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Synthetic Media (synthetic + media)
Selected AbstractsA Cobalt Film Electrode for Nitrite Determination in Natural WaterELECTROANALYSIS, Issue 24 2007Koïkoï Soropogui Abstract In this study a cobalt film electrodeposited on a copper disk (Ø=3.1,mm) was tested as electrode to measure nitrite ions in raw water. This electrode was able to determine the nitrite ions concentration in nondeaerated synthetic media and in natural water. The electrode reached a detection limit of 0.2,,mol L,1 and has a linear concentration range of 0.4 to 2,,mol L,1 NO2,. The influence of several ions such as NO3,, Cl,, SO42,, Mg2+, HCO3, and NH4+ was also tested. The electrode was used to determine the concentration of nitrite ions in a real sample. [source] The effect of sugar concentration and temperature on growth and volatile phenol production by Dekkera bruxellensis in wineFEMS YEAST RESEARCH, Issue 7 2008André Barata Abstract The wine spoilage yeast Dekkera bruxellensis was evaluated for the production of 4-ethylphenol under low concentrations (0.02,20 g L,1) of glucose and fructose in synthetic media. Measurable amounts of 4-ethylphenol were produced over 0.2 g L,1 of each sugar. The yeast growth rate and amount of biomass formed increased from 0.2 to 20 g L,1 of glucose or fructose, being accompanied by increasing production of 4-ethylphenol. In red wines, the production of 4-ethylphenol was only observed in the presence of growing populations of indigenous or inoculated strains of D. bruxellensis. The production rate of 4-ethylphenol varied between 22 and 93 ,g day,1 either with inoculated strains or wild populations in bottled wines. The production rate of 4-ethylphenol as a function of the increase in the number of cells varied from 349 to 1882 ,g L,1 per one log CFU mL,1. The effect of temperature on cellular viability and 4-ethylphenol production was tested in red wines with indigenous or inoculated strains of D. bruxellensis. Incubation temperatures of 15, 20 and 25 °C allowed cellular growth and volatile phenol production. Increasing incubation temperatures to 36 °C induced full viability loss of 10 strains of D. bruxellensis within <12 h. [source] Phytate degradation by micro-organisms in synthetic media and pea flourJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2002M. Fredrikson Aims: To screen micro-organisms for the ability to produce phytase enzyme(s) and to use promising strains for the fermentation of pea flour. Methods and Results: Two methods using the indirect estimation of phytate degradation were evaluated and both shown to be inadequate. A third method, measuring the inositol phosphate (IP3,IP6) content directly during fermentation, was used instead of the indirect estimations of phytate degradation. In synthetic media, some strains required customized conditions, with no accessible phosphorus sources other than phytate, to express phytase activity. The repression of phytase synthesis by inorganic phosphorus was not detected during fermentation with pea flour as substrate and seemed to be less significant with a higher composition complexity of the substrate. None of the tested lactic acid bacteria strains showed phytase activity. Conclusions: The methodology for the phytase screening procedure was shown to be critical. Some of the screening methods and media used in previous publications were found to be inadequate. Significance and Impact of the Study: This paper highlights the pitfalls and difficulties in the evaluation of phytase production by micro-organisms. The study is of great importance for future studies in this area. [source] Production of gliotoxin on natural substrates by Trichoderma virensJOURNAL OF BASIC MICROBIOLOGY, Issue 1 2005R. Anitha Dr. Gliotoxin, an epithiodiketopiperazine toxin produced by the ,Q' strain of Trichoderma virens is essential for curtailing growth and multiplication of phytopathogens (Howellet al. 1993, Fravel 1988). Three isolates (Gv, Gv-A and Gv-V) of Trichoderma virens were grown on natural substrates such as bengal gram hull, gingelly cake, green gram hull, rice bran, soya meal, sugarcane bagasse, soyameal + tapioca, tapioca powder, tapioca peel and wheat bran). It was evident from this study that maximum gliotoxin (64 mg/l) was produced on tapioca powder by the alien isolate Gv. However sugarcane bagasse significantly enhanced gliotoxin production (36 mg/l) in the native isolate Gv-A, when compared to other substrates like greengram hull and rice bran. So far, studies on production of gliotoxin on synthetic media has been reported. We report the production of gliotoxin by T. virens on natural substrates "in vitro" for the first time. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Copper and cadmium extraction from highly concentrated phosphoric acid solutions using calcium alginate gels enclosing bis(2,4,4-trimethylpentyl)thiophosphinic acidJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2006Argune Ocio Abstract The availability of alginate gels enclosing Cyanex 302 [bis(2,4,4-trimethylpentyl)thiophosphinic acid] for the uptake of cadmium and copper from highly concentrated solutions of industrial phosphoric acid wet process phosphoric acid (WPA)] was studied. For this purpose, beads of alginate gels enclosing microdrops of kerosene solutions of the industrial extractant Cyanex 302 at different concentrations were prepared. The experimental procedure gives rise to a composite bead in which alginate is the continuous phase and the organic extractant forms the discrete homogeneously distributed phase within the bead. The equilibrium in this three-phase system (phosphoric acid,extractant solution,alginate gel) was modelled in terms of the corresponding distribution factors, the main chemical reactions and their equilibrium constants. Retention isotherms of both metal ions were obtained experimentally at four concentrations (1.0, 2.5, 5.0 and 7.5 mol L,1) of pure phosphoric acid. High metal removal efficiency, due to liquid,liquid extraction processes, was observed even in the most acidic conditions. High values of the extraction constants were estimated, with the distribution coefficients between aqueous and alginate phase being near unity. Finally, the results obtained with industrial WPA are in close agreement with those predicted by the physicochemical model developed in synthetic media. Copyright © 2006 Society of Chemical Industry [source] Production of fructose and ethanol from media with high sucrose concentrations by a mutant of Saccharomyces cerevisiaeJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2001Hasan Atiyeh Abstract The production of enriched fructose syrups and ethanol from a synthetic medium with high sucrose concentrations was studied in a batch process using Saccharomyces cerevisiae ATCC 36858. The results showed that the fructose yield was above 92% of theoretical values in synthetic media with sucrose concentrations between 180,g,dm,3 and 726,g,dm,3. Ethanol yield was about 82% in media with sucrose concentrations up to 451,g,dm,3. A product containing 178,g,dm,3 fructose, which represents 97% of the total sugar content, and 79,g,dm,3 ethanol was obtained using a medium with 360,g,dm,3 sucrose. The fructose fraction in the carbohydrates content in the produced syrups decreased with increases in the initial sucrose concentration. In a medium with initial sucrose concentration of 574,g,dm,3, the fructose content in the produced broth was 59% of the total carbohydrates. Glycerol and fructo-oligosaccharides were also produced in this process. The produced fructo-oligosaccharides started to be consumed when the concentration of sucrose in the media was less than 30% of its initial value. Complete hydrolysis of these sugars was noticed in media with sucrose concentrations below 451,g,dm,3. These findings will be useful in the production of ethanol and high fructose syrups using sucrose-based raw materials with high concentrations of this carbohydrate. © 2001 Society of Chemical Industry [source] Effects of Whey Permeate-Based Medium on the Proximate Composition of Lentinus edodes in the Submerged CultureJOURNAL OF FOOD SCIENCE, Issue 6 2006Xiaojun Jeffrey Wu ABSTRACT:, Biomass production, crude water-soluble polysaccharide (WSP), ash content, mineral profile, and crude protein content were determined for Lentinus edodes mycelia grown on whey permeate (WP)-based medium with lactose content of 4.5% or defined synthetic medium, and harvested after 5, 10, 15, or 20 d of fermentation at 25 °C. Harvesting time and the type of media interact to alter the chemical content of mycelia. Mycelia grown in WP had greater (P < 0.05) WSP and ash than mycelia grown in the synthetic media. A maximum production of WSP was obtained on the 10th day (4.1 × 102± 71 mg WSP/g dried mycelia) from mycelia grown on the WP-based media. Mycelia grown on WP harvested on the 20th day had the highest value in ash content (18 ± 3%). Potassium was found to be the main constituent in the ash of mushroom mycelia, which was followed by phosphorus, sodium, calcium, and magnesium. A steady increase of ash content was only noted in mycelia grown on WP. The calcium content of WP-grown mycelia was at least 10 times higher compared to mycelia grown in the control media regardless the harvesting time. Data in this research suggested that WP was more favorable than the synthetic media in the production of WSP, which is traditionally known for their medicinal value in L. edodes. [source] MUCILAGINOUS CAPSULE ADSORPTION AND INTRACELLULAR UPTAKE OF COPPER BY KIRCHNERIELLA APERTA (CHLOROCOCCALES)1JOURNAL OF PHYCOLOGY, Issue 2 2002Ana T. Lombardi The purpose of the present investigation was to evaluate possible ecological and physiological functions of mucilaginous capsules produced by the freshwater algae Kirchneriella aperta Teiling (Chlorococcales) as related to copper ions. All experiments were performed using synthetic media under laboratory-controlled conditions. Copper interactions were investigated by distinguishing between adsorption onto the mucilaginous material present at the surface of the cells, intracellular uptake, and differentiation between total dissolved copper and free copper ions in the culture medium. Kirchneriella aperta is sensitive to copper, as revealed by a 96-h EC50 value of 10,9.22 M Cu2+. We demonstrated that the mucilaginous capsules were able to sequester copper ions from the medium through a passive mechanism, thus providing the cell with a mechanism able to postpone the toxic effects of copper. The organic material that diffuses into the test medium as well as the mucilaginous capsules produced by K. aperta both effectively complex copper; thus, toxicity must be related to free copper ions and not the total dissolved copper concentration in the medium. [source] Purification of bioethanol effluent in an UASB reactor system with simultaneous biogas formationBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2003M. Torry-Smith In this study, the prospect of using an Upflow Anaerobic Sludge Blanket (UASB) reactor for detoxification of process water derived from bioethanol production has been investigated. The bioethanol effluent (BEE) originated from wet oxidized wheat straw fermented by Saccharomyces cerevisiae and Thermoanaerobacter mathranii A3M4 to produce ethanol from glucose and xylose, respectively. In batch experiments the methane potential of BEE was determined to 529 mL-CH4/g-VS. In batch degradation experiments it was shown that the presence of BEE had a positive influence on the removal of the inhibitors 2-furoic acid, 4-hydroxyacetophenone, and acetovanillone as compared to conversion of the inhibitors as sole substrate in synthetic media. Furthermore, experiments were carried out treating BEE in a laboratory-scale UASB reactor. The results showed a Chemical Oxygen Demand (COD) removal of 80% (w/w) at an organic loading rate of 29 g-COD/(L · d). GC analysis of the lignocellulosic related potentially inhibitory compounds 2-furoic acid, vanillic acid, homovanillic acid, acetovanillone, syringic acid, acetosyringone, syringol, 4-hydroxybenzoic acid, and 4-hydroxybenzaldehyde showed that all of these compounds were removed from the BEE in the reactor. Implementation of a UASB purification step was found to be a promising approach to detoxify process water from bioethanol production allowing for recirculation of the process water and reduced production costs. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 7,12, 2003. [source] | |||||||||||||