Dr. Ronald P. Kiene
Professor, University of South Alabama
Senior Marine Scientist III,Dauphin Island Sea Lab
Ph.D. 1986, SUNY Stony Brook
Emphasis: Biogeochemistry and microbial ecology; organic sulfur cycling
My research focuses on the role of microorganisms in the cycling of organic matter
and important elements such as sulfur and nitrogen in aquatic systems.
A major focus of my research program is the biogeochemical cycling of dimethylsulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) in the marine water column. We carry out this research in local waters but also on oceanographic cruises all over the world. This field continues to broaden as we have discovered new and important roles for DMSP and its degradation products in the marine ecosystem. DMSP is produced by many, but not all, marine algae who use it as an osmotic solute and potentially an antioxidant. DMSP is degraded by microorganisms to volatile DMS which is a major source of sulfur to the atmosphere. This input of DMS to the atmosphere significantly affects atmospheric chemistry (especially the pH of precipitation) and also the global climate system because DMS is oxidized to sulfate aerosols (tiny crystals of salt). Sulfate aerosols affect climate by directly reflecting solar radiation back to space and by serving as cloud condensation nuclei, which in turn affect how clouds reflect solar radiation.
Here are some brief highlights of ongoing projects
The role of DMSP as an antioxidant in marine algae – With funding from the NSF Biological Oceanography program we are testing the hypothesis that DMSP and its degradation products are important scavengers of reactive oxygen species in cells of marine algae. We are using pure cultures of marine phytoplankton as well as natural populations in seawater to study the physiological responses of the algae to oxidative stresses. One of the responses we are particularly interested in is the algal degradation of DMSP to DMS, catalyzed by DMSP lyase enzymes. We are examining the activity and regulation of DMSP lyase in the oxidative stress physiology of the phytoplankton. With separate funding from EPA we are also examining the oxidative stress physiology of the marsh grass Spartina alterniflora, another DMSP producer.
Current Research Grants
National Science Foundation – Polar Programs-Antarctic Biology and Medicine. Impact of solar radiation and nutrients on biogeochemical cycling of DMSP and DMS in the Ross Sea , Antarctica . (with David Kieber, SUNY ESF).
National Science Foundation – Biocomplexity in the Environment. Complex molecular to global interactions and feedbacks in the marine DMS cycle. (with Patricia Matrai, Bigelow Laboratory, and several other PI’s).
National Science Foundation – Biological Oceanography. Production and dynamics of DMSP and related compounds in response to oxidative stress in marine phytoplankton. (with David Kieber, SUNY ESF ).
National Science Foundation – Microbial genetics. Bacterial Regulation of Organic Sulfur Cycling in the Ocean: A Genomic Approach.. sub-contract from Univ. Georgia , under grant to Mary Ann Moran.
Environmental Protection Agency – Alabama Center for Estuarine Studies. Oxidative stress protection by dimethylsulfoniopropionate(DMSP) in Spartina alterniflora.
|Current Graduate Students||Post Doctoral Associates||Technicians|
|J. Daniel Husband||Doris Slezak||Jennifer Meeks|
|Daniela del Valle|