title: [Distribution of bacteriochlorophyll between the pigment-protein complexes of the sulfur photosynthesizing bacterium Allochromatium minutissimum depending on light intensity at different temperatures].
abstract: Variation of the distribution of bacteriochlorophyll a (BChl a) between external antenna (LH2) and core complexes (LHl + RC) of the photosynthetic membrane of the sulfur bacterium Allochromatium minutissimum was studied at light intensities of 5 and 90 Wt/m2 in the temperature range of 12-43 degrees C. The increase of light intensity was shown to result in a 1.5- to 2-times increase of a photosynthetic unit (PSU). PSU sizes pass through a maximum depending on growth temperature, and the increase of light intensity (5 and 90 Wt/m2) results in a shift of the maximal PSU size to higher temperatures (15 and 20 degrees C, respectively). In the narrow temperature interval of approximately 14-17 degrees C, the ratio of light intensity to PSU size is typical of phototrophs: lower light intensity corresponds to larger PSU size. The pattern of PSU size change depending on light intensity was shown to differ at extreme growth temperatures (12 degrees C and over 35 degrees C). The comparison of Alc. minutissimum PSU size with the data on Rhodobacter capsulatus and Rhodopseudomonas palustris by measuring the effective optical absorption cross-section for the reaction of photoinhibition of respiration shows a two to four times greater size of light-harvesting antenna for Alc. minutissimum, which seems to correspond to the maximum possible limit for purple bacteria.
authors.forename: A A
authors.initials: AA
authors.lastname: Solov'ev
authors.forename: Iu E
authors.initials: IuE
authors.lastname: Erokhin
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002841:Chromatiaceae / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D013696:Temperature
chemical_list: C081521:B800-850 light-harvesting complex, bacteria; D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; C026083:bacteriochlorophyll A proteins, Bacteria