Degradation of Bacteriochlorophyll a in Rhodopseudomonas Sphaeroides R 26

Abstract

A series of pigments of the bacteriopheophytin a spectral type have been isolated from ageing cultures of Rhodopseudomonas sphaeroides strain R26. These pigments are formed in varying amounts, and can be most readily analyzed in vivo by their absorption in the 530 nm spectral range. They are enriched in sedimenting cells, but their formation is not affected by light. By chromatographic comparison with authentic pigments and chemical correlation, the following pigments have been identified: bacteriopheophytin a, bacteriopheophorbide a (which is the predominant product), pyrobacteriopheophorbide a and a fourth, very polar bacteriopheophytin atype product of unknown structure. The major portion of these newly formed pigments is present in the cells in a state, in which the near-infrared absorption band is shifted to longerwavelengths. As shown by low temperature fluorescence spectroscopy, these forms are very similar to bacteriopheophorbidea aggregates. © 1985, Walter de Gruyter. All rights reserved.