[A highly branched storage polyglucan in the thermoacidophilic red microalga Galdieria maxima cells].

The thermoacidophilic red alga Galdieria maxima is capable of heterotrophic growth. The content of carbohydrates in H. maxima grown heterotrophically increases by a factor of 4, reaching as much as 60% of cell dry weight. The increase in the level of carbohydrates in cells is due to accumulation of a storage alpha-glycan. According to a specific cleavage to glucose catalyzed by amyloglucosidase and the high positive specific optical rotation characteristic of polyglucans, this polysaccharide can be classified as a floridean starch. The data of 1H NMR spectroscopy and the results of methylation showed that the average length of the unbranched regions of the polysaccharide molecule is six to seven glucose residues. The degree of branching of the starch molecule of G. maxima is greater than that of storage polysaccharides of other red algae, glycogens of yeast, and phytoglycogens of cyanobacteria.

[Conditions for cyanobacteria L-transformation]. / Izuchenie uslovii L-transformatsii u tsianobakterii.

Anabaena variabilis and Chlorogloea fritschii can easily form L-like colonies that are characterized by their appearance and the morphology of component structures. The colonies consist of morphological elements typical of the L-variants of chemoheterotrophic bacteria: filaments, "grains", ring-shaped cells, etc. Data are presented pertinent to the functional activity of the photosynthetic apparatus of these organisms subjected to L-transformation.

[Utilization of a method of growing microorganisms on millipore filters in order to study their structure with a scanning electron microscope]. / Primenenie metoda vyrashchivaniia mikroorganizmov na milliporovykh fil'trakh dlia izucheniia ikh struktury so skaniruiushchim élektronnym mikroskopom.

A comparative study of bacteria and their L-forms Actinomyces and blue-green algae, taken from centrifugates and grown on Millipore filters, was made with the use of scanning electron microscopy. The study revealed that only in the second case the location of the cells inside the colony was preserved and the architectonics of the colony remained unchanged. The anastomoses between the cells and slime on the cell surface, destroyed when other methods of making the preparations were used, could be easily detected.

[Effect of lysozyme, ethylenediaminetetraacetate, magnesium and mannittol on spheroplast formation in Anacystis nidulans]. / Vliianie lizotsima, étilendiaminotetraatsetata, magniia i mannita na obrazovanie sferoplastov u Anacystis nidulans.

Three periods (the lag period and periods of intensive and decelerated spheroplast formation) can be detected in the action of lysozyme on the cells of Anacystis nidulans; this seems to be due to peculiarities in the cell wall structure of the cyanobacterium and heterogeneity of the culture. EDTA at concentrations of 0.175--0.7 mM has effect on the duration of the lag period but increases the rate of spheroplast formation during the subsequent periods. However, the action of EDTA in complex with lysozyme for 3 hours causes lysis of some of the spheroplasts being formed. The concentration of mannitol below 0.4 M decreases the yield of spheroplasts. The level of intact spheroplasts prepared from A. nidulans suggests that at least part of them is capable of reversing into whole cells.

[Electron microscopic study of thylakoid structure in cyanobacteria]. / Elektronno-mikroskopicheskoe izuchenie struktury tilakoidov u tsianobakterii.

Two or three thylakoids can be detected in Synechococcus elongatus, strain 58, and Plectonema boryanum if sections are successful. Peripheral thylakoids sometimes seem to be connected with the cytoplasmic membrane. Partitions and septa, as well as small electron-dense granules typical of cells which underwent lysis, are found in the intrathylakoidal space. Branching of thylakoids is described. Particles 16 and 11 nm in size whose possible nature is discussed can be discerned on the fracture faces. Phycobilisomes have not been discovered by the technique of freeze-etching.

[Characteristics of the cellular ultrastructural organization of the chemoheterotrophic blue-green alga, Chlorogloea fritschii]. / Osobennosti ul'trastrukturnoi organizatsii kletok khemogetero-trofnoi sinezelenoi vodorosli Chlorogloea fritschii.

Cellular ultrastructural organization was compared in photoautotrophic and chemoheterotrophic cultures of the blue-green alga Chlorogloea fritschii Mitra. Cells at the fourth stage of the life cycle of the culture in the phase of growth were studied in both cases. The structure of thylakoids was the main object of investigation. The cells of investigation. The cells of Chl. fritschii had a peculiar organization when they were cultivated in the dark on a medium containing glucose as a source of carbon and energy. These cells differed from photosynthetic cells by the structure of the cell wall, cytoplasm, and thylakoids. The cell wall can be entirely or partly absent. The cytoplasm has a lower electron density. The cell wall can be entirely or partly absent. The cytoplasm has a lower electron density. The thylakoids are arranged more random and less compact than in the cells grown in the light. Membranes which form these thylakoids, under identical conditions of fixation, contrasting and microscopy of preparations, look usually as one-layered rather than three-layered. Apparently, the ultrastructure of thylakoids on Chl. fritschii reflects the specificity of energy mechanisms that function in cells in the light and in the dark.

[Carbon assimilation pathways in the methylotrophy of Pseudomonas gazotropha]. / Puti assimiliatsii ugleroda pri metilotrofii Pseudomonas gazotropha.

The dynamics of label distribution was studied in the products of 14CH3OH assimilation by the cells of Pseudomonas gazotropha Z-1156. Substances to be first detected were glycolate, glycine and those of the chromatogram "start" spot. Later, the radioactivity was detected in phosphorylated compounds and glycerate. Cell extracts of Ps. gazotropha Z-1156 contained ribosephosphate isomerase, phosphoribulokinase and glyceraldehyde dehydrogenase but not ribulosediphosphate carboxylase. Distribution of the label in the products of 14CH3OH assimilation and the presence of active hydroxypyruvate reductase in the extract suggest that the serine cycle is involved in methylotrophy of Ps. gazotropha Z-1156. This suggestion is confirmed by the presence of active formate dehydrogenase, phosphoenolpyruvate carboxylase, (NADP+, Mn2+)-specific isocitrate dehydrogenase, (NAD, Mg2+)-specific malate dehydrogenase, malate lyase, and isocitrate lyase. The citric acid cycle is open at the alpha-ketoglutarate dehydrogenase system. The dry biomass of Ps. gazotropha Z-1156 contains over 70% of protein.