Pheophytinization of bacteriochlorophyll c and energy transfer in cells of Chlorobium tepidum
Research output: Contribution to journal › Journal article › Research › peer-review
Bacteriochlorophyll (BChl) c in whole cells of Chlorobium tepidum grown at 46 degrees C changed into bacteriopheophytin (BPhe) c within 10 days after reaching full growth. When a small amount of C. tepidum cells in which BChl c had been completely pheophytinized were transferred to a new culture medium, normal growth was observed after a short lag phase, and the absorption spectrum of the growing cells showed the presence of a normal amount of BChl c. During the growth of C. tepidum in the new culture, the BChl c concentration was nearly proportional to the cell density measured by turbidity (OD640). These results indicate that C. tepidum can survive even when BChl c has been completely pheophytinized and that BChl c is newly synthesized in such cells when transferred to a new culture medium. In partly pheophytinized cells, upon excitation of BPhe c at 550 nm the fluorescence emission spectrum showed maxima at 775 and 810 nm, which correspond to emissions from BChl c and BChl a, respectively. This indicates energy transfer from BPhe c to BChl c and BChl a. In cells in which BChl c was completely pheophytinized, fluorescence measurements were indicative of direct energy transfer from BPhe c to baseplate BChl a. These findings suggest that when BChl c in C. tepidum cells is pheophytinized, the product (BPhe c) remains in the chlorosomes and continues to work as a light-harvesting pigment.
Original language | English |
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Journal | Archives of Microbiology |
Volume | 172 |
Issue number | 1 |
Pages (from-to) | 40-44 |
Number of pages | 5 |
ISSN | 0302-8933 |
DOIs | |
Publication status | Published - 1999 |
Bibliographical note
Keywords: Bacteriochlorophylls; Chlorobi; Chromatography, High Pressure Liquid; Hot Temperature; Light; Magnesium; Pheophytins; Spectrometry, Fluorescence; Time Factors
ID: 14095856