Characterization of biopolymers produced by planktonic and biofilm cells of Herbaspirillum lusitanum P6-12.

AIMS: The goal of this study was to characterize biopolymers from two modes of the Herbaspirillum lusitanum P6-12 growth: planktonic, in which cells are free swimming, and biofilm life style, in which the cells are sessile. METHODS AND RESULTS: Differences in biopolymers composition from planktonic and biofilm cells of H. lusitanum strain P6-12 were analysed using Fourier transform infrared spectroscopy (FTIR), sodium dodecyl sulphate-polyacrylamide gel electrophoresis, gas-liquid chromatography and spectrophotometry. A high degree of polymer separation and purification was achieved by ultracentrifugation, and column chromatography allowed us to identify the chemical differences between biopolymers from biofilm and planktonic H. lusitanum. It was shown that planktonic cells of H. lusitanum P6-12 when cultivated in a liquid medium to the end of the exponential phase of growth, produced two high-molecular-weight glycoconjugates (were arbitrarily called CPS-I and CPS-II) of a lipopolysaccharide (LPS) nature and a lipid-polysacharide complex (were arbitrarily called EPS). The EPS, CPS-I, CPS-II had different monosaccharide and lipid compositions. The extracellular polymeric matrix (EPM) produced by the biofilm cells was mostly proteinaceous, with a small amount of carbohydrates (up to 3%). From the biofilm culture medium, a free extracellular polymeric substance (was arbitrarily called fEPS) was obtained that contained proteins and carbohydrates (up to 7%). The cells outside the biofilm had capsules containing high-molecular-weight glycoconjugate (was arbitrarily called CPSFBC ) that consisted of carbohydrates (up to 10%), proteins (up to 16%) and lipids (up to 70%). CONCLUSIONS: During biofilm formation, the bacteria secreted surface biopolymers that differed from those of the planktonic cells. The heterogeneity of the polysaccharide containing biopolymers of the H. lusitanum P6-12 surface is probably conditioned by their different functions in plant colonization and formation of an efficient symbiosis, as well as in cell adaptation to existence in plant tissues. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of the study permit a better understanding of the physiological properties of the biopolymers, for example, in plant-microbe interactions.

[Recipe and application of new oxygen cocktail with high protein content in nutrition of cardiological patients].

The aims of this study was to develop recipe composition and to evaluate the use of new oxygen cocktail with high protein content in the dietary therapy of cardiological patients. Objects of the study were: the control sample - an oxygen-containing product prepared using dairy whey, fruit and berry juice, highly esterified pectin; experimental samples - oxygen-containing products, which differed from the control sample by additional introduction of whey protein hydrolysate. Experimental samples have been modified by adding to them whey protein hydrolysate in the amount of 1-3% from the total weight of composition. Technological scheme to produce protein-carbohydrate basis with high content of protein 3% has been developed, parameters of the production process were worked out. Analysis of product chemical composition has shown that 100 g contained 3.4-3.6 g of protein, 0.2-0.3 g of fat, 6.0-8.0 g of carbohydrates. Food value of the product made up 34-46 kcal (162-196 kJ). Assessment of effectiveness of new oxygen-containing product in the diet in conditions of cardiological hospital was carried out. 30 patients aged 60-75 years were included in local open prospective study, meeting the following criteria: patients with chronic heart failure I-IIА stage I-II functional classes, were hospitalized in the cardiology department, not having contraindications to enteral oxygen therapy and signed an informed consent form. In combination with standard therapy patients received new oxygenated product with high content of protein in the dose 250 ml (from 100 g of the basis) daily for 10 days during the second breakfast. By the end of the observation period, according to results of the survey, the psycho-emotional state of patients improved. It has been found that the developed oxygen-containing product with high protein content in combination with a standard diet and drug therapy of the disease was well tolerated by patients.

[Degradation of fluorene and fluoranthene by the basidiomycete Pleurotus ostreatus].

The dependence of the degree of fluorene and fluoranthene degradation by the fungus Pleurotus ostreatus D1 on the culture medium composition has been studied. Polycyclic aromatic hydrocarbons (PAHs) have been transformed in Kirk's medium (under conditions of laccase production) with the formation of a quinone metabolite and 9-fluorenone upon the use of fluoranthene and fluorene as substrates, respectively. More complete degradation with the formation of an intermediate metabolite, phthalic acid that has undergone subsequent utilization, has occurred in basidiomycete-rich medium (under the production of both laccase and versatile peroxidase). The formation of phthalic acid as a metabolite of fluoranthene degradation by lignolytic fungi has been revealed for the first time. The data allow the supposition that both extracellular laccase and laccase on the mycelium surface can participate in the initial stages of PAH metabolism, while versatile peroxidase is necessary for the oxidation of the formed metabolites. A scheme of fluorene metabolism by Pleurotus ostreatus D1 is suggested.