• Journal of Photoscience
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• v.9 no.2
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• pp.364-366
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• 2002

Photoadaptation of Chlorobium (Cb.) phaeobacteroides was investigated under dim and strong light intensity. Absorption spectra of these whole cellIs were different each other. The Soret band intensity and the Qy bandwidth of BChl e in c디l grown under dim light intensity were smaller and more broadened than those under strong light intensity. From HPLC analysis of the pigments, total carotenoid (Car) / bacterochorolphyll (BChl) e ratio of cell increased wi1h increase of light intensities. But camposition of BChl e hamologs almost unchanged. Cb. phaeobacteroides contains 11 kinds of Car including isorenieratene and beta-isorenieratene as major Car. The campositions of Car were different for cells grown under dim and strong light intensities. In conclusion, Cb. phaeobacteroides changes total amount and canposition of Car to adapt various light intensities, while homolog canposition of BChle unchange.

• Journal of Photoscience
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• v.8 no.3_4
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• pp.93-97
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• 2001

Heterosigma akashiwo has been reported as red-tide causing phytoplankton in the Korean coastal area during summer when they are exposed to high light. It also shows photosynthetic adaptability to strong light during culture in the laboratory. On the basis of these observations, we tried to find out some genes specifically expressed in Heterosimga akashiwo during exposure to high light, assuming that they might have some resistant mechanisms associated with light adaptation. For this purpose, we carried out DD-PCR to detect differentially expressed mRNAs from cells that had been illuminated under high light for 3 days. We found eight cDNA clones that had been expressed specificically for high light. When they were further screened by reverse Northern hybridization, three of them were identified to be positive cDNA clones. When these cDNA fragments were subjected to DNA sequencing and then their base sequences were compared to GenBank database, one of them showed sequence homology 86% identical to the partial sequence of 16S rRNA gene of eubacterium CRO-18.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.1
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• pp.29-34
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• 2003

Recent reports on the phagotrophic feeding of M. rubrum are based on cultivation experiments with novel isolates of this ciliate species from Gomso Bay, Korea. Photo-adapted cryptophyte(CR-MAL01) cultures at high light of 100 $\mu$mol photons m$^{-2}$ s$^{-1}$ (HL) and low light of 10 $\mu$mol photons m$^{-2}$ s$^{-1}$ (LL) were fed to M. rubrum (MR-MAL01) cultures under HL and LL conditions, respectively. Absorbance spectrum by LL M. rubrum showed the same peak at wavelengths around 542nm as that by LL cryptophyte prey, which was not showed in HL M. rubrum. This result supports the implication that light utilization and absorption pattern of M. rubrum population must depend on the status of photo-adaptation of the co-existing population of prey cryptophyte. Consequences of the present research results were discussed in relation to the function of the prey cryptophyte and phagotrophic M. rubrum in marine microbial ecosystem.