Research Starter Grant: Metabolic Pathways in Bacterial Utilization of Hemicellulosic Sugars

Cornell University, Ithaca NY

Investigators

Abstract

Intellectual Merit As part of the cycle of carbon on earth, plants store carbon dioxide into their biomass as organic carbon, which can be subsequently respired back into the atmosphere as carbon dioxide via microbial degradation of plant detritus. Natural microbial respiration of plant biomass is estimated to contribute eight to ten times greater carbon dioxide inputs than human activities. Previous field observations have indicated a dependence of decomposition of plant matter on the type of vegetation cover and that an increase in temperatures can lead to increased decomposition rates. Thus, of important interest is a fundamental understanding of the biological factors controlling the decomposition rates of different plant matter components. However, the biological pathways responsible for the respiration of plant matter components are not well understood. The working hypothesis to be addressed by this research is that the decomposition rates of plant matter are tightly linked to the pathways underlying the catabolism of the different organic moieties in plant matter. Using Pseudomona putida as a model aerobic bacterial organism, the pathways by which hemicellulosic sugars are metabolized will be investigated. The results from this study will contribute to our understanding of the biochemical dynamics underlying the metabolism of plant matter, a necessary pre-requisite to accurate predictions of the feedback response of the global carbon cycle to climate change. Broader Impacts This project will involve the training and participation of young scientists to address global environmental issues at a fundamental level. Given the global importance of this research with environmental implications, the obtained results will be of interest to scientists across various biological and chemical disciplines and to society at-large, and will be published in journals with broad dissemination.