Acclimation of a marine diatom, Chaetoceros gracilis, to ambient levels of UV radiation

Conference · Tue Jan 09 04:00:00 EST 1990 · EOS, Transactions, American Geophysical Union; (United States)

OSTI ID:6617155

Hazzard, C E; Kinzie, III, R A ^[1]; Taguchi, S ^[2]

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1. Univ. of Hawaii, Honolulu (United States)
2. Hokkaido Regional Fishery Lab., Kushiro (Japan)

Semi-continuous cultures of Chaetoceros gracilis were maintained in two ultraviolet (UV) exposure treatments for 23 days in natural sunlight. In one treatment algae received only wavelengths above 380 nm, while the second received total ambient UV. After acclimation, samples from both treatments were incubated in quartz bottles under ambient solar radiation. At the onset of the experiment, the cultures which were grown under reduced UV were growing 44.6% faster than the UV exposed cultures and contained 39.4% more chlorophyll/cell. After 24 hours of exposure to ambient UV, the growth rate for the reduced UV cultures decreased by 635% while that of the UV exposed cultures remained unchanged. Total productivity/chl a was significantly lower in the UV shaded cultures throughout the 24 hour period, while the rate of carbon release though dark respiration was significantly greater in the cultures which had been acclimated in ambient UV conditions. Relative amounts of carbon incorporation into lipids, intermediate weight compounds, polysaccharides and nucleic acids, and protein were significantly different between the treatments in all but the polysaccharide fraction. UV shaded cultures incorporated a higher percentage of fixed carbon into protein and lipid than UV exposed cultures while incorporating less into the intermediate weight compounds. This study suggests that naturally occurring Chaetoceros gracilis cells are able to resist the inhibitory effects of ambient UV radiation by a protective mechanism which is initiated by the presence of UV.

• OSTI ID: 6617155
• Report Number(s): CONF-9002174--
• Conference Information: Journal Name: EOS, Transactions, American Geophysical Union; (United States) Journal Volume: 71:2
• Country of Publication: United States
• Language: English

Related Subjects

560130* -- Radiation Effects on Microorganisms
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALGAE
BIOLOGICAL ADAPTATION
BIOLOGICAL EFFECTS
CARBOHYDRATES
CARBON
CHROMOPHYCOTA
DIATOMS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
GROWTH
LIPIDS
NONMETALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PLANTS
POLYSACCHARIDES
RADIATIONS
RESPIRATION
SACCHARIDES
SOLAR RADIATION
STELLAR RADIATION
ULTRAVIOLET RADIATION
WEIGHT