Areas of Interest
– Organic carbon cycling by microbial communities in marine sediments and seawater
– Structural characterizations and transformations of macromolecular organic matter
– Development/application of novel methods to measure microbial enzyme activities
– Relationships between microbial community composition and function
Dr. Arnosti studies the structure and reactivity of macromolecular organic matter and the role of bacterial communities in organic matter degradation. She specifically is interested in:
- Organic carbon cycling by microbial communities in marine sediments and seawater
- Structural characterizations and transformations of macromolecular organic matter
- Development/application of novel methods to measure microbial enzyme activities
- Relationships between microbial community composition and function
Grants from the American Chemical Society, NSF, and EPA provide support for Dr. Arnosti’s research.
Research & Activities
Work in the Arnosti lab focuses on microbially-driven carbon cycling in the ocean. We uses chemical and microbiological methods to investigate the chemical structure and reactivity of high molecular weight organic matter, and to determine the role of microbial communities in organic matter degradation in seawater, marine sediments, and (sometimes) in freshwater locations.
Current projects include:
- studying carbon cycling under permanently cold conditions, with fieldwork in the Arctic. We are particularly interested in determining the functional consequences of microbial biogeography: the observation that microbial communities in high-latitude environments are different from their more temperate counterparts. Our work to date demonstrates that these differences extend to the manner in which these communities process organic carbon.
- investigating the relationship between microbial community structure and function, work carried out in collaboration with the Teske lab (MASC). One current focal point of this work is on the effects of and aftermath of the Deepwater Horizon oil spill in the Gulf of Mexico.
- developing new means to measure specific steps in microbial carbon cycling is a major focal point of work in the lab. Current efforts focus particularly on development of new probes to measure microbial extracellular enzyme activities in seawater and sediments, and developing methods to measure enzyme activities in deeply-buried sediments. We are also developing new techniques to measure the activities of dissolved enzymes.
- investigating the physics and dynamics of sinking aggregates in the ocean, and the consequences of variable sinking speed for carbon cycling (in collaboration with Brian White (MASC) and colleagues in the Department of Applied Math).
This work is funded primarily by the National Science Foundation; work in the Gulf of Mexico is funded by the Gulf of Mexico Research Consortium (ECOGIG)