Identity and dynamics of the microbial community responsible for carbon monoxide oxidation in marine environments
Citable URI
https://hdl.handle.net/1912/2432Location
Sargasso SeaVineyard Sound, MA
DOI
10.1575/1912/2432Keyword
Carbon monoxide; Oxidation; Seawater; Microbial ecologyAbstract
As colored dissolved organic matter in seawater absorbs UV solar radiation, a variety of simple chemical
species are produced, including carbon monoxide (CO). The ocean surface water is saturated with respect
to CO, and is thus a source of CO to the atmosphere. CO reacts with and removes free-radical compounds,
and may itself contribute to the 'greenhouse' gas content of the atmosphere. An important sink for CO in
seawater is the biological oxidation of CO to CO2 by marine microorganisms. The objectives of this study
are to identify component members of the microbial community responsible for the oxidation of CO in
coastal marine environments through a combination of recent microbiological and molecular approaches,
and to estimate their contributions to total in situ CO bio-oxidation. We utilize an enrichment method that
involves cultivation of bacteria on membrane filters, subsequent incubation with radiolabeled CO, and the
use of autoradiography to screen colonies with the desired phenotype. Cell-specific CO-oxidation activity
is determined for selected purified strains with a time-series 14CO-oxidation method. Molecular phylogeny
based on 16S-rDNA gene sequence information within the context of the large and growing 168 database
determines the phylogenetic relatedness and identity of marine CO-oxidizing bacteria that result from our
cultivation program. The CO oxidizing organisms isolated in this study with greatest activity are closely
related to the Roseobacter and Paracoccus genera of the alpha-proteobacteria, collectively known as the
"marine alpha group". Other microorganisms found to oxidize CO at environmentally relevant rates are
members of beta- and gamma-proteobacteria, and one in the Cytophaga-Flavobacterium-Bacteroides
group.
A collective CO-oxidation activity was calculated from physiological measurements of purified isolates
and abundance estimates of CO-oxidizing marine alpha group organisms. Relative proportions of CO-oxidizing
Roseobacter and Paracoccus cells were resolved microscopically by microautoradiography in
combination with DAPI and fluorescent-labeled oligonucleotide probes (Substrate Tracking
AutoRadiography - Fluorescent In Situ Hybridization (STAR-FISH)). Marine alpha group organisms were
a major component of total cell numbers (45.7%) at the time of sampling (March 2003), and CO-oxidizing
members of the marine alpha group contributed up to 40.7% of total CO oxidation occurring in coastal
waters.
Description
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2003
Collections
Suggested Citation
Thesis: Tolli, John D., "Identity and dynamics of the microbial community responsible for carbon monoxide oxidation in marine environments", 2003-09, DOI:10.1575/1912/2432, https://hdl.handle.net/1912/2432Related items
Showing items related by title, author, creator and subject.
-
A model of the temporal and spatial distribution of carbon monoxide in the mixed layer
Kettle, A. James (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1994-06)A field experiment demonstrated the presence of a diurnal cycle in the concentration of carbon monoxide ([CO]) in the upper ocean at the BATS site. A series of laboratory experiments and numerical simulations were carried ... -
Unexpected diversity of bacteria capable of carbon monoxide oxidation in a coastal marine environment, and contribution of the Roseobacter-cssociated clade to total CO oxidation
Tolli, John D.; Sievert, Stefan M.; Taylor, Craig D. (American Society for Microbiology, 2006-03)The species diversity, phylogenetic affiliations, and physiological activity rates of carbon monoxide-oxidizing microorganisms were investigated, using new isolates from surface waters collected from the coast of New England ... -
Evidence for significant photochemical production of carbon monoxide by particles in coastal and oligotrophic marine waters
Xie, Huixiang; Zafiriou, Oliver C. (American Geophysical Union, 2009-12-09)Carbon monoxide (CO) photoproduction from particulate and chromophoric dissolved organic matter (CDOM) was determined in seawater from open-ocean and coastal areas. In confirmatory tests, poisoned or non-poisoned filtered ...