Please use this identifier to cite or link to this item:
Application of the rate of nucleic acid synthesis to the study of microbial growth and production in seawater
|uhm phd 8421233 uh.pdf||Version for UH users||4.34 MB||Adobe PDF||View/Open|
|uhm phd 8421233 r.pdf||Version for non-UH users. Copying/Printing is not permitted||4.4 MB||Adobe PDF||View/Open|
|Title:||Application of the rate of nucleic acid synthesis to the study of microbial growth and production in seawater|
|Authors:||Winn, Christopher David|
Nucleic acids -- Synthesis
Seawater -- Analysis
|Abstract:||The rate of nucleic acid synthesis was used as a measure of growth and production in planktonic marine microbial assembleages. Synthesis rates were measured by a new procedure which utilizes tritiated adenine as a precursor to both ribonucleic and deoxyribonucleic acid. This methodology provides a measure of the growth and production of the entire microbial community, including both the autotrophic and heterotrophic components, and represents an important advance in the study of aquatic microbiology. The 3H-adenine technique was extensively evaluated in the laboratory. Mathematical modeling was used to examine the relationship between the direct precursor to adenine incorporation and the nucleic acid endproduct. The technique was also calibrated with a variety of representative marine microbes grown under controlled conditions. These studies demonstrated that accurate rates of nucleic acid synthesis can be derived provided a few simple precautions are observed. The procedure was applied to the study of microbial growth and production in both the euphotic and the mesopelagic zones of the oligotrophic oceans around Hawaii. In the euphotic zone, microbial growth rates ranged from 0.5 to 0.8 day^-1, and microbial production integrated over the 0 to 150 m depth interval was 400 mg C m^-2 day^-1. Microbial growth rates in the mesopelagic depth interval were greater than in the overlying waters, and production integrated over the 150 to 900 m depth interval was approximately twice as great as in the euphotic zone. It is hypothesized that organic matter is rapidly and efficiently recycled in the mesopelagic, or that an additional source of energy, beyond that derived from autotrophic production in the euphotic zone, exists in this environment. Direct comparisons were also made of microbial production, extrapolated from DNA synthesis measurements, and 14CO2 primary production on a transect of the equatorial Pacific. In contrast to other direct comparisons of these parameters, microbial production greatly exceeded primary production. It is hypothesized that the 14CO2 primary production technique may have underestimated autotrophic carbon production on this transect. Finally, diel nucleic acid synthesis rates were examined. It is concluded that, whereas some diel variation may exist, nucleic acid synthesis rates remain relatively constant in nature over 24 h periods.|
Thesis (Ph. D.)--University of Hawaii at Manoa, 1984.
Includes bibliographical references.
x, 216 leaves, bound ill. 29 cm
|Rights:||All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.|
|Appears in Collections:||
Ph.D. - Oceanography|
Please email email@example.com if you need this content in ADA-compliant format.
Items in ScholarSpace are protected by copyright, with all rights reserved, unless otherwise indicated.