Accumulation of phosphate and polyphosphate by Cryptococcus humicola and Saccharomyces cerevisiae in the absence of nitrogen

The search for new phosphate-accumulating microorganisms is of interest in connection with the problem of excess phosphate in environment. The ability of some yeast species belonging to ascomycetes and basidiomycetes for phosphate (P (i) ) accumulation in nitrogen-deficient medium was studied. The ascomycetous Saccharomyces cerevisiae and Kuraishia capsulata and basidiomycetous Cryptococcus humicola, Cryptococcus curvatus, and Pseudozyma fusiformata were the best in P (i) removal. The cells of Cryptococcus humicola and S.?cerevisiae took up 40% P (i) from the media containing P (i) and glucose (5 and 30?mM, respectively), and up to 80% upon addition of 5?mM MgSO(4) (.) The cells accumulated P (i) mostly in the form of polyphosphate (PolyP). In the presence of Mg(2+) , the content of PolyP with longer average chain length increased in both yeasts; they both had numerous inclusions fluorescing in the yellow region of the spectrum, typical of DAPI-PolyP complexes. Among the yeast species tested, Cryptococcus humicola is a new promising model organisms to study phosphorus removal from the media and biomineralization in microbial cells.     

Yeasts utilizing the surface-active substance Laurox-9

Yeasts capable of utilizing the non-ionogenic surfactant Laurox-9 were identified as Cryptococcus humicolus (Daszewska) Golubev and Rhodotorula mucilaginosa (J?erg) Harrison. IR spectrometry used for the quantitative assay of Laurox-9 showed that R. mucilaginosa utilized it as a sole carbon source. The first step of Laurox-9 metabolism was its hydrolytic cleavage yielding lauric acid and polyethyleneglycol. Optimal conditions were found for the electron-cytochemical localization of hydrolase involved in the primary degradation of Laurox-9 by yeasts. Its localization of the exocellular components was established.     

Aldehydes and disturbance of carbohydrate metabolism: some consequences and possible approaches to its normalization

There are many well-documented errors of metabolism involving genetic defects that affect carbohydrate utilization. The array of disorders includes the defective utilization of glucose, as well as enzymatic deficiencies in glycolysis and gluconeogenesis, and the pentose phosphate pathway. Besides, there is considerable literature about metabolic syndrome and diabetes. However, the main problem of their origin remains obscure. Also, it is presently beyond doubt that there are various causes of insulin resistance. The development of insulin resistance may be associated not only with insulin production disorders or presence of insulin antagonists but also with modification of the number of receptors and sensitivity of peripheral tissues. The insulin resistance originates from insulin signal transmission defects at its initial stages. It is presently uncertain which mechanisms of adaptation regulation are activated or should be activated under hyperglycemia conditions. This is the main problem of the selection of strategy of hyperglycemia treatment but it is important that aldehydes - the secondary products of lipid peroxidation and protein glycation (malondialdehyde and methylglyoxal) - make a contribution to abnormal metabolism. As far as the role of methylglyoxal in inhibition of antioxidant enzymes is concerned, the involvement of the ketoaldehyde in such processes as oxidative stress, cell proliferation control, and carbohydrate metabolism disorders does not cast any doubt.     

The relationship between the formation of trace reactions and the functional state of rats of different genetic lines]

The level of excitability of the nervous system was enhanced in rats of the Krushinsky--Molodkina (K--M) and Wistar (W) lines by means of dynamic and static physical loads and injections of different doses of al-amphetamine. It was shown that a higher level of excitability of the central nervous system produced in both lines of rats improved memory and increased the rate of formation of a conditioned active aboidance reflex (CAAR). A greater physical load or dose of the stimulant drug in the K-M line of rats resulted in a decrease of all parameters characterizing CAAR, while in the other line they rose in progression. The data obtained are believed to be related to a different genetically conditioned initial level of excitability in the indicated lines of rats--a higher one in the K--M line animals as compared with the W line rats, which determines a different norm of the nervous system responsiveness in the indicated groups of animals.     

The immunological properties of the main outer membrane protein of Legionella

The immunogenic properties of Legionella outer membrane main protein (OMMP) were studied by its effect on the proliferative activity of lymphocytes in guinea pigs. Preliminary immunization with OMMP activated only the specific and nonspecific proliferation of spleen cells. After infection with Legionella, secondary immune response developed in the spleen and lungs of previously immunized animals, in contrast to intact ones, and the nonspecific proliferative activity of lymphocytes in the spleen and lungs of previously immunized animals considerably increased. These results are indicative of the fact that Legionella OMMP, similarly to other Legionella antigens and immunomodulators, may be used for the formation of protective immunity.     

A decrease in the content of immunoreactive alpha- and gamma-endorphins in the blood and the suppression of their hypersecretion under the influence of dexamethasone in emotional stress in monkeys

Daily administration of 12 mg of dexamethasone to monkeys during 10 days resulted in decrease of the levels of alpha- and gamma-endorphins and cortisol 7 days after the first injection. The titers of these peptides in plasma of monkeys. exposed to two hours of immobilization stress were elevated twice above basal levels. The maximum elevation took place 6 hours after the beginning of immobilization. This effect wasn't detected in monkeys, which received 12 mg of dexamethasone during 10 days.     

Bacterial antigenic polysaccharides. 12. Structure and 13C NMR spectrum of the polysaccharide chain of Shigella boydii type 8 lipopolysaccharide

A specific acidic polysaccharide was isolated from Sh. boydii type 8 antigenic lipopolysaccharide after mild hydrolysis followed by chromatography on Sephadex G-50. The polysaccharide consists of D-glucuronic acid, D-galacturonic acid, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose and 2-amino-1,3-propanediol residues in 1:1:1:1:1 ratio. From the results of methylation analysis, partial acid hydrolysis and Smith degradation, the structure of the repeating unit of the specific polysaccharide was deduced as: (Formula: see text). The 13C NMR spectra of native, O-deacetylated and carboxyl-reduced polysaccharides, as well as the spectrum of oligosaccharide produced by Smith degradation were interpreted. The 13C NMR data fully confirmed the structure of the polysaccharide repeating unit.