Mesosome Structure in Chromobacterium violaceum

Abstract

Exponentially growing cells of the gram-negative bacterium Chromobacterium violaceum demonstrate invaginations of the cytoplasmic membrane with a high frequency. These invaginations conform to the ultrastructural appearance of mesosomes of gram-positive bacteria. As many as four mesosomes are observed per cell, each of which may increase the total membrane surface of the cell by 30%. Washing of cells in dilute tris(hydroxymethyl)aminomethane buffer effects a distension of the mesosome “neck” and/or cytoplasmic membrane clarifying the association of the mesosome to the cytoplasmic membrane. Plasmolysis effects an eversion of the mesosome into the plasmolysis vacuole.

Mesosomes: membranous bacterial organelles.

“…31:1098, 1972). It is obvious from studies of gram-negative bacteria that these conditions in most cases cannot or have not been met; e.g., to our knowledge, in only a single case has it been shown that so-called mesosomes of gram-negative cells are extruded upon dissolution of the cell wall (246). In the absence of wide acceptance of the terms "plasmalemmasomes" and "chondrioids" (64,314), which are perhaps in some ways more appropriate, we suggest that all other structures which are shown not to meet these criteria be called intracellular or intracytoplasmic membranes; others which have not been investigated in enough detail to establish these relationships (and yet have some ultrastructural similarities to mesosomes) should be referred to as "mesosome-like" structures or bodies.…”

“…on September 22, 2020 by guest http://mmbr.asm.org/ Downloaded from VOL. 39,1975 (135,281), Caulobacter crescentus (51), Achromobacter (334), Chondrococcus columnaris (226,227), and Chromobacterium violaceum (246). In certain strains of Escherichia coli, well-developed, large intracytoplasmic membrane structures, continuous with the peripheral, inner membrane have been observed under specified growth conditions (4,130,191,208,209,273,328,329).…”

“…) The picture emerging, which is based primarily on the vast literature describing ultrastructural investigations of mesosomes and which is consistent with our extremely limited knowledge of the biochemical and chemical properties of mesosomes, is that these organelles are most likely multifunctional in nature. Difficulties in interpreting the ultrastructural data remain, and some further consideration must be given here to these problems (35,36,174,246). Many conflicting data have been reported concerning the effects of temperature (52,130,273,334), oxygenation (54,64,312), nutrition (35,36,91,99,122,318), physiological age (57,68,120,282,322), divalent cations (28,235,245), and fixation MESOSOMES 419 procedures (33, 124-126, 199, 200, 284) on the presence or absence, size, and ultrastructural appearance of mesosomes in a variety of bacterial cells.…”

“…The septal mesosome represents one type of mesosome which seems fairly universal in the gram-positive bacilli (244). However, individual bacterial cells may contain several mesosomes located at different sites, although considerable controversy exists concerning this point (34,124,148,246). It appears that variation in the numbers and sites of mesosomes, as well as in their ultrastructural appearance (see above), may be related to species, age of the cells, and methods of fixation for electron microscopy (30, 33, 34, 120-122, 124-127, 198-202).…”

The caulobacters: ubiquitous unusual bacteria.

“…A striking feature of caulobacter fine structure is the presence of elaborate mesosomes, known in, but not typical of, chemoheterotrophic gramnegative bacteria (79,229). Large mesosomes are typical of the division site of caulobacters in both fixed (218, 223) and unfixed (31) cells, whether division occurs by constriction (as in Caulobacter) or by septation (as in A. excentricus).…”