THE PHOTOSYNTHETIC APPARATUS OF RHODOSPIRILLUM MOLISCHIANUM

By varying the light intensity and temperature during growth it is possible to obtain cultures of Rhodospirillum molischianum in which the specific bacteriochlorophyll contents differ by as much as fivefold. We used such cultures to compare the changes in the electron microscopic appearance of the...

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Main Authors:	Gibbs, Sarah P., Sistrom, W. R., Worden, Patricia B.
Format:	Online
Language:	English
Published:	The Rockefeller University Press 1965
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106734/

id	pubmed-2106734
recordtype	oai_dc
spelling	pubmed-21067342008-05-01 THE PHOTOSYNTHETIC APPARATUS OF RHODOSPIRILLUM MOLISCHIANUM Gibbs, Sarah P. Sistrom, W. R. Worden, Patricia B. Article By varying the light intensity and temperature during growth it is possible to obtain cultures of Rhodospirillum molischianum in which the specific bacteriochlorophyll contents differ by as much as fivefold. We used such cultures to compare the changes in the electron microscopic appearance of the cells with the changes in the amount and bacteriochlorophyll content of chromatophore material isolated from cell extracts. The cells contained a variable number of internal membranes which are invaginations of the cell membrane. The shape, size, number, and arrangement of the infoldings varied as the specific bacteriochlorophyll content of the cells changed. In cells with little bacteriochlorophyll, the invaginations were mostly tubular. In cells with larger amounts of bacteriochlorophyll, the invaginations were disc-shaped and the discs were appressed together in stacks of 2 to 10 discs each. Variations in the number of discs per stack could be accounted for by a simple statistical model. The average area per disc increased with increasing bacteriochlorophyll content. Quantitative estimations of the relative volumes occupied by membranes in cells with four different bacteriochlorophyll contents showed that the amount of internal membrane alone had no direct relationship with the bacteriochlorophyll content of the cells; however, the total amount of membrane (cell membrane plus internal membrane) was directly proportional to the bacteriochlorophyll content. The specific bacteriochlorophyll content of isolated chromatophore material was proportional to the bacteriochlorophyll content of whole cells; the total amount of chromatophore material was independent of the bacteriochlorophyll content of whole cells. Several possible explanations of this paradoxical discrepancy between the electron microscope observations and the analytical results are discussed. The Rockefeller University Press 1965-08-01 /pmc/articles/PMC2106734/ /pubmed/5865931 Text en Copyright © 1965 by The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Gibbs, Sarah P. Sistrom, W. R. Worden, Patricia B.
spellingShingle	Gibbs, Sarah P. Sistrom, W. R. Worden, Patricia B. THE PHOTOSYNTHETIC APPARATUS OF RHODOSPIRILLUM MOLISCHIANUM
author_facet	Gibbs, Sarah P. Sistrom, W. R. Worden, Patricia B.
author_sort	Gibbs, Sarah P.
title	THE PHOTOSYNTHETIC APPARATUS OF RHODOSPIRILLUM MOLISCHIANUM
title_short	THE PHOTOSYNTHETIC APPARATUS OF RHODOSPIRILLUM MOLISCHIANUM
title_full	THE PHOTOSYNTHETIC APPARATUS OF RHODOSPIRILLUM MOLISCHIANUM
title_fullStr	THE PHOTOSYNTHETIC APPARATUS OF RHODOSPIRILLUM MOLISCHIANUM
title_full_unstemmed	THE PHOTOSYNTHETIC APPARATUS OF RHODOSPIRILLUM MOLISCHIANUM
title_sort	photosynthetic apparatus of rhodospirillum molischianum
description	By varying the light intensity and temperature during growth it is possible to obtain cultures of Rhodospirillum molischianum in which the specific bacteriochlorophyll contents differ by as much as fivefold. We used such cultures to compare the changes in the electron microscopic appearance of the cells with the changes in the amount and bacteriochlorophyll content of chromatophore material isolated from cell extracts. The cells contained a variable number of internal membranes which are invaginations of the cell membrane. The shape, size, number, and arrangement of the infoldings varied as the specific bacteriochlorophyll content of the cells changed. In cells with little bacteriochlorophyll, the invaginations were mostly tubular. In cells with larger amounts of bacteriochlorophyll, the invaginations were disc-shaped and the discs were appressed together in stacks of 2 to 10 discs each. Variations in the number of discs per stack could be accounted for by a simple statistical model. The average area per disc increased with increasing bacteriochlorophyll content. Quantitative estimations of the relative volumes occupied by membranes in cells with four different bacteriochlorophyll contents showed that the amount of internal membrane alone had no direct relationship with the bacteriochlorophyll content of the cells; however, the total amount of membrane (cell membrane plus internal membrane) was directly proportional to the bacteriochlorophyll content. The specific bacteriochlorophyll content of isolated chromatophore material was proportional to the bacteriochlorophyll content of whole cells; the total amount of chromatophore material was independent of the bacteriochlorophyll content of whole cells. Several possible explanations of this paradoxical discrepancy between the electron microscope observations and the analytical results are discussed.
publisher	The Rockefeller University Press
publishDate	1965
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106734/
_version_	1611409090103214080

THE PHOTOSYNTHETIC APPARATUS OF RHODOSPIRILLUM MOLISCHIANUM

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