Bacteria, lactic acid cytoplasm

Kashket, E.R. 1987. Bioenergetics of lactic acid bacteria Cytoplasmic pH and osmotolerance. FEMS Microbiological Reviews 46 233-244. 

Fig. 4.1. Lactic acid bacteria isolated in wine under a scanning electron microscope (Departement de Microscopie Electronique, University of Bordeaux I), (a) Photograph of Lactobacillus plantarum cells (transmission, Lonvaud, 1975) c = cytoplasm pm = plasma membrane cw = cell wall s = septum m = mesosome n = nucleus, (b) Photograph of I uconostoc oenos Oenococcus oeni) (scanning electron microscope).

Cytoplasmic granulations can be revealed by specific coloration techniques. They are insoluble reserve substances of an organic nature polymers of glucose or of the polyester of j6-hydroxybutyric acid. These reserve substances accumulate in the event of a nitrogen deficiency, when a source of carbon is still present. Inclusions of volutin (a polymer of insoluble, inorganic phosphate) are characteristic in lactic acid bacteria, especially certain species of the genus of strictly homofermenta-tive Lactobacillus. Volutin comprises a phosphate reserve available for the synthesis of phosphory-lated molecules such as nucleic acids. 

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