Volutin granules

The eytoplasm is a viscous fluid and contains within it systems of paramount importance. These are the nucleus, responsible for the genehc make-up of the cell, and the ribosomes, whieh are the site of protein synthesis, hi addihon are found granules of reserve material suehas polylydioxybutyric add, an energy reserve, and polyphosphate or volutin granules, the exact funchon of which has not yet been elucidated. The prokaiyohc nueleus or bacterial chromosome exists in the cytoplasm in the form of a loop and is not surrounded by a nuclear membrane. Bacteria cany other chromosomal elements episomes, which are portions of the main chromosome that have become isolated firm it, and plasmids, whieh may be called miniature chromosomes. These are small annular pieees of DNA whieh carry a limited amount of genetic information. 

The oldest and most extensively used method for determination of PolyPs in biological materials, although of course the least accurate, is based on the staining of cells and tissues by certain basic dyes such as toluidine blue, neutral red and methylene blue. The presence of condensed phosphates in the organisms is judged by the appearance in the cells of metachromatically stained granules, or volutin granules. 

The above approach allowed determination of the content and polymerization degree of PolyPs in volutin granules (lacobson et al., 1982), in vacuoles (Trilisenko et al., 2002), and in different PolyP fractions obtained from yeast cells (Vagabov et al., 1998, 2000). As an example, Figure 2.10 shows the 31P NRP spectra of the acid-soluble PolyPs from isolated... 

The presence of PolyPs in these granules is indicated by the following indirect observations. First, volutin granules undergo metachromatic staining by basic dyes, 4,6 -diamino-2-phenylindole (DAPI) fluorescence shifts, and other reactions specific for PolyPs (see... 

Different cellular localization of various PolyP fractions on the basis of examination of their functions and metabolism was first proposed for Chlorella (Miyach, 1961 Miyachi and Miyachi, 1961 Miyachi and Tamiya, 1961 Kanai et al., 1963 Miyachi et al., 1964). In particular, it was shown that this alga possesses PolyP fraction A, which is a constituent of volutin granules and closely involved in nuclear metabolism, and another PolyP fraction C, which is sited adjacent to the chloroplasts and involved in photosynthetic processes. Fractions B and D appeared to be localized in other cell structures. 

Being eukaryotes, algae contain PolyPs in different cell compartments. The intracellular localization of PolyPs in volutine granules of Chlorella fusca and Chlorella pyrenoidosa... 

M. A. Guberniev, L. I. Torbochkina and N. S. Bondareva (1961). The polyphosphate constitution of volutin granules in Actinomyces erythreus (in Russian). Antibiotiki, 6, 5-12. 

H. Hase, S. Miyachi and S. Mihara (1963). A preliminary note on the phosphorus compounds in chloroplasts and volutin granules isolated from Chlorelta cells. In H. Tamiya (Ed.), Microalgae and Photosyntetic Bacteria, University of Tokyo Press, Tokyo, Japan, p. 619. 

H. Rosenberg (1966). The isolation and identification of volutin granules from Tetrahymena. Exp. Cell Res., 41,397 103. 

Unlike animal or plant cells, there is no endoplasmic reticulum to which ribosomes are bound. Bacteria contain storage deposits of certain building blocks. The volutin granules serve as a reserve source of phosphate and are themselves composed of polyphosphates. Poly-p-hydroxybutyrate (PHB) a Upid-Iike material, serves as a carbon and energy source. 

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