Susan Leschine
Humans and other animals comprise microbial communities that are essential for health. In particular, gastrointestinal tracts of animals are colonized by hundreds of microbial species that contribute to nutrition and health in myriad ways, many of which are only now being recognized. Our research is focused on microbes that convert complex plant polymers into chemicals that have commercial value, such as biofuels, or play a direct role in animal and human health. We are testing the hypothesis that these microbes link nutrition to health via their metabolism of plant polysaccharides. Our research is aimed at harnessing the diversity of gut microbial communities and the power of genomics for novel technologies to benefit animal and human health.
Current Research
The diversity of the microbial world is enormous, and microbes constitute a valuable physiological and genetic resource. The overarching goal of our research is to advance understanding of the biology of diverse microorganisms and interactions among these organisms and their environments.
The most abundant organic materials on Earth are plant structural polysaccharides such as cellulose, and the decomposition of these complex carbohydrates is carried out almost exclusively by microorganisms. A major objective of our research program is to expand our knowledge of the physiology, ecology, and diversity of polysaccharide-decomposing members of microbial communities, to discern the nature of key interactions among community members and with their insoluble substrates, and to understand how these interactions may contribute to the efficient degradation of insoluble polysaccharides. Much of our research has focused on Clostridium phytofermentans, a bacterium discovered in forest soil near Quabbin Reservoir, which possesses unique properties including the ability to catalyze the direct conversion of plant biomass to ethanol. Based on the capabilities of this microbe, we developed a technology for cellulosic biofuel production. This technology has been licensed by UMass to a Massachusetts biofuels company.
Most animals lack the enzymatic capacity required to digest cellulose and many other components of plant cell walls, and instead rely on plant biomass-decomposing microbial communities to provide nutrition from plant fiber. Ruminants, a group of herbivorous mammals, degrade forage in a specialized foregut organ, the rumen. The microbial community housed in the rumen plays an essential role in development and health of the ruminant by decomposing and fermenting plant materials, and forming products that serve as essential nutrients. In humans, complex plant carbohydrates, known as “dietary fiber,” serve as substrates for intestinal microbes that ferment these plant polymers to short chain fatty acids, such as butyrate, which are tied to colonic and systemic health.
With the recent explosion of metagenomic data and studies of human and animal microbiomes, it has become apparent that relatives of C. phytofermentans (members of the Lachnospiraceae family) form a significant component of beneficial intestinal microbial communities. This observation has led to the hypothesis that these microbes may form a link between nutrition and health, related to their metabolism and the ability to transform complex plant substances into health-promoting nutrients. Currently, we are testing this hypothesis by examining the potential of these microbes to enhance the nutritional value of fibrous animal feeds.
Learn more at www.vasci.umass.edu/research-faculty/susan-leschine
Academic Background
- PhD University of Pittsburgh
Honors
- Waksman Lecturer, Waksman Foundation for Microbiology; Women to Watch, Mass High Tech: The Journal of New England Technology; Top Ten Women in Cleantech, Earth2Tech; Top 25 Women in Technology, AlwaysOn Network; Top Ten Women of Biofuels, Women In Cleantech & Sustainability; Biotech Humanitarian Award, Biotechnology Industry Organization
