by studying how microbes digest lignocellulose in biomass-rich environments, such as the digestive tract of large herbivores. Anaerobic fungi are native to the gut and rumen of these animals, where they have evolved powerful enzymes to degrade plant biomass. Our goal is to develop new experimental tools to engineer anaerobic fungi for lignocellulose breakdown and biofuel production. To accomplish this goal, we isolated a panel of anaerobic fungi from different herbivores and screened for their ability to degrade several types of lignin-rich grasses and agricultural waste. By focusing on a model anaerobic fungus (Piromyces sp finn), we have employed next-generation sequencing to discover thousands of new genes from this microbe, revealing hundreds of novel cellulases. Additionally, we have characterized key regulatory patterns for these cellulases, which depend on the environment of the fungus. Using this information, new genetic engineering strategies will be developed to manipulate gut fungi at the molecular level. Understanding the biology of these unique microbes will result in the development novel platforms for biofuel and sustainable chemical production.



Michelle A. O’Malley earned a B.S. in Chemical Engineering and Biomedical Engineering from Carnegie Mellon University in 2004. She holds a PhD in Chemical Engineering from the University of Delaware in 2009, where she worked with Prof. Anne Robinson to engineer overproduction of membrane proteins in yeast. O’Malley was a postdoctoral fellow in the Department of Biology at MIT with Chris Kaiser and Aviv Regev, where she developed new strategies for cellulosic biofuel production. She joined the Chemical Engineering faculty at UC-Santa Barbara in 2012, and her research group engineers protein synthesis and cellular behavior for biofuel production and structure-based drug design. O’Malley is the recipient of a DOE Early Career Award, a USDA-NIFA Fellowship, a Whiting Foundation Fellowship, and a NASA-Harriett G. Jenkins predoctoral fellowship.