As a Ph.D. student, I worked in the laboratory of Dr. André-Denis Wright in the Department of Animal Science at the University of Vermont. My thesis work investigated the microorganisms (bacteria, archaea, and protozoa) in the digestive tract of the moose from several geographical locations. In addition to identifying bacteria and ciliate protozoa using high-throughput sequencing, I was the first to identify methanogenic archaea in moose. I also cultured over 100 bacterial isolates form the rumen of moose in Vermont, some of which were then used in a probiotic study to improve fiber digestion in lambs. To test my probiotic in vivo, I was awarded a NIFA Pre-Doctoral Fellowship grant from the USDA in 2013.
I gained experience in aerobic and anaerobic culturing, microbiology and biochemical investigations of bacterial isolates, DNA extraction, PCR, qualitative real-time PCR, high-throughput sequencing library generation, DNA analysis, and animal handling. This breadth of work was accomplished with digesta or fecal samples from alpaca, antelope, beaver, black bear, cows, elephants, giraffe, horses, humans, mice, reindeer, and sheep, though the focus of my graduate work was on the rumen microbiome of moose.
Moose (Alces alces) are the largest member of the Cervidae (deer) family, and can be found across most of Canada, some parts of the northern US and Alaska, Scandinavia, and across Russia. They inhabit mixed deciduous/coniferous, consuming browse such as bark, twigs and leaves of willow, aspen, maple, birch, ash, apple, blueberry, and pine. Additionally, they consume seasonally available aquatic vegetation, which is much higher in salt than most arboreal plants. Overall, the diet of moose is high in fiber, especially cellulose and lignin. As sodium is a limiting nutrient in their diet, moose have several unique characteristics in their digestive tract which allow them to store sodium, or even replace sodium in saliva with potassium. During the lean winter months, they routinely lose up to 20% of their bodyweight. Combined, these attributes provide a unique digestive tract environment and host-microbe interaction. The focus of my graduate studies was to investigate the microorganisms in the digestive tract of the moose, isolate and culture those which degrade fiber, and introduce fibrolytic bacteria into other systems to improve fiber degradation.
Pellegrini, Suzanne Ishaq, “A Comparative Analysis Of The Moose Rumen Microbiota And The Pursuit Of Improving Fibrolytic Systems.” (2015). Graduate College Dissertations and Theses. Paper 365. Dissertation | Seminar | Dissertation Seminar Slides