Sandeep Kumar

Doctor of Philosophy, (Microbiology & Genetics)
Study Completed: 2018
College of Sciences


Thesis Title
Physiology of rumen bacteria associated with low methane emitting sheep

Read article at Massey Research Online: MRO icon

Methane is a byproduct of feed digestion by rumen microorganisms. It contributes about one-third of New Zealand's anthropogenic greenhouse gases. Breeding ruminants that naturally produce less methane is one strategy to reduce emissions. Mr Kumar investigated key bacteria associated with low methane emitting sheep. By studying the physiology of these bacteria, he found that Sharpea and Kandleria (genera) produce mainly lactate as their major end product. He also studied Quinella, an iconic bacterium first seen in sheep rumen contents in 1913, which has not been cultured in the laboratory. By analysing four Quinella genomes assembled from DNA extracted from rumen contents, he found that Quinella has all the genes needed to produce propionate and acetate as well as lactate. Research results showed that all these key bacteria produce little or no hydrogen, a major precursor for methane, explaining why greater abundances of these bacteria leads to lower methane emissions.

Dr Mark Patchett
Dr Peter Janssen
Dr Dragana Gagic