Date of Degree
PhD (Doctor of Philosophy)
First Committee Member
Leonard R MacGillivray
Second Committee Member
Daniel M Quinn
Third Committee Member
Fourth Committee Member
David S Weiss
The biosynthesis of DMSP by phytoplankton and algae has wide ranging impact on marine organisms. Release of DMSP and uptake by marine bacteria leads to the eventual catabolism of this osmolyte. Enzymatic breakdown of DMSP leads to acrylate and volatile DMS production, which is fluxed into the atmosphere. When DMS enters the atmosphere it undergoes oxidation, acting as nucleation sites for water. The nucleation of water, and the subsequent cloud formation increases the albedo and reflects solar radiation. Global climate has therefore been hypothesized to be dependent upon DMSP breakdown to DMS. The enzymatic production of acrylate is also of interest for industrial applications.
Only six enzymes are known to act as a DMSP-lyase, causing the production of DMS. These enzymes are still being discovered, and until recently there was very limited analysis of the biochemical requirements for catalysis. The work presented here investigates these requirements and the structural properties that permit the elimination reaction yielding DMS.
Global cycles are influenced by a variety of sources. These cycles have a wide- ranging impact from crops to climate change. By emitting gasses, bacteria in the ocean have the ability to influence chemistry not only in the oceans, but also in the atmosphere and on the land. The release of gasses into the atmosphere has been shown to have a role in the earth’s ability to regulate the climate. Little is known as to what encourages and dictates the release of climatically active gasses from oceanic bacteria.
The work herein, examines and investigates the chemical properties that govern the breakdown of a chemical found in the ocean to a gas that is discharged into the atmosphere. The optimal amount and speed of this breakdown is modified by a particular set of conditions. Various sets of conditions are required for different enzymes and for each enzyme to carry out the reaction to produce the climatically active gas, a specific set of chemical necessities must be present. The uniqueness of necessities for each enzyme was explored and found that while some requirements are common, there are others that differentiate each enzyme from other similar enzymes. The knowledge of these chemical requirements has the potential to assist in a larger understanding of how the earth is able to regulate the climate through marine bacteria.
DMSP lyase, metal dependent
xx, 126 pages
Includes bibliographical references (pages 117-126).
Copyright © 2017 Adam Eugene Brummett
Brummett, Adam Eugene. "Enzymology of microbial dimethylsulfoniopropionate catabolism." PhD (Doctor of Philosophy) thesis, University of Iowa, 2017.