MCA: Characterizing the role of alternative oxidases in marine bacteria

Oregon State University, Corvallis OR

Investigators

Abstract

Bacteria are abundant on our planet, colonizing diverse environments and playing essential roles in important ecosystem processes such as nutrient cycling. They have an amazing diversity of pathways for generating the energy they need to live and function, and these pathways underlie their survival and ability to contribute to ecosystem processes. Despite this importance, there is a lack of knowledge of how the function of specific energy generation pathways connects to bacterial fitness and these organisms’ role in the function of our environment. This project focuses on better understanding how alternative oxidase (AOX), a component of energy-generating pathways of marine bacteria that play vital roles in nutrient cycling, functions in their growth and survival. This award will allow the investigator to develop skills they will use to discover how alternative oxidase is expressed and functions in diverse bacteria and begin to connect this to nutrient cycling pathways. In addition, the investigator will couple these research activities with student training, outreach to K-12 students in Hawaii and the mainland, and the development of new diversity, equity, and inclusion efforts at their home institution. Research on AOX function in eukaryotes has been a very active area in recent years. Studies in plants, protists, fungi, and animals have revealed a common thread in AOX activity in helping cells deal effectively with environmental stresses and maintain energy balance. However, outside of the investigator’s work in Vibrio fischeri, the physiological role(s) of AOX in marine bacteria is essentially unexplored. Unanswered questions include how AOX functions in diverse bacteria and whether there are commonalities in physiological pathways in AOX-encoding bacteria or correlations between environmental conditions and the presence of aox-encoding bacteria. This project will address these knowledge gaps using three approaches: 1) microrespirometry along with genetic, biochemical, and molecular approaches to determine the physiological role of V. fischeri AOX under environmentally relevant conditions; 2) genetic, molecular, and biochemical approaches to understand the regulation and physiological contribution(s) of AOX in other diverse model marine bacteria; and 3) bioinformatic approaches to identify the genomic features and environmental conditions that correlate with aox abundance and expression. The results of this research will provide valuable new information about AOX regulation and function in bacteria and lay the foundation for further exploration of the influence of bacterial AOX on microbial physiology, marine ecosystem function, and biogeochemical cycling. These results will also provide insight into commonalities in the regulation and function of AOX in different kingdoms of life. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.