scholarly journals Efficiency of synthesis of extracellular polysaccharides strains of Lipomyces yeast

2019 ◽  
Vol 80 (4) ◽  
pp. 269-277
Author(s):  
I. A. Khusainov ◽  
E. R. Yakubov ◽  
Z. A. Kanarskaya ◽  
A. V. Kanarskiy ◽  
I. A. Maximova ◽  
...  
Keyword(s):  
Enzyme Activities ◽  
Low Temperatures ◽  
Soil Formation ◽  
Extracellular Polysaccharide ◽  
Feed Additives ◽  
Point Of View ◽  
Extracellular Polysaccharides ◽  
Mountainous Regions ◽  
Different Strains ◽  
Lipomyces Lipofer

The formation of extracellular polysaccharides is a fairly well-studied property of bacteria that is used for the industrial production of such extracellular bacterial as xanthan, dextran, gellan, hyaluronan, etc.. Polysaccharides synthesized by fungi are also widely used, such as schizophillan and scleroglucan. However, polysaccharides synthesized by yeast and yeast-like fungi have not yet found wide industrial application, with the exception of pullulan produced by Aureobasidium pullulans yeast, although there are a number of promising developments in the use of yeast polysaccharides in medicine. Yeast synthesizes polymers that contain mannans, glucans, phosphomannans, galactomannans, and glucuronoxylmannans. Polysaccharides produced by different species, and sometimes even by different strains of the same species, may differ in chemical composition and structure. Such a variety of composition and properties opens up great prospects for their use in various fields: medicine, chemical, food and cosmetic industries, as well as feed additives. In this regard, the search for new producers of polysaccharides is very relevant. Yeast of the genus Lipomyces is found in the soils of the southern and northern hemispheres of the Earth, except in the high-mountainous regions and tundra soils, where soil formation processes are in early stages of development, but the soils are rich in steppe and forest zones. As a result of the research, it turns out that from the point of view of biomass growth on the presented nutrient medium at the temperatures studied, the strains of the Lipomyces lipofer yeast КБП Y-6267 and КБП Y-6265 attract the most attention, especially at low temperatures. With an increase in temperature, the increase in biomass in these yeasts decreases markedly. As producers of extracellular polysaccharide, it is worth noting the КБП Y-6267 and КБП Y-6264 strains at 20 °C and the КБП Y-6268 strains and the КБП Y-6234 at 30 °C, which indicates the possibility of using for these purposes different species of the genus Lipomyces. At 30 °C, Lipomyces lipofer strains of the КБП Y-6268 and Lipomyces kononenkoae КБП Y-6234 had the highest enzyme activities, however, there was no relationship between enzyme activities, biomass gains and polysaccharide yields at low temperatures.

scholarly journals Antioxidant potential and optimization of production of extracellular polysaccharide by Acinetobacter indicus M6

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ch. Ravi Teja ◽  
Abraham P. Karlapudi ◽  
Neeraja Vallur ◽  
K. Mamatha ◽  
D. John Babu ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Basal Medium ◽  
Extracellular Polysaccharide ◽  
Extracellular Polysaccharides ◽  
Scavenging Activity ◽  
Promising Alternative ◽  
Food Engineering ◽  
The Face

Abstract Background Extracellular polysaccharides (ECPs) produced by biofilm-producing marine bacterium have great applications in biotechnology, pharmaceutical, food engineering, bioremediation, and bio-hydrometallurgy industries. The ECP-producing strain was identified as Acinetobacter indicus M6 species by 16S rDNA analysis. The polymer produced by the isolate was quantified and purified and chemically analyzed, and antioxidant activities have been studied. The face-centered central composite design (FCCCD) was used to design the model. Results The results have clearly shown that the ECP was found to be endowed with significant antioxidative activities. The ECP showed 59% of hydroxyl radical scavenging activity at a concentration of 500 μg/mL, superoxide radical scavenging activity (72.4%) at a concentration of 300 μg/mL, and DPPH˙ radical scavenging activity (72.2%) at a concentration of 500 μg/mL, respectively. Further, HPLC and GC-MS results showed that the isolated ECP was a heteropolymer composed of glucose as a major monomer, and mannose and glucosamine were minor monomers. Furthermore, the production of ECP by Acinetobacter indicus M6 was increased through optimization of nutritional variables, namely, glucose, yeast extract, and MgSO4 by “Response Surface Methodology”. Moreover the production of ECP reached to 2.21 g/L after the optimization of nutritional variables. The designed model is statistically significant and is indicated by the R2 value of 0.99. The optimized medium improved the production of ECP and is two folds higher in comparison with the basal medium. Conclusions Acinetobacter indicus M6 bacterium produces a novel and unique extracellular heteropolysaccharide with highly efficient antioxidant activity. GC-MS analyses elucidated the presence of quite uncommon (1→4)-linked glucose, (1→4)-linked mannose, and (→4)-GlcN-(1→) glycosidic linkages in the backbone. The optimized medium improved the production of ECP and is two folds higher in comparison with the basal medium. The newly optimized medium could be used as a promising alternative for the overproduction of ECP.

Strain distribution and in planta production of an extracellular polysaccharide depolymerase from Bradyrhizobium japonicum

1992 ◽  
Vol 38 (8) ◽  
pp. 857-861 ◽  
Author(s):  
Michael F. Dunn ◽  
Arthur L. Karr
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Root Nodules ◽  
Extracellular Polysaccharide ◽  
Extracellular Polysaccharides ◽  
Neutral Sugar ◽  
In Planta ◽  
In Vitro Production ◽  
Polysaccharide Composition ◽  
Vitro Production

Thirty-four strains of Bradyrhizobium japonicum were screened for the in vitro production of an extracellular polysaccharide depolymerase active against the B. japonicum acidic extracellular polysaccharide that contains mannose, glucose, galactose, and 4-O-methylgalactose as neutral sugar components. Over 90% of tested strains producing this type of extracellular polysaccharide also produced the extracellular polysaccharide depolymerase, whereas strains producing a compositionally different extracellular polysaccharide did not. In addition, representatives of species related to B. japonicum by extracellular polysaccharide composition or host range were also phenotypically depolymerase negative. Depolymerase was also present in soybean root nodules formed by B. japonicum strain 2143. In contrast to the cell-associated depolymerase activity found in free-living cells of this strain, most of the depolymerase activity present in nodules is free of the bacteroids. The widespread occurrence of the depolymerase among B. japonicum strains and the spatiotemporal distribution of its activity in planta are consistent with the enzyme playing a role in the removal of surface extracellular polysaccharide from the microorganism during the infection of nodulation process. Key words: Bradyrhizobium japonicum, soybean, extracellular polysaccharides, extracellular polysaccharide depolymerase, bacteroids.

Optical Transitions in Chalcogenide Glasses From the Point of View of a Barrier-Cluster Model

2008 ◽  
Vol 39-40 ◽  
pp. 253-256
Author(s):  
Ivan Baník
Keyword(s):  
Optical Absorption ◽  
Low Temperatures ◽  
Cluster Model ◽  
Chalcogenide Glasses ◽  
Temperature Shift ◽  
Point Of View ◽  
Optical Transitions ◽  
Influence Of Temperature ◽  
Exponential Tails ◽  
Influence Of Temperature On

A barrier-cluster model of chalcogenide glasses is employed to analyze optical transitions near the absorption edge. The influence of temperature on the optical absorption is studied. The model is used to explain the temperature shift of exponential tails of the optical absorption and the temperature dependence of the optical forbidden-band width at low temperatures.

The influence of asparaginates of iodine, cobalt, selenium and the drug «Creamino» on the metabolism and productive traits of young cattle

2021 ◽  
pp. 32-46
Author(s):  
T. A. Krasnoshchekova ◽  
E. Yu. Zalyubovskaya
Keyword(s):  
Soy Protein ◽  
Red Alga ◽  
Amur Region ◽  
Feed Additives ◽  
Point Of View ◽  
Farm Animals ◽  
Economic Point ◽  
Effi Ciency ◽  
Young Cattle ◽  
Productive Traits

The determining factor in increasing the productivity of farm animals is the provision of comlete feeding of animals through feed additives. Among the functional feed additives containing essential trace elements, a special place under the conditions of the Amur region is given to microadditives of selenium, iodine and cobalt. The Amur region belongs to the biogeochemical region in which the defi ciency of I, Se and Co in feed is from 80 to 95 % compared to the average Russian indicators. The purpose of the work was to compare the eff ect of feed additives made from red alga Ahnfeltia, soy protein asparaginates separately and together with the drug “Creamino” on the growth, development and metabolism of young cattle. Under the conditions of the Amur region on the basis of their own experimental data in the rearing of young cattle, the eff ectiveness of the use of the drug “Creamino” and red alga Ahnfeltia has been scientifi cally justifi ed. The conducted scientifi c and economic and physiological experiments allowed us to determine the eff ect of red anfel on the growth and development, metabolic processes of replacement heifers and the growth rate of steers when they were fed soy protein asparaginates together with the drug “Creamino”. The evaluation of the economic effi ciency of feeding heifers I, Co and Se in organic form as part of soy protein asparaginates and red alga Ahnfeltia has shown a higher economic eff ect per 1 head per day in the 2nd experimental group, where the level of profi tability was 28,6 %. The results of the research and production experiment on steers have shown that from an economic point of view, it is advisable to use I, Co and Se in their rations in the form of soy protein asparaginates together with the drug “Creamino”, feeding of which can signifi cantly increase the economic eff ect, which is 1 head per day of 4,47 rubles with a profi tability level of 31,0 %.

scholarly journals Effect of medium pH and cultivation period on mycelial biomass, polysaccharide, and ligninolytic enzyme production by Ganoderma lucidum from Montenegro

2006 ◽  
Vol 58 (3) ◽  
pp. 179-182 ◽  
Author(s):  
Jelena Vukojevic ◽  
Mirjana Stajic ◽  
Sonja Duletic-Lausevic ◽  
Jasmina Simonic
Keyword(s):  
Ganoderma Lucidum ◽  
Enzyme Production ◽  
Ligninolytic Enzymes ◽  
Extracellular Polysaccharide ◽  
Ligninolytic Enzyme ◽  
Extracellular Polysaccharides ◽  
Medium Ph ◽  
Polysaccharide Production ◽  
Intracellular Polysaccharide ◽  
Maximal Production

The effect of initial medium pH on biomass, extracellular and intracellular polysaccharide, and ligninolytic enzyme production by Ganoderma lucidum was investigated at different pH values after 7 and 14 days of cultivation. Maximal production of biomass was recorded at pH 4.5 and 5.0; maximal production of extracellular polysaccharides at pH 7.0 and 3.0; and maximal production of intracellular polysaccharides at pH 7.0 and 5.5. Ligninolytic enzymes were not produced at any pH of the medium. Maximal biomass production was obtained on the 11th day of cultivation; maximal extracellular polysaccharide production on the 7th day; and maximal intracellular polysaccharide production on the 6th and 10th day of cultivation. .

Extracellular polysaccharide production by Klebsiella pneumoniae and its relationship to virulence

1985 ◽  
Vol 31 (5) ◽  
pp. 472-478 ◽  
Author(s):  
Philip Domenico ◽  
Dana L. Diedrich ◽  
David C. Straus
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Gel Filtration ◽  
Extracellular Polysaccharide ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Extracellular Polysaccharides ◽  
Capsular Polysaccharides ◽  
Separation And Purification ◽  
Serotype 1

Klebsiella pneumoniae serotype 1 and serotype 2 and their capsular variants were examined for production of cell-associated capsular polysaccharides and extracellular capsular polysaccharides. The virulence of these organisms in experimental animals was examined via intraperitoneal injection in mice and transtracheal inoculation into the lungs of rats. It was found that the production of either polysaccharide component correlated with the observed virulence. The extracellular polysaccharides were purified by ethanol precipitation, electrodialysis, extraction with quaternary ammonium salts, and gel filtration. These purification steps allowed for the separation and purification of both the extracellular lipopolysaccharide and the extracellular capsular polysaccharide. Purified extracellular capsular polysaccharide and extracellular lipopolysaccharide were co-injected with K. pneumoniae intraperitoneally into mice to determine if either of these substances would produce an effect on the natural course of infection in these animals. These studies showed that only purified extracellular lipopolysaccharide enhanced the virulence of K. pneumoniae when co-injected into mice, and this virulence enhancement correlated with the content of extracellular lipopolysaccharide, but not extracellular capsular polysaccharide in mixtures of these polysaccharides. Saponification of K. pneumoniae serotype 1 extracellular polysaccharides significantly decreased their virulence-enhancing capabilities in mice, further suggesting that extracellular lipopolysaccharide may play a role in these infections.

Effects of Fluoride, Lithium and Strontium on Extracellular Polysaccharide Production by Streptococcus mutans and Actinomyces viscosus

1981 ◽  
Vol 60 (C) ◽  
pp. 1601-1610 ◽  
Author(s):  
Patrick Treasure
Keyword(s):  
Trace Elements ◽  
Streptococcus Mutans ◽  
Extracellular Polysaccharide ◽  
Water Soluble ◽  
Extracellular Polysaccharides ◽  
Polysaccharide Production

Effects of trace elements on production of extracellular polysaccharides (EPS) by S. mutans and A. viscosus were examined in vitro. Fluoride enhanced EPS production. Lithium and strontium had little effect alone, but tended to reverse the effect of fluoride. The proportion of water-soluble EPS and the proportion of glucosyl-EPS were increased by fluoride.

scholarly journals Gene Characterization and Enzymatic Activities Related to Trehalose Metabolism of In Vitro Reared Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) under Sustained Cold Stress

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 767
Author(s):  
Xin Lü ◽  
Shi-chou Han ◽  
Zhi-gang Li ◽  
Li-ying Li ◽  
Jun Li
Keyword(s):  
Cold Tolerance ◽  
Enzyme Activities ◽  
Low Temperatures ◽  
Insect Pests ◽  
Egg Parasitoid ◽  
Threshold Temperature ◽  
Gene Expressions ◽  
Gene Characterization ◽  
Trichogramma Dendrolimi

Trichogramma spp. is an important egg parasitoid wasp for biocontrol of agriculture and forestry insect pests. Trehalose serves as an energy source or stress protectant for insects. To study the potential role of trehalose in cold resistance on an egg parasitoid, cDNA for trehalose-6-phosphate synthase (TPS) and soluble trehalase (TRE) from Trichogramma dendrolimi were cloned and characterized. Gene expressions and enzyme activities of TdTPS and TdTRE were determined in larvae, prepupae, pupae, and adults at sustained low temperatures, 13 °C and 16 °C. TdTPS and TdTRE expressions had similar patterns with higher levels in prepupae at 13 °C and 16 °C. TdTPS enzyme activities increased with a decrease of temperature, and TdTRE activity in prepupae decreased sharply at these two low temperatures. In vitro reared T. dendrolimi could complete entire development above 13 °C, and the development period was prolonged without cold injury. Results indicated trehalose might regulate growth and the metabolic process of cold tolerance. Moreover, 13 °C is the cold tolerance threshold temperature and the prepupal stage is a critical developmental period for in vitro reared T. dendrolimi. These findings identify a low cost, prolonged development rearing method, and the cold tolerance for T. dendrolimi, which will facilitate improved mass rearing methods for biocontrol.

scholarly journals The reduction of ferric oxalate by isolated chloroplasts

1940 ◽  
Vol 129 (855) ◽  
pp. 238-255 ◽  
Keyword(s):  
Ferrous Iron ◽  
Atmospheric Oxygen ◽  
Dry Weight ◽  
Point Of View ◽  
Potassium Oxalate ◽  
Stellaria Media ◽  
Light Reaction ◽  
Different Strains ◽  
Whole Plants ◽  
Isolated Chloroplasts

1.The isolated chloroplasts from Stellaria media show a progressive fall in activity approaching zero in 3-6 hr. Four different strains of the plant were grown which showed differences in the stability of chloroplasts after removal. 2. Two methods have been used to measure the activity of chloroplasts: ( a ) The measurement with HbO 2 of oxygen produced from ferric potassium oxalate as previously described. ( b ) The measurement of the rate of reduction of methaemoglobin in presence of atmospheric oxygen, the methaemoglobin being reduced by the ferrous iron. 3. The Q o 2 , measured as rate of oxygen production calculated on the basis of dry weight of leaf taken, is about 20. The Q o 2 , measured as rate of methaemoglobin reduction, generally appeared less as the reduction of methaemoglobin by ferrous iron is relatively slow. 4. The reduction of methaemoglobin in presence of ferric potassium oxalate has been studied quantitatively from the point of view of iron, methaemoglobin, and chloroplast concentration. 5. The effect of different light intensities on the ferric oxalate reaction is similar to the effect of varying light intensity on photosynthesis in whole plants and lies within the range of values found by different workers. 6. The ferric oxalate reaction is inhibited by urethane. Phenyl urethane inhibits in much smaller concentrations than ethyl urethane. The effective concentrations of urethane are similar to those affecting photosynthesis. 7. It is concluded from the present observations that the light reaction in vegetable photosynthesis is the production of the oxygen molecule and is not the reduction of carbon dioxide.

Characteristic Properties of Rubber at Low Temperatures. A Discussion of the Stress-Strain Curves of Vulcanized Rubber at Low Temperatures

1934 ◽  
Vol 7 (4) ◽  
pp. 610-617 ◽  
Author(s):  
Takeo Fujiwara ◽  
Toramatsu Tanaka
Keyword(s):  
Physical Properties ◽  
Low Temperatures ◽  
External Heat ◽  
Point Of View ◽  
Special Importance ◽  
Stress Strain ◽  
Experimental Proof ◽  
Vulcanized Rubber ◽  
The Subject ◽  
Two Phases

Abstract The hardening of rubber at low temperatures is one of the well-known physical characteristics of rubber. The loss of elasticity of raw rubber by hardening at 0° to 10° C., its turning to the consistency of glass, and its fragility at −19° C. when cooled with liquid air, and its fibering when stretched to 60–70 per cent previous to breaking, give an experimental proof of the theory of the structure of rubber molecules. Vulcanization makes raw rubber physically less sensitive to heat and to low temperatures, and is of great significance, because it enables vulcanized rubber to be used around −30° C. without losing its elasticity. The effect of external heat on the physical properties, especially on the stress-strain relations, of vulcanized rubber has been discussed mainly for temperatures from −10° to +100° C., and only two papers deal with temperatures from −30° to −60° or −70° C. (cf. Le Blanc and Kröger, Kolloid Z., 37, 205 (1925); Tener, Kingsbury and Holt, Bureau of Standards Technologic Papers Vol. 22, No. 364). Of special importance are a means of recognizing changes m the physical properties (phenomenon of freezing-hard ness) of vulcanized rubber at −30° to −60° or −70° C., and the practical value of such information. Though there is a contradiction in the fundamental meaning of the “cold resistant theory” of rubber, investigations of the two phases of the subject may throw some light on practical problems and widen the scientific point of view.

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