Role of malate dehydrogenase isoforms in the regulation of anabolic and catabolic processes in the colorless sulfur bacterium Beggiatoa leptomitiformis D-402

The functional role of tetrameric and dimeric isoforms of malate dehydrogenase in the carbon metabolism of the colorless sulfur bacterium Beggiatoa leptomitiformis, strain D-402, was studied. This strain can grow both lithotrophically and organotrophically. By using the inhibition analysis, the tetrameric isoenzyme was shown to operate in the glyoxylate cycle and the dimeric one was found to be involved in the TCA cycle. The dynamics of the dimeric isoenzyme conversion to the tetrameric isoform was found to be determined by the rate of thiosulfate oxidation. The regulation of the carbon metabolism in Beggiatoa leptomitiformis is supposed to be accomplished by means of structural and functional changes in the protein molecule of malate dehydrogenase.     

Antibiotic therapy of cystic fibrosis in children]

It is postulated that P. aeruginosa in monoculture or in association with Staphylococcus aureus keeps its leading position in chronic bacterial inflammatory broncho-pulmonary processes in children with cystic fibrosis. Antibiotic resistant strains of Burkholderia cepacia, Stenotrophomonas maltophila, Alcaligenes xylosoxidans were revealed (7.1% of the strains). P. aeruginosa strains were susceptible to aminoglycosides, ciprofloxacin, and polymixin B. Susceptibility of smooth and mucoid forms of P. aeruginosa to ceftazidime stayed at the level of 49.6-57.1%. Such microbial associations as P. aeruginosa sm. + S. aureus, P. aeruginosa sm. + P. aeruginosa muc. + S. aureus were mainly susceptible to ciprofloxacin, aminoglycosides and resistant to ceftasidime. Meropenem, cefepim and ciprofloxacin are highly effective antibiotics for the treatment of broncho-pulmonary processes exacerbations at children with chronic P. aeruginosa cystic fibrosis. Intravenous use of antibiotics out of hospital for the treatment of the children with cystic fibrosis is clinically effective, and is economically and psychologically reasonable. It should be used more widely in medical practice.     

Effect of various phytoimmunocorrectors on fruit and soft fruit cultures

Catalase activity and induction of delayed chlorophyll fluorescence were shown to be the markers of plant native state. The dependence of reaction of the plant to exogenous elicitors, stimulators or inhibitors of defense system, on the age, cultivar and/or species was found. Prolonged effect of the treatment with phytoimmunocorrectors was observed. The necessity of careful choice of elicitors depending on the plant state was shown.