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Sample records for optimized liquid culture

  1. Optimization of liquid overlay technique to formulate heterogenic 3D co-cultures models.

    PubMed

    Costa, Elisabete C; Gaspar, Vítor M; Coutinho, Paula; Correia, Ilídio J

    2014-08-01

    Three-dimensional (3D) cell culture models of solid tumors are currently having a tremendous impact in the in vitro screening of candidate anti-tumoral therapies. These 3D models provide more reliable results than those provided by standard 2D in vitro cell cultures. However, 3D manufacturing techniques need to be further optimized in order to increase the robustness of these models and provide data that can be properly correlated with the in vivo situation. Therefore, in the present study the parameters used for producing multicellular tumor spheroids (MCTS) by liquid overlay technique (LOT) were optimized in order to produce heterogeneous cellular agglomerates comprised of cancer cells and stromal cells, during long periods. Spheroids were produced under highly controlled conditions, namely: (i) agarose coatings; (ii) horizontal stirring, and (iii) a known initial cell number. The simultaneous optimization of these parameters promoted the assembly of 3D characteristic cellular organization similar to that found in the in vivo solid tumors. Such improvements in the LOT technique promoted the assembly of highly reproducible, individual 3D spheroids, with a low cost of production and that can be used for future in vitro drug screening assays.

  2. Optimization of liquid culture conditions of Philippine wild edible mushrooms as potential source of bioactive lipids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With remarkable bioactivities and delightful taste, mushrooms have been a commercial nutraceutical around the world. Mushrooms are cultivated on solid materials. Here we report the successful cultivation of four Philippine edible mushrooms in liquid medium. This work highlights the optimal liquid cu...

  3. Optimization of large-scale culture conditions for the production of cordycepin with Cordyceps militaris by liquid static culture.

    PubMed

    Kang, Chao; Wen, Ting-Chi; Kang, Ji-Chuan; Meng, Ze-Bing; Li, Guang-Rong; Hyde, Kevin D

    2014-01-01

    Cordycepin is one of the most important bioactive compounds produced by species of Cordyceps sensu lato, but it is hard to produce large amounts of this substance in industrial production. In this work, single factor design, Plackett-Burman design, and central composite design were employed to establish the key factors and identify optimal culture conditions which improved cordycepin production. Using these culture conditions, a maximum production of cordycepin was 2008.48 mg/L for 700 mL working volume in the 1000 mL glass jars and total content of cordycepin reached 1405.94 mg/bottle. This method provides an effective way for increasing the cordycepin production at a large scale. The strategies used in this study could have a wide application in other fermentation processes. PMID:25054182

  4. A novel liquid medium for the efficient growth of the salmonid pathogen Piscirickettsia salmonis and optimization of culture conditions.

    PubMed

    Henríquez, Mirtha; González, Ernesto; Marshall, Sergio H; Henríquez, Vitalia; Gómez, Fernando A; Martínez, Irene; Altamirano, Claudia

    2013-01-01

    Piscirickettsia salmonis is the bacterium that causes Piscirickettsiosis, a systemic disease of salmonid fish responsible for significant economic losses within the aquaculture industry worldwide. The growth of the bacterium for vaccine formulation has been traditionally accomplished by infecting eukaryotic cell lines, a process that involves high production costs and is time-consuming. Recent research has demonstrated that it is possible to culture pure P. salmonis in a blood containing (cell-free) medium. In the present work we demonstrate the growth of P. salmonis in a liquid medium free from blood and serum components, thus establishing a novel and simplified bacteriological medium. Additionally, the new media reported provides improved growth conditions for P. salmonis, where biomass concentrations of approximately 800 mg cell dry weight L(-1) were obtained, about eight times higher than those reported for the blood containing medium. A 2- level full factorial design was employed to evaluate the significance of the main medium components on cell growth and an optimal temperature range of 23-27°C was determined for the microorganism to grow in the novel liquid media. Therefore, these results represent a breakthrough regarding P. salmonis research in order to optimize pure P. salmonis growth in liquid blood and serum free medium.

  5. A Novel Liquid Medium for the Efficient Growth of the Salmonid Pathogen Piscirickettsia salmonis and Optimization of Culture Conditions

    PubMed Central

    Marshall, Sergio H.; Henríquez, Vitalia; Gómez, Fernando A.; Martínez, Irene; Altamirano, Claudia

    2013-01-01

    Piscirickettsia salmonis is the bacterium that causes Piscirickettsiosis, a systemic disease of salmonid fish responsible for significant economic losses within the aquaculture industry worldwide. The growth of the bacterium for vaccine formulation has been traditionally accomplished by infecting eukaryotic cell lines, a process that involves high production costs and is time-consuming. Recent research has demonstrated that it is possible to culture pure P. salmonis in a blood containing (cell-free) medium. In the present work we demonstrate the growth of P. salmonis in a liquid medium free from blood and serum components, thus establishing a novel and simplified bacteriological medium. Additionally, the new media reported provides improved growth conditions for P. salmonis, where biomass concentrations of approximately 800 mg cell dry weight L−1 were obtained, about eight times higher than those reported for the blood containing medium. A 2- level full factorial design was employed to evaluate the significance of the main medium components on cell growth and an optimal temperature range of 23–27°C was determined for the microorganism to grow in the novel liquid media. Therefore, these results represent a breakthrough regarding P. salmonis research in order to optimize pure P. salmonis growth in liquid blood and serum free medium. PMID:24039723

  6. Study on optimization of proportion between fermented liquid and traditional cultural medium of bioflocculant production and its flocculant performance considering the aerobic fermentation of rice straw as substrate.

    PubMed

    Zhao, Zhen; Wei, Li; Li, Chun-Ying; Wang, Zhe; Hu, Yi-Wen; Liu, Chang-Chao; Ma, Fang

    2014-11-01

    High cost of traditional culture medium of flocculant is the key element to limit the bioflocculant production. It's therefore much crucial to seek the economic production materials. In this research, part of the traditional culture medium of bioflocculant is replaced by the fermented liquid of rice straw to conduct the discussion on fermentation matching, optimization of fermentation condition and ability of flocculant production. The optimal proportion of aerobic saccharification liquid and traditional cultural medium of flocculant production is 1: 3. The flocculant rates of the economic culture medium of flocculant production are the highest, 65.49% and 71.24%, which are combined by 67d and 109d fermented saccharification liquid and the traditional cultural medium of flocculant production. The growth of flocculant production bacterium is in better situation for composite culture medium of flocculant production. The amount of bioflocculant is 40kg from per ton. The fermentation cost of flocculant saves by 25% comparing with the traditional culture medium. The simple aerobic fermentation technique opens up a new road for low-cost culture medium of flocculant production.

  7. Optimization of the Liquid Culture Medium Composition to Obtain the Mycelium of Agaricus bisporus Rich in Essential Minerals.

    PubMed

    Krakowska, Agata; Reczyński, Witold; Muszyńska, Bożena

    2016-09-01

    Agaricus bisporus species (J.E. Lange) Imbach one of the most popular Basidiomycota species was chosen for the research because of its dietary and medicinal value. The presented herein studies included determination of essential mineral accumulation level in the mycelium of A. bisporus, cultivated on liquid cultures in the medium supplemented with addition of the chosen metals' salts. Quantitative analyses of Zn, Cu, Mg, and Fe in liquid cultures made it possible to determine the relationship between accumulation of the selected mineral in A. bisporus mycelium and the culture conditions. Monitoring of the liquid cultures and determination of the elements' concentrations in mycelium of A. bisporus were performed using the flame technique of AAS method. Concentration of Zn in the mycelium, maintained in the medium with the addition of its salt, was in a very wide range from 95.9 to 4462.0 mg/g DW. In the analyzed A. bisporus mycelium, cultured in the medium enriched with copper salt, this metal concentration changed from 89.79 to 7491.50 mg/g DW; considering Mg in liquid cultured mycelium (medium with Mg addition), its concentration has changed from 0.32 to 10.55 mg/g DW. The medium enriched with iron salts has led to bioaccumulation of Fe in mycelia of A. bisporus. Determined Fe concentration was in the range from 0.62 to 161.28 mg/g DW. The proposed method of liquid A. bisporus culturing on medium enriched with the selected macro- and microelements in proper concentrations ratio have led to obtaining maximal growth of biomass, characterized by high efficiency of the mineral accumulation. As a result, a dietary component of increased nutritive value was obtained. PMID:26857993

  8. Liquid Culture Production of Fungal Microsclerotia.

    PubMed

    Jackson, Mark A; Payne, Angela R

    2016-01-01

    Fungal microsclerotia ("small" sclerotia) are compact hyphal aggregates, typically 50-600 μm in diameter, that are formed under unfavorable nutritional and/or environmental conditions. These structures are often melanized and desiccated to some degree containing endogenous nutritional reserves for use when favorable conditions return. Many fungi, mostly plant pathogens, produce microsclerotia as a survival structure. Liquid culture methods have been developed for producing microsclerotia of the Ascomycota Metarhizium spp, Colletotrichum truncatum, Mycoleptodiscus terrestris, and Trichoderma spp. While these fungi have varying culture conditions that optimize microsclerotia production, all share common nutritional and environmental requirements for microsclerotia formation. Described are the general liquid culture techniques, media components, and harvesting and drying methods necessary to produce stable microsclerotial granules of these fungi. PMID:27565493

  9. [Method of producing fusarin C in perlite-liquid culture medium].

    PubMed

    Li, G; Li, M; Ma, J

    1992-02-01

    For researching the biosynthesis labelled Fusarin C(Fc) by Fuscarium moniliforme, a more quick and convenient method of Fusarin C production and purification were established, and a good liquid culture medium consisted of different kinds organic matters (hydroxy proline, sucrose and glycerin), inorganic salts and perlite replaced corn grit medium. The perlite-liquid culture medium inoculated with the strain of F. moniliforme yields 936mg Fc/kg organic matter with in 14 days of incubation at 28 degrees C. As compared with the corn grit medium, the amount of Fc from perlite-liquid medium was more than that from corn grit medium (831mg Fc/kg corn grit). In all experiments both thin-layer chromatography and high-pressure liquid chromatography were used to confirm the presence of Fc. parameters which were important for the optimal biosynthesis of Fc included hydroxy proline and sucrose concentrations, incubated time/temperature and amount of perlite. The 40g of sucrose/L liquid culture was optimal concentration for Fusarin C production. Of three contained N-matter tested, hydroxy proline was the best sources of N-atom for Fusarin C. Under the absence of hydroxy proline, the Fc wasn't synthesized in perlite-liquid culture medium by F. moniliforme. A culture time/temperature study of Fc production was done, and the optimal Fc amounts was synthesized after incubation for 14 days at 28 degrees C on perlite-liquid culture medium.

  10. Reconstituted skin in culture: a simple method with optimal differentiation.

    PubMed

    Basset-Séguin, N; Culard, J F; Kerai, C; Bernard, F; Watrin, A; Demaille, J; Guilhou, J J

    1990-09-01

    Human skin is a unique organ, which can be reconstituted in vitro and represents an interesting system for studying cell proliferation and differentiation. A simple technique for producing reconstituted skin with optimal epidermal differentiation is described and characterized. A 4-mm punch biopsy of normal human skin is deposited on the epidermal side of mortified de-epidermized human dermis maintained at the air-liquid interface with a metallic support. The culture medium contains insulin, epidermal growth factor (EGF), cholera toxin, hydrocortisone, penicillin/streptomycin and fungizone. A well-differentiated epidermis develops within 15 days. Morphological and ultrastructural studies show a neoepidermis resembling normal skin. Differentiation markers such as involucrin, filaggrin, and various cytokeratins detected with pancytokeratin antibody are present and confirm this resemblance. The keratin profile is comparable to that observed in other skin culture models. A basement-membrane-like structure is reconstituted with hemidesmosomes and anchoring-filament formation. Bullous pemphigoid (BP) antigen is observed at the dermo-epidermal junction after 21 days of culture. Moreover, both dermal substrates and punch biopsies can be kept frozen for long-term storage, with little or no loss of epidermal growth kinetics and morphology. This skin culture technique is rapid, simple, economical and reproducible. Characterization has here shown high-quality epidermal differentiation. Scientists interested in epidermal in vitro studies should take interest in all these advantages. PMID:1703096

  11. Optimization of Cultural Conditions for Antioxidant Exopolysaccharides from Xerocomus badius Grown in Shrimp Byproduct

    PubMed Central

    Gao, Xiujun; Yan, Peisheng; Liu, Xin; Wang, Jianbing; Yu, Jiajia

    2016-01-01

    To optimize the production conditions for exopolysaccharides with higher antioxidant activities from Xerocomus badius cultured in shrimp byproduct medium, Plackett-Burman design, path of steepest ascent, and response surface methodology were explored. Based on the results of Plackett-Burman design and path of steepest ascent, a Box-Behnken design was applied to optimization and the regression models. The optimal cultural condition for high yield and antioxidant activity of the exopolysaccharides was determined to be 10.347% of solid-to-liquid ratio, a 4.322% content of bran powder, and a 1.217% concentration of glacial acetic acid. Culturing with the optimal cultural conditions resulted in an exopolysaccharides yield of 4.588 ± 0.346 g/L and a total antioxidant activity of 2.956 ± 0.105 U/mg. These values are consistent with the values predicted by the corresponding regression models (RSD < 5%). PMID:26998481

  12. Application of impediometry to rapid assessment of liquid culture media.

    PubMed

    Strassburger, J; Hossbach, J; Seidel, R

    1991-01-01

    The impedance method provides as unique opportunity to determine microbial activity and kinetics. Since the metabolic processes depend on the nature and quality of the culture medium, impediometry allows the assessment of liquid culture media. Impedance microbiology represents an approach to quantitative microbiology. We investigated the influence of pH, composition and variation of the amounts of industrially made dry media, overheating during the dissolving or sterilisation processes, and qualitative differences between batches of the same culture medium. Using glucose broth as an example, we showed that impediometry allows quantitative, microbial assessment of culture media. Inaccurate preparation of the culture medium could be detected quickly by the use of impediometry. The method is very simple to perform, requires no sample preparation, allows rapid assessment of liquid culture media, and interprets results automatically with the aid of a microcomputer. PMID:1863317

  13. Optimized Liquid-Liquid Extractive Rerefining of Spent Lubricants

    PubMed Central

    Kamal, Muhammad Ashraf; Khan, Fasihullah

    2014-01-01

    Central composite design methodology has been employed to model the sludge yield data obtained during liquid-liquid extractive rerefining of spent lubricants using an alcohol (1-butanol) and a ketone (methyl ethyl ketone) as prospective solvents. The study has resulted in two reasonably accurate multivariate process models that relate the sludge yield (R2 = 0.9065 and 0.9072 for alcohol and ketone, resp.) to process variables (settling time t, operating temperature T, and oil to solvent ratio r). Construction of such models has allowed the maximization of the sludge yield (more than 8% and 3% in case of alcohol and ketone, resp.) so that the extraction of useable oil components from spent lubricants can economically be performed under extremely mild conditions (t = 16.7 h, T = 10°C, and r = 2) and fairly moderate conditions (t = 26.6 h, T = 10°C, and r = 5) established for the alcohol and ketone correspondingly. Based on these performance parameters alcohol appears to be superior over ketone for this extraction process. Additionally extractive treatment results in oil stocks with lesser quantity of environmentally hazardous polyaromatic hydrocarbons that are largely left in the separated sludge. PMID:24688388

  14. Efficiency of neural network-based combinatorial model predicting optimal culture conditions for maximum biomass yields in hairy root cultures.

    PubMed

    Mehrotra, Shakti; Prakash, O; Khan, Feroz; Kukreja, A K

    2013-02-01

    KEY MESSAGE : ANN-based combinatorial model is proposed and its efficiency is assessed for the prediction of optimal culture conditions to achieve maximum productivity in a bioprocess in terms of high biomass. A neural network approach is utilized in combination with Hidden Markov concept to assess the optimal values of different environmental factors that result in maximum biomass productivity of cultured tissues after definite culture duration. Five hidden Markov models (HMMs) were derived for five test culture conditions, i.e. pH of liquid growth medium, volume of medium per culture vessel, sucrose concentration (%w/v) in growth medium, nitrate concentration (g/l) in the medium and finally the density of initial inoculum (g fresh weight) per culture vessel and their corresponding fresh weight biomass. The artificial neural network (ANN) model was represented as the function of these five Markov models, and the overall simulation of fresh weight biomass was done with this combinatorial ANN-HMM. The empirical results of Rauwolfia serpentina hairy roots were taken as model and compared with simulated results obtained from pure ANN and ANN-HMMs. The stochastic testing and Cronbach's α-value of pure and combinatorial model revealed more internal consistency and skewed character (0.4635) in histogram of ANN-HMM compared to pure ANN (0.3804). The simulated results for optimal conditions of maximum fresh weight production obtained from ANN-HMM and ANN model closely resemble the experimentally optimized culture conditions based on which highest fresh weight was obtained. However, only 2.99 % deviation from the experimental values could be observed in the values obtained from combinatorial model when compared to the pure ANN model (5.44 %). This comparison showed 45 % better potential of combinatorial model for the prediction of optimal culture conditions for the best growth of hairy root cultures.

  15. Optimized suspension culture: the rotating-wall vessel

    NASA Technical Reports Server (NTRS)

    Hammond, T. G.; Hammond, J. M.

    2001-01-01

    Suspension culture remains a popular modality, which manipulates mechanical culture conditions to maintain the specialized features of cultured cells. The rotating-wall vessel is a suspension culture vessel optimized to produce laminar flow and minimize the mechanical stresses on cell aggregates in culture. This review summarizes the engineering principles, which allow optimal suspension culture conditions to be established, and the boundary conditions, which limit this process. We suggest that to minimize mechanical damage and optimize differentiation of cultured cells, suspension culture should be performed in a solid-body rotation Couette-flow, zero-headspace culture vessel such as the rotating-wall vessel. This provides fluid dynamic operating principles characterized by 1) solid body rotation about a horizontal axis, characterized by colocalization of cells and aggregates of different sedimentation rates, optimally reduced fluid shear and turbulence, and three-dimensional spatial freedom; and 2) oxygenation by diffusion. Optimization of suspension culture is achieved by applying three tradeoffs. First, terminal velocity should be minimized by choosing microcarrier beads and culture media as close in density as possible. Next, rotation in the rotating-wall vessel induces both Coriolis and centrifugal forces, directly dependent on terminal velocity and minimized as terminal velocity is minimized. Last, mass transport of nutrients to a cell in suspension culture depends on both terminal velocity and diffusion of nutrients. In the transduction of mechanical culture conditions into cellular effects, several lines of evidence support a role for multiple molecular mechanisms. These include effects of shear stress, changes in cell cycle and cell death pathways, and upstream regulation of secondary messengers such as protein kinase C. The discipline of suspension culture needs a systematic analysis of the relationship between mechanical culture conditions and

  16. Optimizing heterosurface adsorbent synthesis for liquid chromatography

    NASA Astrophysics Data System (ADS)

    Bogoslovskii, S. Yu.; Serdan, A. A.

    2016-03-01

    The structural and geometric parameters of a silica matrix (SM) for the synthesis of heterosurface adsorbents (HAs) are optimized. Modification is performed by shielding the external surfaces of alkyl-modified silica (AS) using human serum albumin and its subsequent crosslinking. The structural and geometric characteristics of the SM, AS, and HA are measured via low-temperature nitrogen adsorption. It is found that the structural characteristics of AS pores with diameters D < 6 nm do not change during HA synthesis, while the volume of pores with diameters of 6 nm < D < 9 nm shrinks slightly due to the adsorption of albumin in the pore orifices. It is established that the volume of pores with diameters D > 9 nm reduces significantly due to adsorption of albumin. It is concluded that silica gel with a maximum pore size distribution close to 5 nm and a minimal proportion of pores with D > 9 nm is optimal for HA synthesis; this allows us to achieve the greatest similarity between the chromatographic retention parameters for HA and AS. The suitability of the synthesized adsorbents for analyzing drugs in biological fluids through direct sample injection is confirmed by chromatography. It was found that the percentage of the protein fraction detected at the outlet of the chromatographic column is 98%.

  17. Trends in High Performance Liquid Chromatography for Cultural Heritage.

    PubMed

    Degano, Ilaria; La Nasa, Jacopo

    2016-04-01

    The separation, detection and quantitation of specific species contained in a sample in the field of Cultural Heritage requires selective, sensitive and reliable methods. Procedures based on liquid chromatography fulfil these requirements and offer a wide range of applicability in terms of analyte types and concentration range. The main applications of High Performance Liquid Chromatography in this field are related to the separation and detection of dyestuffs in archaeological materials and paint samples by reversed-phase liquid chromatography with suitable detectors. The relevant literature will be revised, with particular attention to sample treatment strategies and future developments. Reversed phase chromatography has also recently gained increasing importance in the analysis of lipid binders and lipid materials in archaeological residues: the main advantages and disadvantages of the new approaches will be discussed. Finally, the main applications of ion chromatography and size exclusion chromatography in the field of Cultural Heritage will be revised in this chapter. PMID:27573145

  18. Trends in High Performance Liquid Chromatography for Cultural Heritage.

    PubMed

    Degano, Ilaria; La Nasa, Jacopo

    2016-04-01

    The separation, detection and quantitation of specific species contained in a sample in the field of Cultural Heritage requires selective, sensitive and reliable methods. Procedures based on liquid chromatography fulfil these requirements and offer a wide range of applicability in terms of analyte types and concentration range. The main applications of High Performance Liquid Chromatography in this field are related to the separation and detection of dyestuffs in archaeological materials and paint samples by reversed-phase liquid chromatography with suitable detectors. The relevant literature will be revised, with particular attention to sample treatment strategies and future developments. Reversed phase chromatography has also recently gained increasing importance in the analysis of lipid binders and lipid materials in archaeological residues: the main advantages and disadvantages of the new approaches will be discussed. Finally, the main applications of ion chromatography and size exclusion chromatography in the field of Cultural Heritage will be revised in this chapter.

  19. Docetaxel-loaded thermosensitive liquid suppository: optimization of rheological properties.

    PubMed

    Yeo, Woo Hyun; Ramasamy, Thiruganesh; Kim, Dong-Wuk; Cho, Hyuk Jun; Kim, Yong-Il; Cho, Kwan Hyung; Yong, Chul Soon; Kim, Jong Oh; Choi, Han-Gon

    2013-12-01

    The main purpose of this work was to optimize the rheological properties of docetaxel (DCT)-loaded thermosensitive liquid suppositories for rectal administration. DCT-loaded liquid suppositories were prepared by a cold method and characterized in terms of physicochemical and viscoelastic properties. Major formulation parameters including poloxamer (P407) and Tween 80 were optimized to adjust the thermogelling and mucoadhesive properties for rectal administration. Notably, the gel strength and mucoadhesive force significantly increased with the increase in these variables. Furthermore, DCT incorporation did not alter the viscoelastic behavior, and the mean particle size of nanomicelles in it was approximately 16 nm with a distinct spherical shape. The formulation existed as liquid at room temperature and transformed into gel at physiological temperature through the reverse gelation phenomenon. Thus, DCT-loaded thermosensitive liquid suppositories [DCT/P407/P188/Tween 80 (0.25/11/15/10 %)] with optimal gel properties were easy to prepare and administer rectally, and might enable the gel to stay in the rectum without getting out from rectum.

  20. Characterization and optimization of liquid electrodes for lateral dielectrophoresis.

    PubMed

    Demierre, Nicolas; Braschler, Thomas; Linderholm, Pontus; Seger, Urban; van Lintel, Harald; Renaud, Philippe

    2007-03-01

    Using the concept of insulator-based "electrodeless" dielectrophoresis, we present a novel geometry for shaping electric fields to achieve lateral deviation of particles in liquid flows. The field is generated by lateral planar metal electrodes and is guided along access channels to the active area in the main channel. The equipotential surfaces at the apertures of the access channels behave as vertical "liquid" electrodes injecting the current into the main channel. The field between a pair of adjacent liquid electrodes generates the lateral dielectrophoretic force necessary for particle manipulation. We use this force for high-speed deviation of particles. By adding a second pair of liquid electrodes, we focus a particle stream. The position of the focused stream can be swept across the channel by adjusting the ratio of the voltages applied to the two pairs. Based on conformal mapping, we provide an analytical model for estimating the potential at the liquid electrodes and the field distribution in the main channel. We show that the simulated particle trajectories agree with observations. Finally, we show that the model can be used to optimize the device geometry in different applications. PMID:17330167

  1. Optimal design of porous structures for the fastest liquid absorption.

    PubMed

    Shou, Dahua; Ye, Lin; Fan, Jintu; Fu, Kunkun

    2014-01-14

    Porous materials engineered for rapid liquid absorption are useful in many applications, including oil recovery, spacecraft life-support systems, moisture management fabrics, medical wound dressings, and microfluidic devices. Dynamic absorption in capillary tubes and porous media is driven by the capillary pressure, which is inversely proportional to the pore size. On the other hand, the permeability of porous materials scales with the square of the pore size. The dynamic competition between these two superimposed mechanisms for liquid absorption through a heterogeneous porous structure may lead to an overall minimum absorption time. In this work, we explore liquid absorption in two different heterogeneous porous structures [three-dimensional (3D) circular tubes and porous layers], which are composed of two sections with variations in radius/porosity and height. The absorption time to fill the voids of porous constructs is expressed as a function of radius/porosity and height of local sections, and the absorption process does not follow the classic Washburn's law. Under given height and void volume, these two-section structures with a negative gradient of radius/porosity against the absorption direction are shown to have faster absorption rates than control samples with uniform radius/porosity. In particular, optimal structural parameters, including radius/porosity and height, are found that account for the minimum absorption time. The liquid absorption in the optimized porous structure is up to 38% faster than in a control sample. The results obtained can be used a priori for the design of porous structures with excellent liquid management property in various fields.

  2. Multivariable optimization of liquid rocket engines using particle swarm algorithms

    NASA Astrophysics Data System (ADS)

    Jones, Daniel Ray

    Liquid rocket engines are highly reliable, controllable, and efficient compared to other conventional forms of rocket propulsion. As such, they have seen wide use in the space industry and have become the standard propulsion system for launch vehicles, orbit insertion, and orbital maneuvering. Though these systems are well understood, historical optimization techniques are often inadequate due to the highly non-linear nature of the engine performance problem. In this thesis, a Particle Swarm Optimization (PSO) variant was applied to maximize the specific impulse of a finite-area combustion chamber (FAC) equilibrium flow rocket performance model by controlling the engine's oxidizer-to-fuel ratio and de Laval nozzle expansion and contraction ratios. In addition to the PSO-controlled parameters, engine performance was calculated based on propellant chemistry, combustion chamber pressure, and ambient pressure, which are provided as inputs to the program. The performance code was validated by comparison with NASA's Chemical Equilibrium with Applications (CEA) and the commercially available Rocket Propulsion Analysis (RPA) tool. Similarly, the PSO algorithm was validated by comparison with brute-force optimization, which calculates all possible solutions and subsequently determines which is the optimum. Particle Swarm Optimization was shown to be an effective optimizer capable of quick and reliable convergence for complex functions of multiple non-linear variables.

  3. A simple and cost effective liquid culture system for the micropropagation of two commercially important apple rootstocks.

    PubMed

    Mehta, Mohina; Ram, Raja; Bhattacharya, Amita

    2014-07-01

    The two commercially important apple rootstocks i.e., MM106 and B9 were micropropagated using a liquid culture system. Three different strengths of 0.8% agar solidified PGR free basal MS medium were first tested to optimize the culture media for both the rootstocks. Full strength medium (MS0) supported maximum in vitro growth, multiplication, rooting and survival under field conditions as opposed to quarter and half strength media. When three different volumes of liquid MS0 were tested, highest in vitro growth, multiplication, rooting and also survival under field conditions were achieved in 20 mL liquid MS0. The cost of one litre of liquid medium was also reduced by 8 times to Rs. 6.29 as compared to solid medium. The cost of 20 mL medium was further reduced to Rs. 0.125.

  4. Skull-bound perception and precision optimization through culture.

    PubMed

    Paton, Bryan; Skewes, Josh; Frith, Chris; Hohwy, Jakob

    2013-06-01

    Clark acknowledges but resists the indirect mind-world relation inherent in prediction error minimization (PEM). But directness should also be resisted. This creates a puzzle, which calls for reconceptualization of the relation. We suggest that a causal conception captures both aspects. With this conception, aspects of situated cognition, social interaction and culture can be understood as emerging through precision optimization.

  5. Optimization of Lipase Production by a Rhizopus MR12 in Shake Culture

    NASA Astrophysics Data System (ADS)

    Kader, R.; Yousuf, A.; Hoq, M. M.

    Rhizopus sp. a mould of mucor family, excrete lipase when cultured on lipolytic media. The Rhizopus sp. produced a larger clear zone on tributyrin agar medium suggesting its esterase activity. It was further investigated in liquid medium in order to optimize the lipase production conditions under shake culture. Lipase production was found to be maximum with medium containing maltose (1%) and peptone (5%) as carbon and nitrogen sources, respectively with Rhizopus sp. The enzyme production was profoundly influenced by initial pH of the medium and optimum value of this parameter was found to be 6.0. Maximum enzyme production was obtained at 30°C with a shaking rate of 200 rpm. Ca2+ was found to stimulate lipase production, while it was strongly inhabited by Hg2+. Lipase production was increased about 23.7% under optimized cultivation conditions over olive oil-peptone medium.

  6. Optimizing settling conditions for treatment of liquid hog manure.

    PubMed

    Trias, M; Mortula, M M; Hu, Z; Gagnon, G A

    2004-08-01

    Sedimentation is a widely used separation method for treating agricultural waste. There are several chemical and biological characteristics, which can affect the settling behavior and liquid waste. The optimization of cation balances and potential for nitrification are among these processes. In addition to sedimentation, it can also affect the dewaterability of the samples. Liquid hog manure was used during the laboratory based experiments to investigate the effects of Ca2+ and Mg2+ ions and nitrification inhibition on the overall settling and dewatering characteristics. The results indicated that settling and dewatering characteristics improved during the course of the experiments. However, the improvement in settling and dewatering characteristics was inconsistent and not statistically significant. Cation addition in aerated reactor increased the highest settling velocity (94%). The improvement in dewaterability, as quantified by capillary suction time, was also not consistent. The greatest filterability observed in the supernatant was a capillary suction time of 40 s for a M:D ratio of 2:1. Initial NH 4 + concentration was more important than the nitrification inhibitor, as the presence of nitrification inhibitor increased the nitrification rate by over 300% because of the high initial NH 4 + concentration and low volatile suspended solid. The results from these experiments provide the basis for further field evaluation of cation optimization. PMID:15366563

  7. Optimizing settling conditions for treatment of liquid hog manure.

    PubMed

    Trias, M; Mortula, M M; Hu, Z; Gagnon, G A

    2004-08-01

    Sedimentation is a widely used separation method for treating agricultural waste. There are several chemical and biological characteristics, which can affect the settling behavior and liquid waste. The optimization of cation balances and potential for nitrification are among these processes. In addition to sedimentation, it can also affect the dewaterability of the samples. Liquid hog manure was used during the laboratory based experiments to investigate the effects of Ca2+ and Mg2+ ions and nitrification inhibition on the overall settling and dewatering characteristics. The results indicated that settling and dewatering characteristics improved during the course of the experiments. However, the improvement in settling and dewatering characteristics was inconsistent and not statistically significant. Cation addition in aerated reactor increased the highest settling velocity (94%). The improvement in dewaterability, as quantified by capillary suction time, was also not consistent. The greatest filterability observed in the supernatant was a capillary suction time of 40 s for a M:D ratio of 2:1. Initial NH 4 + concentration was more important than the nitrification inhibitor, as the presence of nitrification inhibitor increased the nitrification rate by over 300% because of the high initial NH 4 + concentration and low volatile suspended solid. The results from these experiments provide the basis for further field evaluation of cation optimization.

  8. Optimization to the Culture Conditions for Phellinus Production with Regression Analysis and Gene-Set Based Genetic Algorithm

    PubMed Central

    Li, Zhongwei; Xin, Yuezhen; Wang, Xun; Sun, Beibei; Xia, Shengyu; Li, Hui

    2016-01-01

    Phellinus is a kind of fungus and is known as one of the elemental components in drugs to avoid cancers. With the purpose of finding optimized culture conditions for Phellinus production in the laboratory, plenty of experiments focusing on single factor were operated and large scale of experimental data were generated. In this work, we use the data collected from experiments for regression analysis, and then a mathematical model of predicting Phellinus production is achieved. Subsequently, a gene-set based genetic algorithm is developed to optimize the values of parameters involved in culture conditions, including inoculum size, PH value, initial liquid volume, temperature, seed age, fermentation time, and rotation speed. These optimized values of the parameters have accordance with biological experimental results, which indicate that our method has a good predictability for culture conditions optimization. PMID:27610365

  9. Optimization to the Culture Conditions for Phellinus Production with Regression Analysis and Gene-Set Based Genetic Algorithm.

    PubMed

    Li, Zhongwei; Xin, Yuezhen; Wang, Xun; Sun, Beibei; Xia, Shengyu; Li, Hui; Zhu, Hu

    2016-01-01

    Phellinus is a kind of fungus and is known as one of the elemental components in drugs to avoid cancers. With the purpose of finding optimized culture conditions for Phellinus production in the laboratory, plenty of experiments focusing on single factor were operated and large scale of experimental data were generated. In this work, we use the data collected from experiments for regression analysis, and then a mathematical model of predicting Phellinus production is achieved. Subsequently, a gene-set based genetic algorithm is developed to optimize the values of parameters involved in culture conditions, including inoculum size, PH value, initial liquid volume, temperature, seed age, fermentation time, and rotation speed. These optimized values of the parameters have accordance with biological experimental results, which indicate that our method has a good predictability for culture conditions optimization. PMID:27610365

  10. Optimization to the Culture Conditions for Phellinus Production with Regression Analysis and Gene-Set Based Genetic Algorithm

    PubMed Central

    Li, Zhongwei; Xin, Yuezhen; Wang, Xun; Sun, Beibei; Xia, Shengyu; Li, Hui

    2016-01-01

    Phellinus is a kind of fungus and is known as one of the elemental components in drugs to avoid cancers. With the purpose of finding optimized culture conditions for Phellinus production in the laboratory, plenty of experiments focusing on single factor were operated and large scale of experimental data were generated. In this work, we use the data collected from experiments for regression analysis, and then a mathematical model of predicting Phellinus production is achieved. Subsequently, a gene-set based genetic algorithm is developed to optimize the values of parameters involved in culture conditions, including inoculum size, PH value, initial liquid volume, temperature, seed age, fermentation time, and rotation speed. These optimized values of the parameters have accordance with biological experimental results, which indicate that our method has a good predictability for culture conditions optimization.

  11. Optimizing culture medium for meristem tissue culture of several Saccharum species and commercial hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The optimal range of medium nutrients and plant growth regulators (PGR) was investigated for in vitro culture of diverse sugarcane species and cultivars. Macro-nutrients, nitrogen (N), phosphorous (P) and potassium (K), were essential for growth of leaf primordia. Although the best concentration of ...

  12. Podospora anserina does not senesce when serially passaged in liquid culture.

    PubMed Central

    Turker, M S; Cummings, D J

    1987-01-01

    A procedure was developed for the prolonged growth of the ascomycete fungus Podospora anserina in liquid culture to determine the effects of such growth on the senescence phenotype. Senescence in P. anserina, which is maternally inherited and associated with the excision and amplification of specific mitochondrial plasmids, occurs when this species is grown on solid medium. In two independent experiments no evidence of senescence was observed as mycelia were serially passaged in liquid culture. Further, when separable mycelial masses, termed puff balls, from the liquid cultures were plated on solid medium, a significant increase in their average longevity was observed. The apparent immortality of P. anserina in liquid culture was not dependent upon mitochondrial DNA rearrangements, nor was it affected by the presence of a previously described senescence plasmid, alpha senDNA. Evidence was obtained indicating that growth in liquid culture exerts selective pressure to maintain the wild-type mitochondrial genome. Images PMID:3804968

  13. Optimizing the performance of a solar liquid piston pump

    NASA Astrophysics Data System (ADS)

    Murphy, C. L.

    The 0.1-m solar liquid piston pump (SLPP) model is shown to exhibit stable operation over a wide range of conditions, provided the heat input (at T = 85 C) and the heat rejected (at T = 22 C) are maintained above the critical values for stalling. Under these conditions, the pumps operation is affected primarily by the heating coil position and the geometries of the inlet and outlet water tubes. It is found that the optimum output power of the model SLPP is 4.5 W at a pumping heat of 2 m, a mass flow rate of 0.23 kg/s, and an overall efficiency of 1%. It is noted that further optimization of the model would at best only marginally increase the output power and efficiency. It is thought that larger mass flow rates can be obtained by increasing the cross sectional area of the working tube and/or staging a number of pumps in parallel. It is possible to increase the pump head by staging a number of pumps in series.

  14. Optimizing liquid effluent monitoring at a large nuclear complex.

    PubMed

    Chou, Charissa J; Barnett, D Brent; Johnson, Vernon G; Olson, Phil M

    2003-12-01

    Effluent monitoring typically requires a large number of analytes and samples during the initial or startup phase of a facility. Once a baseline is established, the analyte list and sampling frequency may be reduced. Although there is a large body of literature relevant to the initial design, few, if any, published papers exist on updating established effluent monitoring programs. This paper statistically evaluates four years of baseline data to optimize the liquid effluent monitoring efficiency of a centralized waste treatment and disposal facility at a large defense nuclear complex. Specific objectives were to: (1) assess temporal variability in analyte concentrations, (2) determine operational factors contributing to waste stream variability, (3) assess the probability of exceeding permit limits, and (4) streamline the sampling and analysis regime. Results indicated that the probability of exceeding permit limits was one in a million under normal facility operating conditions, sampling frequency could be reduced, and several analytes could be eliminated. Furthermore, indicators such as gross alpha and gross beta measurements could be used in lieu of more expensive specific isotopic analyses (radium, cesium-137, and strontium-90) for routine monitoring. Study results were used by the state regulatory agency to modify monitoring requirements for a new discharge permit, resulting in an annual cost savings of US dollars 223,000. This case study demonstrates that statistical evaluation of effluent contaminant variability coupled with process knowledge can help plant managers and regulators streamline analyte lists and sampling frequencies based on detection history and environmental risk. PMID:15160897

  15. Optimizing liquid effluent monitoring at a large nuclear complex.

    PubMed

    Chou, Charissa J; Barnett, D Brent; Johnson, Vernon G; Olson, Phil M

    2003-12-01

    Effluent monitoring typically requires a large number of analytes and samples during the initial or startup phase of a facility. Once a baseline is established, the analyte list and sampling frequency may be reduced. Although there is a large body of literature relevant to the initial design, few, if any, published papers exist on updating established effluent monitoring programs. This paper statistically evaluates four years of baseline data to optimize the liquid effluent monitoring efficiency of a centralized waste treatment and disposal facility at a large defense nuclear complex. Specific objectives were to: (1) assess temporal variability in analyte concentrations, (2) determine operational factors contributing to waste stream variability, (3) assess the probability of exceeding permit limits, and (4) streamline the sampling and analysis regime. Results indicated that the probability of exceeding permit limits was one in a million under normal facility operating conditions, sampling frequency could be reduced, and several analytes could be eliminated. Furthermore, indicators such as gross alpha and gross beta measurements could be used in lieu of more expensive specific isotopic analyses (radium, cesium-137, and strontium-90) for routine monitoring. Study results were used by the state regulatory agency to modify monitoring requirements for a new discharge permit, resulting in an annual cost savings of US dollars 223,000. This case study demonstrates that statistical evaluation of effluent contaminant variability coupled with process knowledge can help plant managers and regulators streamline analyte lists and sampling frequencies based on detection history and environmental risk.

  16. Statistical culture-based strategies to enhance chlamydospore production by Trichoderma harzianum SH2303 in liquid fermentation.

    PubMed

    Li, Ya-Qian; Song, Kai; Li, Ya-Chai; Chen, Jie

    2016-08-01

    Trichoderma-based formulations are applied as commercial biocontrol agents for soil-borne plant pathogens. Chlamydospores are active propagules in Trichoderma spp., but their production is currently limited due to a lack of optimal liquid fermentation technology. In this study, we explored response surface methodologies for optimizing fermentation technology in Trichoderma SH2303. Our initial studies, using the Plackett-Burman design, identified cornmeal, glycerol, and initial pH levels as the most significant factors (P<0.05) for enhancing the production of chlamydospores. Subsequently, we applied the Box-Behnken design to study the interactions between, and optimal levels of, a number of factors in chlamydospore production. These statistically predicted results indicated that the highest number of chlamydospores (3.6×10(8) spores/ml) would be obtained under the following condition: corn flour 62.86 g/L, glycerol 7.54 ml/L, pH 4.17, and 6-d incubation in liquid fermentation. We validated these predicted values via three repeated experiments using the optimal culture and achieved maximum chlamydospores of 4.5×10(8) spores/ml, which approximately a 8-fold increase in the number of chlamydospores produced by T. harzianum SH2303 compared with that before optimization. These optimized values could help make chlamydospore production cost-efficient in the future development of novel biocontrol agents. PMID:27487807

  17. Statistical culture-based strategies to enhance chlamydospore production by Trichoderma harzianum SH2303 in liquid fermentation*

    PubMed Central

    Li, Ya-qian; Song, Kai; Li, Ya-chai; Chen, Jie

    2016-01-01

    Trichoderma-based formulations are applied as commercial biocontrol agents for soil-borne plant pathogens. Chlamydospores are active propagules in Trichoderma spp., but their production is currently limited due to a lack of optimal liquid fermentation technology. In this study, we explored response surface methodologies for optimizing fermentation technology in Trichoderma SH2303. Our initial studies, using the Plackett-Burman design, identified cornmeal, glycerol, and initial pH levels as the most significant factors (P<0.05) for enhancing the production of chlamydospores. Subsequently, we applied the Box-Behnken design to study the interactions between, and optimal levels of, a number of factors in chlamydospore production. These statistically predicted results indicated that the highest number of chlamydospores (3.6×108 spores/ml) would be obtained under the following condition: corn flour 62.86 g/L, glycerol 7.54 ml/L, pH 4.17, and 6-d incubation in liquid fermentation. We validated these predicted values via three repeated experiments using the optimal culture and achieved maximum chlamydospores of 4.5×108 spores/ml, which approximately a 8-fold increase in the number of chlamydospores produced by T. harzianum SH2303 compared with that before optimization. These optimized values could help make chlamydospore production cost-efficient in the future development of novel biocontrol agents. PMID:27487807

  18. Culture Conditions for Production of Biomass, Adenosine, and Cordycepin from Cordyceps sinensis CS1197: Optimization by Desirability Function Method

    PubMed Central

    Ghatnur, Shashidhar M.; Parvatam, Giridhar; Balaraman, Manohar

    2015-01-01

    Background: Cordyceps sinensis (CS) is a traditional Chinese medicine contains potent active metabolites such as nucleosides and polysaccharides. The submerged cultivation technique is studied for the large scale production of CS for biomass and metabolites production. Objective: To optimize culture conditions for large-scale production of CS1197 biomass and metabolites production. Materials and Methods: The CS1197 strain of CS was isolated from dead larvae of natural CS and the authenticity was assured by the presence of two major markers adenosine and cordycepin by high performance liquid chromatography and mass spectrometry. A three-level Box-Behnken design was employed to optimize process parameters culturing temperature, pH, and inoculum volume for the biomass yield, adenosine and cordycepin. The experimental results were regressed to a second-order polynomial equation by a multiple regression analysis for the prediction of biomass yield, adenosine and cordycepin production. Multiple responses were optimized based on desirability function method. Results: The desirability function suggested the process conditions temperature 28°C, pH 7 and inoculum volume 10% for optimal production of nutraceuticals in the biomass. The water extracts from dried CS1197 mycelia showed good inhibition for 2 diphenyl-1-picrylhydrazyl and 2,2-azinobis-(3-ethyl-benzo-thiazoline-6-sulfonic acid-free radicals. Conclusion: The result suggests that response surface methodology-desirability function coupled approach can successfully optimize the culture conditions for CS1197. SUMMARY Authentication of CS1197 strain by the presence of adenosine and cordycepin and culturing period was determined to be for 14 daysContent of nucleosides in natural CS was found higher than in cultured CS1197 myceliumBox-Behnken design to optimize critical cultural conditions: temperature, pH and inoculum volumeWater extract showed better antioxidant activity proving credible source of natural antioxidants

  19. Water permeability of primary mouse keratinocyte cultures grown at the air-liquid interface

    SciTech Connect

    Cumpstone, M.B.; Kennedy, A.H.; Harmon, C.S.; Potts, R.O.

    1989-04-01

    In order to study the development of the epidermal permeability barrier in vitro, tritiated water (HTO) flux was measured across murine keratinocytes cultured at the air-liquid interface. Using a micro-diffusion technique, it was shown that air-liquid cultures form areas where the water diffusion is comparable to that of intact neonatal mouse skin. When water permeability is measured over a large area of the culture surface, however, significantly higher flux is obtained. These results show that under the culture conditions used, areas of water barrier comparable to intact neonatal mouse skin coexist with regions of less complete barrier formation.

  20. Dissolved oxygen levels affect microsclerotia formation by liquid cultures of metarhizium brunneum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sclerotia, overwintering propagules formed by some fungi when faced with adverse nutritional or environmental conditions, are composed of melanized hyphal aggregates capable of withstanding desiccation, oxidative stress, and UV radiation. Using liquid culture fermentation, we identified nutritional...

  1. Survival of Suspension-cultured Sycamore Cells Cooled to the Temperature of Liquid Nitrogen.

    PubMed

    Sugawara, Y; Sakai, A

    1974-11-01

    Suspension-cultured cells of sycamore (Acer pseudoplatanus L.) which were immersed in liquid nitrogen after prefreezing to the temperatures from -30 to -50 C in the presence of dimethylsulfoxide and glucose as cryoprotective additive could proliferate vigorously when rewarmed rapidly in water at 40 C. For maintaining high viability of the cells after immersion in liquid nitrogen, it seems to be essential to use the cells at the later lag phase or the early cell division phase. This study provides a possibility for long term preservation in liquid nitrogen of plant-cultured lines.

  2. Gas-liquid chromatography in routine processing of blood cultures for detecting anaerobic bacteraemia.

    PubMed Central

    Reig, M; Molina, D; Loza, E; Ledesma, M A; Meseguer, M A

    1981-01-01

    Gas-liquid chromatography was performed on 233 positive blood cultures and findings were compared with culture results. Obligate anaerobic bacteria were recovered from 78 out of 79 blood cultures containing butyric or iso-valeric acids, or both; from 28 out of 69 blood cultures containing succinic acid; and from only one out of 41 blood cultures containing succinic but not butyric or iso-valeric acid. Good correlations (88%) were found for the recovery of anaerobic bacteria and the detection of butyric and/or iso-valeric acids. Detecting volatile fatty acids by gas-liquid chromatography performed on blood cultures at the first signs of growth can therefore provide an early and reliable indication of the presence of anaerobic bacteria. PMID:7014645

  3. Regulation for Optimal Liquid Products during Biomass Pyrolysis: A Review

    NASA Astrophysics Data System (ADS)

    Wang, F.; Hu, L. J.; Zheng, Y. W.; Huang, Y. B.; Yang, X. Q.; Liu, C.; Kang, J.; Zheng, Z. F.

    2016-08-01

    The liquid product obtained from biomass pyrolysis is very valuable that it could be used for extraction of chemicals as well as for liquid fuel. The desire goal is to obtain the most bio-oil with desired higher heating value (HHV), high physicochemical stability. The yields and chemical composition of products from biomass pyrolysis are closely related to the feedstock, pyrolysis parameters and catalysts. Current researches mainly concentrated on the co-pyrolysis of different biomass and introduce of novel catalysts as well as the combined effect of catalysts and pyrolysis parameters. This review starts with the chemical composition of biomass and the fundamental parameters and focuses on the influence of catalysts on bio-oil. What is more, the pyrolysis facilities at commercial scales were also involved. The classic researches and the current literature about the yield and composition of products (mainly liquid products) are summarized.

  4. Human Performance Optimization: Culture Change and Paradigm Shift.

    PubMed

    Deuster, Patricia A; OʼConnor, Francis G

    2015-11-01

    The term "Human Performance Optimization" (HPO) emerged across the Department of Defense (DoD) around 2006 when the importance of human performance for military success on the battlefield was acknowledged. Likewise, the term Total Force Fitness (TFF) arose as a conceptual framework within DoD in response to the need for a more holistic approach to the unparalleled operational demands with multiple deployments and strains on the United States Armed Forces. Both HPO and TFF are frameworks for enhancing and sustaining the health, well-being, and performance among our warriors and their families; they are fundamental to accomplishing our nation's mission. A demands-resources model for HPO is presented within the context of TFF to assist in operationalizing actions to enhance performance. In addition, the role leaders can serve is discussed; leaders are uniquely postured in the military chain of command to directly influence a culture of fitness for a ready force, and promote the concept that service members are ultimately responsible for their fitness and performance. PMID:26506199

  5. Human Performance Optimization: Culture Change and Paradigm Shift.

    PubMed

    Deuster, Patricia A; OʼConnor, Francis G

    2015-11-01

    The term "Human Performance Optimization" (HPO) emerged across the Department of Defense (DoD) around 2006 when the importance of human performance for military success on the battlefield was acknowledged. Likewise, the term Total Force Fitness (TFF) arose as a conceptual framework within DoD in response to the need for a more holistic approach to the unparalleled operational demands with multiple deployments and strains on the United States Armed Forces. Both HPO and TFF are frameworks for enhancing and sustaining the health, well-being, and performance among our warriors and their families; they are fundamental to accomplishing our nation's mission. A demands-resources model for HPO is presented within the context of TFF to assist in operationalizing actions to enhance performance. In addition, the role leaders can serve is discussed; leaders are uniquely postured in the military chain of command to directly influence a culture of fitness for a ready force, and promote the concept that service members are ultimately responsible for their fitness and performance.

  6. Optimization design of a Lamb wave device for density sensing of nonviscous liquid.

    PubMed

    Chen, Zhijun; Li, Lianger; Shi, Wenkang; Guo, Huawei

    2007-10-01

    A Lamb wave device composed of a piezoelectric plate loaded with a nonviscous liquid layer is presented. The relation between the Lamb wave phase velocity and the liquid density can be used for liquid density sensing. In this paper, utilizing the partial wave theory, the concept of effective permittivity is introduced to analyze the Lamb wave's excitation and the phase velocity calculation under a certain liquid density. The interface between the Lamb wave device and the liquid layer is metallized to eliminate the influence of liquid electrical properties when sensing liquid density. Based on the theory model, the phase difference measurement method is adopted to study the device's sensitivity to liquid density. In order to achieve high sensitivity to liquid density with sufficient excitation efficiency of Lamb wave, the optimal parameters of the Lamb wave device including plate thickness and cut orientation are obtained by numerical calculation. The experimental results are found to be in agreement with the theoretical simulations, verifying the validity of the theory model and the practicability of the optimization design.

  7. Enhanced production of Fumigaclavine C in liquid culture of Aspergillus fumigatus under a two-stage process.

    PubMed

    Zhu, Yi-Xiang; Yao, Ling-Yun; Jiao, Rui-Hua; Lu, Yan-Hua; Tan, Ren-Xiang

    2014-01-01

    Fumigaclavine C (FC) produced by Aspergillus fumigatus is a conidiation associated ergot alkaloid with strong anti-inflammatory activity. However, its wide application has been severely limited by low FC production from submerged culture. In this work, a novel two-stage culture process by combining shake culture with static culture was proposed to enhance the production of FC. After the process optimization, the FC production reached 62.7 mg/L, which was significantly higher than ever report. For scaling up this new culture process, the gas-liquid interfacial area per unit volume (Agas-liq) was identified as the key factor. The results showed that in a combined stirred-static bioreactor system, a maximum FC production (58.97 mg/L) was obtained at an Agas-liq value of 1.30 cm(2)/mL. These results demonstrated that two-stage culture is an efficient strategy to enhance FC production and the information obtained will be useful to production of this powerful bioactive compound on a large scale. PMID:24291794

  8. Solid matrix and liquid culture procedures for growth of potatoes

    NASA Astrophysics Data System (ADS)

    Tibbitts, T. W.; Cao, W.

    1994-11-01

    This report discusses the advantages and limitations of several different procedures for growth of potatoes for CELSS. Solution culture, in which roots and stolons are submerged, and aeroponic culture were not found useful for potatoes because stolons did not produce tubers unless a severe stress was applied to the plants. In detailed comparison studies, three selected culture systems were compared, nutrient film technique (NFT), NFT with shallow media, and pot culture with deep media. For the NFT and NFT plus shallow media, plants were grown in 0.3 m2 trays and for the deep medium culture, in 20 liter pots. A 1 cm depth of arcillite, a baked montmorillonite clay, was used as shallow media (NFT-arc). Peatvermiculite mixture was used to fill the pots for the deep media. Nutrient solution, modified half-strength Hoagland's was recirculated among the tray culture plants with pH automatically controlled at 5.5, and conductivity maintained ~ 1100 μS cm-1 by adding stock nutrients or renewing the solution. A separate nutrient solution was used to water the pot plants four times daily to excess and the excess was discarded. Plants of Norland cv. were utilized and transplanted from sterile-propagated stem cutting plantlets. The plants were grown for 66 days under 12 h photoperiod in a first study and grown for 54 days under 24 h photoperiod in a second study. Under both photoperiods, total plant growth was greater in NFT-arc than in either NFT or pot culture. Under 12 h photoperiod, tuber dry weight was 30% higher with NFT-arc, but 50% lower with NFT, than with pot culture. Under 24 h photoperiod, however, tuber dry weight in both NFT and NFT-arc was only 20% of that in pot culture. The NFT and NFT-arc produced a greater shoot growth and larger number of small tubers than pot culture, especially with 24 h photoperiod. It is concluded that there are serious limitations to the use of NFT alone for growth of potatoes in a CELSS system. These limitations can be minimized by

  9. Solid matrix and liquid culture procedures for growth of potatoes.

    PubMed

    Tibbitts, T W; Cao, W

    1994-11-01

    This report discusses the advantages and limitations of several different procedures for growth of potatoes for CELSS. Solution culture, in which roots and stolons are submerged, and aeroponic culture were not found useful for potatoes because stolons did not produce tubers unless a severe stress was applied to the plants. In detailed comparison studies, three selected culture systems were compared, nutrient film technique (NFT), NFT with shallow media, and pot culture with deep media. For the NFT and NFT plus shallow media, plants were grown in 0.3 m2 trays and for the deep medium culture, in 20 liter pots. A 1 cm depth of arcillite, a baked montmorillonite clay, was used as shallow media (NFT-arc). Peat-vermiculite mixture was used to fill the pots for the deep media. Nutrient solution, modified half-strength Hoagland's, was recirculated among the tray culture plants with pH automatically controlled at 5.5, and conductivity maintained at approximately 1100 microS cm-1 by adding stock nutrients or renewing the solution. A separate nutrient solution was used to water the pot plants four times daily to excess and the excess was discarded. Plants of Norland cv. were utilized and transplanted from sterile-propagated stem cutting plantlets. The plants were grown for 66 days under 12 h photoperiod in a first study and grown for 54 days under 24 h photoperiod in a second study. Under both photoperiods, total plant growth was greater in NFT-arc than in either NFT or pot culture. Under 12 h photoperiod, tuber dry weight was 30% higher with NFT-arc, but 50% lower with NFT, than with pot culture. Under 24 h photoperiod, however, tuber dry weight in both NFT and NFT-arc was only 20% of that in pot culture. The NFT and NFT-arc produced a greater shoot growth and larger number of small tubers than pot culture, especially with 24 h photoperiod. It is concluded that there are serious limitations to the use of NFT alone for growth of potatoes in a CELSS system. These limitations

  10. Orthogonal array design for the optimization of ionic liquid-based dispersive liquid-liquid microextraction of benzophenone-type UV filters.

    PubMed

    Ye, Lei; Liu, Juanjuan; Yang, Xin; Peng, Yan; Xu, Li

    2011-03-01

    In the present study, dispersive liquid-liquid microextraction (DLLME) using an ionic liquid (IL) as the extractant was successfully developed to extract four benzophenone-type UV filters from the different water matrices. Orthogonal array experimental design (OAD), based on five factors and four levels (L(16)(4(5))), was employed to optimize IL-dispersive liquid-liquid microextraction procedure. The five factors included pH of sample solution, the volume of IL and methanol addition, extraction time and the amount of salt added. The optimal extraction condition was as follows. Sample solution was at a pH of 2.63 in the presence of 60 mg/mL sodium chloride; 30 μL IL and 15 μL methanol were used as extractant and disperser solvent, respectively; extraction was achieved by vortexing for 4 min. Using high-performance liquid chromatography-UV analysis, the limits of detection of the target analytes ranged between 1.9 and 6.4 ng/mL. The linear ranges were between 10 or 20 ng/mL and 1000 ng/mL. This procedure afforded a convenient, fast and cost-saving operation with high extraction efficiency for the model analytes. Spiked waters from two rivers and one lake were examined by the developed method. For the swimming pool water, the standard addition method was employed to determine the actual concentrations of the UV filters. PMID:21290603

  11. Optimization of ultrasound assisted dispersive liquid-liquid microextraction of six antidepressants in human plasma using experimental design.

    PubMed

    Fernández, P; Taboada, V; Regenjo, M; Morales, L; Alvarez, I; Carro, A M; Lorenzo, R A

    2016-05-30

    A simple Ultrasounds Assisted-Dispersive Liquid Liquid Microextraction (UA-DLLME) method is presented for the simultaneous determination of six second-generation antidepressants in plasma by Ultra Performance Liquid Chromatography with Photodiode Array Detector (UPLC-PDA). The main factors that potentially affect to DLLME were optimized by a screening design followed by a response surface design and desirability functions. The optimal conditions were 2.5 mL of acetonitrile as dispersant solvent, 0.2 mL of chloroform as extractant solvent, 3 min of ultrasounds stirring and extraction pH 9.8.Under optimized conditions, the UPLC-PDA method showed good separation of antidepressants in 2.5 min and good linearity in the range of 0.02-4 μg mL(-1), with determination coefficients higher than 0.998. The limits of detection were in the range 4-5 ng mL(-1). The method precision (n=5) was evaluated showing relative standard deviations (RSD) lower than 8.1% for all compounds. The average recoveries ranged from 92.5% for fluoxetine to 110% for mirtazapine. The applicability of DLLME/UPLC-PDA was successfully tested in twenty nine plasma samples from antidepressant consumers. Real samples were analyzed by the proposed method and the results were successfully submitted to comparison with those obtained by a Liquid Liquid Extraction-Gas Chromatography - Mass Spectrometry (LLE-GC-MS) method. The results confirmed the presence of venlafaxine in most cases (19 cases), followed by sertraline (3 cases) and fluoxetine (3 cases) at concentrations below toxic levels.

  12. Optimal synthesis and characterization of Ag nanofluids by electrical explosion of wires in liquids

    PubMed Central

    2011-01-01

    Silver nanoparticles were produced by electrical explosion of wires in liquids with no additive. In this study, we optimized the fabrication method and examined the effects of manufacturing process parameters. Morphology and size of the Ag nanoparticles were determined using transmission electron microscopy and field-emission scanning electron microscopy. Size and zeta potential were analyzed using dynamic light scattering. A response optimization technique showed that optimal conditions were achieved when capacitance was 30 μF, wire length was 38 mm, liquid volume was 500 mL, and the liquid type was deionized water. The average Ag nanoparticle size in water was 118.9 nm and the zeta potential was -42.5 mV. The critical heat flux of the 0.001-vol.% Ag nanofluid was higher than pure water. PMID:21711757

  13. Optimization of culture conditions for Gardnerella vaginalis biofilm formation.

    PubMed

    Machado, Daniela; Palmeira-de-Oliveira, Ana; Cerca, Nuno

    2015-11-01

    Bacterial vaginosis is the leading vaginal disorder in women in reproductive age. Although bacterial vaginosis is related with presence of a biofilm composed predominantly by Gardnerella vaginalis, there has not been a detailed information addressing the environmental conditions that influence the biofilm formation of this bacterial species. Here, we evaluated the influence of some common culture conditions on G. vaginalis biofilm formation, namely inoculum concentration, incubation period, feeding conditions and culture medium composition. Our results showed that culture conditions strongly influenced G. vaginalis biofilm formation and that biofilm formation was enhanced when starting the culture with a higher inoculum, using a fed-batch system and supplementing the growth medium with maltose.

  14. Optimizing the performance of a solar liquid piston pump

    NASA Astrophysics Data System (ADS)

    Murphy, C. L.

    Utilization of solar energy for pumping water for irrigation or storage is discussed. Oscillations of a Freon 113 liquid column are generated in a working tube when a continuous flow of hot water, and cooling water, are supplied to heated and cooling coils located in the tube. The oscillations are converted into a pump (SLPP) model exhibited self starting, stable operation over a wide range of conditions, provides the inlet hot water heat source and inlet cooling water heat sink are above and below the critical values for stalling at a given pump head. The operation of the SLPP model, is primarily affected by the heating coil position within the working tube, and the geometries of the inlet and outlet water tubes.

  15. Dense cultures of Neisseria gonorrhoeae in liquid medium.

    PubMed

    Brookes, R; Hedén, C G

    1967-03-01

    Cultivation of Neisseria gonorrhoeae was effected in a conical glass culture vessel surrounded by a constant-temperature water jacket, and with facilities for stirring, aeration, and pH measurement and control. With the use of an aerated peptone-based medium, containing polypropylene glycol to prevent foam build-up, the yields obtained over the pH range from 5.8 to 7.4 were determined. The greatest yield was obtained at pH 6.4 when the dry weight was 1.5 g/liter. At pH 7.2 to 7.6, lysis was extensive.

  16. Optimization of screening for radioactivity in urine by liquid scintillation.

    SciTech Connect

    Shanks, Sonoya Toyoko; Reese, Robert P.; Preston, Rose T.

    2007-08-01

    Numerous events have or could have resulted in the inadvertent uptake of radionuclides by fairly large populations. Should a population receive an uptake, valuable information could be obtained by using liquid scintillation counting (LSC) techniques to quickly screen urine from a sample of the affected population. This study investigates such LSC parameters as discrimination, quench, volume, and count time to yield guidelines for analyzing urine in an emergency situation. Through analyzing variations of the volume and their relationships to the minimum detectable activity (MDA), the optimum ratio of sample size to scintillating chemical cocktail was found to be 1:3. Using this optimum volume size, the alpha MDA varied from 2100 pCi/L for a 30-second count time to 35 pCi/L for a 1000-minute count time. The typical count time used by the Sandia National Laboratories Radiation Protection Sample Diagnostics program is 30 minutes, which yields an alpha MDA of 200 pCi/L. Because MDA is inversely proportional to the square root of the count time, count time can be reduced in an emergency situation to achieve the desired MDA or response time. Note that approximately 25% of the response time is used to prepare the samples and complete the associated paperwork. It was also found that if the nuclide of interest is an unknown, pregenerated discriminator settings and efficiency calibrations can be used to produce an activity value within a factor of two, which is acceptable for a screening method.

  17. Designing & Optimizing a Moving Magnet Pump for Liquid Sodium Systems

    NASA Astrophysics Data System (ADS)

    Hvasta, Michael G.

    Advanced materials such as NF-616, NF-709, HT-UPS, and silicon carbide (SiC) have greater strength than traditional structural materials such as 316-SS. Thus, using these high-strength materials to build sodium-cooled fast reactors (SFRs) could potentially reduce construction costs by lessening the required amount of material, and increase the efficiency of electromagnetic pumps by limiting ohmic heating within the pump duct walls. However, information pertaining to the sodium-compatibility of these alloys and ceramics is very sparse. Therefore, two separate test facilities were built to study the impact of both static and dynamic sodium corrosion The dynamic test facility enabled sodium corrosion to be studied under prototypic SFR operating conditions (T = 500 [C], V = 9.35 [m/s], CO = 2-3 [wppm]). The oxygen concentration, CO, within the dynamic test facility was maintained using a cold trap and measured with a plugging meter. The flow rate of the sodium was measured using a calibrated electromagnetic flowmeter. A moving magnet pump (MMP) was used to move the liquid sodium past the corrosion samples at a high velocity. Using newly developed theory, it was found that MMP performance could be accurately modeled and predicted for a wide variety of pump configurations.

  18. Optimization of extraction of phenolic acids from a vegetable waste product using a pressurized liquid extractor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato tubers are eaten worldwide for their nutritional value, but potato peels are often disposed as waste. This study identified the phenolic acids content in potato peels, tuber, and developed an optimized method for extraction of phenolic acids from potato peels using a pressurized liquid extrac...

  19. Optimization of pH controlled liquid hot water pretreatment of corn stover.

    PubMed

    Mosier, Nathan; Hendrickson, Richard; Ho, Nancy; Sedlak, Miroslav; Ladisch, Michael R

    2005-12-01

    Controlled pH, liquid hot water pretreatment of corn stover has been optimized for enzyme digestibility with respect to processing temperature and time. This processing technology does not require the addition of chemicals such as sulfuric acid, lime, or ammonia that add cost to the process because these chemicals must be neutralized or recovered in addition to the significant expense of the chemicals themselves. Second, an optimized controlled pH, liquid hot water pretreatment process maximizes the solubilization of the hemicellulose fraction as liquid soluble oligosaccharides while minimizing the formation of monomeric sugars. The optimized conditions for controlled pH, liquid hot water pretreatment of a 16% slurry of corn stover in water was found to be 190 degrees C for 15 min. At the optimal conditions, 90% of the cellulose was hydrolyzed to glucose by 15FPU of cellulase per gram of glucan. When the resulting pretreated slurry, in undiluted form, was hydrolyzed by 11FPU of cellulase per gram of glucan, a hydrolyzate containing 32.5 g/L glucose and 18 g/L xylose was formed. Both the xylose and the glucose in this undiluted hydrolyzate were shown to be fermented by recombinant yeast 424A(LNH-ST) to ethanol at 88% of theoretical yield.

  20. Cordyceamides A and B from the Culture Liquid of Cordyceps sinensis (BERK.) SACC.

    PubMed

    Jia, Jing-Ming; Tao, Hai-Hua; Feng, Bao-Min

    2009-01-01

    Two new aurantiamides named as cordyceamides A and B were isolated from the culture liquid of Cordyceps sinensis (BERK.) SACC., along with one known compound, aurantiamide acetate. Their structures were elucidated as N-benzoyl-L-tyrosinyl-L-phenylalaninol acetate and N-benzoyl-L-tyrosinyl-L-p-hydroxyphenylalaninol acetate by 1D, 2D-NMR techniques and comparison with literatures. PMID:19122327

  1. Optimization of culture conditions for Gardnerella vaginalis biofilm formation.

    PubMed

    Machado, Daniela; Palmeira-de-Oliveira, Ana; Cerca, Nuno

    2015-11-01

    Bacterial vaginosis is the leading vaginal disorder in women in reproductive age. Although bacterial vaginosis is related with presence of a biofilm composed predominantly by Gardnerella vaginalis, there has not been a detailed information addressing the environmental conditions that influence the biofilm formation of this bacterial species. Here, we evaluated the influence of some common culture conditions on G. vaginalis biofilm formation, namely inoculum concentration, incubation period, feeding conditions and culture medium composition. Our results showed that culture conditions strongly influenced G. vaginalis biofilm formation and that biofilm formation was enhanced when starting the culture with a higher inoculum, using a fed-batch system and supplementing the growth medium with maltose. PMID:26381661

  2. Optimization of a dispersive liquid-liquid microextraction method for the analysis of benzotriazoles and benzothiazoles in water samples.

    PubMed

    Pena, Ma Teresa; Vecino-Bello, X; Casais, Ma Carmen; Mejuto, Ma Carmen; Cela, Rafael

    2012-02-01

    A simple and rapid dispersive liquid-liquid microextraction method has been developed for the determination of 11 benzotriazoles and benzothiazoles in water samples. Tri-n-butylphosphate (TBP) was used as extractant, thus avoiding the use of toxic water-immiscible chlorinated solvents. The influence of several variables (e.g., type and volume of dispersant and extraction solvents, sample pH, ionic strength, etc.) on the performance of the sample preparation step was systematically evaluated. Analytical determinations were carried out by high-performance liquid chromatography with fluorescence and UV detection and liquid chromatography-electrospray ionization-tandem mass spectrometry. The optimized method exhibited a good precision level with relative standard deviation values between 3.7% and 8.4%. Extraction yields ranging from 67% to 97% were obtained for all of these considered compounds. Finally, the proposed method was successfully applied to the analysis of benzotriazoles and benzothiazoles in real water samples (tap, river, industrial waters, and treated and raw wastewaters). PMID:22134495

  3. Optimal 3-D culture of primary articular chondrocytes for use in the Rotating Wall Vessel Bioreactor

    PubMed Central

    Mellor, Liliana F.; Baker, Travis L.; Brown, Raquel J.; Catlin, Lindsey W.; Oxford, Julia Thom

    2014-01-01

    INTRODUCTION Reliable culturing methods for primary articular chondrocytes are essential to study the effects of loading and unloading on joint tissue at the cellular level. Due to the limited proliferation capacity of primary chondrocytes and their tendency to dedifferentiate in conventional culture conditions, long-term culturing conditions of primary chondrocytes can be challenging. The goal of this study was to develop a suspension culturing technique that not only would retain the cellular morphology but also maintain gene expression characteristics of primary articular chondrocytes. METHODS Three-dimensional culturing methods were compared and optimized for primary articular chondrocytes in the rotating wall vessel bioreactor, which changes the mechanical culture conditions to provide a form of suspension culture optimized for low shear and turbulence. We performed gene expression analysis and morphological characterization of cells cultured in alginate beads, Cytopore-2 microcarriers, primary monolayer culture, and passaged monolayer cultures using reverse transcription-PCR and laser scanning confocal microscopy. RESULTS Primary chondrocytes grown on Cytopore-2 microcarriers maintained the phenotypical morphology and gene expression pattern observed in primary bovine articular chondrocytes, and retained these characteristics for up to 9 days. DISCUSSION Our results provide a novel and alternative culturing technique for primary chondrocytes suitable for studies that require suspension such as those using the rotating wall vessel bioreactor. In addition, we provide an alternative culturing technique for primary chondrocytes that can impact future mechanistic studies of osteoarthritis progression, treatments for cartilage damage and repair, and cartilage tissue engineering. PMID:25199120

  4. Optimization of Buffalo (Bubalus bubalis) Embryonic Stem Cell Culture System

    PubMed Central

    Zandi, Mohammad; Muzaffar, Musharifa; Shah, Syed Mohmad; Kumar Singh, Manoj; Palta, Prabhat; Kumar Singla, Suresh; Manik, Radheysham; Chauhan, Manmohan Singh

    2015-01-01

    Objective In order to retain an undifferentiated pluripotent state, embryonic stem (ES) cells have to be cultured on feeder cell layers. However, use of feeder layers limits stem cell research, since experimental data may result from a combined ES cell and feeder cell response to various stimuli. Materials and Methods In this experimental study, a buffalo ES cell line was established from in vitro derived blastocysts and characterized by the Alkaline phosphatase (AP) and immunoflourescence staining of various pluripotency markers. We examined the effect of various factors like fibroblast growth factor 2 (FGF-2), leukemia inhibitory factor (LIF) and Y-27632 to support the growth and maintenance of bubaline ES cells on gelatin coated dishes, in order to establish feeder free culture systems. We also analyzed the effect of feeder-conditioned media on stem cell growth in gelatin based cultures both in the presence as well as in the absence of the growth factors. Results The results showed that Y-27632, in the presence of FGF-2 and LIF, resulted in higher colony growth and increased expression of Nanog gene. Feeder-Conditioned Medium resulted in a significant increase in growth of buffalo ES cells on gelatin coated plates, however, feeder layer based cultures produced better results than gelatin based cultures. Feeder layers from buffalo fetal fibroblast cells can support buffalo ES cells for more than two years. Conclusion We developed a feeder free culture system that can maintain buffalo ES cells in the short term, as well as feeder layer based culture that can support the long term maintenance of buffalo ES cells. PMID:26199905

  5. Effects of selenium and light wavelengths on liquid culture of Cordyceps militaris Link.

    PubMed

    Dong, J Z; Liu, M R; Lei, C; Zheng, X J; Wang, Y

    2012-04-01

    To investigate the effects of selenium and light wavelengths on the growth of liquid-cultured Cordyceps militaris and the main active components' accumulation, culture conditions as selenium selenite concentrations and light of different wavelengths were studied. The results are: adenosine accumulation proved to be significantly selenium dependent (R(2) = 0.9403) and cordycepin contents were determined to be not significantly selenium dependent (R(2) = 0.3845) but significantly enhanced by selenium except for 20 ppm; there were significant differences in cordycepin contents, adenosine contents, and mycelium growth caused by light wavelengths: cordycepin, blue light > pink light > daylight, darkness, red light; adenosine, red light > pink light, darkness, daylight, blue light; and mycelium growth, red light > pink light, darkness, daylight > blue light. In conclusion, light wavelength had a significant influence on production of mycelia, adenosine, and cordycepin, so lightening wavelength should be changed according to target products in the liquid culture of C. militaris. PMID:22434354

  6. Technique for the optimization of the powerhead configuration and performance of liquid rocket engines

    NASA Astrophysics Data System (ADS)

    St. Germain, Brad David

    The development and optimization of liquid rocket engines is an integral part of space vehicle design, since most Earth-to-orbit launch vehicles to date have used liquid rockets as their main propulsion system. Rocket engine design tools range in fidelity from very simple conceptual level tools to full computational fluid dynamics (CFD) simulations. The level of fidelity of interest in this research is a design tool that determines engine thrust and specific impulse as well as models the powerhead of the engine. This is the highest level of fidelity applicable to a conceptual level design environment where faster running analyses are desired. The optimization of liquid rocket engines using a powerhead analysis tool is a difficult problem, because it involves both continuous and discrete inputs as well as a nonlinear design space. Example continuous inputs are the main combustion chamber pressure, nozzle area ratio, engine mixture ratio, and desired thrust. Example discrete variable inputs are the engine cycle (staged-combustion, gas generator, etc.), fuel/oxidizer combination, and engine material choices. Nonlinear optimization problems involving both continuous and discrete inputs are referred to as Mixed-Integer Nonlinear Programming (MINLP) problems. Many methods exist in literature for solving MINLP problems; however none are applicable for this research. All of the existing MINLP methods require the relaxation of the discrete variables as part of their analysis procedure. This means that the discrete choices must be evaluated at non-discrete values. This is not possible with an engine powerhead design code. Therefore, a new optimization method was developed that uses modified response surface equations to provide lower bounds of the continuous design space for each unique discrete variable combination. These lower bounds are then used to efficiently solve the optimization problem. The new optimization procedure was used to find optimal rocket engine designs

  7. Optimizing a culture medium for biomass and phenolic compounds production using Ganoderma lucidum

    PubMed Central

    Zárate-Chaves, Carlos Andrés; Romero-Rodríguez, María Camila; Niño-Arias, Fabián Camilo; Robles-Camargo, Jorge; Linares-Linares, Melva; Rodríguez-Bocanegra, María Ximena; Gutiérrez-Rojas, Ivonne

    2013-01-01

    The present work was aimed at optimizing a culture medium for biomass production and phenolic compounds by using Ganoderma lucidum. The culture was optimized in two stages; a Plackett-Burman design was used in the first one for identifying key components in the medium and a central composite design was used in the second one for optimizing their concentration. Both responses (biomass and phenolic compounds) were simultaneously optimized by the latter methodology regarding desirability, and the optimal concentrations obtained were 50.00 g/L sucrose, 13.29 g/L yeast extract and 2.99 g/L olive oil. Maximum biomass production identified in these optimal conditions was 9.5 g/L and that for phenolic compounds was 0.0452 g/L, this being 100% better than that obtained in the media usually used in the laboratory. Similar patterns regarding chemical characterization and biological activity towards Aspergillus sp., from both fruiting body and mycelium-derived secondary metabolites and extracts obtained in the proposed medium were observed. It was shown that such statistical methodologies are useful for optimizing fermentation and, in the specific case of G. lucidum, optimizing processes for its production and its metabolites in submerged culture as an alternative to traditional culture. PMID:24159308

  8. The benefits of social influence in optimized cultural markets.

    PubMed

    Abeliuk, Andrés; Berbeglia, Gerardo; Cebrian, Manuel; Van Hentenryck, Pascal

    2015-01-01

    Social influence has been shown to create significant unpredictability in cultural markets, providing one potential explanation why experts routinely fail at predicting commercial success of cultural products. As a result, social influence is often presented in a negative light. Here, we show the benefits of social influence for cultural markets. We present a policy that uses product quality, appeal, position bias and social influence to maximize expected profits in the market. Our computational experiments show that our profit-maximizing policy leverages social influence to produce significant performance benefits for the market, while our theoretical analysis proves that our policy outperforms in expectation any policy not displaying social signals. Our results contrast with earlier work which focused on showing the unpredictability and inequalities created by social influence. Not only do we show for the first time that, under our policy, dynamically showing consumers positive social signals increases the expected profit of the seller in cultural markets. We also show that, in reasonable settings, our profit-maximizing policy does not introduce significant unpredictability and identifies "blockbusters". Overall, these results shed new light on the nature of social influence and how it can be leveraged for the benefits of the market. PMID:25831093

  9. The benefits of social influence in optimized cultural markets.

    PubMed

    Abeliuk, Andrés; Berbeglia, Gerardo; Cebrian, Manuel; Van Hentenryck, Pascal

    2015-01-01

    Social influence has been shown to create significant unpredictability in cultural markets, providing one potential explanation why experts routinely fail at predicting commercial success of cultural products. As a result, social influence is often presented in a negative light. Here, we show the benefits of social influence for cultural markets. We present a policy that uses product quality, appeal, position bias and social influence to maximize expected profits in the market. Our computational experiments show that our profit-maximizing policy leverages social influence to produce significant performance benefits for the market, while our theoretical analysis proves that our policy outperforms in expectation any policy not displaying social signals. Our results contrast with earlier work which focused on showing the unpredictability and inequalities created by social influence. Not only do we show for the first time that, under our policy, dynamically showing consumers positive social signals increases the expected profit of the seller in cultural markets. We also show that, in reasonable settings, our profit-maximizing policy does not introduce significant unpredictability and identifies "blockbusters". Overall, these results shed new light on the nature of social influence and how it can be leveraged for the benefits of the market.

  10. Optimization of expression conditions for soluble protein by using a robotic system of multi-culture vessels.

    PubMed

    Ahn, Woo-Sung; Ahn, Ji-Young; Jung, Chan-Hun; Hwang, Kwang Yeon; Kim, Eunice Eunkyeong; Kim, Joon; Im, Hana; Kim, Jin-Oh; Yu, Myeong-Hee; Lee, Cheolju

    2007-11-01

    We have developed a robotic system for an automated parallel cell cultivation process that enables screening of induction parameters for the soluble expression of recombinant protein. The system is designed for parallelized and simultaneous cultivation of up to 24 different types of cells or a single type of cell at 24 different conditions. Twenty-four culture vessels of about 200 ml are arranged in four columns x six rows. The system is equipped with four independent thermostated waterbaths, each of which accommodates six culture vessels. A two-channel liquid handler is attached in order to distribute medium from the reservoir to the culture vessels, to transfer seed or other reagents, and to take an aliquot from the growing cells. Cells in each vessel are agitated and aerated by sparging filtered air. We tested the system by growing Escherichia coli BL21(DE3) cells harboring a plasmid for a model protein, and used it in optimizing protein expression conditions by varying the induction temperature and the inducer concentration. The results revealed the usefulness of our custom-made cell cultivation robot in screening optimal conditions for the expression of soluble proteins.

  11. Miniature lens design and optimization with liquid lens element via genetic algorithm

    NASA Astrophysics Data System (ADS)

    Fang, Yi-Chin; Tsai, Chen-Mu

    2008-07-01

    This paper proposes a design and optimization method via (GA) genetic algorithm applied to a newly developed optical element: the liquid lens as a fast focus group. This design takes advantage of quick focus which works simultaneously with modern CMOS sensors in order to significantly improve image quality. Such improvement is important, especially for medical imaging technology such as laparoscopy. However, this optical design with a liquid lens element has not achieved success yet; one of the major reasons is the lack of anomalous dispersion glass and their Abbe number, which complicates the correction of aberrations, limits its availability. From the point of view of aberration theory, most aberrations, particularly in the axial chromatic and lateral color aberration of an optical lens, play the same role as the selection of optical glass. Therefore, in the present research, some optical layouts with a liquid lens are first discussed; next, genetic algorithms are used to replace traditional LDS (least damping square) to search for the best solution using a liquid lens and find the best glass sets for the combination of anomalous dispersion glass and materials inside a liquid lens. During optimization work, the 'geometric optics' theory and 'multiple dynamic crossover and random gene mutation' technique are employed. Through implementation of the algorithms proposed in this paper, satisfactory elimination of axial and lateral color aberration can be achieved.

  12. A Microfluidic Cell Co-Culture Platform with a Liquid Fluorocarbon Separator

    PubMed Central

    Brewer, Bryson M.; Shi, Mingjian; Edd, Jon F.; Webb, Donna J.; Li, Deyu

    2014-01-01

    A microfluidic cell co-culture platform that uses a liquid fluorocarbon oil barrier to separate cells into different culture chambers has been developed. Characterization indicates that the oil barrier could be effective for multiple days, and a maximum pressure difference between the oil barrier and aqueous media in the cell culture chamber could be as large as ∼3.43 kPa before the oil barrier fails. Biological applications have been demonstrated with the separate transfection of two groups of primary hippocampal neurons with two different fluorescent proteins and subsequent observation of synaptic contacts between the neurons. In addition, the quality of the fluidic seal provided by the oil barrier is shown to be greater than that of an alternative solid-PDMS valve barrier design by testing the ability of each device to block low molecular weight CellTracker dyes used to stain cells in the culture chambers. PMID:24420386

  13. Optimization of Aqueous Biphasic Tumor Spheroid Microtechnology for Anti-Cancer Drug Testing in 3D Culture

    PubMed Central

    Lemmo, Stephanie; Atefi, Ehsan; Luker, Gary D.; Tavana, Hossein

    2014-01-01

    Tumor spheroids are three-dimensional clusters of cancer cells that exhibit characteristics of poorly perfused tumors and hence present a relevant model for testing the efficacy of anti-cancer compounds. The use of spheroids for drug screening is hindered by technological complexities for high throughput generation of consistent size spheroids individually addressable by drug compounds. Here we present and optimize a simple spheroid technology based on the use of an aqueous two-phase system. Cancer cells confined in a drop of the denser aqueous dextran phase are robotically dispensed into a microwell containing the immersion aqueous polyethylene glycol phase. Cells remain within the drop and form a viable spheroid, without a need for any external stimuli. The size of resulting spheroids is sensitive to volume variations of dispensed drops from the air displacement pipetting head of a commercial liquid handling robot. Therefore, we parametrically optimize the process of dispensing of dextran phase drops. For a given cell density, this optimization reproducibly generates consistent size spheroids in standard 96-well plates. In addition, we evaluate the use of a commercial biochemical assay to examine cellular viability of cancer cell spheroids. Spheroids show a dose-dependent response to cisplatin similar to a monolayer culture. However unlike their two-dimensional counterpart, spheroids exhibit resistance to paclitaxel treatment. This technology, which uses only commercially-available reagents and equipment, can potentially expedite anti-cancer drug discovery. Although the use of robotics makes the ATPS spheroid technology particularly useful for drug screening applications, this approach is compatible with simpler liquid handling techniques such as manual micropipetting and offers a straightforward method of 3D cell culture in research laboratories. PMID:25221631

  14. Pre-culturing of nodal explants in thidiazuron supplemented liquid medium improves in vitro shoot multiplication of Cassia angustifolia.

    PubMed

    Siddique, I; Abdullwahab Bukhari, N; Perveen, K; Siddiqui, I; Anis, M

    2013-09-01

    An in vitro propagation system for Cassia angustifolia Vahl. has been developed. Due to the presence of sennosides, the demand of this plant has increased manyfold in global market. Multiple shoots were induced by culturing nodal explants excised from mature plants on a liquid Murashige and Skoog [8] medium supplemented with 5-100 μM of thidiazuron (TDZ) for different treatment duration (4, 8, 12 and 16 d). The optimal level of TDZ supplemented to the culture medium was 75 μM for 12 d induction period followed by subculturing in MS medium devoid of TDZ as it produced maximum regeneration frequency (87%), mean number of shoots (9.6 ± 0.33) and shoot length (4.4 ± 0.46 cm) per explant. A culture period longer than 12 d with TDZ resulted in the formation of fasciated or distorted shoots. Ex vitro rooting was achieved when the basal cut end of regenerated shoots was dipped in 200 μM indole-3-butyric acid (IBA) for half an hour followed by their transplantation in plastic pots filled with sterile soilrite where 85% plantlets grew well and all exhibited normal development. The present findings describe an efficient and rapid plant regeneration protocol that can further be used for genetic transformation studies. PMID:24013898

  15. Analysis of acetoin and diacetyl in bacterial culture supernatants by gas-liquid chromatography.

    PubMed

    Lee, S M; Drucker, D B

    1975-09-01

    The acetoin and diacetyl contents of culture supernatants of Voges-Proskauer-positive "viridans" streptotocci, Klebsiella pneumoniae and Staphylococcus aureus, were determined by a gas liquid chromatographic procedure, in which supernatants were extracted with diethyl ether and diacetyl was measured on columns of 10% (wt/wt) polyethylene glycol 400 (PEG 400) at 73 C. Acetoin was converted to diacetyl, before analysis, by a simple oxidation procedure with ferric chloride and without a distillation step. Streptococcal culture supernatants were shown by this method to contain only acetoin; supernatants of K. pneumoniae and S. aureus contained both acetoin and diacetyl.

  16. Irradiance optimization of outdoor microalgal cultures using solar tracked photobioreactors.

    PubMed

    Hindersin, Stefan; Leupold, Marco; Kerner, Martin; Hanelt, Dieter

    2013-03-01

    Photosynthetic activity and temperature regulation of microalgal cultures (Chlorella vulgaris and Scenedesmus obliquus) under different irradiances controlled by a solar tracker and different cell densities were studied in outdoor flat panel photobioreactors. An automated process control unit regulated light and temperature as well as pH value and nutrient concentration in the culture medium. CO2 was supplied using flue gas from an attached combined block heat and power station. Photosynthetic activity was determined by pulse amplitude modulation fluorometry. Compared to the horizontal irradiance of 55 mol photons m(-2) d(-1) on a clear day, the solar tracked photobioreactors enabled a decrease and increase in the overall light absorption from 19 mol photons m(-2) d(-1) (by rotation out of direct irradiance) to 79 mol photons m(-2) d(-1) (following the position of the sun). At biomass concentrations below 1.1 g cell dry weight (CDW) L(-1), photoinhibition of about 35 % occurred at irradiances of ≥1,000 μmol photons m(-2) s(-1) photosynthetic active radiation (PAR). Using solar tracked photobioreactors, photoinhibition can be reduced and at optimum biomass concentration (≥2.3 g CDW L(-1)), the culture was irradiated up to 2,000 μmol photons m(-2) s(-1) to overcome light limitation with biomass yields of 0.7 g CDW mol photons(-1) and high photosynthetic activities indicated by an effective quantum yield of 0.68 and a maximum quantum yield of 0.80 (F v/F m). Overheating due to high irradiance was avoided by turning the PBR out of the sun or using a cooling system, which maintained the temperature close to the species-specific temperature optima. PMID:22847362

  17. Irradiance optimization of outdoor microalgal cultures using solar tracked photobioreactors.

    PubMed

    Hindersin, Stefan; Leupold, Marco; Kerner, Martin; Hanelt, Dieter

    2013-03-01

    Photosynthetic activity and temperature regulation of microalgal cultures (Chlorella vulgaris and Scenedesmus obliquus) under different irradiances controlled by a solar tracker and different cell densities were studied in outdoor flat panel photobioreactors. An automated process control unit regulated light and temperature as well as pH value and nutrient concentration in the culture medium. CO2 was supplied using flue gas from an attached combined block heat and power station. Photosynthetic activity was determined by pulse amplitude modulation fluorometry. Compared to the horizontal irradiance of 55 mol photons m(-2) d(-1) on a clear day, the solar tracked photobioreactors enabled a decrease and increase in the overall light absorption from 19 mol photons m(-2) d(-1) (by rotation out of direct irradiance) to 79 mol photons m(-2) d(-1) (following the position of the sun). At biomass concentrations below 1.1 g cell dry weight (CDW) L(-1), photoinhibition of about 35 % occurred at irradiances of ≥1,000 μmol photons m(-2) s(-1) photosynthetic active radiation (PAR). Using solar tracked photobioreactors, photoinhibition can be reduced and at optimum biomass concentration (≥2.3 g CDW L(-1)), the culture was irradiated up to 2,000 μmol photons m(-2) s(-1) to overcome light limitation with biomass yields of 0.7 g CDW mol photons(-1) and high photosynthetic activities indicated by an effective quantum yield of 0.68 and a maximum quantum yield of 0.80 (F v/F m). Overheating due to high irradiance was avoided by turning the PBR out of the sun or using a cooling system, which maintained the temperature close to the species-specific temperature optima.

  18. Monitoring utilizations of amino acids and vitamins in culture media and Chinese hamster ovary cells by liquid chromatography tandem mass spectrometry.

    PubMed

    Qiu, Jinshu; Chan, Pik Kay; Bondarenko, Pavel V

    2016-01-01

    Monitoring amino acids and vitamins is important for understanding human health, food nutrition and the culture of mammalian cells used to produce therapeutic proteins in biotechnology. A method including ion pairing reversed-phase liquid chromatography with tandem mass spectrometry was developed and optimized to quantify 21 amino acids and 9 water-soluble vitamins in Chinese hamster ovary (CHO) cells and culture media. By optimizing the chromatographic separation, scan time, monitoring time window, and sample preparation procedure, and using isotopically labeled (13)C, (15)N and (2)H internal standards, low limits of quantitation (≤0.054 mg/L), good precision (<10%) and good accuracy (100±10%) were achieved for nearly all the 30 compounds. Applying this method to CHO cell extracts, statistically significant differences in the metabolite levels were measured between two cell lines originated from the same host, indicating differences in genetic makeup or metabolic activities and nutrient supply levels in the culture media. In a fed-batch process of manufacturing scale bioreactors, two distinguished trends for changes in amino acid concentrations were identified in response to feeding. Ten essential amino acids showed a zigzag pattern with maxima at the feeding days, and 9 non-essential amino acids displayed a smoothly changing profile as they were mainly products of cellular metabolism. Five of 9 vitamins accumulated continuously during the culture period, suggesting that they were fed in access. The method serves as an effective tool for the development and optimization of mammalian cell cultures. PMID:26355770

  19. Monitoring utilizations of amino acids and vitamins in culture media and Chinese hamster ovary cells by liquid chromatography tandem mass spectrometry.

    PubMed

    Qiu, Jinshu; Chan, Pik Kay; Bondarenko, Pavel V

    2016-01-01

    Monitoring amino acids and vitamins is important for understanding human health, food nutrition and the culture of mammalian cells used to produce therapeutic proteins in biotechnology. A method including ion pairing reversed-phase liquid chromatography with tandem mass spectrometry was developed and optimized to quantify 21 amino acids and 9 water-soluble vitamins in Chinese hamster ovary (CHO) cells and culture media. By optimizing the chromatographic separation, scan time, monitoring time window, and sample preparation procedure, and using isotopically labeled (13)C, (15)N and (2)H internal standards, low limits of quantitation (≤0.054 mg/L), good precision (<10%) and good accuracy (100±10%) were achieved for nearly all the 30 compounds. Applying this method to CHO cell extracts, statistically significant differences in the metabolite levels were measured between two cell lines originated from the same host, indicating differences in genetic makeup or metabolic activities and nutrient supply levels in the culture media. In a fed-batch process of manufacturing scale bioreactors, two distinguished trends for changes in amino acid concentrations were identified in response to feeding. Ten essential amino acids showed a zigzag pattern with maxima at the feeding days, and 9 non-essential amino acids displayed a smoothly changing profile as they were mainly products of cellular metabolism. Five of 9 vitamins accumulated continuously during the culture period, suggesting that they were fed in access. The method serves as an effective tool for the development and optimization of mammalian cell cultures.

  20. Multi-residue method for determination of selected neonicotinoid insecticides in honey using optimized dispersive liquid-liquid microextraction combined with liquid chromatography-tandem mass spectrometry.

    PubMed

    Jovanov, Pavle; Guzsvány, Valéria; Franko, Mladen; Lazić, Sanja; Sakač, Marijana; Šarić, Bojana; Banjac, Vojislav

    2013-07-15

    The objective of this study was to develop analytical method based on optimized dispersive liquid-liquid microextraction (DLLME) as a pretreatment procedure combined with reversed phase liquid chromatographic separation on C18 column and isocratic elution for simultaneous MS/MS determination of selected neonicotinoid insecticides in honey. The LC-MS/MS parameters were optimized to unequivocally provide good chromatographic separation, low detection (LOD, 0.5-1.0 μg kg(-1)) and quantification (LOQ, 1.5-2.5 μg kg(-1)) limits for acetamiprid, clothianidin, thiamethoxam, imidacloprid, dinotefuran, thiacloprid and nitenpyram in honey samples. Using different types (chloroform, dichloromethane) and volumes of extraction (0.5-3.0 mL) and dispersive (acetonitrile; 0.0-1.0 mL) solvent and by mathematical modeling it was possible to establish the optimal sample preparation procedure. Matrix-matched calibration and blank honey sample spiked in the concentration range of LOQ-100.0 μg kg(-1) were used to compensate the matrix effect and to fulfill the requirements of SANCO/12495/2011 for the accuracy (R 74.3-113.9%) and precision (expressed in terms of repeatability (RSD 2.74-11.8%) and within-laboratory reproducibility (RSDs 6.64-16.2%)) of the proposed method. The rapid (retention times 1.5-9.9 min), sensitive and low solvent consumption procedure described in this work provides reliable, simultaneous, and quantitative method applicable for the routine laboratory analysis of seven neonicotinoid residues in real honey samples.

  1. Multi-residue method for determination of selected neonicotinoid insecticides in honey using optimized dispersive liquid-liquid microextraction combined with liquid chromatography-tandem mass spectrometry.

    PubMed

    Jovanov, Pavle; Guzsvány, Valéria; Franko, Mladen; Lazić, Sanja; Sakač, Marijana; Šarić, Bojana; Banjac, Vojislav

    2013-07-15

    The objective of this study was to develop analytical method based on optimized dispersive liquid-liquid microextraction (DLLME) as a pretreatment procedure combined with reversed phase liquid chromatographic separation on C18 column and isocratic elution for simultaneous MS/MS determination of selected neonicotinoid insecticides in honey. The LC-MS/MS parameters were optimized to unequivocally provide good chromatographic separation, low detection (LOD, 0.5-1.0 μg kg(-1)) and quantification (LOQ, 1.5-2.5 μg kg(-1)) limits for acetamiprid, clothianidin, thiamethoxam, imidacloprid, dinotefuran, thiacloprid and nitenpyram in honey samples. Using different types (chloroform, dichloromethane) and volumes of extraction (0.5-3.0 mL) and dispersive (acetonitrile; 0.0-1.0 mL) solvent and by mathematical modeling it was possible to establish the optimal sample preparation procedure. Matrix-matched calibration and blank honey sample spiked in the concentration range of LOQ-100.0 μg kg(-1) were used to compensate the matrix effect and to fulfill the requirements of SANCO/12495/2011 for the accuracy (R 74.3-113.9%) and precision (expressed in terms of repeatability (RSD 2.74-11.8%) and within-laboratory reproducibility (RSDs 6.64-16.2%)) of the proposed method. The rapid (retention times 1.5-9.9 min), sensitive and low solvent consumption procedure described in this work provides reliable, simultaneous, and quantitative method applicable for the routine laboratory analysis of seven neonicotinoid residues in real honey samples. PMID:23622535

  2. Genetic algorithm to optimize the design of main combustor and gas generator in liquid rocket engines

    NASA Astrophysics Data System (ADS)

    Son, Min; Ko, Sangho; Koo, Jaye

    2014-06-01

    A genetic algorithm was used to develop optimal design methods for the regenerative cooled combustor and fuel-rich gas generator of a liquid rocket engine. For the combustor design, a chemical equilibrium analysis was applied, and the profile was calculated using Rao's method. One-dimensional heat transfer was assumed along the profile, and cooling channels were designed. For the gas-generator design, non-equilibrium properties were derived from a counterflow analysis, and a vaporization model for the fuel droplet was adopted to calculate residence time. Finally, a genetic algorithm was adopted to optimize the designs. The combustor and gas generator were optimally designed for 30-tonf, 75-tonf, and 150-tonf engines. The optimized combustors demonstrated superior design characteristics when compared with previous non-optimized results. Wall temperatures at the nozzle throat were optimized to satisfy the requirement of 800 K, and specific impulses were maximized. In addition, the target turbine power and a burned-gas temperature of 1000 K were obtained from the optimized gas-generator design.

  3. Diamagnetic levitation enhances growth of liquid bacterial cultures by increasing oxygen availability.

    PubMed

    Dijkstra, Camelia E; Larkin, Oliver J; Anthony, Paul; Davey, Michael R; Eaves, Laurence; Rees, Catherine E D; Hill, Richard J A

    2011-03-01

    Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to reproduce aspects of weightlessness, on the Earth. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 h, to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture and reduces the sedimentation rate of the cells. Further experiments and microarray gene analysis show that the increase in growth rate is owing to enhanced oxygen availability. We also demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause convection during the aerobic phases of bacterial growth. We propose that this convection enhances oxygen availability by transporting oxygen around the liquid culture. Since this process results from the strong magnetic field, it is not present in other weightless environments, e.g. in Earth orbit. Hence, these results are of significance and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena. PMID:20667843

  4. Diamagnetic levitation enhances growth of liquid bacterial cultures by increasing oxygen availability

    PubMed Central

    Dijkstra, Camelia E.; Larkin, Oliver J.; Anthony, Paul; Davey, Michael R.; Eaves, Laurence; Rees, Catherine E. D.; Hill, Richard J. A.

    2011-01-01

    Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to reproduce aspects of weightlessness, on the Earth. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 h, to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture and reduces the sedimentation rate of the cells. Further experiments and microarray gene analysis show that the increase in growth rate is owing to enhanced oxygen availability. We also demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause convection during the aerobic phases of bacterial growth. We propose that this convection enhances oxygen availability by transporting oxygen around the liquid culture. Since this process results from the strong magnetic field, it is not present in other weightless environments, e.g. in Earth orbit. Hence, these results are of significance and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena. PMID:20667843

  5. Dispositional optimism and physical wellbeing: the relevance of culture, gender, and socioeconomic status.

    PubMed

    Khallad, Yacoub

    2013-01-01

    The present study examined the relationship between dispositional optimism and physical wellbeing (as reflected in physical symptom reporting) in two groups of American and Jordanian college students. It also assessed moderation effects of culture, gender, and socioeconomic status (SES). Participants were administered a questionnaire consisting of items pertaining to dispositional optimism (as measured by the Revised Life Orientation Test, LOT-R) along with items assessing physical symptom reporting and sociodemographic factors (e.g., gender, socioeconomic status). The results revealed significant negative correlations between dispositional optimism and physical symptom reporting for both American and Jordanian participants, although the magnitude of the correlation for the American group was noticeably larger than that for the Jordanian group. The results also showed that women, especially Jordanians, were more likely than men to report physical symptoms. Among Jordanians, physical symptom reporting was more common among those of lower SES. No statistically significant differences in physical symptom reporting were found between American men and women or between the two cultural groups. Multiple regression analyses revealed no statistically significant interactions between optimism and cultural background, optimism and gender, or optimism and SES. Overall, the results suggest that optimism is the factor most predictive of physical symptom reporting, followed by SES and gender. These results corroborate previous findings on the relationship between dispositional optimism and physical wellbeing, and point to crosscultural differences in relationship patterns. These differences suggest that although personality characteristics such as optimism may play an important role in the physical wellbeing of both Western and non-Western groups, the influence of sociodemographic factors such as gender and SES and their interaction with cultural variables must not be overlooked.

  6. On-line optimal control for fed-batch culture of baker's yeast production

    SciTech Connect

    Wu, W.T.; Chen, K.C.; Chiou, H.W.

    1985-05-01

    A method of on-line optimal control for fed-batch culture of bakers yeast production is proposed. The feed rate is taken as the control variable. The specific growth rate of the yeast is the output variable and is determined from the balance equation of oxygen. A moving model is obtained by using the data from the feed rate and the specific growth rate. Based on the moving model, an optimal feed rate for fed-batch culture is then achieved. 11 references.

  7. Rational approach to optimize cellulase mixtures for hydrolysis of regenerated cellulose containing residual ionic liquid.

    PubMed

    Engel, Philip; Krull, Susan; Seiferheld, Bianca; Spiess, Antje C

    2012-07-01

    For the efficient production of glucose for platform chemicals or biofuels, cellulosic biomass is pretreated and subsequently hydrolyzed with cellulases. Although ionic liquids (IL) are known to effectively pretreat cellulosic biomass, the hydrolysis of IL pretreated biomass has not been optimized so far. Here, we present a semi-empirical model to rationally optimize the hydrolysis of pretreated α-cellulose - regenerated from IL and containing residual IL from the pretreatment. First, the influence of the IL MMIM DMP on the individual cellulases endoglucanase I, cellobiohydrolase I and β-glucosidase was investigated. Second, an enzyme loading-dependent model was developed to describe kinetics for the individual cellulases and cellulase mixtures. Third, this model was used to optimize the cellulase mixture for the efficient hydrolysis of regenerated cellulose containing residual IL. Finally, we could significantly increase the initial hydrolysis rate in 10% (v/v) MMIM DMP by 49% and the sugar yield by 10% points. PMID:22100231

  8. Dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for determination of benzoate and sorbate in yogurt drinks and method optimization by central composite design.

    PubMed

    Kamankesh, Marzieh; Mohammadi, Abdorreza; Tehrani, Zohreh Modarres; Ferdowsi, Roohallah; Hosseini, Hedayat

    2013-05-15

    A new method based on dispersive liquid-liquid microextraction (DLLME) followed by high-performance liquid chromatography (HPLC) for determination of benzoate and sorbate salts in yogurt drinks was developed. The effective parameters in DLLME process, including volume of extraction and disperser solvents, pH and salt effect, were optimized using response surface methodology (RSM) based on central composite design. The yogurt drink samples were extracted using NaOH and Carrez solutions (potassium hexaferrocyanide and zinc acetate) were used for sedimentation of proteins. For DLLME, a mixture of extraction solvent (1-octanol) and disperser solvent (ethanol) was rapidly injected into the sample solution by syringe and cloudy solution is formed. Subsequently, the upper 1-octanol layer was analyzed by HPLC. The detection limits for benzoate and sorbate were 0.06 ng mL(-1) and 0.15 ng mL(-1), respectively. The relative standard deviations (RSD) for seven analyses were 4.96% for benzoate and 4.58% for sorbate. The proposed method demonstrated good linearity and high enrichment factor. A clean separation and good chromatogram is readily achieved without the presence of matrix interference. A comparison of this method with previous methods demonstrated that the proposed method is an accurate, rapid and reliable sample-pretreatment method that gives very good enrichment factors and detection limits for extracting and determining sorbate and benzoate in yogurt drink samples. PMID:23618139

  9. Optimized measurement of radium-226 concentration in liquid samples with radon-222 emanation.

    PubMed

    Perrier, Frédéric; Aupiais, Jean; Girault, Frédéric; Przylibski, Tadeusz A; Bouquerel, Hélène

    2016-06-01

    Measuring radium-226 concentration in liquid samples using radon-222 emanation remains competitive with techniques such as liquid scintillation, alpha or mass spectrometry. Indeed, we show that high-precision can be obtained without air circulation, using an optimal air to liquid volume ratio and moderate heating. Cost-effective and efficient measurement of radon concentration is achieved by scintillation flasks and sufficiently long counting times for signal and background. More than 400 such measurements were performed, including 39 dilution experiments, a successful blind measurement of six reference test solutions, and more than 110 repeated measurements. Under optimal conditions, uncertainties reach 5% for an activity concentration of 100 mBq L(-1) and 10% for 10 mBq L(-1). While the theoretical detection limit predicted by Monte Carlo simulation is around 3 mBq L(-1), a conservative experimental estimate is rather 5 mBq L(-1), corresponding to 0.14 fg g(-1). The method was applied to 47 natural waters, 51 commercial waters, and 17 wine samples, illustrating that it could be an option for liquids that cannot be easily measured by other methods. Counting of scintillation flasks can be done in remote locations in absence of electricity supply, using a solar panel. Thus, this portable method, which has demonstrated sufficient accuracy for numerous natural liquids, could be useful in geological and environmental problems, with the additional benefit that it can be applied in isolated locations and in circumstances when samples cannot be transported. PMID:26998570

  10. Optimized measurement of radium-226 concentration in liquid samples with radon-222 emanation.

    PubMed

    Perrier, Frédéric; Aupiais, Jean; Girault, Frédéric; Przylibski, Tadeusz A; Bouquerel, Hélène

    2016-06-01

    Measuring radium-226 concentration in liquid samples using radon-222 emanation remains competitive with techniques such as liquid scintillation, alpha or mass spectrometry. Indeed, we show that high-precision can be obtained without air circulation, using an optimal air to liquid volume ratio and moderate heating. Cost-effective and efficient measurement of radon concentration is achieved by scintillation flasks and sufficiently long counting times for signal and background. More than 400 such measurements were performed, including 39 dilution experiments, a successful blind measurement of six reference test solutions, and more than 110 repeated measurements. Under optimal conditions, uncertainties reach 5% for an activity concentration of 100 mBq L(-1) and 10% for 10 mBq L(-1). While the theoretical detection limit predicted by Monte Carlo simulation is around 3 mBq L(-1), a conservative experimental estimate is rather 5 mBq L(-1), corresponding to 0.14 fg g(-1). The method was applied to 47 natural waters, 51 commercial waters, and 17 wine samples, illustrating that it could be an option for liquids that cannot be easily measured by other methods. Counting of scintillation flasks can be done in remote locations in absence of electricity supply, using a solar panel. Thus, this portable method, which has demonstrated sufficient accuracy for numerous natural liquids, could be useful in geological and environmental problems, with the additional benefit that it can be applied in isolated locations and in circumstances when samples cannot be transported.

  11. Scalable 96-well Plate Based iPSC Culture and Production Using a Robotic Liquid Handling System.

    PubMed

    Conway, Michael K; Gerger, Michael J; Balay, Erin E; O'Connell, Rachel; Hanson, Seth; Daily, Neil J; Wakatsuki, Tetsuro

    2015-01-01

    Continued advancement in pluripotent stem cell culture is closing the gap between bench and bedside for using these cells in regenerative medicine, drug discovery and safety testing. In order to produce stem cell derived biopharmaceutics and cells for tissue engineering and transplantation, a cost-effective cell-manufacturing technology is essential. Maintenance of pluripotency and stable performance of cells in downstream applications (e.g., cell differentiation) over time is paramount to large scale cell production. Yet that can be difficult to achieve especially if cells are cultured manually where the operator can introduce significant variability as well as be prohibitively expensive to scale-up. To enable high-throughput, large-scale stem cell production and remove operator influence novel stem cell culture protocols using a bench-top multi-channel liquid handling robot were developed that require minimal technician involvement or experience. With these protocols human induced pluripotent stem cells (iPSCs) were cultured in feeder-free conditions directly from a frozen stock and maintained in 96-well plates. Depending on cell line and desired scale-up rate, the operator can easily determine when to passage based on a series of images showing the optimal colony densities for splitting. Then the necessary reagents are prepared to perform a colony split to new plates without a centrifugation step. After 20 passages (~3 months), two iPSC lines maintained stable karyotypes, expressed stem cell markers, and differentiated into cardiomyocytes with high efficiency. The system can perform subsequent high-throughput screening of new differentiation protocols or genetic manipulation designed for 96-well plates. This technology will reduce the labor and technical burden to produce large numbers of identical stem cells for a myriad of applications. PMID:26068617

  12. Optimizing enrichment culture conditions for detecting Helicobacter pylori in foods.

    PubMed

    Jiang, Xiuping; Doyle, Michael P

    2002-12-01

    The survival and growth of Helicobacter pylori under enrichment conditions in fresh, autoclaved and irradiated ground beef were determined. H. pylori grew in autoclaved ground beef at 37 degrees C under microaerobic conditions in brain heart infusion broth with 7% horse serum at pH 7.3 after 3 to 7 days of lag time but did not grow within 7 days in irradiated (10 kGy) ground beef under the same enrichment conditions. Adjustment of the enrichment broth to pH 5.5 enabled the growth (ca. 2 log10 CFU/ml) of H. pylori within 7 days in the presence of irradiated ground beef and the prolific growth (ca. 3 to 4 log10 CFU/ml) of H. pylori within 3 days in the presence of autoclaved beef. H. pylori in fresh ground beef could not be isolated from enrichment media with antibiotics; however. H. pylori ureA could be detected by polymerase chain reaction (PCR) in such enrichment media after 1 to 3 days of incubation at 37 degrees C. The addition of supplements, i.e., 0.3% mucin, 0.05% ferrous sulfate, and 0.05% sodium pyruvate or 0.008 M urea, or the adjustment of the enrichment broth pH to 5.5 or 4.5 enabled the detection of H. pylori ureA in enrichment media incubated for 1, 2, 3, and/or 7 days at 37 degrees C. H. pylori in sterile milk refrigerated at 4 degrees C at an initial level of 10(6) CFU/ml was inactivated to an undetectable level within 6 days; however, H. pylori was not detected either by a PCR assay or by the plating of enrichment cultures of 120 raw bovine milk samples. PMID:12495015

  13. [Absence of mutagenic effect of Pseudomonas syringae pv. atrofaciens 9400 and Pantoea agglomerans P324 culture liquids].

    PubMed

    Bohdan, Iu M; Butsenko, L M; Pasichnyk, L A; Hvozdiak, R I

    2010-01-01

    The mutagenic activity of the culture liquids of phytopathogenic strain Pseudomonas syringae pv. atrofaciens 9400 and epiphytic strain Pantoea agglomerans P324 was studied in the Ames test and Allium cepa-test. In pro- and eucariotic test-systems no effect of the culture liquids of these bacteria on spontaneous mutations of Salmonella typhimurium TA98 and TA100 or chromosome aberrations in the cells of Allium cepa root apical meristem was found. PMID:20812509

  14. Optimization of culture parameters for production of podophyllotoxin in suspension culture of Podophyllum hexandrum.

    PubMed

    Chattopadhyay, Saurabh; Srivastava, A K; Bisaria, V S

    2002-01-01

    The root explants of the germinated seedlings of Podophyllum hexandrum were grown in MS medium supplemented with indole acetic acid (IAA) (2 mg/L) and activated charcoal (0.5%), and healthy callus culture was obtained after incubation for 3 wk at 20 degrees C. The cultivation of plant cells in shake flask was associated with problems such as clumping of cells and browning of media, which were solved by the addition of pectinase and polyvinylpyrrolidone. The effect of major media components and carbon source was studied on the growth and podophyllotoxin production in suspension culture. It was found that glucose was a better carbon source than sucrose and that NH4+:NO3- ratio (total nitrogen concentration of 60 mM) and PO4(3-) did not have much effect on the growth and product formation. The relative effect of culture parameters (inoculum level, pH, IAA, glucose, NH4+:NO3- ratio, and PO4(3-)) on the overall growth and product response of the plant cell suspension culture was further investigated by Plackett-Burman design. This indicated that inoculum level, glucose, IAA, and pH had significant effects on growth and production of podophyllotoxin. To identify the exact optimum concentrations of these parameters on culture growth and podophyllotoxin production, central composite design experiments were formulated. The overall response equations with respect to growth and podophyllotoxin production as a function of these culture parameters were developed and used to determine the optimum concentrations of these parameters, which were pH 6.0, 1.25 mg/L of IAA, 72 g/L of glucose, and inoculum level of 8 g/L.

  15. Molecular simulations of imidazolium-based tricyanomethanide ionic liquids using an optimized classical force field.

    PubMed

    Vergadou, Niki; Androulaki, Eleni; Hill, Jörg-Rüdiger; Economou, Ioannis G

    2016-03-01

    Imidazolium-based ionic liquids (ILs) incorporating the tricyanomethanide ([TCM(-)]) anion are studied using an optimized classical force field. These ILs are very promising candidates for use in a wide range of cutting-edge technologies and, to our knowledge, it is the first time that this IL family is subject to a molecular simulation study with the use of a classical atomistic force field. The [C4mim(+)][TCM(-)] ionic liquid at 298.15 K and at atmospheric pressure was used as the basis for force field optimization which primarily involved the determination of the Lennard-Jones parameters of [TCM(-)] and the implementation of three quantum mechanical schemes for the calculation of the partial charge distribution and the identification of the appropriate scaling factor for the reduction of the total ionic charge. The optimized force field was validated by performing simulations of the 1-alkyl-3-methylimidazolium tricyanomethanide ([Cnmim(+)][TCM(-)], n = 2, 4, 6, and 8) IL family at various temperatures. The results for density, self-diffusivity and viscosity are in very good agreement with the available experimental data for all ILs verifying that the force field reliably reproduces the behaviour of the imidazolium-based [TCM(-)] IL family in a wide temperature range. Furthermore, a detailed analysis of the microscopic structure and the complex dynamic behaviour of the ILs under study was performed. PMID:26878611

  16. Optimization of dispersive liquid-liquid microextraction for preconcentration and spectrophotometric determination of phenols in Chabahar Bay seawater after derivatization with 4-aminoantipyrine.

    PubMed

    Nassiri, Mahmoud; Zahedi, Mir Mahdi; Pourmortazavi, Seied Mahdi; Yousefzade, Mehdi

    2014-09-15

    We have optimized dispersive liquid-liquid microextraction to preconcentrate trace phenolic compounds after derivatization with 4-aminoantipyrine in artificial sea water for spectrophotometric determination. Factors such as reaction time (7.5 min), pH (9.5), solvent (chloroform), dispersing solvent (ethanol), and volume ratio of dispersing to organic phase (11:1) were optimized. Under optimum conditions, the limit of detection was 0.18 μg/L and the linearity range 1-900 μg/L. The relative standard deviation and enrichment factor were 6% (n=7) and 920, respectively. The results demonstrate the efficiency of coupling the 5530 APHA standard for derivation and dispersive liquid-liquid microextraction of phenolic compounds from seawater samples. Using this method, total phenol content in seawater from several locations in Chabahar Bay (southeast Iran) was estimated at 27.8-74.8 μg/L.

  17. Topology optimization for the design of folding liquid crystal elastomer actuators.

    PubMed

    Fuchi, Kazuko; Ware, Taylor H; Buskohl, Philip R; Reich, Gregory W; Vaia, Richard A; White, Timothy J; Joo, James J

    2015-10-01

    Aligned liquid crystal elastomers (LCEs) are capable of undergoing large reversible shape change in response to thermal stimuli and may act as actuators for many potential applications such as self-assembly and deployment of micro devices. Recent advances in LCE patterning tools have demonstrated sub-millimetre control of director orientation, enabling the preparation of materials with arbitrarily complex director fields. However, without design tools to connect the 2D director pattern with the activated 3D shape, LCE design relies on intuition and trial and error. Here we present a design methodology to generate reliable folding in monolithic LCEs designed with topology optimization. The distributions of order/disorder and director orientations are optimized so that the remotely actuated deformation closely matches a target deformation for origami folding. The optimal design exhibits a strategy to counteract the mechanical frustration that may lead to an undesirable deformation, such as anti-clastic bending. Multi-hinge networks were developed using insights from the optimal hinge designs and were demonstrated through the fabrication and reversible actuation of a self-folding box. Topology optimization provides an important step towards leveraging the opportunities afforded by LCE patterning into functional designs. PMID:26270868

  18. Development and optimization of a new culture media using extruded bean as nitrogen source.

    PubMed

    Batista, Karla A; Fernandes, Kátia F

    2015-01-01

    The composition of a culture medium is one of the most important parameters to be analyzed in biotechnological processes with industrial purposes, because around 30-40% of the production costs were estimated to be accounted for the cost of the growth medium [1]. Since medium optimization using a one-factor-at-a-time approach is time-consuming, expensive, and often leads to misinterpretation of results, statistical experimental design has been applied to medium optimization for growth and metabolite production [2-5]. In this scenario, the use of mixture design to develop a culture medium containing a cheaper nitrogen source seems to be more appropriate and simple. In this sense, the focus of this work is to present a detailed description of the steps involved in the development of a optimized culture medium containing extruded bean as nitrogen source. •In a previous work we tested a development of new culture media based on the composition of YPD medium, aiming to reduce bioprocess costs as well as to improve the biomass production and heterologous expression.•The developed medium was tested for growth of Saccharomyces cerevisiae and Pichia pastoris (GS 115).•The use of culture media containing extruded bean as sole nitrogen source showed better biomass production and protein expression than those observed in the standard YPD medium. PMID:26150984

  19. Development and optimization of a new culture media using extruded bean as nitrogen source

    PubMed Central

    Batista, Karla A.; Fernandes, Kátia F.

    2015-01-01

    The composition of a culture medium is one of the most important parameters to be analyzed in biotechnological processes with industrial purposes, because around 30–40% of the production costs were estimated to be accounted for the cost of the growth medium [1]. Since medium optimization using a one-factor-at-a-time approach is time-consuming, expensive, and often leads to misinterpretation of results, statistical experimental design has been applied to medium optimization for growth and metabolite production [2], [3], [4], [5]. In this scenario, the use of mixture design to develop a culture medium containing a cheaper nitrogen source seems to be more appropriate and simple. In this sense, the focus of this work is to present a detailed description of the steps involved in the development of a optimized culture medium containing extruded bean as nitrogen source. • In a previous work we tested a development of new culture media based on the composition of YPD medium, aiming to reduce bioprocess costs as well as to improve the biomass production and heterologous expression. • The developed medium was tested for growth of Saccharomyces cerevisiae and Pichia pastoris (GS 115). • The use of culture media containing extruded bean as sole nitrogen source showed better biomass production and protein expression than those observed in the standard YPD medium. PMID:26150984

  20. Optimization of culture conditions of Fusarium solani for the production of neoN-methylsansalvamide.

    PubMed

    Lee, Hee-Seok; Phat, Chanvorleak; Nam, Woo-Seon; Lee, Chan

    2014-01-01

    The aim of this study was to optimize the culture conditions of Fusarium solani KCCM90040 on cereal grain for the production of neoN-methylsansalvamide, a novel low-molecular-weight cyclic pentadepsipeptide exhibiting cytotoxic and multidrug resistance reversal effects. From the analysis of variance results using response surface methodology, temperature, initial moisture content, and growth time were shown to be important parameters for the production of neoN-methylsansalvamide on cereal grain. A model was established in the present study to describe the relationship between environmental conditions and the production of neoN-methylsansalvamide on rice, the selected cereal grain. The optimal culture conditions were determined at 25.79 °C with the initial moisture content of 40.79%, and 16.19 days of growth time. This report will give important information concerning the optimization of environmental conditions using statistic methodology for the production of a new cyclic pentadepsipeptide from fungi.

  1. Enzyme-assisted extraction and ionic liquid-based dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for determination of patulin in apple juice and method optimization using central composite design.

    PubMed

    Mohammadi, Abdorreza; Tavakoli, Rouya; Kamankesh, Marzieh; Rashedi, Hamid; Attaran, Abdolmohammad; Delavar, Mostafa

    2013-12-01

    A simple and highly sensitive analytical methodology for isolation and determination of patulin in apple-juice samples, based on enzyme-assisted extraction (EAE) and ionic liquid-based dispersive liquid-liquid microextraction (IL-DLLME) was developed and optimized. Enzymes play essential roles in eliminating interference and increasing the extraction efficiency of patulin. Apple-juice samples were treated with pectinase and amylase. A mixture of 80 μL ionic liquid and 600 μL methanol (disperser solvent) was used for the IL-DLLME process. The sedimented phase was analyzed by high-performance liquid chromatography (HPLC). Experimental parameters controlling the performance of DLLME, were optimized using response surface methodology (RSM) based on central composite design (CCD). Under optimum conditions, the calibration curves showed high levels of linearity (R(2)>0.99) for patulin in the range of 1-200 ng g(-1). The relative standard deviation (RSD) for the seven analyses was 7.5%. The limits of detection (LOD) and limits of quantification (LOQ) were 0.15 ng g(-1) and 0.5 ng g(-1), respectively. The merit figures, compared with other methods, showed that new proposed method is an accurate, precise and reliable sample-pretreatment method that substantially reduces sample matrix interference and gives very good enrichment factors and detection limits for investigation trace amount of patulin in apple-juice samples.

  2. Optimization of the culture condition for an antitumor bacterium Serratia proteamacula 657 and identification of the active compounds.

    PubMed

    Miao, Li; Wang, Xueling; Jiang, Wei; Yang, Shengping; Zhou, Huiru; Zhai, Youpeng; Zhou, Xiaojian; Dong, Kunming

    2013-05-01

    Exploration of novel active anti-tumor compounds from marine microbes for pharmaceutical applications has been a continuously hot spot in natural product research. Bacterial growth and metabolites may greatly vary under different culture conditions. In this study, the effects of different culture conditions and medium components on the growth and bioactive metabolites of Serratia proteamacula 657, an anti-tumor bacterium found in our previous study, were investigated. The results showed that lower temperature, weak acidic condition and solid fermentation favored the bacterial growth and the production of active compounds. Four components in the culture medium, NaCl, peptone, yeast extract and MgSO4, were found important to the bacterial growth and active compounds production in medium optimization. Under the optimized condition of solid state fermentation at pH 6.0-7.0, 23-25 °C, with the MgSO4-free medium containing 10.0 g/L peptone, 1.0 g/L yeast extract and 19.45 g/L NaCl, the antitumor activity of S. proteamacula 657 and the yield of crude extracts increased about 15 times and 6 times than the sample obtained in the original liquid fermentation, respectively. The active components in the metabolites of S. proteamacula 657 were identified as a homolog of prodigiosin, a red bacterial pigment, based on the analysis of the NMR and GC-MS. The bacterium S. proteamacula 657, which is adapted to lower temperature, produced prodigiosin-like pigments with highly antitumor activity, suggesting the bacterium is a potential new source for prodigiosin production.

  3. Organizational transformation: a model for joint optimization of culture change and evidence-based design.

    PubMed

    Hamilton, D Kirk; Orr, Robin Diane; Raboin, W Ellen

    2008-01-01

    Healthcare organizations face continuous and accelerating external change and thus must be prepared to manage their own change initiatives proactively. Given that many believe that the U.S. healthcare system is broken and most healthcare organizations are dealing with pervasive problems, some organizations may choose to seek transformational change to achieve the six aims identified by the Institute of Medicine: healthcare that is safe, effective, patient-centered, timely, efficient, and equitable. Transformational change will almost certainly involve organizational culture. Culture change may be most effective when linked to other organizational change initiatives such as organizational strategy, structure, policies, procedures, and recruiting. Significant organizational change often requires accompanying facility change. There is an interdependent relationship between facility design and organizational culture. They affect each other and both impact organizational performance. Sociotechnical theory promotes joint optimization of the social (culture) and technical (facilities) aspects of an organization to achieve sustained positive change. To achieve organizational transformation and to sustain positive change, organizations must be prepared to adopt collaborative efforts in culture change and facility design. The authors propose a model for accomplishing joint optimization of culture change and evidence-based facility design.

  4. Liquid chromatographic method for determination of water in soils and the optimization of anion separations by capillary zone electrophoresis

    SciTech Connect

    Benz, N.

    1994-10-01

    A liquid chromatographic method for the determination of water in soil or clay samples is presented. In a separate study, the optimization of electrophoretic separation of alkylated phenolate ions was optimized by varying the pH and acetonitrile concentration of the buffer solutions.

  5. Approaches to Optimizing Animal Cell Culture Process: Substrate Metabolism Regulation and Protein Expression Improvement

    NASA Astrophysics Data System (ADS)

    Zhang, Yuanxing

    Some high value proteins and vaccines for medical and veterinary applications by animal cell culture have an increasing market in China. In order to meet the demands of large-scale productions of proteins and vaccines, animal cell culture technology has been widely developed. In general, an animal cell culture process can be divided into two stages in a batch culture. In cell growth stage a high specific growth rate is expected to achieve a high cell density. In production stage a high specific production rate is stressed for the expression and secretion of qualified protein or replication of virus. It is always critical to maintain high cell viability in fed-batch and perfusion cultures. More concern has been focused on two points by the researchers in China. First, the cell metabolism of substrates is analyzed and the accumulation of toxic by-products is decreased through regulating cell metabolism in the culture process. Second, some important factors effecting protein expression are understood at the molecular level and the production ability of protein is improved. In pace with the rapid development of large-scale cell culture for the production of vaccines, antibodies and other recombinant proteins in China, the medium design and process optimization based on cell metabolism regulation and protein expression improvement will play an important role. The chapter outlines the main advances in metabolic regulation of cell and expression improvement of protein in animal cell culture in recent years.

  6. Optimization of liquid scintillation measurements applied to smears and aqueous samples collected in industrial environments

    NASA Astrophysics Data System (ADS)

    Chapon, Arnaud; Pigrée, Gilbert; Putmans, Valérie; Rogel, Gwendal

    Search for low-energy β contaminations in industrial environments requires using Liquid Scintillation Counting. This indirect measurement method supposes a fine control from sampling to measurement itself. Thus, in this paper, we focus on the definition of a measurement method, as generic as possible, for both smears and aqueous samples' characterization. That includes choice of consumables, sampling methods, optimization of counting parameters and definition of energy windows, using the maximization of a Figure of Merit. Detection limits are then calculated considering these optimized parameters. For this purpose, we used PerkinElmer Tri-Carb counters. Nevertheless, except those relative to some parameters specific to PerkinElmer, most of the results presented here can be extended to other counters.

  7. Automated dynamic fed-batch process and media optimization for high productivity cell culture process development.

    PubMed

    Lu, Franklin; Toh, Poh Choo; Burnett, Iain; Li, Feng; Hudson, Terry; Amanullah, Ashraf; Li, Jincai

    2013-01-01

    Current industry practices for large-scale mammalian cell cultures typically employ a standard platform fed-batch process with fixed volume bolus feeding. Although widely used, these processes are unable to respond to actual nutrient consumption demands from the culture, which can result in accumulation of by-products and depletion of certain nutrients. This work demonstrates the application of a fully automated cell culture control, monitoring, and data processing system to achieve significant productivity improvement via dynamic feeding and media optimization. Two distinct feeding algorithms were used to dynamically alter feed rates. The first method is based upon on-line capacitance measurements where cultures were fed based on growth and nutrient consumption rates estimated from integrated capacitance. The second method is based upon automated glucose measurements obtained from the Nova Bioprofile FLEX® autosampler where cultures were fed to maintain a target glucose level which in turn maintained other nutrients based on a stoichiometric ratio. All of the calculations were done automatically through in-house integration with a Delta V process control system. Through both media and feed strategy optimization, a titer increase from the original platform titer of 5 to 6.3 g/L was achieved for cell line A, and a substantial titer increase of 4 to over 9 g/L was achieved for cell line B with comparable product quality. Glucose was found to be the best feed indicator, but not all cell lines benefited from dynamic feeding and optimized feed media was critical to process improvement. Our work demonstrated that dynamic feeding has the ability to automatically adjust feed rates according to culture behavior, and that the advantage can be best realized during early and rapid process development stages where different cell lines or large changes in culture conditions might lead to dramatically different nutrient demands.

  8. a System which Uses a Continuous Optimization Approach for the Design of AN Optimum Extractant Molecule for Use in Liquid-Liquid Extraction.

    NASA Astrophysics Data System (ADS)

    Naser, Samer Fahim

    The design of an extractant molecule for use in liquid-liquid extraction, traditionally a combinatorial optimization problem, has been solved using continuous optimization. UNIFAC, a thermodynamic group contribution method which allows the calculation of an activity coefficient of a component from its chemical structure, was used as the basis for all calculations. A computer system was developed which employs a three step procedure. First, the error in the liquid-liquid equilibrium relations resulting from the specification of a target separation criteria is minimized by continuously varying the functional groups in the design group pool. Second, the theoretical molecule obtained from the first step is used as a starting point to optimize up to seven separation criteria by variation of functional groups and mole fractions to obtain the optimum theoretical extractant molecule which satisfies the equilibrium relations. Third, the theoretical molecule is used to generate alternative extractant molecules which contain integer functional group values only. Numeric molecular structure constraints were developed which help maintain the feasibility of molecules in the first two steps, and allow the rejection of infeasible molecules in the third step. These constraints include limits on boiling point and molecular weight. The system developed was successfully tested on several separation problems and has suggested extractants as good or better than ones currently in use. This is the first reported use of continuous optimization in molecular design. For large design pools, this approach, as opposed to combinatorial optimization, is several orders of magnitude faster.

  9. Survival of enterobacteria in liquid cultures during microwave radiation and conventional heating.

    PubMed

    Papadopoulou, C; Demetriou, D; Panagiou, A; Levidiotou, S; Gessouli, H; Ionnides, K; Antoniades, G

    1995-09-01

    Bacteria in food have been reported to survive in larger numbers after processing by microwave radiation than after conventional processing. The bactericidal effect of a domestic microwave oven (SHARP R-7280) on certain pathogenic enterobacteria species was investigated in vitro, in comparison with conventional heating (boiling). The death rates of different nosocomial strains of Escherichia coli, Salmonella sofia, Salmonella enteritidis, Proteus mirabilis and Pseudomonas aeruginosa were tested. The microwave oven and the conventional heating system used were both calibrated in order to calculate temperatures from exposure times. For each strain duplicate samples of 25 ml of pure culture with concentrations at least 10(6) cfu/ml were exposed to microwave radiation. An equal number of samples of the same volume and concentration were exposed to conventional heating. Subsequently all samples were examined qualitatively and quantitatively following standard microbiological procedures. The results indicate that microwaves have an efficient bactericidal effect on the enterobacteria in liquid cultures.

  10. Magneto-responsive liquid crystalline elastomer nanocomposites as potential candidates for dynamic cell culture substrates.

    PubMed

    Herrera-Posada, Stephany; Mora-Navarro, Camilo; Ortiz-Bermudez, Patricia; Torres-Lugo, Madeline; McElhinny, Kyle M; Evans, Paul G; Calcagno, Barbara O; Acevedo, Aldo

    2016-08-01

    Recently, liquid crystalline elastomers (LCEs) have been proposed as active substrates for cell culture due to their potential to attach and orient cells, and impose dynamic mechanical signals through the application of external stimuli. In this report, the preparation of anisotropic and oriented nematic magnetic-sensitized LCEs with iron oxide nanoparticles, and the evaluation of the effect of particle addition at low concentrations on the resultant structural, thermal, thermo-mechanical, and mechanical properties is presented. Phase transformations produced by heating in alternating magnetic fields were investigated in LCEs in contact with air, water, and a common liquid cell culture medium was also evaluated. The inclusion of nanoparticles into the elastomers displaced the nematic-to-isotropic phase transition, without affecting the nematic structure as evidenced by similar values of the order parameter, while reducing the maximum thermomechanical deformations. Remote and reversible deformations of the magnetic LCEs were achieved through the application of alternating magnetic fields, which induces the nematic-isotropic phase transition through nanoparticle heat generation. Formulation parameters can be modified to allow for remote actuation at values closer to the human physiological temperature range and within the range of deformations that can affect the cellular behavior of fibroblasts. Finally, a collagen surface treatment was performed to improve compatibility with NIH-3T3 fibroblast cultures, which enabled the attachment and proliferation of fibroblasts on substrates with and without magnetic particles under quiescent conditions. The LCEs developed in this work, which are able to deform and experience stress changes by remote contact-less magnetic stimulation, may allow for further studies on the effect of substrate morphology changes and dynamic mechanical properties during in vitro cell culture.

  11. Magneto-responsive liquid crystalline elastomer nanocomposites as potential candidates for dynamic cell culture substrates.

    PubMed

    Herrera-Posada, Stephany; Mora-Navarro, Camilo; Ortiz-Bermudez, Patricia; Torres-Lugo, Madeline; McElhinny, Kyle M; Evans, Paul G; Calcagno, Barbara O; Acevedo, Aldo

    2016-08-01

    Recently, liquid crystalline elastomers (LCEs) have been proposed as active substrates for cell culture due to their potential to attach and orient cells, and impose dynamic mechanical signals through the application of external stimuli. In this report, the preparation of anisotropic and oriented nematic magnetic-sensitized LCEs with iron oxide nanoparticles, and the evaluation of the effect of particle addition at low concentrations on the resultant structural, thermal, thermo-mechanical, and mechanical properties is presented. Phase transformations produced by heating in alternating magnetic fields were investigated in LCEs in contact with air, water, and a common liquid cell culture medium was also evaluated. The inclusion of nanoparticles into the elastomers displaced the nematic-to-isotropic phase transition, without affecting the nematic structure as evidenced by similar values of the order parameter, while reducing the maximum thermomechanical deformations. Remote and reversible deformations of the magnetic LCEs were achieved through the application of alternating magnetic fields, which induces the nematic-isotropic phase transition through nanoparticle heat generation. Formulation parameters can be modified to allow for remote actuation at values closer to the human physiological temperature range and within the range of deformations that can affect the cellular behavior of fibroblasts. Finally, a collagen surface treatment was performed to improve compatibility with NIH-3T3 fibroblast cultures, which enabled the attachment and proliferation of fibroblasts on substrates with and without magnetic particles under quiescent conditions. The LCEs developed in this work, which are able to deform and experience stress changes by remote contact-less magnetic stimulation, may allow for further studies on the effect of substrate morphology changes and dynamic mechanical properties during in vitro cell culture. PMID:27157764

  12. Application of Sigmoidal Transformation Functions in Optimization of Micellar Liquid Chromatographic Separation of Six Quinolone Antibiotics.

    PubMed

    Hadjmohammadi, Mohammadreza; Salary, Mina

    2016-03-01

    A chemometrics approach has been used to optimize the separation of six quinolone compounds by micellar liquid chromatography (MLC). A Derringer's desirability function, a multicriteria decision-making (MCDM) method, was tested for evaluation of two different measures of chromatographic performance (resolution and analysis time). The effect of three experimental parameters on a chromatographic response function (CRF) expressed as a product of two sigmoidal desirability functions was investigated. The sigmoidal functions were used to transform the optimization criteria, resolution and analysis time into the desirability values. The factors studied were the concentration of sodium dodecyl sulfate, butanol content and pH of the mobile phase. The experiments were done according to the face-centered cube central composite design, and the calculated CRF values were fitted to a polynomial model to correlate the CRF values with the variables and their interactions. The developed regression model showed good descriptive and predictive ability (R(2) = 0.815, F = 6.919, SE = 0.038, [Formula: see text]) and used, by a grid search algorithm, to optimize the chromatographic conditions for the separation of the mixture. The efficiency of prediction of polynomial model was confirmed by performing the experiment under the optimal conditions.

  13. Optimization of liquid jet system for laser-induced breakdown spectroscopy analysis

    NASA Astrophysics Data System (ADS)

    Skočovská, Katarína; Novotný, Jan; Prochazka, David; Pořízka, Pavel; Novotný, Karel; Kaiser, Jozef

    2016-04-01

    A complex optimization of geometrical and temporal parameters of a jet system (developed in Laser-induced breakdown spectroscopy (LIBS) laboratory of Brno University of Technology) for direct elemental analysis of samples in a liquid state of matter using LIBS was carried out. First, the peristaltic pump was synchronized with the flashlamp of the ablation laser, which reduced variation of the ablated sample amount. Also, the fluctuation of the laser ray angle incident on the jet surface was diminished. Such synchronization reduced signal standard deviations and thus increased repeatability of the measurements. Then, laser energy and distance of the focusing lens from the sample were optimized. The gate delay time and the gate width were optimized for single pulse (SP) experiments; the gate delay time and the inter-pulse delay were optimized for the use of double pulse (DP) variant. Results were assessed according to the highest signal to noise ratios and the lowest relative standard deviations of the signal. The sensitivity of the single pulse and the double pulse LIBS for the detection of heavy metals traces, copper (Cu i at 324.754 nm) and lead (Pb i at 405.781 nm), in aqueous solution of copper (ii) sulfate and lead (ii) acetate, was estimated in terms of limits of detection (LODs). As a result, sensitivity improvement of DP LIBS system was observed, the LOD of Cu obtained with DP was calculated 40% lower than LOD gained from SP technique.

  14. Biodegradation of Endocrine Disruptors in Solid-Liquid Two-Phase Partitioning Systems by Enrichment Cultures

    PubMed Central

    dos Santos, Silvia Cristina Cunha; Ouellette, Julianne; Juteau, Pierre; Lépine, François; Déziel, Eric

    2013-01-01

    Naturally occurring and synthetic estrogens and other molecules from industrial sources strongly contribute to the endocrine disruption of urban wastewater. Because of the presence of these molecules in low but effective concentrations in wastewaters, these endocrine disruptors (EDs) are only partially removed after most wastewater treatments, reflecting the presence of these molecules in rivers in urban areas. The development of a two-phase partitioning bioreactor (TPPB) might be an effective strategy for the removal of EDs from wastewater plant effluents. Here, we describe the establishment of three ED-degrading microbial enrichment cultures adapted to a solid-liquid two-phase partitioning system using Hytrel as the immiscible water phase and loaded with estrone, estradiol, estriol, ethynylestradiol, nonylphenol, and bisphenol A. All molecules except ethynylestradiol were degraded in the enrichment cultures. The bacterial composition of the three enrichment cultures was determined using 16S rRNA gene sequencing and showed sequences affiliated with bacteria associated with the degradation of these compounds, such as Sphingomonadales. One Rhodococcus isolate capable of degrading estrone, estradiol, and estriol was isolated from one enrichment culture. These results highlight the great potential for the development of TPPB for the degradation of highly diluted EDs in water effluents. PMID:23728808

  15. Culturing of Human Nasal Epithelial Cells at the Air Liquid Interface

    PubMed Central

    Müller, Loretta; Brighton, Luisa E.; Carson, Johnny L.; Fischer, William A.; Jaspers, Ilona

    2013-01-01

    In vitro models using human primary epithelial cells are essential in understanding key functions of the respiratory epithelium in the context of microbial infections or inhaled agents. Direct comparisons of cells obtained from diseased populations allow us to characterize different phenotypes and dissect the underlying mechanisms mediating changes in epithelial cell function. Culturing epithelial cells from the human tracheobronchial region has been well documented, but is limited by the availability of human lung tissue or invasiveness associated with obtaining the bronchial brushes biopsies. Nasal epithelial cells are obtained through much less invasive superficial nasal scrape biopsies and subjects can be biopsied multiple times with no significant side effects. Additionally, the nose is the entry point to the respiratory system and therefore one of the first sites to be exposed to any kind of air-borne stressor, such as microbial agents, pollutants, or allergens. Briefly, nasal epithelial cells obtained from human volunteers are expanded on coated tissue culture plates, and then transferred onto cell culture inserts. Upon reaching confluency, cells continue to be cultured at the air-liquid interface (ALI), for several weeks, which creates more physiologically relevant conditions. The ALI culture condition uses defined media leading to a differentiated epithelium that exhibits morphological and functional characteristics similar to the human nasal epithelium, with both ciliated and mucus producing cells. Tissue culture inserts with differentiated nasal epithelial cells can be manipulated in a variety of ways depending on the research questions (treatment with pharmacological agents, transduction with lentiviral vectors, exposure to gases, or infection with microbial agents) and analyzed for numerous different endpoints ranging from cellular and molecular pathways, functional changes, morphology, etc. In vitro models of differentiated human nasal epithelial

  16. Culturing of human nasal epithelial cells at the air liquid interface.

    PubMed

    Müller, Loretta; Brighton, Luisa E; Carson, Johnny L; Fischer, William A; Jaspers, Ilona

    2013-10-08

    In vitro models using human primary epithelial cells are essential in understanding key functions of the respiratory epithelium in the context of microbial infections or inhaled agents. Direct comparisons of cells obtained from diseased populations allow us to characterize different phenotypes and dissect the underlying mechanisms mediating changes in epithelial cell function. Culturing epithelial cells from the human tracheobronchial region has been well documented, but is limited by the availability of human lung tissue or invasiveness associated with obtaining the bronchial brushes biopsies. Nasal epithelial cells are obtained through much less invasive superficial nasal scrape biopsies and subjects can be biopsied multiple times with no significant side effects. Additionally, the nose is the entry point to the respiratory system and therefore one of the first sites to be exposed to any kind of air-borne stressor, such as microbial agents, pollutants, or allergens. Briefly, nasal epithelial cells obtained from human volunteers are expanded on coated tissue culture plates, and then transferred onto cell culture inserts. Upon reaching confluency, cells continue to be cultured at the air-liquid interface (ALI), for several weeks, which creates more physiologically relevant conditions. The ALI culture condition uses defined media leading to a differentiated epithelium that exhibits morphological and functional characteristics similar to the human nasal epithelium, with both ciliated and mucus producing cells. Tissue culture inserts with differentiated nasal epithelial cells can be manipulated in a variety of ways depending on the research questions (treatment with pharmacological agents, transduction with lentiviral vectors, exposure to gases, or infection with microbial agents) and analyzed for numerous different endpoints ranging from cellular and molecular pathways, functional changes, morphology, etc. In vitro models of differentiated human nasal epithelial

  17. Optimization of refractive liquid crystal lenses using an efficient multigrid simulation.

    PubMed

    Milton, Harry; Brimicombe, Paul; Morgan, Philip; Gleeson, Helen; Clamp, John

    2012-05-01

    A multigrid computational model has been developed to assess the performance of refractive liquid crystal lenses, which is up to 40 times faster than previous techniques. Using this model, the optimum geometries producing an ideal parabolic voltage distribution were deduced for refractive liquid crystal lenses with diameters from 1 to 9 mm. The ratio of insulation thickness to lens diameter was determined to be 1:2 for small diameter lenses, tending to 1:3 for larger lenses. The model is used to propose a new method of lens operation with lower operating voltages needed to induce specific optical powers. The operating voltages are calculated for the induction of optical powers between + 1.00 D and + 3.00 D in a 3 mm diameter lens, with the speed of the simulation facilitating the optimization of the refractive index profile. We demonstrate that the relationship between additional applied voltage and optical power is approximately linear for optical powers under + 3.00 D. The versatility of the computational simulation has also been demonstrated by modeling of in-plane electrode liquid crystal devices.

  18. Using response surface analysis to optimize the quality of ultrapasteurized liquid whole egg.

    PubMed

    Dawson, P L; Martinez-Dawson, R

    1998-03-01

    Response surface analysis (RSA) is used to show the effects of a range of heat pasteurization times and temperature combinations on several quality factors of liquid egg. The purpose of this paper is not to suggest the rigid processing time and temperature combinations to give maximum quality but to illustrate that RSA can be used as a tool to predict individual and multiple egg functional properties resulting from various processing conditions. The application of heat will change the quality and functional properties of the liquid egg. This paper describes the application of RSA to the changes in soluble protein, alpha-amylase, solids content, viscosity, and the height of cakes made with processed liquid whole egg (LWE). The Mallow's Cp statistic is used to determine the best model while minimizing the number of terms in the model. By using this method of choosing the model, the number of terms desired in the model can be first determined then the best fit can be determined from the possible models. The time and temperature combinations are in the ultra-high temperature range for eggs (30, 60, and 95 s each at 64, 68, and 72 C). The RSA may be used to optimize the quality and functionality of LWE while ensuring the safety of the product. This information can be used (with further testing) to maximize desirable and minimize undesirable product properties.

  19. Optimizing the radiosensitive liquid-core microcapsules for the targeting of chemotherapeutic agents

    NASA Astrophysics Data System (ADS)

    Harada, S.; Ehara, S.; Ishii, K.; Yamazaki, H.; Matsuyama, S.; Kamiya, T.; Sakai, T.; Arakawa, K.; Sato, T.; Oikawa, S.

    2007-07-01

    Microcapsules consisting of alginate and hyaluronic acid that can be decomposed by radiation are currently under development. In this study, the composition of the microcapsule material was optimized by changing the amounts of alginate and hyaluronic acid. Solutions of 0.025%, 0.05%, 0.1%, 0.2%, or 0.4% (wt./vol.) hyaluronic acid were mixed into a 0.2% alginate solution. To these mixtures, carboplatin (0.2 mmol) was added and the resulting material was used for the capsule preparation. The capsules were prepared by spraying the material into a CaCl 2 solution (0.34 mol/l) using a microatomizer. These capsules were irradiated by a single dose of 2, 5, or 10 Gy 60Co γ-ray radiation. Immediately after irradiation, the releasing of core content of microcapsule was determined, using a micro particle induced X-ray emission (PIXE) camera. The average diameter of the microcapsules was 22.3 ± 3.3 μm, and that of the liquid core was 10.2 ± 4.3 μm. The maximum radiation-induced content release was observed with liquid-core microcapsules containing 0.1% hyaluronic acid and 0.2% alginate. Our liquid-core microcapsules suggest a new potential use for radiation: the targeted delivery of the chemotherapeutic agents or radiosensitizers. This offers the prospect of increased combined effectiveness of radiation with chemotherapy or radiosensitization and decreased adverse side effects.

  20. Curcumin-Loaded Lipid Cubic Liquid Crystalline Nanoparticles: Preparation, Optimization, Physicochemical Properties and Oral Absorption.

    PubMed

    He, Xiuli; Li, Qinghua; Liu, Xiuju; Wu, Guangsheng; Zhai, Guangxi

    2015-08-01

    In order to improve the oral absorption of curcumin, curcumin-loaded lipid cubic liquid crystalline nanoparticles were prepared and evaluated in vitro and in vivo. The hot and high-pressure homogenization method was used to prepare the nanoparticles. The formulation and process were optimized by uniform design with drug loading and entrapment efficiency as index, and physicochemical properties were also investigated. Spherical nanoparticles were observed under transmission electron microscope (TEM), with average particle size of 176.1 nm, zeta potential of -25.19 mV, average drug loading of (1.5 ± 0.2)% and entrapment efficiency of (95 ± 1.8)%. The in vitro release of curcumin from the nanoparticle formulation showed a sustained property, while the pharmacokinetics results after oral administration of curcumin loaded lipid cubic liquid crystalline nanoparticles in rat showed that the oral absorption of curcumin fitted one-compartment model and relative bioavailability was 395.56% when compared to crude curcumin. It can be concluded from these results that the lipid cubic liquid crystalline nanoparticles, as carriers, can markedly improve the oral absorption of curcumin.

  1. Antifatigue Activity of Liquid Cultured Tricholoma matsutake Mycelium Partially via Regulation of Antioxidant Pathway in Mouse

    PubMed Central

    Li, Quan; Wang, Yanzhen; Cai, Guangsheng; Kong, Fange; Wang, Xiaohan; Liu, Yang; Yang, Chuanbin; Wang, Di; Teng, Lirong

    2015-01-01

    Tricholoma matsutake has been popular as food and biopharmaceutical materials in Asian countries for its various pharmacological activities. The present study aims to analyze the antifatigue effects on enhancing exercise performance of Tricholoma matsutake fruit body (ABM) and liquid cultured mycelia (TM) in mouse model. Two-week Tricholoma matsutake treatment significantly enhances the exercise performance in weight-loaded swimming, rotating rod, and forced running test. In TM- and ABM-treated mice, some factors were observed at 60 min after swimming compared with nontreated mice, such as the increased levels of adenosine triphosphate (ATP), antioxidative enzymes, and glycogen and the reduced levels of malondialdehyde and reactive oxygen species in muscle, liver, and/or serum. Further data obtained from western blot show that CM and ABM have strongly enhanced the activation of 5′-AMP-activated protein kinase (AMPK), and the expressions of peroxisome proliferator have activated receptor γ coactivator-1α (PGC-1α) and phosphofructokinase-1 (PFK-1) in liver. Our data suggest that both Tricholoma matsutake fruit body and liquid cultured mycelia possess antifatigue effects related to AMPK-linked antioxidative pathway. The information uncovered in our study may serve as a valuable resource for further identification and provide experimental evidence for clinical trials of Tricholoma matsutake as an effective agent against fatigue related diseases. PMID:26697489

  2. Antifatigue Activity of Liquid Cultured Tricholoma matsutake Mycelium Partially via Regulation of Antioxidant Pathway in Mouse.

    PubMed

    Li, Quan; Wang, Yanzhen; Cai, Guangsheng; Kong, Fange; Wang, Xiaohan; Liu, Yang; Yang, Chuanbin; Wang, Di; Teng, Lirong

    2015-01-01

    Tricholoma matsutake has been popular as food and biopharmaceutical materials in Asian countries for its various pharmacological activities. The present study aims to analyze the antifatigue effects on enhancing exercise performance of Tricholoma matsutake fruit body (ABM) and liquid cultured mycelia (TM) in mouse model. Two-week Tricholoma matsutake treatment significantly enhances the exercise performance in weight-loaded swimming, rotating rod, and forced running test. In TM- and ABM-treated mice, some factors were observed at 60 min after swimming compared with nontreated mice, such as the increased levels of adenosine triphosphate (ATP), antioxidative enzymes, and glycogen and the reduced levels of malondialdehyde and reactive oxygen species in muscle, liver, and/or serum. Further data obtained from western blot show that CM and ABM have strongly enhanced the activation of 5'-AMP-activated protein kinase (AMPK), and the expressions of peroxisome proliferator have activated receptor γ coactivator-1α (PGC-1α) and phosphofructokinase-1 (PFK-1) in liver. Our data suggest that both Tricholoma matsutake fruit body and liquid cultured mycelia possess antifatigue effects related to AMPK-linked antioxidative pathway. The information uncovered in our study may serve as a valuable resource for further identification and provide experimental evidence for clinical trials of Tricholoma matsutake as an effective agent against fatigue related diseases. PMID:26697489

  3. Optimization of Conditions for In Vitro Culture of the Microphallid Digenean Gynaecotyla adunca

    PubMed Central

    West, Jenna; Mitchell, Alexandra; Pung, Oscar J.

    2014-01-01

    In vitro cultivation of digeneans would aid the development of effective treatments and studies of the biology of the parasites. The goal of this study was to optimize culture conditions for the trematode, Gynaecotyla adunca. Metacercariae of the parasite from fiddler crabs, Uca pugnax, excysted in trypsin, were incubated overnight to permit fertilization, and were cultured in different conditions to find those that resulted in maximum worm longevity and egg production. When cultured in media lacking serum, worms lived longer in Hanks balanced salt solution and Dulbecco's Modified Eagle medium/F-12 (DME/F-12) than in RPMI-1640 but produced the most eggs in DME/F-12. Worm longevity and egg production increased when worms were grown in DME/F-12 supplemented with 20% chicken, horse, or newborn calf serum but the greatest number of eggs was deposited in cultures containing horse or chicken serum. Horse serum was chosen over chicken serum due to the formation of a precipitate in chicken serum. The optimal concentration of horse serum with respect to egg production ranged from 5 to 20%. Infectivity of eggs deposited by worms in culture was tested by feeding eggs to mud snails, Ilyanassa obsoleta. None of these snails produced G. adunca cercariae. PMID:24795817

  4. Habitus and Flow in Primary School Musical Practice: Relations between Family Musical Cultural Capital, Optimal Experience and Music Participation

    ERIC Educational Resources Information Center

    Valenzuela, Rafael; Codina, Nuria

    2014-01-01

    Based on Bourdieu's idea that cultural capital is strongly related to family context, we describe the relations between family musical cultural capital and optimal experience during compulsory primary school musical practice. We analyse whether children from families with higher levels of musical cultural capital, and specifically with regard…

  5. On the model-based optimization of secreting mammalian cell (GS-NS0) cultures.

    PubMed

    Kiparissides, A; Pistikopoulos, E N; Mantalaris, A

    2015-03-01

    The global bio-manufacturing industry requires improved process efficiency to satisfy the increasing demands for biochemicals, biofuels, and biologics. The use of model-based techniques can facilitate the reduction of unnecessary experimentation and reduce labor and operating costs by identifying the most informative experiments and providing strategies to optimize the bioprocess at hand. Herein, we investigate the potential of a research methodology that combines model development, parameter estimation, global sensitivity analysis, and selection of optimal feeding policies via dynamic optimization methods to improve the efficiency of an industrially relevant bioprocess. Data from a set of batch experiments was used to estimate values for the parameters of an unstructured model describing monoclonal antibody (mAb) production in GS-NS0 cell cultures. Global Sensitivity Analysis (GSA) highlighted parameters with a strong effect on the model output and data from a fed-batch experiment were used to refine their estimated values. Model-based optimization was used to identify a feeding regime that maximized final mAb titer. An independent fed-batch experiment was conducted to validate both the results of the optimization and the predictive capabilities of the developed model. The successful integration of wet-lab experimentation and mathematical model development, analysis, and optimization represents a unique, novel, and interdisciplinary approach that addresses the complicated research and industrial problem of model-based optimization of cell based processes.

  6. Optimization of culture conditions for flexirubin production by Chryseobacterium artocarpi CECT 8497 using response surface methodology.

    PubMed

    Venil, Chidambaram Kulandaisamy; Zakaria, Zainul Akmar; Ahmad, Wan Azlina

    2015-01-01

    Flexirubins are the unique type of bacterial pigments produced by the bacteria from the genus Chryseobacterium, which are used in the treatment of chronic skin disease, eczema etc. and may serve as a chemotaxonomic marker. Chryseobacterium artocarpi CECT 8497, an yellowish-orange pigment producing strain was investigated for maximum production of pigment by optimizing medium composition employing response surface methodology (RSM). Culture conditions affecting pigment production were optimized statistically in shake flask experiments. Lactose, l-tryptophan and KH2PO4 were the most significant variables affecting pigment production. Box Behnken design (BBD) and RSM analysis were adopted to investigate the interactions between variables and determine the optimal values for maximum pigment production. Evaluation of the experimental results signified that the optimum conditions for maximum production of pigment (521.64 mg/L) in 50 L bioreactor were lactose 11.25 g/L, l-tryptophan 6 g/L and KH2PO4 650 ppm. Production under optimized conditions increased to 7.23 fold comparing to its production prior to optimization. Results of this study showed that statistical optimization of medium composition and their interaction effects enable short listing of the significant factors influencing maximum pigment production from Chryseobacterium artocarpi CECT 8497. In addition, this is the first report optimizing the process parameters for flexirubin type pigment production from Chryseobacterium artocarpi CECT 8497.

  7. Optimization of culture parameters and novel strategies to improve protein solubility.

    PubMed

    Arya, Ranjana; Sabir, Jamal S M; Bora, Roop S; Saini, Kulvinder S

    2015-01-01

    The production of recombinant proteins, in soluble form in a prokaryotic expression system, still remains a challenge for the biotechnologist. Innovative strategies have been developed to improve protein solubility in various protein overexpressing hosts. In this chapter, we would focus on methods currently available and amenable to "desired modifications," such as (a) the use of molecular chaperones; (b) the optimization of culture conditions; (c) the reengineering of a variety of host strains and vectors with affinity tags; and (d) optimal promoter strengths. All these parameters are evaluated with the primary objective of increasing the solubilization of recombinant protein(s) during overexpression in Escherichia coli. PMID:25447858

  8. Genetic algorithm for the medium optimization of the microalga Nannochloropsis gaditana cultured to aquaculture.

    PubMed

    Camacho-Rodríguez, J; Cerón-García, M C; Fernández-Sevilla, J M; Molina-Grima, E

    2015-02-01

    A genetic algorithm has been used to optimize the composition of the culture medium for growing the microalga Nannochloropsis gaditana, based on the nutrients composition of the commercial medium ALGAL. This strategy was carried out through the implementation of 270 experiments spread over nine generations, which allowed achieving an eicosapentaenoic acid (EPA) productivity of 17.8 m gL(-1) d(-1) in a continuous culture of N. gaditana, with an increase of 23% compared to the commercial medium. The EPA yield on nitrogen and phosphorous, 0.042 and 1.146 g(EPA) g(s)(-1), respectively, were 40% and 5-fold higher, respectively, than the values obtained with the nitrogen-optimized ALGAL medium. This improvement was obtained with the medium G-8, which also allowed reducing the requirement of several nutrients such as P, Mo, Mn in 74%, 69% and 66%, respectively, as well as the thiamine content a 46%.

  9. Optimization of a Brayton cryocooler for ZBO liquid hydrogen storage in space

    NASA Astrophysics Data System (ADS)

    Deserranno, D.; Zagarola, M.; Li, X.; Mustafi, S.

    2014-11-01

    NASA is evaluating and developing technology for long-term storage of cryogenic propellant in space. A key technology is a cryogenic refrigerator which intercepts heat loads to the storage tank, resulting in a reduced- or zero-boil-off condition. Turbo-Brayton cryocoolers are particularly well suited for cryogen storage applications because the technology scales well to high capacities and low temperatures. In addition, the continuous-flow nature of the cycle allows direct cooling of the cryogen storage tank without mass and power penalties associated with a cryogenic heat transport system. To quantify the benefits and mature the cryocooler technology, Creare Inc. performed a design study and technology demonstration effort for NASA on a 20 W, 20 K cryocooler for liquid hydrogen storage. During the design study, we optimized these key components: three centrifugal compressors, a modular high-capacity plate-fin recuperator, and a single-stage turboalternator. The optimization of the compressors and turboalternator were supported by component testing. The optimized cryocooler has an overall flight mass of 88 kg and a specific power of 61 W/W. The coefficient of performance of the cryocooler is 23% of the Carnot cycle. This is significantly better performance than any 20 K space cryocooler existing or under development.

  10. Modelling of Microalgae Culture Systems with Applications to Control and Optimization.

    PubMed

    Bernard, Olivier; Mairet, Francis; Chachuat, Benoît

    2016-01-01

    Mathematical modeling is becoming ever more important to assess the potential, guide the design, and enable the efficient operation and control of industrial-scale microalgae culture systems (MCS). The development of overall, inherently multiphysics, models involves coupling separate submodels of (i) the intrinsic biological properties, including growth, decay, and biosynthesis as well as the effect of light and temperature on these processes, and (ii) the physical properties, such as the hydrodynamics, light attenuation, and temperature in the culture medium. When considering high-density microalgae culture, in particular, the coupling between biology and physics becomes critical. This chapter reviews existing models, with a particular focus on the Droop model, which is a precursor model, and it highlights the structure common to many microalgae growth models. It summarizes the main developments and difficulties towards multiphysics models of MCS as well as applications of these models for monitoring, control, and optimization purposes.

  11. Genotypes-Independent Optimization of Nitrogen Supply for Isolated Microspore Cultures in Barley.

    PubMed

    Lu, Ruiju; Chen, Zhiwei; Gao, Runhong; He, Ting; Wang, Yifei; Xu, Hongwei; Guo, Guimei; Li, Yingbo; Liu, Chenghong; Huang, Jianhua

    2016-01-01

    To establish a high-efficiency system of isolated microspore culture for different barley genotypes, we investigated the effects of nitrogen sources and concentrations on callus induction and plant regeneration in different barley genotypes. The results showed that the organic nitrogen sources greatly increased the callus induction, and the great reduction of total nitrogen sources would significantly decrease the callus induction. And the further optimization experiments revealed that the increasing of organic nitrogen sources was much important in callus induction while it seemed different in plant regeneration. Based on the great effects of organic nitrogen on callus induction, the medium of N6-ANO1/4-2000 might be the best choice for the microspore culture system. In addition, the phylogenetic analysis indicated that there were clear differences of genetic backgrounds among these barley genotypes, and it also suggested that this medium for microspore culture had widespread utilization in different barley genotypes. PMID:27525264

  12. Progresses and challenges in optimization of human pluripotent stem cell culture.

    PubMed

    Lin, Ge; Xu, Ren-He

    2010-09-01

    The pressing demand to elucidate the biology of human embryonic stem (ES) cells and to realize their therapeutic potential has greatly promoted the progresses in the optimization of the culture systems used for this highly promising cell type. These progresses include the characterization of exogenous regulators of pluripotency and differentiation, the development of animal-free, defined, and scalable culture systems, and some pioneering efforts to establish good manufactory practice facilities to derive and expand clinical-grade human ES cells and their derivatives. All of these advancements appear to be also applicable to the derivation and culture of human induced pluripotent stem cells, an ES cell-like cell type derived from somatic cells via reprogramming. This review attempts to summarize these progresses and discuss some of the remaining challenges.

  13. Genotypes-Independent Optimization of Nitrogen Supply for Isolated Microspore Cultures in Barley

    PubMed Central

    Lu, Ruiju; Chen, Zhiwei; Gao, Runhong; He, Ting; Wang, Yifei; Xu, Hongwei; Guo, Guimei; Li, Yingbo

    2016-01-01

    To establish a high-efficiency system of isolated microspore culture for different barley genotypes, we investigated the effects of nitrogen sources and concentrations on callus induction and plant regeneration in different barley genotypes. The results showed that the organic nitrogen sources greatly increased the callus induction, and the great reduction of total nitrogen sources would significantly decrease the callus induction. And the further optimization experiments revealed that the increasing of organic nitrogen sources was much important in callus induction while it seemed different in plant regeneration. Based on the great effects of organic nitrogen on callus induction, the medium of N6-ANO1/4-2000 might be the best choice for the microspore culture system. In addition, the phylogenetic analysis indicated that there were clear differences of genetic backgrounds among these barley genotypes, and it also suggested that this medium for microspore culture had widespread utilization in different barley genotypes. PMID:27525264

  14. Optimization of culture medium compositions for gellan gum production by a halobacterium Sphingomonas paucimobilis.

    PubMed

    Zhang, Jun; Dong, Ya-chen; Fan, Lin-lin; Jiao, Zhi-hua; Chen, Qi-he

    2015-01-22

    The effect of culture medium compositions on gellan gum production produced by fermentation with a halobacterium Sphingomonas paucimobilis QHZJUJW CGMCC2428 was studied. In this work, a fractional factorial design was applied to investigate the main factors that affected gellan gum production by S. paucimobilis QHZJUJW CGMCC2428. Sucrose was the best carbon source for gellan gum and peptone displayed better inducing effect. Central composite design and response surface methodology were adopted to derive a statistical model for optimizing submerged culture medium composition. These experimental results showed that the optimum culture medium for producing gellan gum was composed of 40.00 (w/v) sucrose, 3.00% peptone (w/v), MgSO4 (w/v), 9.20% KH2PO4 (w/v), 7.50% Na2HPO4 (w/v), 4.30% K2SO4 (w/v), pH 6.8-7.0. The maximal gellan gum was 19.89±0.68 g/L, which was agreed closely with the predicated value (20.12 g/L). After incubated for 72 h under the optimized culture medium in 5-L bioreactor, the gellan gum fermentation reached about 19.90±0.68 g/L, which was higher than that in the initial cultivation medium.

  15. Mutagenesis breeding of high echinocandin B producing strain and further titer improvement with culture medium optimization.

    PubMed

    Zou, Shu-Ping; Zhong, Wei; Xia, Chao-Jie; Gu, Ya-Nan; Niu, Kun; Zheng, Yu-Guo; Shen, Yin-Chu

    2015-10-01

    A combination of microbial strain improvement and statistical optimization is investigated to maximize echinocandin B (ECB) production from Aspergillus nidulans ZJB-0817. A classical sequential mutagenesis was studied first by using physical (ultraviolet irradiation at 254 nm) and chemical mutagens (lithium chloride and sodium nitrite). Mutant strain ULN-59 exhibited 2.1-fold increase in ECB production to 1583.1 ± 40.9 mg/L when compared with the parent strain (750.8 ± 32.0 mg/L). This is the first report where mutagenesis is applied in Aspergillus to improve ECB production. Further, fractional factorial design and central composite design were adopted to optimize the culture medium for increasing ECB production by the mutant ULN-59. Results indicated that four culture media including peptone, K2HPO4, mannitol and L-ornithine had significant effects on ECB production. The optimized medium provided another 1.4-fold increase in final ECB concentration to 2285.6 ± 35.6 mg/L compared to the original medium. The results of this study indicated the combined application of a classical mutation and medium optimization can improve effectively ECB production from A. nidulans and could be a promising tool to improve other secondary metabolites production by fungal strains.

  16. Initial eye movements during face identification are optimal and similar across cultures

    PubMed Central

    Or, Charles C.-F.; Peterson, Matthew F.; Eckstein, Miguel P.

    2015-01-01

    Culture influences not only human high-level cognitive processes but also low-level perceptual operations. Some perceptual operations, such as initial eye movements to faces, are critical for extraction of information supporting evolutionarily important tasks such as face identification. The extent of cultural effects on these crucial perceptual processes is unknown. Here, we report that the first gaze location for face identification was similar across East Asian and Western Caucasian cultural groups: Both fixated a featureless point between the eyes and the nose, with smaller between-group than within-group differences and with a small horizontal difference across cultures (8% of the interocular distance). We also show that individuals of both cultural groups initially fixated at a slightly higher point on Asian faces than on Caucasian faces. The initial fixations were found to be both fundamental in acquiring the majority of information for face identification and optimal, as accuracy deteriorated when observers held their gaze away from their preferred fixations. An ideal observer that integrated facial information with the human visual system's varying spatial resolution across the visual field showed a similar information distribution across faces of both races and predicted initial human fixations. The model consistently replicated the small vertical difference between human fixations to Asian and Caucasian faces but did not predict the small horizontal leftward bias of Caucasian observers. Together, the results suggest that initial eye movements during face identification may be driven by brain mechanisms aimed at maximizing accuracy, and less influenced by culture. The findings increase our understanding of the interplay between the brain's aims to optimally accomplish basic perceptual functions and to respond to sociocultural influences. PMID:26382003

  17. Optimizing the electrochemical performance of imidazolium-based polymeric ionic liquids by varying tethering groups

    NASA Astrophysics Data System (ADS)

    Jia, Zhe

    candidates for this purpose, were attached as tethering groups to imidazolium cations in order to optimize the Tg and ionic conductivities. Previous research on oligomer/polymer electrolytes showed that attaching PEO to the imidazolium cation lowered the Tg of ILs and increased their conductivity. PEO is also chemically stable, dissolves metal ions, and when incorporated into ionic liquids, provides a solvent free electrolyte. A series of IL model compounds and PILs were first synthesized with various lengths of PEO attached on the imidazole. The thermophysical and electrochemical properties of ILs and PILs, including density, viscosity, conductivity and thermal properties were characterized in order to investigate the effect of tethering groups.

  18. Numerical simulation for optimizing mode shaping and supercontinuum flatness of liquid filled seven-core photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Tian, Liang; Wei, Li; Guoying, Feng

    2015-05-01

    A seven-core photonic crystal fiber filled with commercial index-matching liquids is designed to optimize mode shaping and supercontinuum flatness. Numerical simulation of supercontinuum generation in these liquid-filled seven-core PCFs is conducted at 25 °C. The definition of spectral flatness measure is used to quantitatively describe SC flatness. Numerical simulations are performed to study the propagation of femtosecond pulse in the liquid-filled seven-core PCFs. Results show that mode shaping and supercontinuum flatness can be easily optimized and modified using the index-matching liquids in seven-core PCF without varying the structure of the air rings around the guiding cores. Simulations also show that 50 fs pulses with a center wavelength of 1064 nm generate relatively flat SC spectra in the 25 cm-long liquid-filled PCF. A flat spectral bandwidth of 400 nm (900-1300 nm) is achieved with an applied pump power of 30 kW. The simulation results demonstrate that using index-matching liquids to fill the inner ring of the seven-core PCF optimizes mode shaping and generates flat SC spectrum in specified wavelength region. Results further demonstrate that the SC flatness increased with increasing PCF dispersion corresponding to pump wavelength, on the premise that generated enough spectrum width, when the pump worked in the normal dispersion region. Temperature barely affects the spectrum flatness, but can affect spectrum broadening.

  19. Design and optimization of photonic crystal fiber for liquid sensing applications

    NASA Astrophysics Data System (ADS)

    Arif, Md. Faizul Huq; Ahmed, Kawsar; Asaduzzaman, Sayed; Azad, Md. Abul Kalam

    2016-06-01

    This paper proposes a hexagonal photonic crystal fiber (H-PCF) structure with high relative sensitivity for liquid sensing; in which both core and cladding are microstructures. Numerical investigation is carried out by employing the full vectorial finite element method (FEM). The analysis has been done in four stages of the proposed structure. The investigation shows that the proposed structure achieves higher relative sensitivity by increasing the diameter of the innermost ring air holes in the cladding. Moreover, placing a single channel instead of using a group of tiny channels increases the relative sensitivity effectively. Investigating the effects of different parameters, the optimized structure shows significantly higher relative sensitivity with a low confinement loss.

  20. Liquid chromatography-photolysis-electrochemical detection for organoiodides. 1. Optimization and application

    SciTech Connect

    Selavka, C.M.; Krull, I.S.

    1987-11-15

    An improved high-performance liquid chromatographic detection method has been applied for the trace determination of iodinated organic compounds. The method, which incorporates postcolumn, on-line UV irradiation prior to oxidative electrochemical (EC) detection, exploits the facile photochemical dissociation of the C-I bond to form anionic iodide and a number of solvolyzed products. Following bond cleavage, iodide, is readily detected amperometrically a moderate oxidative potentials, allowing for the determination of a number of organoiodides at the 25-75 pg level. Following optimization of experimental parameters, the detection approach is linear over 3 orders of magnitude, and enhanced selectivity is demonstrated through the utilization of chromatographic retention times, dual electrode response ratios, and qualitative lamp on/off responses for analyte identification. The method is validated in a single-blind study and is successfully applied to the determination of liothyronine (T/sub 3/) in tablets.

  1. Design and optimization of photonic crystal fiber for liquid sensing applications

    NASA Astrophysics Data System (ADS)

    Arif, Md. Faizul Huq; Ahmed, Kawsar; Asaduzzaman, Sayed; Azad, Md. Abul Kalam

    2016-09-01

    This paper proposes a hexagonal photonic crystal fiber (H-PCF) structure with high relative sensitivity for liquid sensing; in which both core and cladding are microstructures. Numerical investigation is carried out by employing the full vectorial finite element method (FEM). The analysis has been done in four stages of the proposed structure. The investigation shows that the proposed structure achieves higher relative sensitivity by increasing the diameter of the innermost ring air holes in the cladding. Moreover, placing a single channel instead of using a group of tiny channels increases the relative sensitivity effectively. Investigating the effects of different parameters, the optimized structure shows significantly higher relative sensitivity with a low confinement loss.

  2. Optoelectronic optimization of mode selective converter based on liquid crystal on silicon

    NASA Astrophysics Data System (ADS)

    Wang, Yongjiao; Liang, Lei; Yu, Dawei; Fu, Songnian

    2016-03-01

    We carry out comprehensive optoelectronic optimization of mode selective converter used for the mode division multiplexing, based on liquid crystal on silicon (LCOS) in binary mode. The conversion error of digital-to-analog (DAC) is investigated quantitatively for the purpose of driving the LCOS in the application of mode selective conversion. Results indicate the DAC must have a resolution of 8-bit, in order to achieve high mode extinction ratio (MER) of 28 dB. On the other hand, both the fast axis position error of half-wave-plate (HWP) and rotation angle error of Faraday rotator (FR) have negative influence on the performance of mode selective conversion. However, the commercial products provide enough angle error tolerance for the LCOS-based mode selective converter, taking both of insertion loss (IL) and MER into account.

  3. Optimization of the Hewlett-Packard particle-beam liquid chromatography-mass spectrometry interface by statistical experimental design.

    PubMed

    Huang, S K; Garza, N R

    1995-06-01

    Optimization of both sensitivity and ionization softness for the Hewlett-Packard particle-beam liquid chromatography-mass spectrometry interface has been achieved by using a statistical experimental design with response surface modeling. Conditions for both optimized sensitivity and ionization softness were found to occur at 55-lb/in.(2) nebulizer flow, 35°C desolvation chamber temperature with approximately 45% organic modifier in the presence of 0.02-F ammonium acetate and a liquid chromatography flow rate of 0.2 mL/min.

  4. Toxicity of ionic liquids: eco(cyto)activity as complicated, but unavoidable parameter for task-specific optimization.

    PubMed

    Egorova, Ksenia S; Ananikov, Valentine P

    2014-02-01

    Rapid progress in the field of ionic liquids in recent decades led to the development of many outstanding energy-conversion processes, catalytic systems, synthetic procedures, and important practical applications. Task-specific optimization emerged as a sharpening stone for the fine-tuning of structure of ionic liquids, which resulted in unprecedented efficiency at the molecular level. Ionic-liquid systems showed promising opportunities in the development of green and sustainable technologies; however, the chemical nature of ionic liquids is not intrinsically green. Many ionic liquids were found to be toxic or even highly toxic towards cells and living organisms. In this Review, we show that biological activity and cytotoxicity of ionic liquids dramatically depend on the nature of a biological system. An ionic liquid may be not toxic for particular cells or organisms, but may demonstrate high toxicity towards another target present in the environment. Thus, a careful selection of biological activity data is a must for the correct assessment of chemical technologies involving ionic liquids. In addition to the direct biological activity (immediate response), several indirect effects and aftereffects are of primary importance. The following principal factors were revealed to modulate toxicity of ionic liquids: i) length of an alkyl chain in the cation; ii) degree of functionalization in the side chain of the cation; iii) anion nature; iv) cation nature; and v) mutual influence of anion and cation.

  5. Optimization of a steaming with liquid smoke smoking process of Mediterranean mussel (Mytilus galloprovincialis).

    PubMed

    Petridis, Dimitris; Zotos, Anastasios; Kampouris, Theodoros; Roumelioti, Zoi

    2013-02-01

    Mussel samples were brined in 0%, 10% and 20% sodium chloride solutions and steamed with 2%, 5% and 8% liquid smoke at 1 (atmospheric pressure), 1.5 and 2 bar pressures. Sodium chloride and moisture content and instrumental color were analyzed. They were also objectively and hedonically assessed by 35 and 70 panellists, respectively, for their smoked flavor, saltiness, juiciness and color. The sodium chloride content was influenced by the brine concentration and brightness by the smoke and brine concentrations. The smoked flavor significantly and linearly (p = 0.018) influenced by the liquid smoke and brine concentration. A linear effect (p < 0.001) of brine concentration (p < 0.001) on sensory saltiness was expectedly observed. Brine concentration affected not only the saltiness but also the juiciness of the mussel smoked products. All factors of the study produced a significant linear effect (p = 0.008) on the intensity of color. Brine concentration was the only process variable affecting all the hedonic sensory variables in a curvilinear mode. The optimal hedonic conditions of the mussel products were achieved at smoke concentrations 3.8-8%, brine level from 8.5% to 13.5% at pressure 1 bar and from 11.5% to 16.5% at pressure 1.5 bar. All hedonic variables reached their maximum likeliness between 9 and 13. The optimal objective saltiness and juiciness varied between moderate and adequate salty and juicy product. The physicochemical variables employed in the study were adequately perceived by the panellists' sensory objective assessment as redundancy analysis revealed. Sodium chloride and moisture were the most important chemical variables (R (2 )= 42% and 13%, respectively). PMID:23239761

  6. A Janus-paper PDMS platform for air-liquid interface cell culture applications

    NASA Astrophysics Data System (ADS)

    Rahimi, Rahim; Ochoa, Manuel; Donaldson, Amy; Parupudi, Tejasvi; Dokmeci, Mehmet R.; Khademhosseini, Ali; Ghaemmaghami, Amir; Ziaie, Babak

    2015-05-01

    A commercially available Janus paper with one hydrophobic (polyethylene-coated) face and a hygroscopic/hydrophilic one is irreversibly bonded to a polydimethylsiloxane (PDMS) substrate incorporating microfluidic channels via corona discharge surface treatment. The bond strength between the polymer-coated side and PDMS is characterized as a function of corona treatment time and annealing temperature/time. A maximum strength of 392 kPa is obtained with a 2 min corona treatment followed by 60 min of annealing at 120 °C. The water contact angle of the corona-treated polymer side decreases with increased discharge duration from 98° to 22°. The hygroscopic/hydrophilic side is seeded with human lung fibroblast cells encapsulated in a methacrylated gelatin (GelMA) hydrogel to show the potential of this technology for nutrient and chemical delivery in an air-liquid interface cell culture.

  7. Multivariate optimization of the hollow fibre liquid phase microextraction of muscimol in human urine samples.

    PubMed

    Ncube, Somandla; Poliwoda, Anna; Tutu, Hlanganani; Wieczorek, Piotr; Chimuka, Luke

    2016-10-15

    A liquid phase microextraction based on hollow fibre followed by liquid chromatographic determination was developed for the extraction and quantitation of the hallucinogenic muscimol from urine samples. Method applicability on polar hallucinogens was also tested on two alkaloids, a psychedelic hallucinogen, tryptamine and a polar amino acid, tryptophan which exists in its charged state in the entire pH range. A multivariate design of experiments was used in which a half fractional factorial approach was applied to screen six factors (donor phase pH, acceptor phase HCl concentration, carrier composition, stirring rate, extraction time and salt content) for their extent of vitality in carrier mediated liquid microextractions. Four factors were deemed essential for the effective extraction of each analyte. The vital factors were further optimized for the extraction of single-spiked analyte solutions using a central composite design. When the simultaneous extraction of analytes was performed under universal factor conditions biased towards maximizing the enrichment of muscimol, a good composite desirability value of 0.687 was obtained. The method was finally applied on spiked urine samples with acceptable enrichments of 4.1, 19.7 and 24.1 obtained for muscimol, tryptophan and tryptamine respectively. Matrix-based calibration curves were used to address matrix effects. The r(2) values of the matrix-based linear regression prediction models ranged from 0.9933 to 0.9986. The linearity of the regression line of the matrix-based calibration curves for each analyte was directly linked to the analyte enrichment repeatability which ranged from an RSD value of 8.3-13.1%. Limits of detection for the developed method were 5.12, 3.10 and 0.21ngmL(-1) for muscimol, tryptophan and tryptamine respectively. The developed method has proven to offer a viable alternative for the quantitation of muscimol in human urine samples.

  8. Optimized ion acceleration using high repetition rate, variable thickness liquid crystal targets

    NASA Astrophysics Data System (ADS)

    Poole, Patrick; Willis, Christopher; Cochran, Ginevra; Andereck, C. David; Schumacher, Douglass

    2015-11-01

    Laser-based ion acceleration is a widely studied plasma physics topic for its applications to secondary radiation sources, advanced imaging, and cancer therapy. Recent work has centered on investigating new acceleration mechanisms that promise improved ion energy and spectrum. While the physics of these mechanisms is not yet fully understood, it has been observed to dominate for certain ranges of target thickness, where the optimum thickness depends on laser conditions including energy, pulse width, and contrast. The study of these phenomena is uniquely facilitated by the use of variable-thickness liquid crystal films, first introduced in P. L. Poole et al. PoP21, 063109 (2014). Control of the formation parameters of these freely suspended films such as volume, temperature, and draw speed allows on-demand thickness variability between 10 nanometers and several 10s of microns, fully encompassing the currently studied thickness regimes with a single target material. The low vapor pressure of liquid crystal enables in-situ film formation and unlimited vacuum use of these targets. Details on the selection and optimization of ion acceleration mechanism with target thickness will be presented, including recent experiments on the Scarlet laser facility and others. This work was performed with support from the DARPA PULSE program through a grant from AMRDEC and by the NNSA under contract DE-NA0001976.

  9. Optimized setup for two-dimensional convection experiments in thin liquid films

    NASA Astrophysics Data System (ADS)

    Winkler, Michael; Abel, Markus

    2016-06-01

    We present a novel experimental setup to investigate two-dimensional thermal convection in a freestanding thin liquid film. Such films can be produced in a controlled way on the scale of 5-1000 nm. Our primary goal is to investigate convection patterns and the statistics of reversals in Rayleigh-Bénard convection with varying aspect ratio. Additionally, questions regarding the physics of liquid films under controlled conditions can be investigated, like surface forces, or stability under varying thermodynamical parameters. The film is suspended in a frame which can be adjusted in height and width to span an aspect ratio range of Γ = 0.16-10. The top and bottom frame elements can be set to specific temperature within T = 15 °C to 55 °C. A thickness to area ratio of approximately 108 enables only two-dimensional fluid motion in the time scales relevant for turbulent motion. The chemical composition of the film is well-defined and optimized for film stability and reproducibility and in combination with carefully controlled ambient parameters allows the comparison to existing experimental and numerical data.

  10. [Optimization of liquid ammonia treatment for enzymatic hydrolysis of Saccharum arundinaceum to fermentable sugars].

    PubMed

    Liu, Jianjun; Peng, Hehuan; Zhao, Xiangjun; Cheng, Cheng; Chen, Feng; Shao, Qianjun

    2013-03-01

    China has abundant available marginal land that can be used for cultivation of lignocellulosic energy plants. Saccharum arundinaceum Retz. is a potential energy crop with both high biomass yield and low soil fertility requirements. It can be planted widely as cellulosic ethanol feedstock in southern China. In the present work Saccharum arundinaceum was pretreated by liquid ammonia treatment (LAT) to overcome biomass recalcitrance, followed by enzymatic hydrolysis. The monosaccharide contents (glucose, xylose, and arabinose) of the enzymatic hydrolysate were determined by high performance liquid chromatography. Experimental results show that the optimal LAT pretreatment conditions were 130 0C, 2:1 (W/W) ammonia to biomass ratio, 80% moisture content (dry weight basis) and 5 min residence time. Approximately 69.34% glucan and 82.60% xylan were converted after 72 h enzymatic hydrolysis at 1% glucan loading using 15 FPU/(g of glucan) of cellulase. The yields of glucose and xylose were 573% and 1 056% higher than those of the untreated biomass, and the LAT-pretreated substrates obtained an 8-fold higher of total monosaccharide yield than untreated substrates. LAT pretreatment was an effective to increase the enzymatic digestibility of Saccharum arundinaceum compared to acid impregnated steam explosion and similar to that of acid treatment and ammonia fiber expansion treatment.

  11. Optimized setup for two-dimensional convection experiments in thin liquid films.

    PubMed

    Winkler, Michael; Abel, Markus

    2016-06-01

    We present a novel experimental setup to investigate two-dimensional thermal convection in a freestanding thin liquid film. Such films can be produced in a controlled way on the scale of 5-1000 nm. Our primary goal is to investigate convection patterns and the statistics of reversals in Rayleigh-Bénard convection with varying aspect ratio. Additionally, questions regarding the physics of liquid films under controlled conditions can be investigated, like surface forces, or stability under varying thermodynamical parameters. The film is suspended in a frame which can be adjusted in height and width to span an aspect ratio range of Γ = 0.16-10. The top and bottom frame elements can be set to specific temperature within T = 15 °C to 55 °C. A thickness to area ratio of approximately 10(8) enables only two-dimensional fluid motion in the time scales relevant for turbulent motion. The chemical composition of the film is well-defined and optimized for film stability and reproducibility and in combination with carefully controlled ambient parameters allows the comparison to existing experimental and numerical data. PMID:27370492

  12. Optimizing culture conditions for free-living stages of the nematode parasite Strongyloides ratti.

    PubMed

    Dulovic, Alex; Puller, Vadim; Streit, Adrian

    2016-09-01

    The rat parasitic nematode Strongyloides ratti (S. ratti) has recently emerged as a model system for various aspects of parasite biology and evolution. In addition to parasitic parthenogenetic females, this species can also form facultative free-living generations of sexually reproducing adults. These free-living worms are bacteriovorous and grow very well when cultured in the feces of their host. However, in fecal cultures the worms are rather difficult to find for observation and experimental manipulation. Therefore, it has also been attempted to raise S. ratti on Nematode Growth Media (NGM) plates with Escherichia coli OP50 as food, exactly as described for the model nematode Caenorhabditis elegans. Whilst worms did grow on these plates, their longevity and reproductive output compared to fecal cultures were dramatically reduced. In order to improve the culture success we tested other plates occasionally used for C. elegans and, starting from the best performing one, systematically varied the plate composition, the temperature and the food in order to further optimize the conditions. Here we present a plate culturing protocol for free-living stages of S. ratti with strongly improved reproductive success and longevity. PMID:27334397

  13. Liquid biopsy and therapeutic response: Circulating tumor cell cultures for evaluation of anticancer treatment

    PubMed Central

    Khoo, Bee Luan; Grenci, Gianluca; Jing, Tengyang; Lim, Ying Bena; Lee, Soo Chin; Thiery, Jean Paul; Han, Jongyoon; Lim, Chwee Teck

    2016-01-01

    The lack of a robust anticancer drug screening system to monitor patients during treatment delays realization of personalized treatment. We demonstrate an efficient approach to evaluate drug response using patient-derived circulating tumor cell (CTC) cultures obtained from liquid biopsy. Custom microfabricated tapered microwells were integrated with microfluidics to allow robust formation of CTC clusters without pre-enrichment and subsequent drug screening in situ. Rapid feedback after 2 weeks promotes immediate intervention upon detection of drug resistance or tolerance. The procedure was clinically validated with blood samples (n = 73) from 55 patients with early-stage, newly diagnosed, locally advanced, or refractory metastatic breast cancer. Twenty-four of these samples were used for drug evaluation. Cluster formation potential correlated inversely with increased drug concentration and therapeutic treatment. This new and robust liquid biopsy technique can potentially evaluate patient prognosis with CTC clusters during treatment and provide a noninvasive and inexpensive assessment that can guide drug discovery development or therapeutic choices for personalized treatment. PMID:27453941

  14. Insights into an Optimization of Plasmodium vivax Sal-1 In Vitro Culture: The Aotus Primate Model

    PubMed Central

    Obaldía, Nicanor; Nuñez, Marlon; Dutary, Sahir; Lim, Caeul; Barnes, Samantha; Kocken, Clemens H. M.; Duraisingh, Manoj T.; Adams, John H.; Pasini, Erica M.

    2016-01-01

    Malaria is one of the most significant tropical diseases, and of the Plasmodium species that cause human malaria, P. vivax is the most geographically widespread. However, P. vivax remains a relatively neglected human parasite since research is typically limited to laboratories with direct access to parasite isolates from endemic field settings or from non-human primate models. This restricted research capacity is in large part due to the lack of a continuous P. vivax in vitro culture system, which has hampered the ability for experimental research needed to gain biological knowledge and develop new therapies. Consequently, efforts to establish a long-term P. vivax culture system are confounded by our poor knowledge of the preferred host cell and essential nutrients needed for in vitro propagation. Reliance on very heterogeneous P. vivax field isolates makes it difficult to benchmark parasite characteristics and further complicates development of a robust and reliable culture method. In an effort to eliminate parasite variability as a complication, we used a well-defined Aotus-adapted P. vivax Sal-1 strain to empirically evaluate different short-term in vitro culture conditions and compare them with previous reported attempts at P. vivax in vitro culture Most importantly, we suggest that reticulocyte enrichment methods affect invasion efficiency and we identify stabilized forms of nutrients that appear beneficial for parasite growth, indicating that P. vivax may be extremely sensitive to waste products. Leuko-depletion methods did not significantly affect parasite development. Formatting changes such as shaking and static cultures did not seem to have a major impact while; in contrast, the starting haematocrit affected both parasite invasion and growth. These results support the continued use of Aotus-adapted Sal-1 for development of P. vivax laboratory methods; however, further experiments are needed to optimize culture conditions to support long-term parasite

  15. Pressurized liquid extraction of anthocyanins and biflavonoids from Schinus terebinthifolius Raddi: A multivariate optimization.

    PubMed

    Feuereisen, Michelle M; Gamero Barraza, Mariana; Zimmermann, Benno F; Schieber, Andreas; Schulze-Kaysers, Nadine

    2017-01-01

    Response surface methodology was employed to investigate the effects of pressurized liquid extraction (PLE) parameters on the recovery of phenolic compounds (anthocyanins, biflavonoids) from Brazilian pepper (Schinus terebinthifolius Raddi) fruits. The effects of temperature, static time, and ethanol as well as acid concentration on the polyphenol yield were described well by quadratic models (p<0.0001). A significant influence of the ethanol concentration (p<0.0001) and several interactions (p<0.05) were identified. Identification of the biflavonoid I3',II8-binaringenin in drupes of S. terebinthifolius was achieved by UHPLC-MS(2). Interestingly, at high extraction temperatures (>75°C), an artifact occurred and was tentatively identified as a diastereomer of I3',II8-binaringenin. Multivariate optimization led to high yields of phenolic compounds from the exocarp/drupes at 100/75°C, 10/10min, 54.5/54.2% ethanol, and 5/0.03% acetic acid. This study demonstrates that PLE is well suited for the extraction of phenolic compounds from S. terebinthifolius and can efficiently be optimized by response surface methodology. PMID:27507511

  16. Optimization of cyanide extraction from wastewater using emulsion liquid membrane system by response surface methodology.

    PubMed

    Xue, Juan Qin; Liu, Ni Na; Li, Guo Ping; Dang, Long Tao

    2016-01-01

    To solve the disposal problem of cyanide wastewater, removal of cyanide from wastewater using a water-in-oil emulsion type of emulsion liquid membrane (ELM) was studied in this work. Specifically, the effects of surfactant Span-80, carrier trioctylamine (TOA), stripping agent NaOH solution and the emulsion-to-external-phase-volume ratio on removal of cyanide were investigated. Removal of total cyanide was determined using the silver nitrate titration method. Regression analysis and optimization of the conditions were conducted using the Design-Expert software and response surface methodology (RSM). The actual cyanide removals and the removals predicted using RSM analysis were in close agreement, and the optimal conditions were determined to be as follows: the volume fraction of Span-80, 4% (v/v); the volume fraction of TOA, 4% (v/v); the concentration of NaOH, 1% (w/v); and the emulsion-to-external-phase volume ratio, 1:7. Under the optimum conditions, the removal of total cyanide was 95.07%, and the RSM predicted removal was 94.90%, with a small exception. The treatment of cyanide wastewater using an ELM is an effective technique for application in industry. PMID:27533852

  17. Do Airway Epithelium Air–Liquid Cultures Represent the In Vivo Airway Epithelium Transcriptome?

    PubMed Central

    Dvorak, Anna; Tilley, Ann E.; Shaykhiev, Renat; Wang, Rui; Crystal, Ronald G.

    2011-01-01

    Human airway epithelial cells cultured in vitro at the air–liquid interface (ALI) form a pseudostratified epithelium that forms tight junctions and cilia, and produces mucin. These cells are widely used in models of differentiation, injury, and repair. To assess how closely the transcriptome of ALI epithelium matches that of in vivo airway epithelial cells, we used microarrays to compare the transcriptome of human large airway epithelial cells cultured at the ALI with the transcriptome of large airway epithelium obtained via bronchoscopy and brushing. Gene expression profiling showed that global gene expression correlated well between ALI cells and brushed cells, but with some differences. Gene expression patterns mirrored differences in proportions of cell types (ALIs have higher percentages of basal cells, whereas brushed cells have higher percentages of ciliated cells), that is, ALI cells expressed higher levels of basal cell–related genes, and brushed cells expressed higher levels of cilia-related genes. Pathway analysis showed that ALI cells had increased expression of cell cycle and proliferation genes, whereas brushed cells had increased expression of cytoskeletal organization and humoral immune response genes. Overall, ALI cells provide a good representation of the in vivo airway epithelial transcriptome, but for some biologic questions, the differences between in vitro and in vivo environments need to be considered. PMID:20525805

  18. Development of an optimized medium, strain and high-throughput culturing methods for Methylobacterium extorquens.

    PubMed

    Delaney, Nigel F; Kaczmarek, Maria E; Ward, Lewis M; Swanson, Paige K; Lee, Ming-Chun; Marx, Christopher J

    2013-01-01

    Methylobacterium extorquens strains are the best-studied methylotrophic model system, and their metabolism of single carbon compounds has been studied for over 50 years. Here we develop a new system for high-throughput batch culture of M. extorquens in microtiter plates by jointly optimizing the properties of the organism, the growth media and the culturing system. After removing cellulose synthase genes in M. extorquens strains AM1 and PA1 to prevent biofilm formation, we found that currently available lab automation equipment, integrated and managed by open source software, makes possible reliable estimates of the exponential growth rate. Using this system, we developed an optimized growth medium for M. extorquens using response surface methodologies. We found that media that used EDTA as a metal chelator inhibited growth and led to inconsistent culture conditions. In contrast, the new medium we developed with a PIPES buffer and metals chelated by citrate allowed for fast and more consistent growth rates. This new Methylobacterium PIPES ('MP') medium was also robust to large deviations in its component ingredients which avoided batch effects from experiments that used media prepared at different times. MP medium allows for faster and more consistent growth than other media used for M. extorquens.

  19. Optimization of cultural conditions for conversion of glycerol to ethanol by Enterobacter aerogenes S012

    PubMed Central

    2013-01-01

    The aim of this research is to optimize the cultural conditions for the conversion of glycerol to ethanol by Enterobacter aerogenes S012. Taguchi method was used to screen the cultural conditions based on their signal to noise ratio (SN). Temperature (°C), agitation speed (rpm) and time (h) were found to have the highest influence on both glycerol utilization and ethanol production by the organism while pH had the lowest. Full factorial design, statistical analysis, and regression model equation were used to optimize the selected cultural parameters for maximum ethanol production. The result showed that fermentation at 38°C and 200 rpm for 48 h would be ideal for the bacteria to produce maximum amount of ethanol from glycerol. At these optimum conditions, ethanol production, yield and productivity were 25.4 g/l, 0.53 g/l/h, and 1.12 mol/mol-glycerol, repectively. Ethanol production increased to 26.5 g/l while yield and productivity decreased to 1.04 mol/mol-glycerol and 0.37 g/l/h, respectively, after 72 h. Analysis of the fermentation products was performed using HPLC, while anaerobic condition was created by purging the fermentation vessel with nitrogen gas. PMID:23388539

  20. Studies of mineralization in tissue culture: optimal conditions for cartilage calcification

    NASA Technical Reports Server (NTRS)

    Boskey, A. L.; Stiner, D.; Doty, S. B.; Binderman, I.; Leboy, P.

    1992-01-01

    The optimal conditions for obtaining a calcified cartilage matrix approximating that which exists in situ were established in a differentiating chick limb bud mesenchymal cell culture system. Using cells from stage 21-24 embryos in a micro-mass culture, at an optimal density of 0.5 million cells/20 microliters spot, the deposition of small crystals of hydroxyapatite on a collagenous matrix and matrix vesicles was detected by day 21 using X-ray diffraction, FT-IR microscopy, and electron microscopy. Optimal media, containing 1.1 mM Ca, 4 mM P, 25 micrograms/ml vitamin C, 0.3 mg/ml glutamine, no Hepes buffer, and 10% fetal bovine serum, produced matrix resembling the calcifying cartilage matrix of fetal chick long bones. Interestingly, higher concentrations of fetal bovine serum had an inhibitory effect on calcification. The cartilage phenotype was confirmed based on the cellular expression of cartilage collagen and proteoglycan mRNAs, the presence of type II and type X collagen, and cartilage type proteoglycan at the light microscopic level, and the presence of chondrocytes and matrix vesicles at the EM level. The system is proposed as a model for evaluating the events in cell mediated cartilage calcification.

  1. Optimization of culture conditions of Fusarium solani for the production of neoN-methylsansalvamide.

    PubMed

    Lee, Hee-Seok; Phat, Chanvorleak; Nam, Woo-Seon; Lee, Chan

    2014-01-01

    The aim of this study was to optimize the culture conditions of Fusarium solani KCCM90040 on cereal grain for the production of neoN-methylsansalvamide, a novel low-molecular-weight cyclic pentadepsipeptide exhibiting cytotoxic and multidrug resistance reversal effects. From the analysis of variance results using response surface methodology, temperature, initial moisture content, and growth time were shown to be important parameters for the production of neoN-methylsansalvamide on cereal grain. A model was established in the present study to describe the relationship between environmental conditions and the production of neoN-methylsansalvamide on rice, the selected cereal grain. The optimal culture conditions were determined at 25.79 °C with the initial moisture content of 40.79%, and 16.19 days of growth time. This report will give important information concerning the optimization of environmental conditions using statistic methodology for the production of a new cyclic pentadepsipeptide from fungi. PMID:25130748

  2. Optimization of Betanodavirus culture and enumeration in striped snakehead fish cells.

    PubMed

    Hick, Paul; Tweedie, Alison; Whittington, Richard J

    2011-05-01

    An optimized culture method for detection of infection of fish with the Red spotted grouper nervous necrosis virus (RGNNV) genotype of betanodavirus in striped snakehead (SSN-1, Channa striatus) cells is described. Inoculation of fish tissue homogenates at the same time or within 4 hr of seeding the SSN-1 cells was as sensitive as the method recommended by the World Organization for Animal Health, where homogenates were adsorbed onto an established cell monolayer. Such modification halved the time required and the costs of consumables, and reduced the potential for error when processing large numbers of samples. Positive culture results were obtained from 88.3% of 392 fish tissue homogenates in which RGNNV was detected using a quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay; 99.7% of 943 tissue homogenates, which were qRT-PCR negative, were cell culture negative. Cytopathic effect (CPE) was characterized by large intracytoplasmic vacuoles in 0.1-60% of cells. Detachment of affected cells from the culture surface resulting in progressive disruption of the monolayer occurred in 46.4% of primary cultures and 96.0% of subcultures of positive samples. Identification of CPE that did not disrupt the cell monolayer increased estimates of the 50% tissue culture infective dose (TCID(50)) by 1.07-2.79 logs (95% confidence interval). The predicted mean TCID(50)/ml was 3.3 logs higher when cells were inoculated less than 36 hr after subculture at less than 80% confluence compared to cells inoculated at greater than 80% confluence and more than 36 hr after subculture (P < 0.05).

  3. Serum and supplement optimization for EU GMP-compliance in cardiospheres cell culture.

    PubMed

    Chimenti, Isotta; Gaetani, Roberto; Forte, Elvira; Angelini, Francesco; De Falco, Elena; Zoccai, Giuseppe Biondi; Messina, Elisa; Frati, Giacomo; Giacomello, Alessandro

    2014-04-01

    Cardiac progenitor cells (CPCs) isolated as cardiospheres (CSs) and CS-derived cells (CDCs) are a promising tool for cardiac cell therapy in heart failure patients, having CDCs already been used in a phase I/II clinical trial. Culture standardization according to Good Manufacturing Practices (GMPs) is a mandatory step for clinical translation. One of the main issues raised is the use of xenogenic additives (e.g. FBS, foetal bovine serum) in cell culture media, which carries the risk of contamination with infectious viral/prion agents, and the possible induction of immunizing effects in the final recipient. In this study, B27 supplement and sera requirements to comply with European GMPs were investigated in CSs and CDCs cultures, in terms of process yield/efficiency and final cell product gene expression levels, as well as phenotype. B27- free CS cultures produced a significantly reduced yield and a 10-fold drop in c-kit expression levels versus B27+ media. Moreover, autologous human serum (aHS) and two different commercially available GMP AB HSs were compared with standard research-grade FBS. CPCs from all HSs explants had reduced growth rate, assumed a senescent-like morphology with time in culture, and/or displayed a significant shift towards the endothelial phenotype. Among three different GMP gamma-irradiated FBSs (giFBSs) tested, two provided unsatisfactory cell yields, while one performed optimally, in terms of CPCs yield/phenotype. In conclusion, the use of HSs for the isolation and expansion of CSs/CDCs has to be excluded because of altered proliferation and/or commitment, while media supplemented with B27 and the selected giFBS allows successful EU GMP-complying CPCs culture. PMID:24444305

  4. Some optimal culture conditions for production of cyclosporin a by Fusarium roseum

    PubMed Central

    Ismaiel, Ahmed A.; El-Sayed, A.; Mahmoud, Asmaa A.

    2010-01-01

    A suitable chemically defined culture medium was selected and some optimal conditions for the production of the highly immunosuppressive compound, cyclosporin A (Cyc A) are reported. Medium of the following composition was favorable for the production of Cyc A by Fusarium roseum: glucose, 30; NaNO3, 2; KH2PO4, 1; MgSO4.7H2O, 0.5 and KCL, 0.5 (g/l). Maximum productivity of Cyc A was achieved at pH 6.0 when 50 ml of the fermentation medium/250 ml flask, inoculated with five fungal agar discs (6 mm, diameter) of 7-days old F. roseum culture after incubation at 30 ºC at 120 rpm for 7 days. PMID:24031594

  5. Optimized “In Vitro” Culture Conditions for Human Rheumatoid Arthritis Synovial Fibroblasts

    PubMed Central

    Lattuada, Donatella; Crotta, Katia; Truzzi, Marcello Claudio; Corradini, Costantino; Marelli, Ornella

    2014-01-01

    The composition of synovial fluid in rheumatoid arthritis (RA) is complex and strongly influences the microenvironment of joints and it is an inseparable element of the disease. Currently, “in vitro” studies are performed on RA cells cultured in the presence of either recombinant proinflammatory cytokines-conditioned medium or medium alone. In this study, we evaluated the use of synovial fluid, derived from RA patients, as optimal culture condition to perform “in vitro” studies on RA synovial fibroblasts. We observed that synovial fluid is more effective in inducing cell proliferation with respect to TNF-alpha or culture medium alone. Spontaneous apoptosis in fibroblasts was also decreased in response to synovial fluid. The expression of proinflammatory cytokines in the presence of synovial fluid was significantly elevated with respect to cells cultured with TNF-alpha or medium, and the overall morphology of cells was also modified. In addition, modulation of intracellular calcium dynamics elicited in response to synovial fluid or TNF-alpha exposure is different and suggests a role for the purinergic signalling in the modulation of the effects. These results emphasize the importance of using RA synovial fluid in “in vitro” studies involving RA cells, in order to reproduce faithfully the physiopathological environmental characteristic of RA joints. PMID:25548436

  6. [Optimization of the composition of the medium for thrombolytic enzyme biosynthesis in pure and mixed cultures].

    PubMed

    Gesheva, V I; Maksimov, V N; Landau, N S; Egorov, N S

    1982-01-01

    The medium for the biosynthesis of exoproteases with the thrombolytic action in monocultures and mixed cultures of actinomycetes was optimized in several steps using the method of complete and fractional factor experiments. When Actinomyces rimosus was cultivated on the selected medium, the productivity of the mycelium rose, the fibrinolytic activity increased three-fold, and the caseinolytic activity became 2.2 times greater. During mixed cultivation of A. rimosus and A. violaceus on this medium, fibrinolysis increased six times comparing with the A. rimosus monoculture growth on the original medium while caseinolysis became only 3.7 times greater, which increased the specificity for fibrin twice. PMID:7045597

  7. Liquid semen storage in elephants (Elephas maximus and Loxodonta africana): species differences and storage optimization.

    PubMed

    Kiso, Wendy K; Brown, Janine L; Siewerdt, Frank; Schmitt, Dennis L; Olson, Deborah; Crichton, Elizabeth G; Pukazhenthi, Budhan S

    2011-01-01

    Artificial insemination plays a key role in the genetic management of elephants in zoos. Because freshly extended semen is typically used for artificial insemination in elephants, it has become imperative to optimize conditions for liquid storage and semen transport. The objectives of this study were to examine the interactions between different extenders and storage temperatures on sperm total motility, progressive motility, and acrosomal integrity in Asian (Elephas maximus) and African (Loxodonta africana) elephants. Ejaculates were collected by rectal massage, diluted using a split-sample technique in 5 semen extenders: TL-Hepes (HEP), Modena (MOD), Biladyl (BIL), TEST refrigeration medium (TES), and INRA96 (INR), maintained at 35°C, 22°C, or 4°C. At 0, 4, 6, 12, and 24 hours, aliquots were removed and assessed for sperm total motility, progressive motility, and acrosomal integrity. After 24 hours of storage, African elephant spermatozoa exhibited greater longevity and higher values in sperm quality parameters compared with those of Asian elephants. In both species, semen storage at 35°C resulted in a sharp decline in all sperm quality parameters after 4 hours of storage, whereas storage at 22°C and 4°C facilitated sperm survival. In Asian elephants, MOD and HEP were most detrimental, whereas BIL, TES, and INR maintained motility up to 12 hours when spermatozoa were cooled to 22°Cor4°C. In African elephants, there were no differences among extenders. All media maintained good sperm quality parameters at 22°C or 4°C. However, although MOD, BIL, and INR were most effective at lower temperatures, HEP and TES maintained sperm motility at all storage temperatures. This study demonstrated sperm sensitivity to components of various semen extenders and storage temperatures and offers recommendations for semen extender choices for liquid semen storage for both Asian and African elephants.

  8. Optimization of oxygen mass transfer in a multiphase bioreactor with perfluorodecalin as a second liquid phase.

    PubMed

    Amaral, Priscilla F F; Freire, Mara G; Rocha-Leão, Maria Helena M; Marrucho, Isabel M; Coutinho, João A P; Coelho, Maria Alice Z

    2008-02-15

    Oxygenation is an important parameter involved in the design and operation of mixing-sparging bioreactors and it can be analyzed by means of the oxygen mass transfer coefficient (k(L)a). The operational conditions of a stirred, submerged aerated 2-L bioreactor have been optimized by studying the influence of a second liquid phase with higher oxygen affinity (perfluorodecalin or olive oil) in the k(L)a. Using k(L)a measurements, the influence of the following parameters on the oxygen transfer rate was evaluated: the volume of working medium, the type of impellers and their position, the organic phase concentration, the aqueous phase composition, and the concentration of inactive biomass. This study shows that the best experimental conditions were achieved with a perfluorodecalin volume fraction of 0.20, mixing using two Rushton turbines with six vertical blades and in the presence of YPD medium as the aqueous phase, with a k(L)a value of 64.6 h(-1). The addition of 20% of perfluorodecalin in these conditions provided a k(L)a enhancement of 25% when pure water was the aqueous phase and a 230% enhancement when YPD medium was used in comparison to their respective controls (no perfluorodecalin). Furthermore it is shown that the presence of olive oil as a second liquid phase is not beneficial to the oxygen transfer rate enhancement, leading to a decrease in the k(L)a values for all the concentrations studied. It was also observed that the magnitude of the enhancement of the k(L)a values by perfluorodecalin depends on the biomass concentration present. PMID:17787007

  9. Cross-Cultural Comparison of the Effects of Optimism, Intrinsic Motivation, and Family Relations on Vocational Identity

    ERIC Educational Resources Information Center

    Shin, Yun-Jeong; Kelly, Kevin R.

    2013-01-01

    This study explored the effects of optimism, intrinsic motivation, and family relations on vocational identity in college students in the United States and South Korea. The results yielded support for the hypothesized multivariate model. Across both cultures, optimism was an important contributing factor to vocational identity, and intrinsic…

  10. Aflatoxin B1 degradation by liquid cultures and lysates of three bacterial strains.

    PubMed

    Adebo, Oluwafemi Ayodeji; Njobeh, Patrick Berka; Sidu, Sibusiso; Tlou, Matsobane Godfrey; Mavumengwana, Vuyo

    2016-09-16

    Aflatoxin contamination remains a daunting issue to address in food safety. In spite of the efforts geared towards prevention and elimination of this toxin, it still persists in agricultural commodities. This has necessitated the search for other measures such as microbial degradation to combat this hazard. In this study, we investigated the biodegradation of aflatoxin B1 (AFB1), using lysates of three bacterial strains (Pseudomonas anguilliseptica VGF1, Pseudomonas fluorescens and Staphylococcus sp. VGF2) isolated from a gold mine aquifer. The bacterial cells were intermittently lysed in the presence and absence of protease inhibitors to obtain protease free lysates, subsequently incubated with AFB1 for 3, 6, 12, 24, and 48h to investigate whether any possible AFB1 degradation occurred using high performance liquid chromatography (HPLC) for detection. Results obtained revealed that after 6h of incubation, protease inhibited lysates of Staphylococcus sp. VGF2 demonstrated the highest degradation capacity of 100%, whereas P. anguilliseptica VGF1 and P. fluorescens lysates degraded AFB1 by 66.5 and 63%, respectively. After further incubation to 12h, no residual AFB1 was detected for all the lysates. Lower degrading ability was however observed for liquid cultures and uninhibited lysates. Data on cytotoxicity studies against human lymphocytes showed that the degraded products were less toxic than the parent AFB1. From this study, it can thus be deduced that the mechanism of degradation by these bacterial lysates is enzymatic. This study shows the efficacy of crude bacterial lysates for detoxifying AFB1 indicating potential for application in the food and feed industry. PMID:27294556

  11. Geographic Differences in Time to Culture Conversion in Liquid Media: Tuberculosis Trials Consortium Study 28. Culture Conversion Is Delayed in Africa

    PubMed Central

    Mac Kenzie, William R.; Heilig, Charles M.; Bozeman, Lorna; Johnson, John L.; Muzanye, Grace; Dunbar, Denise; Jost, Kenneth C.; Diem, Lois; Metchock, Beverly; Eisenach, Kathleen; Dorman, Susan; Goldberg, Stefan

    2011-01-01

    Background Tuberculosis Trials Consortium Study 28, was a double blind, randomized, placebo-controlled, phase 2 clinical trial examining smear positive pulmonary Mycobacterium tuberculosis. Over the course of intensive phase therapy, patients from African sites had substantially delayed and lower rates of culture conversion to negative in liquid media compared to non-African patients. We explored potential explanations of this finding. Methods In TBTC Study 28, protocol-correct patients (n = 328) provided spot sputum specimens for M. tuberculosis culture in liquid media, at baseline and weeks 2, 4, 6 and 8 of study therapy. We compared sputum culture conversion for African and non-African patients stratified by four baseline measures of disease severity: AFB smear quantification, extent of disease on chest radiograph, cavity size and the number of days to detection of M. tuberculosis in liquid media using the Kaplan-Meier product-limit method. We evaluated specimen processing and culture procedures used at 29 study laboratories serving 27 sites. Results African TB patients had more extensive disease at enrollment than non-African patients. However, African patients with the least disease by the 4 measures of disease severity had conversion rates on liquid media that were substantially lower than conversion rates in non-African patients with the greatest extent of disease. HIV infection, smoking and diabetes did not explain delayed conversion in Africa. Some inter-site variation in laboratory processing and culture procedures within accepted practice for clinical diagnostic laboratories was found. Conclusions Compared with patients from non-African sites, African patients being treated for TB had delayed sputum culture conversion and lower sputum conversion rates in liquid media that were not explained by baseline severity of disease, HIV status, age, smoking, diabetes or race. Further investigation is warranted into whether modest variation in laboratory

  12. Mueller-Stokes characterization and optimization of a liquid crystal on silicon display showing depolarization.

    PubMed

    Márquez, A; Moreno, I; Iemmi, C; Lizana, A; Campos, J; Yzuel, M J

    2008-02-01

    In this paper we characterize the polarimetric properties of a liquid crystal on silicon display (LCoS), including depolarization and diattenuation which are usually not considered when applying the LCoS in diffractive or adaptive optics. On one hand, we have found that the LCoS generates a certain degree (that can be larger than a 10%) of depolarized light, which depends on the addressed gray level and on the incident state of polarization (SOP), and can not be ignored in the above mentioned applications. The main origin of the depolarized light is related with temporal fluctuations of the SOP of the light reflected by the LCoS. The Mueller matrix of the LCoS is measured as a function of the gray level, which enables for a numerical optimization of the intensity modulation configurations. In particular we look for maximum intensity contrast modulation or for constant intensity modulation. By means of a heuristic approach we show that, using elliptically polarized light, amplitude-mostly or phase-mostly modulation can be obtained at a wavelength of 633 nm.

  13. Optimization of pressurized liquid extraction of carotenoids and chlorophylls from Chlorella vulgaris.

    PubMed

    Cha, Kwang Hyun; Lee, Hee Ju; Koo, Song Yi; Song, Dae-Geun; Lee, Dong-Un; Pan, Cheol-Ho

    2010-01-27

    Pressurized liquid extraction (PLE) was applied to the extraction of carotenoids and chlorophylls from the green microalga Chlorella vulgaris. Four extraction techniques such as maceration (MAC), Soxhlet extraction (SOX), ultrasound assisted extraction (UAE), and PLE were compared, and both the extraction temperature (50, 105, and 160 degrees C) and the extraction time (8, 19, and 30 min), which are the two main factors for PLE, were optimized with a central composite design to obtain the highest extraction efficiency. The extraction solvent (90% ethanol/water) could adequately extract the functional components from C. vulgaris. PLE showed higher extraction efficiencies than MAC, SOX, and UAE. Temperature was the key parameter having the strongest influence on the extraction of carotenoids and chlorophylls from chlorella. In addition, high heat treatment (>110 degrees C) by PLE minimized the formation of pheophorbide a, a harmful chlorophyll derivative. These results indicate that PLE may be a useful extraction method for the simultaneous extraction of carotenoids and chlorophylls from C. vulgaris. PMID:20028017

  14. Optimization of large-scale pseudotargeted metabolomics method based on liquid chromatography-mass spectrometry.

    PubMed

    Luo, Ping; Yin, Peiyuan; Zhang, Weijian; Zhou, Lina; Lu, Xin; Lin, Xiaohui; Xu, Guowang

    2016-03-11

    Liquid chromatography-mass spectrometry (LC-MS) is now a main stream technique for large-scale metabolic phenotyping to obtain a better understanding of genomic functions. However, repeatability is still an essential issue for the LC-MS based methods, and convincing strategies for long time analysis are urgently required. Our former reported pseudotargeted method which combines nontargeted and targeted analyses, is proved to be a practical approach with high-quality and information-rich data. In this study, we developed a comprehensive strategy based on the pseudotargeted analysis by integrating blank-wash, pooled quality control (QC) sample, and post-calibration for the large-scale metabolomics study. The performance of strategy was optimized from both pre- and post-acquisition sections including the selection of QC samples, insertion frequency of QC samples, and post-calibration methods. These results imply that the pseudotargeted method is rather stable and suitable for large-scale study of metabolic profiling. As a proof of concept, the proposed strategy was applied to the combination of 3 independent batches within a time span of 5 weeks, and generated about 54% of the features with coefficient of variations (CV) below 15%. Moreover, the stability and maximal capability of a single analytical batch could be extended to at least 282 injections (about 110h) while still providing excellent stability, the CV of 63% metabolic features was less than 15%. Taken together, the improved repeatability of our strategy provides a reliable protocol for large-scale metabolomics studies.

  15. Sample volume optimization for radon-in-water detection by liquid scintillation counting.

    PubMed

    Schubert, Michael; Kopitz, Juergen; Chałupnik, Stanisław

    2014-08-01

    Radon is used as environmental tracer in a wide range of applications particularly in aquatic environments. If liquid scintillation counting (LSC) is used as detection method the radon has to be transferred from the water sample into a scintillation cocktail. Whereas the volume of the cocktail is generally given by the size of standard LSC vials (20 ml) the water sample volume is not specified. Aim of the study was an optimization of the water sample volume, i.e. its minimization without risking a significant decrease in LSC count-rate and hence in counting statistics. An equation is introduced, which allows calculating the ²²²Rn concentration that was initially present in a water sample as function of the volumes of water sample, sample flask headspace and scintillation cocktail, the applicable radon partition coefficient, and the detected count-rate value. It was shown that water sample volumes exceeding about 900 ml do not result in a significant increase in count-rate and hence counting statistics. On the other hand, sample volumes that are considerably smaller than about 500 ml lead to noticeably lower count-rates (and poorer counting statistics). Thus water sample volumes of about 500-900 ml should be chosen for LSC radon-in-water detection, if 20 ml vials are applied.

  16. Effect of pressure, particle size, and time on optimizing performance in liquid chromatography.

    PubMed

    Carr, Peter W; Wang, Xiaoli; Stoll, Dwight R

    2009-07-01

    Although the principles of optimization of high-performance liquid chromatography (HPLC) have a long history starting with the work of Giddings in the 1960s and continuing with work by Knox and Guiochon extending into the 1990s we continue to see statements that flatly contradict theory. A prominent example is the notion that optimum "performance", as measured by plate count, is always obtained by operating conventional length columns (e.g., 5-15 cm) at eluent velocities corresponding to the minimum plate height in the van Deemter curve. In the past decade the introduction of "Poppe plots" by Poppe and "kinetic plots" by Desmet and others has simplified the selection of "optimum" conditions, but it is evident that many workers are not entirely comfortable with this framework. Here we derive a set of simple, yet accurate, equations that allow rapid calculation of the column length and eluent velocity that will give either the maximum plate count in a given time or a given plate count in the shortest time. Equations are developed for the optimum column length, eluent velocity, and thus plate count for both the cases when particle size is preselected and when particle size is optimized along with eluent velocity and column length. Although both of these situations have been previously considered the implications of the resulting equations have not been previously made explicit. Lack of full understanding of the consequences of the differences between these two cases is very important and responsible for many erroneous conclusions. The simple closed-form equations that result from this work complement the graphical, iterative approaches of Poppe and Desmet; the resulting compact framework allows practitioners to rapidly and effectively find the operating parameters needed to achieve a specific separation goal in the shortest time and to compare emerging technologies (e.g., high pressure, high temperature, and different particle types) in terms of their impact on

  17. Haloxyfop mode of action in liquid cultures of proso millet: An analysis of haloxyfop sensitivity changes during growth

    SciTech Connect

    Irzyk, G.P.

    1989-01-01

    Haloxyfop is a grass-selective herbicide that inhibits acetyl-CoA carboxylase in species that are not tolerant to the herbicide. Liquid cultures of proso millet (Panicum miliaceum) cells treated with haloxyfop at different phases of growth exhibited different levels of sensitivity to the herbicide. Treatment of 1-d cultures with 1 {mu}M haloxyfop completely inhibited growth within 48 h. In contrast, 1 mM haloxyfop was required to elicit a similar response in 4-, 7-, or 10-d cultures. Calculated IC{sub 50} values indicated a 300-fold decrease in haloxyfop sensitivity during the period from 1 to 4 d. This period of growth coincided with the greatest increase in cell number during culture growth and suggested that dividing cells are most sensitive to haloxyfop. Uptake and metabolism of {sup 14}C-haloxyfop in 1-d and 4-d cultures were compared. In both cultures, amounts of radiolabel uptake were similar. Almost all radioactivity extracted from 1- and 4-d cells was present as the parent compound. These results suggested that the sensitivity change was related to other factors. Acetyl-CoA carboxylase activity of proso millet cells, measured in vitro by the acetyl-CoA-dependent incorporation of {sup 14} C-bicarbonate into an acid-stable product, was essentially constant during culture growth. Micromolar concentrations of haloxyfop significantly inhibited acetyl-CoA carboxylase activity from both sensitive and insensitive cultures. Thus, the change in the sensitivity of cultures to haloxyfop was not correlated with changes in acetyl-CoA carboxylase abundance, activity, or sensitivity to haloxyfop during culture growth. In vivo incorporation of {sup 14}C-acetate into lipids was decreased by 1 {mu}M haloxyfop in both 1-d and 4-d cultures at the earliest sampling times but the amount of inhibition was significantly greater in the sensitive cultures.

  18. Establishment and culture optimization of a new type of pituitary immortalized cell line

    SciTech Connect

    Kokubu, Yuko; Asashima, Makoto; Kurisaki, Akira

    2015-08-07

    The pituitary gland is a center of the endocrine system that controls homeostasis in an organism by secreting various hormones. The glandular anterior pituitary consists of five different cell types, each expressing specific hormones. However, their regulation and the appropriate conditions for their in vitro culture are not well defined. Here, we report the immortalization of mouse pituitary cells by introducing TERT, E6, and E7 transgenes. The immortalized cell lines mainly expressed a thyrotroph-specific thyroid stimulating hormone beta (Tshb). After optimization of the culture conditions, these immortalized cells proliferated and maintained morphological characteristics similar to those of primary pituitary cells under sphere culture conditions in DMEM/F12 medium supplemented with N2, B27, basic FGF, and EGF. These cell lines responded to PKA or PKC pathway activators and induced the expression of Tshb mRNA. Moreover, transplantation of the immortalized cell line into subcutaneous regions and kidney capsules of mice further increased Tshb expression. These results suggest that immortalization of pituitary cells with TERT, E6, and E7 transgenes is a useful method for generating proliferating cells for the in vitro analysis of pituitary regulatory mechanisms. - Highlights: • Mouse pituitary cell lines were immortalized by introducing TERT, E6, and E7. • The immortalized cell lines mainly expressed thyroid stimulating hormone beta. • The cell lines responded to PKA or PKC pathway activators, and induced Tshb.

  19. Optimization of culture medium and modeling of curdlan production from Paenibacillus polymyxa by RSM and ANN.

    PubMed

    Rafigh, Sayyid Mahdi; Yazdi, Ali Vaziri; Vossoughi, Manouchehr; Safekordi, Ali Akbar; Ardjmand, Mehdi

    2014-09-01

    Paenibacillus polymyxa ATCC 21830 was used for the production of curdlan gum for first time. A Box-Behnken experimental design was applied to optimize six variables of batch fermentation culture each at three levels. Statistical analyses were employed to investigate the direct and interactive effects of variables on curdlan production. Optimum cultural conditions were temperature (50°C), pH (7), fermentation time (96 h), glucose (100 g/L), yeast extract (3 g/L) and agitation speed (150 rpm). The yield of curdlan production was 6.89 g/L at optimum condition medium. Response surface methodology (RSM) and artificial neural network (ANN) were used to model cultural conditions of curdlan production. The maximum yield of curdlan production were predicted to be 6.68 and 6.85 g/L by RSM and ANN at optimum condition. The prediction capabilities of RSM and ANN were then statistically compared. The results showed that the ANN model is much more accurate in prediction as compared to the RSM. The infrared (IR) and NMR spectra, the thermogram of DSC and pattern of X-ray diffraction for the curdlan of the present study were almost identical to those of the commercial curdlan sample. The average molecular weight of the purified curdlan was determined to be 170 kDa by gel permeation chromatography. PMID:25062991

  20. An axenic plant culture system for optimal growth in long-term studies.

    PubMed

    Henry, Amelia; Doucette, William; Norton, Jeanette; Jones, Scott; Chard, Julie; Bugbee, Bruce

    2006-01-01

    The symbiotic co-evolution of plants and microbes leads to difficulties in understanding which of the two components is responsible for a given environmental response. Plant-microbe studies greatly benefit from the ability to grow plants in axenic (sterile) culture. Several studies have used axenic plant culture systems, but experimental procedures are often poorly documented, the plant growth environment is not optimal, and axenic conditions are not rigorously verified. We developed a unique axenic system using inert components that promotes plant health and can be kept sterile for at least 70 d. Crested wheatgrass (Agropyron cristatum cv. CDII) plants were grown in sand within flow-through glass columns that were positively pressured with filtered air. Plant health was optimized by regulating temperature, light level, CO2 concentration, humidity, and nutrients. The design incorporates several novel aspects, such as pretreatment of the sand with Fe, graduated sand layers to optimize the air-water balance of the root zone, and modification of a laminar flow hood to serve as a plant growth chamber. Adaptations of several sterile techniques were necessary for maintenance of axenic conditions. Axenic conditions were verified by plating and staining leachates as well as a rhizoplane stain. This system was designed to study nutrient and water stress effects on root exudates, but is useful for assessing a broad range of plant-microbe-environment interactions. Based on total organic C analysis, 74% of exudates was recovered in the leachate, 6% was recovered in the bulk sand, and 17% was recovered in the rhizosphere sand. Carbon in the leachate after 70 d reached 255 microg d(-1). Fumaric, malic, malonic, oxalic, and succinic acids were measured as components of the root exudates.

  1. An Axenic Plant Culture System for Optimal Growth in Long-Term Studies: Design and Maintenance

    NASA Technical Reports Server (NTRS)

    Henry, Amelia; Doucette, William; Norton, Jeanette; Jones, Scott; Chard, Julie; Bugbee, Bruce

    2006-01-01

    The symbiotic co-evolution of plants and microbes leads to difficulties in understanding which of the two components is responsible for a given environmental response. Plant-microbe studies greatly benefit from the ability to grow plants in axenic (sterile) culture. Several studies have used axenic plant culture systems, but experimental procedures are often poorly documented, the plant growth environment is not optimal, and axenic conditions are not rigorously verified. We developed a unique axenic system using inert components that promotes plant health and can be kept sterile for at least 70 d. Crested wheatgrass (Agropyron cristatum cv. DII) plants were grown in sand within flow-through glass columns that were positively pressured with filtered air. Plant health was optimized by regulating temperature, light level, CO2 concentration, humidity, and nutrients. The design incorporates several novel aspects, such as pretreatment of the sand with Fe, graduated sand layers to optimize the air-water balance of the root zone, and modification of a laminar flow hood to serve as a plant growth chamber. Adaptations of several sterile techniques were necessary for maintenance of axenic conditions. Axenic conditions were verified by plating and staining leachates as well as rhizoplane stain. This system was designed to study nutrient and water stress effects on root exudates, but is useful for assessing a broad range of plant-microbe-environment interactions. Based on total organic C analysis, 74% of exudates was recovered in the leachate, 6% was recovered in the bulk sand, and 17% was recovered in the rhizosphere sand. Carbon in the leachate after 70 d reached 255 micro-g/d. Fumaric, malic, malonic, oxalic, and succinic acids were measured as components of the root exudates.

  2. Determination of cocaine and norcocaine in plasma and cell cultures using high-performance liquid chromatography.

    PubMed

    Bouis, P; Taccard, G; Boelsterli, U A

    1990-04-01

    A new simple high-performance liquid chromatographic (HPLC) method was developed for the determination of cocaine and norcocaine. Cocaine and norcocaine in biological samples were buffered to pH 9.0, extracted with diethyl ether and reextracted in a 0.1% aqueous solution of tetramethylammonium hydrogen sulfate (TMAHS) with a theoretical yield of extraction of 100%. The HPLC elution of cocaine and norcocaine was performed using a Spherisorb RP-18, 100 mm x 4.6 mm I.D., 5 microns particle size column with a mobile phase containing acetonitrile-0.1% TMAHS aqueous solution (60:40). The compounds were entirely separated, and a reliable limit of quantitation was set at 20 ng/ml when extracted from 0.5 ml of plasma. No interference with 26 other drugs was found. Cocaine and norcocaine stability studies showed that their half-lives in human plasma incubated at 37 degrees C were 50.8 and 43.2 min, respectively. In contrast, plasma from dogs or rats exhibited only weak or no enzymatic esterase activity towards cocaine and norcocaine resulting in less rapid degradation. Hydrolysis could be efficiently inhibited with sodium fluoride and prevented by storage of the sample at -20 degrees C. The highly sensitive assay also allowed the assessment of the oxidative metabolism pathway of cocaine to norcocaine in primary rat hepatocyte cultures.

  3. A Proteomic Study of Pectin Degrading Enzymes Secreted by Botrytis cinerea Grown in Liquid Culture

    PubMed Central

    Shah, Punit; Gutierrez-Sanchez, Gerardo; Orlando, Ron; Bergmann, Carl

    2009-01-01

    Botrytis cinerea is a pathogenic filamentous fungus which infects more than 200 plant species. The enzymes secreted by B. cinerea play an important role in the successful colonization of a host plant. Some of the secreted enzymes are involved in the degradation of pectin, a major component of the plant cell wall. A total of 126 proteins secreted by B. cinerea were identified by growing the fungus on highly or partially esterified pectin, or on sucrose in liquid culture. Sixty-seven common proteins were identified in each of the growth conditions, of which 50 proteins exhibited a Signal P motif. Thirteen B. cinerea proteins with functions related to pectin degradation were identified in both pectin growth conditions, while only four were identified in sucrose. Our results indicate it is unlikely that the activation of B. cinerea from the dormant state to active infection is solely dependent on changes in the degree of esterification of the pectin component of the plant cell wall. Further, these results suggest that future studies of the B. cinerea secretome in infections of ripe and unripe fruits will provide important information that will describe the mechanisms that the fungus employs to access nutrients and decompose tissues. PMID:19526562

  4. Long-term storage of aerobic granules in liquid media: viable but non-culturable status.

    PubMed

    Wan, Chunli; Zhang, Qinlan; Lee, Duu-Jong; Wang, Yayi; Li, Jieni

    2014-08-01

    Long-term storage and successful reactivation after storage are essential for practical applications of aerobic granules on wastewater treatment. This study cultivated aerobic granules (SI) in sequencing batch reactors and then stored the granules at 4 °C in five liquid media (DI water (SW), acetone (SA), acetone/isoamyl acetate mix (SAA), saline water (SS), and formaldehyde (SF)) for over 1 year. The first four granules were then successfully reactivated in 24h cultivation. The specific oxygen uptake rates (SOUR) of the granules followed SI>SS>SA>SAA>SW>SF; and the corresponding granular strengths (10 min ultrasound) followed SI>SA=SS>SAA>SW>SF. During storage the granular cells secreted excess quantities of cyclic-diguanylate (c-di-GMP) and pentaphosphate (ppGpp) as responses to the stringent challenges. We proposed that to force cells in granules (Alphaproteobacteria, Flavobacteria, Betaproteobacteria, Gammaproteobacteria, Actinobacteria, Sphingobacteria, and Clostridia) entering viable but non-culturable (VBNC) status is the key of success for extended period storage of granules. PMID:24950091

  5. Surviving death-anxieties in liquid modern times: examining Zygmunt Bauman's cultural theory of death and dying.

    PubMed

    Higo, Masa

    2012-01-01

    Despite his prominence as a leading contemporary social theorist, Zygmunt Bauman's long-term writing on the cultural theory of death and dying has largely been overlooked in the sociological literature of death and dying, particularly in the United States. Bauman uniquely theorizes how we survive death-anxieties today: Contemporary, liquid modern culture has engaged us in ceaseless pursuit of the unattainable consumer sensation of bodily fitness as a way to suppress and thus survive our death-anxieties. Bauman also argues that the prevalence of this cultural formula to survive death-anxieties has simultaneously increased, more than ever before in social history, the volume of individual responsibility for restlessly coping with existential anxieties in the societies of consumers. While unique and insightful, his theoretical argument has a limitation; largely succeeding Freud's classic view of mortality, Bauman's contemporary theory may lead us to neglect potentially important social, cultural, and historical variations in how mortality has been understood.

  6. Surviving death-anxieties in liquid modern times: examining Zygmunt Bauman's cultural theory of death and dying.

    PubMed

    Higo, Masa

    2012-01-01

    Despite his prominence as a leading contemporary social theorist, Zygmunt Bauman's long-term writing on the cultural theory of death and dying has largely been overlooked in the sociological literature of death and dying, particularly in the United States. Bauman uniquely theorizes how we survive death-anxieties today: Contemporary, liquid modern culture has engaged us in ceaseless pursuit of the unattainable consumer sensation of bodily fitness as a way to suppress and thus survive our death-anxieties. Bauman also argues that the prevalence of this cultural formula to survive death-anxieties has simultaneously increased, more than ever before in social history, the volume of individual responsibility for restlessly coping with existential anxieties in the societies of consumers. While unique and insightful, his theoretical argument has a limitation; largely succeeding Freud's classic view of mortality, Bauman's contemporary theory may lead us to neglect potentially important social, cultural, and historical variations in how mortality has been understood. PMID:23057247

  7. Determination of alachlor and its metabolite 2,6-diethylaniline in microbial culture medium using online microdialysis enriched-sampling coupled to high-performance liquid chromatography.

    PubMed

    Chen, Chi-Zen; Yan, Cheing-Tong; Kumar, Ponnusamy Vinoth; Huang, Jenn-Wen; Jen, Jen-Fon

    2011-08-10

    In this study, a simple and novel microdialysis sampling technique incorporating hollow fiber liquid phase microextraction (HF-LPME) coupled online to high-performance liquid chromatography (HPLC) for the one-step sample pretreatment and direct determination of alachlor (2-chloro-2',6'-diethyl-N -(methoxymethyl)acetanilide) and its metabolite 2,6-diethylaniline (2,6-DEA) in microbial culture medium has been developed. A reversed-phase C-18 column was utilized to separate alachlor and 2,6-DEA from other species using an acetonitrile/water mixture (1:1) containing 0.1 M phosphate buffer solution at pH 7.0 as the mobile phase. Detection was carried out with a UV detector operated at 210 nm. Parameters that influenced the enrichment efficiency of online HF-LPME sampling, including the length of the hollow fiber, the perfusion solvent and its flow rate, the pH, and the salt added in sample solution, as well as chromatographic conditions were thoroughly optimized. Under optimal conditions, excellent enrichment efficiency was achieved by the microdialysis of a sample solution (pH 7.0) using hexane as perfusate at the flow rate of 4 μL/min. Detection limits were 72 and 14 ng/mL for alachlor and 2,6-DEA, respectively. The enrichment factors were 403 and 386 (RSD < 5%) for alachlor and 2,6-DEA, respectively, when extraction was performed by using a 40 cm regenerated cellulose hollow fiber and hexane as perfusion solvent at the flow rate of 0.1 μL/min. The proposed method provides a sensitive, flexible, fast, and eco-friendly procedure to enrich and determine alachlor and its metabolite (2,6-DEA) in microbial culture medium. PMID:21707080

  8. Optimal design of scalable photo-bioreactor for phototropic culturing of Haematococcus pluvialis.

    PubMed

    Yoo, Jae Jun; Choi, Seung Phill; Kim, Byung Woo; Sim, Sang Jun

    2012-01-01

    The unicellular green microalgae, Haematococcus pluvialis, has been examined as a microbial source for the production of astaxanthin, which has been suggested as a food supplement for humans and is also prescribed as an ingredient in eye drops because of its powerful anti-oxidant properties. In this study, we estimated the effects of the slope of a V-shaped bottom design, the volumetric flow rate of air, height/diameter (H/D) ratio, and diameter of an air sparger on the performance of a photo-bioreactor. These parameters were selected because they are recognized as important factors effecting the mixing that produces increased cell density in the reactor. The mixing effect can be measured by changes in optical density in the bioreactor over a period of time. A 6 L indoor photo-bioreactor was prepared in a short time period of 24 h for the performance study. A bioreactor designed with a V-shaped bottom with a slope of 60° showed an optical density change of 0.052 at 680 nm, which was sixfold less than the change in a photo-bioreactor designed with a flat bottom. Studies exploring the effects of bioreactor configuration and a porous metal sparger with a 10 μm pore size showed the best performance at an H/D ratio of 6:1 and a sparger diameter of 1.3 cm, respectively. The optimal rate of air flow was 0.2 vvm. The indoor culture of microalgae in the photo-bioreactor was subsequently carried for an application study using the optimal values established for the important factors. The indoor culture system was composed of a light source controlled according to cell phase, a carbon dioxide feeder, a bag-type reactor with an H/D ratio of 6:1, and a temperature controller. Results demonstrated the efficient production of microalgal cells and astaxanthin in the amounts of 2.62 g/L and 78.37 mg/L, respectively, when using adequate hydrodynamic mixing. Furthermore, the optimal design of a photo-bioreactor can be applied for the phototropic culturing of other microalgae for

  9. Monitoring the oleuropein content of olive leaves and fruits using ultrasound- and salt-assisted liquid-liquid extraction optimized by response surface methodology and high-performance liquid chromatography.

    PubMed

    Ismaili, Ahmad; Heydari, Rouhollah; Rezaeepour, Reza

    2016-01-01

    A novel and rapid ultrasound- and salt-assisted liquid-liquid extraction coupled with high-performance liquid chromatography has been optimized by response surface methodology for the determination of oleuropein from olive leaves. Box-Behnken design was used for optimizing the main parameters including ultrasound time (A), pH (B), salt concentration (C), and volume of miscible organic solvent (D). In this technique, a mixture of plant sample and extraction solvent was subjected to ultrasound waves. After ultrasound-assisted extraction, phase separation was performed by the addition of salt to the liquid phase. The optimal conditions for the highest extraction yield of oleuropein were ultrasound time, 30 min; volume of organic solvent, 2.5 mL; salt concentration, 25% w/v; and sample pH, 4. Experimental data were fitted with a quadratic model. Analysis of variance results show that BC interaction, A(2) , B(2) , C(2) , and D(2) are significant model terms. Unlike the conventional extraction methods for plant extracts, no evaporation and reconstitution operations were needed in the proposed technique.

  10. Optimization of liquid media and biosafety assessment for algae-lysing bacterium NP23.

    PubMed

    Liao, Chunli; Liu, Xiaobo; Shan, Linna

    2014-09-01

    To control algal bloom caused by nutrient pollution, a wild-type algae-lysing bacterium was isolated from the Baiguishan reservoir in Henan province of China and identified as Enterobacter sp. strain NP23. Algal culture medium was optimized by applying a Placket-Burman design to obtain a high cell concentration of NP23. Three minerals (i.e., 0.6% KNO3, 0.001% MnSO4·H2O, and 0.3% K2HPO4) were found to be independent factors critical for obtaining the highest cell concentration of 10(13) CFU/mL, which was 10(4) times that of the control. In the algae-lysing experiment, the strain exhibited a high lysis rate for the 4 algae test species, namely, Chlorella vulgari, Scenedesmus, Microcystis wesenbergii, and Chlorella pyrenoidosa. Acute toxicity and mutagenicity tests showed that the bacterium NP23 had no toxic and mutagenic effects on fish, even in large doses such as 10(7) or 10(9) CFU/mL. Thus, Enterobacter sp. strain NP23 has strong potential application in the microbial algae-lysing project. PMID:25188453

  11. Optimization of an air–liquid interface exposure system for assessing toxicity of airborne nanoparticles

    PubMed Central

    Latvala, Siiri; Hedberg, Jonas; Möller, Lennart; Odnevall Wallinder, Inger; Karlsson, Hanna L.

    2016-01-01

    Abstract The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs) to human health. To mimic pulmonary exposure, we have developed an air–liquid interface (ALI) exposure system for direct deposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic exposure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate how the deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolic activity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flow rate and electrostatic field strength. The highest amount of deposited particles (2.2 μg cm–2) at cell‐free conditions following 2 h exposure was observed for the highest flow rate (390 ml min–1) and the strongest electrostatic field (±2 kV). This was estimated corresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system. Cells exposed to AgNPs (0.45 and 0.74 μg cm–2) showed significantly (P < 0.05) reduced metabolic activities (64 and 46%, respectively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitro exposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd. PMID:26935862

  12. Optimization of the in-needle extraction device for the direct flow of the liquid sample through the sorbent layer.

    PubMed

    Pietrzyńska, Monika; Voelkel, Adam

    2014-11-01

    In-needle extraction was applied for preparation of aqueous samples. This technique was used for direct isolation of analytes from liquid samples which was achieved by forcing the flow of the sample through the sorbent layer: silica or polymer (styrene/divinylbenzene). Specially designed needle was packed with three different sorbents on which the analytes (phenol, p-benzoquinone, 4-chlorophenol, thymol and caffeine) were retained. Acceptable sampling conditions for direct analysis of liquid sample were selected. Experimental data collected from the series of liquid samples analysis made with use of in-needle device showed that the effectiveness of the system depends on various parameters such as breakthrough volume and the sorption capacity, effect of sampling flow rate, solvent effect on elution step, required volume of solvent for elution step. The optimal sampling flow rate was in range of 0.5-2 mL/min, the minimum volume of solvent was at 400 µL level. PMID:25127610

  13. Development and Optimization of a Flocculation Procedure for Improved Solid-Liquid Separation of Digested Biomass

    SciTech Connect

    Patton, Caroline; Lischeske, James J.; Sievers, David A.

    2015-11-03

    One viable treatment method for conversion of lignocellulosic biomass to biofuels begins with saccharification (thermochemical pretreatment and enzymatic hydrolysis), followed by fermentation or catalytic upgrading to fuels such as ethanol, butanol, or other hydrocarbons. The post-hydrolysis slurry is typically 4-8 percent insoluble solids, predominantly consisting of lignin. Suspended solids are known to inhibit fermentation as well as poison catalysts and obstruct flow in catalyst beds. Thus a solid-liquid separation following enzymatic hydrolysis would be highly favorable for process economics, however the material is not easily separated by filtration or gravimetric methods. Use of a polyacrylamide flocculant to bind the suspended particles in a corn stover hydrolyzate slurry into larger flocs (1-2mm diameter) has been found to be extremely helpful in improving separation. Recent and ongoing research on novel pretreatment methods yields hydrolyzate material with diverse characteristics. Therefore, we need a thorough understanding of rapid and successful flocculation design in order to quickly achieve process design goals. In this study potential indicators of flocculation performance were investigated in order to develop a rapid analysis method for flocculation procedure in the context of a novel hydrolyzate material. Flocculation conditions were optimized on flocculant type and loading, pH, and mixing time. Filtration flux of the hydrolyzate slurry was improved 170-fold using a cationic polyacrylamide flocculant with a dosing of approximately 22 mg flocculant/g insoluble solids at an approximate pH of 3. With cake washing, sugar recovery exceeded 90 percent with asymptotic yield at 15 L wash water/kg insoluble solids.

  14. Determination of optimal ionic liquid for organic single-crystal field-effect transistors

    NASA Astrophysics Data System (ADS)

    Ono, S.; Miwa, K.; Seki, S.

    2016-02-01

    We investigate organic single-crystal field-effect transistors with various ionic liquids as gate dielectric. We find that the mobility of the field-effect transistors for both p-type and n-type organic semiconductors increases with decreasing total capacitance of the ionic liquid. However, it does not depend on the ion species at the interface between the organic semiconductor and the ionic liquid. By choosing an appropriate ionic liquid, a high carrier mobility of 12.4 cm2/V s in rubrene single crystals (p-type) and 0.13 cm2/V s in 7.7.8.8-Tetracyanoquinodimethane single crystals (n-type) are achieved. This study clarifies the influence of ionic liquids on the device performance of organic field-effect transistors and shows a way to maximize carrier mobility at the solid/liquid interface.

  15. Increased diazinon hydrolysis to 2-isopropyl-6-methyl-4-pyrimidinol in liquid medium by a specific Streptomyces mixed culture.

    PubMed

    Briceño, G; Schalchli, H; Rubilar, O; Tortella, G R; Mutis, A; Benimeli, C S; Palma, G; Diez, M C

    2016-08-01

    Actinobacteria identified as Streptomyces spp. were evaluated for their ability to remove diazinon as the only carbon source from a liquid medium. Single cultures of Streptomyces strains were exposed to diazinon at a concentration of 50 mg L(-1). After 96 h incubation, six of the eight cultures grew and five strains showed an increase in their total protein concentrations and changes in their protein profile. Up to 32% of the diazinon was removed by the single Streptomyces cultures. A compatibility assay showed that the different Streptomyces species were not antagonistic. Twenty-six mixed cultures were then prepared. Diazinon removal was increased when mixed cultures were used, and maximum diazinon removal of 62% was observed when the Streptomyces spp. strains AC5, AC9, GA11 and ISP13 were mixed; this was defined as the selected mixed culture (SMC). Diazinon removal was positively influenced by the addition of glucose into the liquid medium. Our study showed a diazinon degradation rate of 0.025 h(-1), half-life of 28 h(-1) and 2-isopropyl-6-methyl-4-pyrimidinol (IMHP) production of 0.143 mg L h(-1). Rapid diazinon hydrolysis to IMHP was associated with a decrease in the pH of the medium as a consequence of microbial glucose metabolism and organic acid exudation. Moreover, the SMC of Streptomyces was able to remove IMHP. This work constitutes a new, if not the only, report on diazinon degradation by mixed cultures of Streptomyces spp. Given the high levels of diazinon removal, the SMC formed by four Streptomyces strains has the potential to be used to treat the diazinon present in environmental matrices. PMID:27176942

  16. Increased diazinon hydrolysis to 2-isopropyl-6-methyl-4-pyrimidinol in liquid medium by a specific Streptomyces mixed culture.

    PubMed

    Briceño, G; Schalchli, H; Rubilar, O; Tortella, G R; Mutis, A; Benimeli, C S; Palma, G; Diez, M C

    2016-08-01

    Actinobacteria identified as Streptomyces spp. were evaluated for their ability to remove diazinon as the only carbon source from a liquid medium. Single cultures of Streptomyces strains were exposed to diazinon at a concentration of 50 mg L(-1). After 96 h incubation, six of the eight cultures grew and five strains showed an increase in their total protein concentrations and changes in their protein profile. Up to 32% of the diazinon was removed by the single Streptomyces cultures. A compatibility assay showed that the different Streptomyces species were not antagonistic. Twenty-six mixed cultures were then prepared. Diazinon removal was increased when mixed cultures were used, and maximum diazinon removal of 62% was observed when the Streptomyces spp. strains AC5, AC9, GA11 and ISP13 were mixed; this was defined as the selected mixed culture (SMC). Diazinon removal was positively influenced by the addition of glucose into the liquid medium. Our study showed a diazinon degradation rate of 0.025 h(-1), half-life of 28 h(-1) and 2-isopropyl-6-methyl-4-pyrimidinol (IMHP) production of 0.143 mg L h(-1). Rapid diazinon hydrolysis to IMHP was associated with a decrease in the pH of the medium as a consequence of microbial glucose metabolism and organic acid exudation. Moreover, the SMC of Streptomyces was able to remove IMHP. This work constitutes a new, if not the only, report on diazinon degradation by mixed cultures of Streptomyces spp. Given the high levels of diazinon removal, the SMC formed by four Streptomyces strains has the potential to be used to treat the diazinon present in environmental matrices.

  17. Production of microsclerotia by Brazilian strains of Metarhizium spp. using submerged liquid culture fermentation.

    PubMed

    Mascarin, Gabriel Moura; Kobori, Nilce Naomi; de Jesus Vital, Rayan Carlos; Jackson, Mark Alan; Quintela, Eliane Dias

    2014-05-01

    We investigated the potential production and desiccation tolerance of microsclerotia (MS) by Brazilian strains of Metarhizium anisopliae (Ma), M. acridum (Mc) and M. robertsii (Mr). These fungi were grown in a liquid medium containing 16 g carbon l⁻¹ with a carbon:nitrogen ratio of 50:1. One hundred milliliters cultures were grown in 250 ml Erlenmeyer flasks in a rotary incubator shaker at 28 °C and 200 rpm for 5 days. Five-day-old MS were harvested, mixed with diatomaceous earth (DE) and air-dried for 2 days at 30 °C. The air-dried MS-DE granular preparations were milled by mortar + pestle and stored in centrifuged tubes at either 26 or -20 °C. Desiccation tolerance and conidia production were assessed for dried MS granules by measuring hyphal germination after incubation for 2 days on water agar plates at 26 °C and for conidia production following 7 days incubation. Yields of MS by all strains of Metarhizium were 6.1-7.3 × 10⁶ l⁻¹ after 3 days growth with maximum MS yields (0.7-1.1 × 10⁷ l⁻¹) after 5 days growth. No differences in biomass accumulation were observed after 3 days growth, whereas Ma-CG168 showed the highest biomass accumulation after 5 days growth. Dried MS-DE preparations of all fungal strains were equally tolerant to desiccation (≥93 % germination) and the highest conidia production was obtained by MS granules of Mc-CG423 (4 × 10⁹ conidia g⁻¹). All MS granules showed similar stability after storage at either 26 or -20 °C for 3.5 months.

  18. Dynamic metabolic modeling of a microaerobic yeast co-culture: predicting and optimizing ethanol production from glucose/xylose mixtures

    PubMed Central

    2013-01-01

    Background A key step in any process that converts lignocellulose to biofuels is the efficient fermentation of both hexose and pentose sugars. The co-culture of respiratory-deficient Saccharomyces cerevisiae and wild-type Scheffersomyces stipitis has been identified as a promising system for microaerobic ethanol production because S. cerevisiae only consumes glucose while S. stipitis efficiently converts xylose to ethanol. Results To better predict how these two yeasts behave in batch co-culture and to optimize system performance, a dynamic flux balance model describing co-culture metabolism was developed from genome-scale metabolic reconstructions of the individual organisms. First a dynamic model was developed for each organism by estimating substrate uptake kinetic parameters from batch pure culture data and evaluating model extensibility to different microaerobic growth conditions. The co-culture model was constructed by combining the two individual models assuming a cellular objective of total growth rate maximization. To obtain accurate predictions of batch co-culture data collected at different microaerobic conditions, the S. cerevisiae maximum glucose uptake rate was reduced from its pure culture value to account for more efficient S. stipitis glucose uptake in co-culture. The dynamic co-culture model was used to predict the inoculum concentration and aeration level that maximized batch ethanol productivity. The model predictions were validated with batch co-culture experiments performed at the optimal conditions. Furthermore, the dynamic model was used to predict how engineered improvements to the S. stipitis xylose transport system could improve co-culture ethanol production. Conclusions These results demonstrate the utility of the dynamic co-culture metabolic model for guiding process and metabolic engineering efforts aimed at increasing microaerobic ethanol production from glucose/xylose mixtures. PMID:23548183

  19. Optimizing NTS-polyplex as a tool for gene transfer to cultured dopamine neurons.

    PubMed

    Hernandez-Baltazar, Daniel; Martinez-Fong, Daniel; Trudeau, Louis-Eric

    2012-01-01

    The study of signal transduction in dopamine (DA)-containing neurons as well as the development of new therapeutic approaches for Parkinson's disease requires the selective expression of transgenes in such neurons. Here we describe optimization of the use of the NTS-polyplex, a gene carrier system taking advantage of neurotensin receptor internalization, to transfect mouse DA neurons in primary culture. The plasmids DsRed2 (4.7 kbp) and VGLUT2-Venus (11 kbp) were used to compare the ability of this carrier system to transfect plasmids of different sizes. We examined the impact of age of the neurons (1, 3, 5 and 8 days after seeding), of culture media used during the transfection (Neurobasal with B27 vs. conditioned medium) and of three molar ratios of plasmid DNA to carrier. While the NTS-polyplex successfully transfected both plasmids in a control N1E-115 cell line, only the pDsRed2 plasmid could be transfected in primary cultured DA neurons. We achieved 20% transfection efficiency of pDsRed2 in DA neurons, with 80% cell viability. The transfection was demonstrated pharmacologically to be dependent on activation of neurotensin receptors and to be selective for DA neurons. The presence of conditioned medium for transfection was found to be required to insure cell viability. Highest transfection efficiency was achieved in the most mature neurons. In contrast, transfection with the VGLUT2-Venus plasmid produced cell damage, most likely due to the high molar ratios required, as evidenced by a 15% cell viability of DA neurons at the three molar ratios tested (1:36, 1:39 and 1:42). We conclude that, when used at molar ratios lower than 1:33, the NTS-polyplex can selectively transfect mature cultured DA neurons with only low levels of toxicity. Our results provide evidence that the NTS-polyplex has good potential for targeted gene delivery in cultured DA neurons, an in vitro system of great use for the screening of new therapeutic approaches for Parkinson's disease.

  20. Growth and differentiation of primary and passaged equine bronchial epithelial cells under conventional and air-liquid-interface culture conditions

    PubMed Central

    2011-01-01

    Background Horses develop recurrent airway obstruction (RAO) that resembles human bronchial asthma. Differentiated primary equine bronchial epithelial cells (EBEC) in culture that closely mimic the airway cells in vivo would be useful to investigate the contribution of bronchial epithelium in inflammation of airway diseases. However, because isolation and characterization of EBEC cultures has been limited, we modified and optimized techniques of generating and culturing EBECs from healthy horses to mimic in vivo conditions. Results Large numbers of EBEC were obtained by trypsin digestion and successfully grown for up to 2 passages with or without serum. However, serum or ultroser G proved to be essential for EBEC differentiation on membrane inserts at ALI. A pseudo-stratified muco-ciliary epithelium with basal cells was observed at differentiation. Further, transepithelial resistance (TEER) was more consistent and higher in P1 cultures compared to P0 cultures while ciliation was delayed in P1 cultures. Conclusions This study provides an efficient method for obtaining a high-yield of EBECs and for generating highly differentiated cultures. These EBEC cultures can be used to study the formation of tight junction or to identify epithelial-derived inflammatory factors that contribute to lung diseases such as asthma. PMID:21649893

  1. Establishment and Characterization of an Air-Liquid Canine Corneal Organ Culture Model To Study Acute Herpes Keratitis

    PubMed Central

    Harman, Rebecca M.; Bussche, Leen; Ledbetter, Eric C.

    2014-01-01

    ABSTRACT Despite the clinical importance of herpes simplex virus (HSV)-induced ocular disease, the underlying pathophysiology of the disease remains poorly understood, in part due to the lack of adequate virus–natural-host models in which to study the cellular and viral factors involved in acute corneal infection. We developed an air-liquid canine corneal organ culture model and evaluated its susceptibility to canine herpesvirus type 1 (CHV-1) in order to study ocular herpes in a physiologically relevant natural host model. Canine corneas were maintained in culture at an air-liquid interface for up to 25 days, and no degenerative changes were observed in the corneal epithelium during cultivation using histology for morphometric analyses, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assays, and transmission electron microscopy (TEM). Next, canine corneas were inoculated with CHV-1 for 48 h, and at that time point postinfection, viral plaques could be visualized in the corneal epithelium and viral DNA copies were detected in both the infected corneas and culture supernatants. In addition, we found that canine corneas produced proinflammatory cytokines in response to CHV-1 infection similarly to what has been described for HSV-1. This emphasizes the value of our model as a virus–natural-host model to study ocular herpesvirus infections. IMPORTANCE This study is the first to describe the establishment of an air-liquid canine corneal organ culture model as a useful model to study ocular herpesvirus infections. The advantages of this physiologically relevant model include the fact that (i) it provides a system in which ocular herpes can be studied in a virus–natural-host setting and (ii) it reduces the number of experimental animals needed. In addition, this long-term explant culture model may also facilitate research in other fields where noninfectious and infectious ocular diseases of dogs and humans are being studied. PMID

  2. [Optimization of Chlorella pyrenoidosa-15 photoheterotrophic culture and its use in wastewater treatment].

    PubMed

    Wang, Xiu-jin; Li, Zhao-sheng; Xing, Guan-lan; Li, Zhuo-ning; Yuan, Hong-li; Yang, Jin-shui

    2012-08-01

    To improve the biomass and lipid productivity of the microalgae Chlorella pyrenoidosa-15, the carbon and nitrogen sources were screened to culture it heterotrophically. The best carbon and nitrogen sources were glucose and soy peptone, respectively. The carbon and nitrogen concentrations were optimized with the help of response surface design. The maximum biomass productivity was predicted to be 0.62 g x (L x d)(-1) with glucose and soy peptone concentrations of 17.53 g x L(-1) and 8.67 g x L(-1), respectively. The results of response surface design were validated with biomass productivity of 0.63 g x (L x d)(-1) and lipid content of 19.25%. The lipid productivity reached 121.3 mg x (L x d)(-1). In the research of Chlorella pyrenoidosa-15 cultured in non-autoclaved Beijing urban wastewater, the maximum algae biomass dry weight of 1.00 g x L(-1) was achieved with a lipid content of 24.12%. Results also showed that the treatment using Chlorella pyrenoidosa-15 effectively reduced the COD values and total nitrogen content in the wastewater, with a COD degradation rate of 80.9%, and a 69% decrease in total nitrogen content. PMID:23213898

  3. Optimization of Three Dimensional Culturing of the HepG2 Cell Line in Fibrin Scaffold

    PubMed Central

    Banihashemi, Mehrzad; Mohkam, Milad; Safari, Azam; Nezafat, Navid; Negahdaripour, Manica; Mohammadi, Fatemeh; Kianpour, Sedigheh; Ghasemi, Younes

    2015-01-01

    Background: A potential treatment for healing hepatic tissue is delivering isolated hepatic cells to the site of injury to promote hepatic cells formation. In this technology, providing an appropriate injectable system for delivery of hepatic cells is an important issue. In this regard, fibrin scaffolds were designed with many advantages over other scaffolds like cell delivery vehicles for biodegradation, biocompatibility and hemostasis. Objectives: The aim of this study was to determine suitable cell culture circumstances for HepG2 cell proliferation and differentiation in 3D fibrin scaffolds by evaluating Ca2+ concentrations, cell numbers, various ratios of plasma/RPMI 1640 and thickness of fibrin scaffold. Materials and Methods: In a one-stage experimental design, Box-Behnken design strategy was performed by Minitab 15 software (version 15, Minitab. State College, PA) with three factors at three levels (low, medium and high) and 27 runs for identification of the effects of ratio of plasma/RPMI 1640, Ca2+ concentration and thickness on the formation of fibrin gel scaffold and 3D HepG2 culture. Results: The optimal concentrations for fibrin scaffold fabrication were achieved by adding 0.15 mol CaCl2 (50 µL) and 1 × 105 cells to 1:4 of plasma/RPMI 1640 ratio (500 µL with 2.3 mm thickness per well). Conclusions: Our approach provided easy handle method using inexpensive materials like human plasma instead of purified fibrinogen to fabricate fibrin scaffold. PMID:25861316

  4. Recombinant bromelain production in Escherichia coli: process optimization in shake flask culture by response surface methodology

    PubMed Central

    2012-01-01

    Bromelain, a cysteine protease with various therapeutic and industrial applications, was expressed in Escherichia coli, BL21-AI clone, under different cultivation conditions (post-induction temperature, L-arabinose concentration and post-induction period). The optimized conditions by response surface methodology using face centered central composite design were 0.2% (w/v) L-arabinose, 8 hr and 25°C. The analysis of variance coupled with larger value of R2 (0.989) showed that the quadratic model used for the prediction was highly significant (p < 0.05). Under the optimized conditions, the model produced bromelain activity of 9.2 U/mg while validation experiments gave bromelain activity of 9.6 ± 0.02 U/mg at 0.15% (w/v) L-arabinose, 8 hr and 27°C. This study had innovatively developed cultivation conditions for better production of recombinant bromelain in shake flask culture. PMID:22336426

  5. A low-cost culture medium for the production of Nannochloropsis gaditana biomass optimized for aquaculture.

    PubMed

    Camacho-Rodríguez, J; Cerón-García, M C; González-López, C V; Fernández-Sevilla, J M; Contreras-Gómez, A; Molina-Grima, E

    2013-09-01

    Nannochloropsis gaditana is a microalga with a high nutritional value and a protein and polyunsaturated fatty acid (PUFA) content that makes it interesting as a feed in aquaculture. To maximize its productivity and nutritional value in large-scale culture, a well-known commercial medium was optimized to the most favorable nutrient level using commercial fertilizers. Optimal growth conditions were obtained in the alternative fertilizer-based medium at a nitrogen concentration of 11.3 mM, a phosphorus concentration of 0.16 mM, and a micronutrient concentration of 30 μL L(-1). This alternative medium allowed to obtain a biomass concentration similar to that achieved when using the commercial formula but with a reduction in Cu, Fe, and Mo content of 71%, 89%, and 99%, respectively. A maximum biomass productivity of 0.51 g L(-1) d(-1) was obtained. The eicosapentaenoic acid and protein contents of the biomass were 2.84% and 44% of dry weight, respectively. PMID:23863872

  6. Optimized culture condition for enhancing lytic performance of waste activated sludge by Geobacillus sp. G1.

    PubMed

    Yang, Chunxue; Zhou, Aijuan; Hou, Yanan; Zhang, Xu; Guo, Zechong; Wang, Aijie; Liu, Wenzong

    2014-01-01

    Hydrolysis is known as the rate-limiting step during waste activated sludge (WAS) digestion. The optimization of the culture conditions of Geobacillus sp. G1 for enhancing WAS hydrolysis was conducted in this study with uniform design and response surface methodology. Taking the lysis rate of Escherichia coli as the response, the Plackett-Burman design was used to screen the most important variables. Experimental results showed that the maximum predicted lysis rate of E. coli was 50.9% for 4 h treatment time with concentrations of skim milk, NaCl and NH4SO4 at 10.78, 4.36 and 11.28 g/L, respectively. The optimized dosage ratio of Geobacillus sp. G1 to WAS was 35%:65% (VG1:VWAS). Under this condition, soluble protein was increased to 695 mg chemical oxygen demand (COD)/L, which was 5.0 times higher than that obtained in the control (140 mg COD/L). The corresponding protease activity reached 1.1 Eu/mL. Scanning electron microscopy showed that abundant cells were apparently lysed with treatment of Geobacillus sp. G1.

  7. A low-cost culture medium for the production of Nannochloropsis gaditana biomass optimized for aquaculture.

    PubMed

    Camacho-Rodríguez, J; Cerón-García, M C; González-López, C V; Fernández-Sevilla, J M; Contreras-Gómez, A; Molina-Grima, E

    2013-09-01

    Nannochloropsis gaditana is a microalga with a high nutritional value and a protein and polyunsaturated fatty acid (PUFA) content that makes it interesting as a feed in aquaculture. To maximize its productivity and nutritional value in large-scale culture, a well-known commercial medium was optimized to the most favorable nutrient level using commercial fertilizers. Optimal growth conditions were obtained in the alternative fertilizer-based medium at a nitrogen concentration of 11.3 mM, a phosphorus concentration of 0.16 mM, and a micronutrient concentration of 30 μL L(-1). This alternative medium allowed to obtain a biomass concentration similar to that achieved when using the commercial formula but with a reduction in Cu, Fe, and Mo content of 71%, 89%, and 99%, respectively. A maximum biomass productivity of 0.51 g L(-1) d(-1) was obtained. The eicosapentaenoic acid and protein contents of the biomass were 2.84% and 44% of dry weight, respectively.

  8. Defining an optimal surface chemistry for pluripotent stem cell culture in 2D and 3D

    NASA Astrophysics Data System (ADS)

    Zonca, Michael R., Jr.

    new avenue for stem cell culture and maintenance using an optimal organic-based chemistry.

  9. Safety Evaluation of Dry Powder Formulations by Direct Dispersion onto Air-Liquid Interface Cultured Cell Layer.

    PubMed

    Asai, Ayumu; Okuda, Tomoyuki; Yamauchi, Tomoyo; Sugiura, Yuka; Okamoto, Hirokazu

    2016-01-01

    Most safety evaluations of dry powder inhalers (DPIs) using cultured cells have been performed with dry powder formulations dissolved in a medium. However, this method is not considered to be suitable to evaluate the safety of inhaled dry powder formulations correctly since it cannot reflect the actual phenomenon on the respiratory epithelial surface. In this study, we established a novel in-vitro safety evaluation system suitable for DPIs by combining an air-liquid interface cultured cell layer and a device for dispersing dry powders, and evaluated the safety of candidate excipients of dry powders for inhalation. The safety of excipients (sugars, amino acids, cyclodextrins, and positive controls) in solutions was compared using submerged cell culture systems with a conventional 96-well plate and Transwell(®). The sensitivity of the cells grown in Transwell(®) was lower than that of those grown in the 96-well plate. Dry powders were prepared by spray-drying and we evaluated their safety with a novel in-vitro safety evaluation system using an air-liquid interface cultured cell layer. Dry powders decreased the cell viability with doses more than solutions. On the other hand, dissolving the dry powders attenuated their cytotoxicity. This suggested that the novel in-vitro safety evaluation system would be suitable to evaluate the safety of DPIs with high sensitivity.

  10. Identification of a New Marine Bacterial Strain SD8 and Optimization of Its Culture Conditions for Producing Alkaline Protease.

    PubMed

    Cui, Hongxia; Yang, Muyang; Wang, Liping; Xian, Cory J

    2015-01-01

    While much attention has been given to marine microorganisms for production of enzymes, which in general are relatively more stable and active compared to those from plants and animals, studies on alkaline protease production from marine microorganisms have been very limited. In the present study, the alkaline protease producing marine bacterial strain SD8 isolated from sea muds in the Geziwo Qinhuangdao sea area of China was characterized and its optimal culture conditions were investigated. Strain SD8 was initially classified to belong to genus Pseudomonas by morphological, physiological and biochemical characterizations, and then through 16S rDNA sequence it was identified to be likely Pseudomonas hibiscicola. In addition, the culture mediums, carbon sources and culture conditions of strain SD8 were optimized for maximum production of alkaline protease. Optimum enzyme production (236U/mL when cultured bacteria being at 0.75 mg dry weight/mL fermentation broth) was obtained when the isolate at a 3% inoculum size was grown in LB medium at 20 mL medium/100mL Erlenmeyer flask for 48h culture at 30°C with an initial of pH 7.5. This was the first report of strain Pseudomonas hibiscicola secreting alkaline protease, and the data for its optimal cultural conditions for alkaline protease production has laid a foundation for future exploration for the potential use of SD8 strain for alkaline protease production.

  11. Induction of a photomixotrophic plant cell culture of Helianthus annuus and optimization of culture conditions for improved α-tocopherol production.

    PubMed

    Geipel, Katja; Song, Xue; Socher, Maria Lisa; Kümmritz, Sibylle; Püschel, Joachim; Bley, Thomas; Ludwig-Müller, Jutta; Steingroewer, Juliane

    2014-03-01

    Tocopherols, collectively known as vitamin E, are lipophilic antioxidants, which are synthesized only by photosynthetic organisms. Due to their enormous potential to protect cells from oxidative damage, tocopherols are used, e.g., as nutraceuticals and additives in pharmaceuticals. The most biologically active form of vitamin E is α-tocopherol. Most tocopherols are currently produced via chemical synthesis. Nevertheless, this always results in a racemic mixture of different and less effective stereoisomers because the natural isomer has the highest biological activity. Therefore, tocopherols synthesized in natural sources are preferred for medical purposes. The annual sunflower (Helianthus annuus L.) is a well-known source for α-tocopherol. Within the presented work, sunflower callus and suspension cultures were established growing under photomixotrophic conditions to enhance α-tocopherol yield. The most efficient callus induction was achieved with sunflower stems cultivated on solid Murashige and Skoog medium supplemented with 30 g l(-1) sucrose, 0.5 mg l(-1) of the auxin 1-naphthalene acetic acid, and 0.5 mg l(-1) of the cytokinin 6-benzylaminopurine. Photomixotrophic sunflower suspension cultures were induced by transferring previously established callus into liquid medium. The effects of light intensity, sugar concentration, and culture age on growth rate and α-tocopherol synthesis rate were characterized. A considerable increase (max. 230%) of α-tocopherol production in the cells was obtained within the photomixotrophic cell culture compared to a heterotrophic cell culture. These results will be useful for improving α-tocopherol yields of plant in vitro cultures.

  12. A polysaccharide isolated from the liquid culture of Lentinus edodes (shiitake) mushroom mycelia containing black rice bran protects mice against a Salmonella lipopolysaccharide-induced endotoxemia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endotoxemia (sepsis, septic shock) is an inflammatory, virulent disease that results mainly from bacterial infection. The present study investigates the inhibitory effect of the bio-processed polysaccharide (BPP) isolated from the edible Lentinus edodes liquid mycelial mushroom culture supplemented...

  13. Effects of extracellular matrix proteins on macrophage differentiation, growth, and function: comparison of liquid and agar culture systems

    NASA Technical Reports Server (NTRS)

    Armstrong, J. W.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Both spaceflight and skeletal unloading suppress the haematopoietic differentiation of macrophages (Sonnenfeld et al., Aviat. Space Environ. Med., 61:648-653, 1990; Armstrong et al., J. Appl. Physiol., 75:2734-2739, 1993). The mechanism behind this reduction in haematopoiesis has yet to be elucidated. However, changes in bone marrow extracellular matrix (ECM) may be involved. To further understand the role of ECM products in macrophage differentiation, we have performed experiments evaluating the effects of fibronectin, laminin, collagen type I, and collagen type IV on macrophage development and function. Bone marrow-derived macrophages cultured on four different ECM substrates in liquid culture medium showed less growth than those cultured on plastic. Significant morphological differences were seen on each of the substrates used. Phenotypically and functionally, as measured by class II major histocompatibility molecule (MHCII) expression, MAC-2 expression, and the secretion of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), these macrophages were similar. In contrast, bone marrow-derived macrophages cultured in suspension, using agar, showed no difference in growth when exposed to ECM proteins. However, IL-6 and TNF-alpha secretion was affected by fibronectin, laminin, collagen type I, and collagen type IV in a concentration-dependent manner. We conclude that the ECM products fibronectin, laminin, collagen type I, and collagen type IV have profound effects on macrophage development and function. Additionally, we suggest that an ECM-supplemented agar culture system provides an environment more analogous to in vivo bone marrow than does a traditional liquid culture system.

  14. Ionic Liquids as Electrolytes for Electrochemical Double-Layer Capacitors: Structures that Optimize Specific Energy.

    PubMed

    Mousavi, Maral P S; Wilson, Benjamin E; Kashefolgheta, Sadra; Anderson, Evan L; He, Siyao; Bühlmann, Philippe; Stein, Andreas

    2016-02-10

    Key parameters that influence the specific energy of electrochemical double-layer capacitors (EDLCs) are the double-layer capacitance and the operating potential of the cell. The operating potential of the cell is generally limited by the electrochemical window of the electrolyte solution, that is, the range of applied voltages within which the electrolyte or solvent is not reduced or oxidized. Ionic liquids are of interest as electrolytes for EDLCs because they offer relatively wide potential windows. Here, we provide a systematic study of the influence of the physical properties of ionic liquid electrolytes on the electrochemical stability and electrochemical performance (double-layer capacitance, specific energy) of EDLCs that employ a mesoporous carbon model electrode with uniform, highly interconnected mesopores (3DOm carbon). Several ionic liquids with structurally diverse anions (tetrafluoroborate, trifluoromethanesulfonate, trifluoromethanesulfonimide) and cations (imidazolium, ammonium, pyridinium, piperidinium, and pyrrolidinium) were investigated. We show that the cation size has a significant effect on the electrolyte viscosity and conductivity, as well as the capacitance of EDLCs. Imidazolium- and pyridinium-based ionic liquids provide the highest cell capacitance, and ammonium-based ionic liquids offer potential windows much larger than imidazolium and pyridinium ionic liquids. Increasing the chain length of the alkyl substituents in 1-alkyl-3-methylimidazolium trifluoromethanesulfonimide does not widen the potential window of the ionic liquid. We identified the ionic liquids that maximize the specific energies of EDLCs through the combined effects of their potential windows and the double-layer capacitance. The highest specific energies are obtained with ionic liquid electrolytes that possess moderate electrochemical stability, small ionic volumes, low viscosity, and hence high conductivity, the best performing ionic liquid tested being 1-ethyl-3

  15. Business-objective-directed, constraint-based multivariate optimization of high-performance liquid chromatography operational parameters.

    PubMed

    Chester, T L

    2003-10-24

    The goal of a separation can be defined in terms of business needs. One goal often used is to provide the required separation in minimum time, but many other goals are also possible. These include maximizing resolution within an analysis-time limit, or minimizing the overall cost. The remaining requirements of the separation can be applied as constraints in the optimization of the goal. We will present a flexible, business-objective-based approach for optimizing the operational parameters of high performance liquid chromatography (HPLC) methods. After selecting the stationary phase and the mobile-phase components, several isocratic experiments are required to build a retention model. Multivariate optimization is performed, within the model, to find the best combination of the parameters being varied so that the result satisfies the goal to the fullest extent possible within the constraints. Interdependencies of parameters can be revealed by plotting the loci of optimal variable values or the function being optimized against a constraint. We demonstrate the concepts with a model separation originally requiring a 54 min analysis time. Multivariate optimization reduces the predicted analysis time to as short as 8 min, depending on the goals and constraints specified. PMID:14601838

  16. Ultrastructural and Immunocytochemical Studies on the H2O2-Producing Enzyme Pyranose Oxidase in Phanerochaete chrysosporium Grown under Liquid Culture Conditions

    PubMed Central

    Daniel, Geoffrey; Volc, Jindrich; Kubatova, Elena; Nilsson, Thomas

    1992-01-01

    The ultrastructural distribution of the sugar-oxidizing enzyme pyranose 2-oxidase (POD) in hyphae of Phanerochaete chrysosporium K-3 grown under liquid culture conditions optimal for the enzyme's production was studied by transmission electron microscopy immunocytochemistry. Using the 3-dimethylaminobenzoic acid-3-methyl-2-benzothiazolinone hydrazone hydrochloride H2O2 peroxidase spectrophotometric assay, POD was detected in mycelial extracts from days 7 to 18, with maximum activity recorded on day 12. Onset of POD activity occurred in the secondary phase of hyphal development at a time of stationary growth, glucose limitation, and pH increase. POD was also detected extracellularly in the culture fluid from days 7 to 18, with maximum activity recorded on day 13. At early stages of development (3 to 4 days), using anti-POD antibodies and immunogold labeling, POD was localized in multivesicular and electron-dense bodies and in cell membrane regions. After 10 to 12 days of growth, at maximum POD activity, POD was concentrated within the periplasmic space where it was associated with membrane-bound vesicles and other membrane structures. At later stages of development (17 to 18 days), when the majority of hyphae were lysed, POD was observed associated with residual intracellular membrane systems and vesicles. Transmission electron microscopy immunocytochemical studies also demonstrated an extracellular distribution of the enzyme at the stationary growth phase, showing its association with fungal extracellular slime. In studies of ligninolytic cultures of the same fungus, POD was found to have a similar intracellular and extracellular distribution in slime as that recorded for cultures grown with cornsteep. POD's peripheral cytoplasmic distribution shows similarities to the cellular distribution of that reported previously for H2O2-dependent lignin and manganese peroxidases in P. chrysosporium. Images PMID:16348809

  17. Nanoemulsion liquid preconcentrates for raloxifene hydrochloride: optimization and in vivo appraisal.

    PubMed

    Elsheikh, Manal A; Elnaggar, Yosra S R; Gohar, Eman Y; Abdallah, Ossama Y

    2012-01-01

    Raloxifene hydrochloride (RLX) is a selective estrogen-receptor modulator for treatment of osteoporosis and prevention of breast and endometrial cancer. By virtue of extensive presystemic clearance, RLX bioavailability is only 2%. The current study aimed to tailor and characterize RLX-loaded self-nanoemulsifying drug-delivery systems (SNEDDS) using bioactive excipients affecting drug metabolism. The potential of oral nanocarriers to enhance RLX delivery to endocrine target organs was assessed in fasted and fed female Wistar rats using high-performance liquid chromatography. RLX was loaded in the dissolved and dispersed status in the alkalinized (A-SNEDDS) and nonalkalinized (NA-SNEDDS) systems, respectively. Optimization and assessment relied on solubility studies, emulsification efficiency, phase diagrams, dilution robustness, cloud point, particle size, zeta potential (ZP), polydispersity index (PDI), and transmission electron microscopy. In vitro release was assessed using dialysis bag versus dissolution cup methods. NA-SNEDDS were developed with suitable globule size (38.49 ± 4.30 nm), ZP (31.70 ± 3.58 mV), PDI (0.31 ± 0.02), and cloud point (85°C). A-SNEDDS exhibited good globule size (35 ± 2.80 nm), adequate PDI (0.28 ± 0.06), and lower ZP magnitude (-21.20 ± 3.46 mV). Transmission electron microscopy revealed spherical globules and contended data of size analysis. Release studies demonstrated a nonsignificant enhancement of RLX release from NA-SNEDDS compared to drug suspension with the lowest release shown by A-SNEDDS. A conflicting result was elucidated from in vivo trial. A significant enhancement in RLX uptake by endocrine organs was observed after nanocarrier administration compared to RLX suspension. In vivo studies reflected a poor in vitro/in vivo correlation, recommended nanocarrier administration before meals, and did not reveal any advantage for drug loading in the solubilized form (A-SNEDDS). To conclude, NA-SNEDDS possessed superior in

  18. Bacillus coagulans tolerance to 1-ethyl-3-methylimidazolium-based ionic liquids in aqueous and solid-state thermophilic culture.

    PubMed

    Simmons, Christopher W; Reddy, Amitha P; Vandergheynst, Jean S; Simmons, Blake A; Singer, Steven W

    2014-01-01

    The use of ionic liquids (ILs) to disrupt the recalcitrant structure of lignocellulose and make polysaccharides accessible to hydrolytic enzymes is an emerging technology for biomass pretreatment in lignocellulosic biofuel production. Despite efforts to reclaim and recycle IL from pretreated biomass, residual IL can be inhibitory to microorganisms used for downstream fermentation. As a result, pathways for IL tolerance are needed to improve the activity of fermentative organisms in the presence of IL. In this study, microbial communities from compost were cultured under high-solids and thermophilic conditions in the presence of 1-ethyl-3-methylimidazolium-based ILs to enrich for IL-tolerant microorganisms. A strain of Bacillus coagulans isolated from an IL-tolerant community was grown in liquid and solid-state culture in the presence of the ILs 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) or 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]) to gauge IL tolerance. Viability and respiration varied with the concentration of IL applied and the type of IL used. B. coagulans maintained growth and respiration in the presence of 4 wt% IL, a concentration similar to that present on IL-pretreated biomass. In the presence of both [C2mim][OAc] and [C2mim][Cl] in liquid culture, B. coagulans grew at a rate approximately half that observed in the absence of IL. However, in solid-state culture, the bacteria were significantly more tolerant to [C2mim][Cl] compared with [C2mim][OAc]. B. coagulans tolerance to IL under industrially relevant conditions makes it a promising bacterium for understanding mechanisms of IL tolerance and discovering IL tolerance pathways for use in other microorganisms, particularly those used in bioconversion of IL-pretreated plant biomass. PMID:24376258

  19. [Optimization of in vitro culture conditions for human amniotic epithelial cells and expression of stem cell markers].

    PubMed

    Chen, You-Yi; Lu, Yan; Wang, Ke; Wang, Yan; Wu, Dong-Ying; Liu, Bin; Yang, Ying; Lü, Shuang-Hong

    2011-04-01

    This study was purposed to optimize the culture conditions of the human amniotic epithelium cells (hAEC) in vitro, and detect the expression of hAEC pluripotent markers. Amnion tissues were separated from the underlying chorion through the spongy layer immediately after elective cesarean section of healthy pregnancy women at term. After the subsequent exposure to trypsin digestion, hAEC were cultured in DMEM with different supplements. The growth and proliferation potential of hAEC was evaluated, and the expression of cultured hAEC pluripotent markers was detected by using flow cytometry and immunohistochemistry methods. The results indicated that when being cultured in the mediums similar to that of embryonic stem cell culture supplemented with 10 ng/ml EGF, the hAEC grew better and the time for passage was shortened. In addition, compared to other culture conditions, under this condition, the cells could be passaged up to 5 times as much without obvious morphological changes, and the pluripotent marker SSEA-4 was detected in the cultured cells by flow cytometry. Meanwhile, the detection of immunofluorescence showed the expression of vimentin in cultured hAEC was strengthened as compared with primary cells. It is concluded that the culture condition similar to that for embryonic stem cells supplemented with EGF facilitates the proliferation and passage of hAEC in vitro.

  20. Optimization of culture conditions for an efficient xeno-feeder free limbal cell culture system towards ocular surface regeneration.

    PubMed

    Varghese, Viji Mary; Prasad, Tilak; Kumary, T V

    2010-10-01

    Ex vivo expansion of limbal stem cells from a small biopsy and its subsequent transplantation is the golden choice of treatment for limbal stem cell deficiency. Use of murine 3T3 feeder layer is a prerequisite for this ex vivo expansion. There is an ever-increasing demand for feeder free cultures to avoid xenotoxicity and transmission of xeno-diseases to human system. This study was aimed to establish an efficient xeno-feeder free limbal culture system towards ocular surface regeneration. To study the effect of initial dispase treatment and culture system used, migratory distance of cells from explants was analyzed from phase contrast images using "interactive measurements" of Qwin software (Leica). Expression of p63 in different culture systems was studied by immunofluorescent staining, followed by quantitative confocal microscopy (Carl Zeiss). Results showed dispase treatment was not necessary for establishing limbal explant culture. A combination of Iscove's modified Dulbecco's medium and Panserin 801 resulted in formation of autofeeder layer with maintenance of progenitor characteristics, thus mimicking natural tissue architecture. Further analysis of this culture system showed that cells could be cultured till confluency. Immunofluorescent staining of ABCG2 revealed presence of stem cell marker in the confluent cell layer. Scanning Electron Micrographs demonstrated homogenous population of tightly packed cells in this culture system. Replacement of bovine serum with autologous serum did not affect morphology or growth of cells in this culture system. This study will be a major step in the development of xeno-feeder free epithelial equivalents towards ocular surface reconstruction. PMID:20196106

  1. Overproduction of a potential red pigment by a specific self-immobilization biomembrane-surface liquid culture of Penicillium novae-zeelandiae.

    PubMed

    Hailei, Wang; Ping, Li; Yufeng, Liu; Zhifang, Ren; Gang, Wang

    2012-10-01

    A specific self-immobilization biomembrane-surface liquid culture (SIBSLC) was developed to overproduce a potential penicillium red pigment. Statistic analysis shows that both glucose concentration and membrane diameter are important factors influencing the yield of red pigment. After the optimization using central composite experimental design, the maximum yield of red pigment in shake flask reaches 4.25 g/l. The growth of strain HSD07B consists of three phases, and the pigment secreted in the decelerated phase, is originated from the interior of biomembrane where glucose exhaustion occurs. In addition, the batch and continuous SIBSLC were conducted for production of the pigment, and the latter was more competitive in consideration of the fact that it not only increased 61.5 % of pigment productivity, but also simplified the production process. Moreover, the pigment produced by SIBSLC is potentially acceptable for food applications although it is distinguished from the co-cultured red pigment we reported previously in components. PMID:22476766

  2. Screening and characterization of Isochrysis strains and optimization of culture conditions for docosahexaenoic acid production.

    PubMed

    Liu, Jin; Sommerfeld, Milton; Hu, Qiang

    2013-06-01

    Isochrysis is a genus of marine unicellular microalgae that produces docosahexaenoic acid (DHA, C22:6), a very long chain polyunsaturated fatty acid (PUFA) of significant health and nutritional value. Mass cultivation of Isochrysis for DHA production for human consumption has not been established due to disappointing low DHA productivity obtained from commonly used Isochrysis strains. In this study, 19 natural Isochrysis strains were screened for DHA yields and the results showed that the cellular DHA content ranged from 6.8 to 17.0 % of total fatty acids with the highest DHA content occurring in the exponential growth phase. Isochrysis galbana #153180 exhibited the greatest DHA production potential and was selected for further investigation. The effects of different light intensities, forms, and concentrations of nitrogen, phosphorus, and salinity on growth and DHA production of I. galbana #153180 were studied in a bubble column photobioreactor (PBR). Under favorable culture conditions, I. galbana #153180 contained DHA up to 17.5 % of total fatty acids or 1.7 % of cell dry weight. I. galbana #153180 was further tested in outdoor flat-plate PBRs varying in light path length, starting cell density (SCD), and culture mode (batch versus semicontinuous). When optimized, record high biomass and DHA productivity of I. galbana #153180 of 0.72 g L(-1) day(-1) and 13.6 mg L(-1) day(-1), or 26.4 g m(-2) day(-1) and 547.7 mg m(-2) day(-1), respectively, were obtained, suggesting that I. galbana #153180 may be a desirable strain for commercial production of DHA.

  3. Optimization of culture conditions of Arnica montana L.: effects of mycorrhizal fungi and competing plants.

    PubMed

    Jurkiewicz, Anna; Ryszka, Przemyslaw; Anielska, Teresa; Waligórski, Piotr; Białońska, Dobroslawa; Góralska, Katarzyna; Tsimilli-Michael, Merope; Turnau, Katarzyna

    2010-06-01

    Arnica montana is a rare plant that needs special protection because of its intensive harvesting for medicinal purposes. The present work was aimed at finding optimal culture conditions for Arnica plants in order to enable their successful reintroduction into their natural stands. Plants were cultivated under controlled greenhouse conditions on substrata with different nitrogen (N) concentration. As Arnica is always colonized by arbuscular mycorrhizal fungi (AMF) in nature, a fact that has been overlooked in other similar projects, we, here, applied and tested different inocula. We found that they differed in their effectiveness, both in establishing symbiosis, assessed by the colonization parameters, and in improving the performance of Arnica, evaluated by the photosynthetic parameters derived from the fluorescence transients (JIP-test), with the inocula containing G. intraradices or composed of several Glomus strains being the most effective. The comparison was possible only on substrata with medium N, since high N did not permit the formation of mycorrhiza, while at low N, few nonmycorrhizal plants survived until the measurements and mycorrhizal plants, which were well growing, exhibited a high heterogeneity. Analysis of secondary metabolites showed clearly that mycorrhization was associated with increased concentrations of phenolic acids in roots. For some of the inocula used, a tendency for increase of the level of phenolic acids in shoots and of sesquiterpene lactones, both in roots and in shoots, was also observed. We also studied the interactions between A. montana and Dactylis glomerata, known to compete with Arnica under field conditions. When specimens from both species were cultured together, there was no effect on D. glomerata, but Arnica could retain a photosynthetic performance that permitted survivability only in the presence of AMF; without AMF, the photosynthetic performance was lower, and the plants were eventually totally outcompeted.

  4. Novel technique for scaling up of micropropagated Ruta graveolens shoots using liquid culture systems: a step towards commercialization.

    PubMed

    Diwan, Renuka; Malpathak, Nutan

    2008-06-01

    Wide applications of Ruta graveolens L. in pharmaceutical industry has led to increased interest in large-scale plant production, with emphasis on use of in vitro cultures. Earlier reports describe use of in vitro germinated seedlings for raising shoot cultures and not regeneration. There is only a single regeneration protocol of R. graveolens; however, it employs conventional labour intensive techniques deterring automation. The aim of present investigation was to establish a cost effective protocol for large-scale plant production. We report for the first time a one-step protocol with improved regeneration efficiency for multiple shoots induction employing liquid culture systems. Effect of polyamines (putrescine and spermine) on growth and furanocoumarin was studied. Addition of spermine enhanced the number of multiple shoots formed (2.5-fold) and reduced the time taken by half. Spermine addition resulted in 1.47-fold in furanocoumarin production. The selected shoot line, RS2 was successfully scaled up to 5L in culture vessels, with 1.53-fold increase in biomass without affecting the productivity of these cultures. This proves to be a commercially feasible alternative to bioreactors for large-scale biomass and furanocoumarin production.

  5. Optimizing Immobilized Enzyme Performance in Cell-Free Environments to Produce Liquid Fuels

    SciTech Connect

    Belfort, Georges; Grimaldi, Joseph J.

    2015-01-27

    Limitations on biofuel production using cell culture (Escherichia coli, Clostridium, Saccharomyces cerevisiae, brown microalgae, blue-green algae and others) include low product (alcohol) concentrations (≤0.2 vol%) due to feedback inhibition, instability of cells, and lack of economical product recovery processes. To overcome these challenges, an alternate simplified biofuel production scheme was tested based on a cell-free immobilized enzyme system. Using this cell free system, we were able to obtain about 2.6 times higher concentrations of iso-butanol using our non-optimized system as compared with live cell systems. This process involved two steps: (i) converts acid to aldehyde using keto-acid decarboxylase (KdcA), and (ii) produces alcohol from aldehyde using alcohol dehydrogenase (ADH) with a cofactor (NADH) conversion from inexpensive formate using a third enzyme, formate dehydrogenase (FDH). To increase stability and conversion efficiency with easy separations, the first two enzymes were immobilized onto methacrylate resin. Fusion proteins of labile KdcA (fKdcA) were expressed to stabilize the covalently immobilized KdcA. Covalently immobilized ADH exhibited long-term stability and efficient conversion of aldehyde to alcohol over multiple batch cycles without fusions. High conversion rates and low protein leaching were achieved by covalent immobilization of enzymes on methacrylate resin. The complete reaction scheme was demonstrated by immobilizing both ADH and fKdcA and using FDH free in solution. The new system without in situ removal of isobutanol achieved a 55% conversion of ketoisovaleric acid to isobutanol at a concentration of 0.5 % (v/v). Further increases in titer will require continuous removal of the isobutanol using our novel brush membrane system that exhibits a 1.5 fold increase in the separation factor of isobutanol from water versus that obtained for commercial silicone rubber membranes. These bio-inspired brush membranes are based on the

  6. Long-term xeno-free culture of human pluripotent stem cells on hydrogels with optimal elasticity

    PubMed Central

    Higuchi, Akon; Kao, Shih-Hsuan; Ling, Qing-Dong; Chen, Yen-Ming; Li, Hsing-Fen; Alarfaj, Abdullah A.; Munusamy, Murugan A.; Murugan, Kadarkarai; Chang, Shih-Chang; Lee, Hsin-Chung; Hsu, Shih-Tien; Kumar, S. Suresh; Umezawa, Akihiro

    2015-01-01

    The tentative clinical application of human pluripotent stem cells (hPSCs), such as human embryonic stem cells and human induced pluripotent stem cells, is restricted by the possibility of xenogenic contamination resulting from the use of mouse embryonic fibroblasts (MEFs) as a feeder layer. Therefore, we investigated hPSC cultures on biomaterials with different elasticities that were grafted with different nanosegments. We prepared dishes coated with polyvinylalcohol-co-itaconic acid hydrogels grafted with an oligopeptide derived from vitronectin (KGGPQVTRGDVFTMP) with elasticities ranging from 10.3 to 30.4 kPa storage moduli by controlling the crosslinking time. The hPSCs cultured on the stiffest substrates (30.4 kPa) tended to differentiate after five days of culture, whereas the hPSCs cultured on the optimal elastic substrates (25 kPa) maintained their pluripotency for over 20 passages under xeno-free conditions. These results indicate that cell culture matrices with optimal elasticity can maintain the pluripotency of hPSCs in culture. PMID:26656754

  7. Aspergillus oryzae S2 alpha-amylase production under solid state fermentation: optimization of culture conditions.

    PubMed

    Sahnoun, Mouna; Kriaa, Mouna; Elgharbi, Fatma; Ayadi, Dorra-Zouari; Bejar, Samir; Kammoun, Radhouane

    2015-04-01

    Aspergillus oryzae S2 was assayed for alpha-amylase production under solid state fermentation (SSF). In addition to AmyA and AmyB already produced in monitored submerged culture, the strain was noted to produce new AmyB oligomeric forms, in particular a dominant tetrameric form named AmyC. The latter was purified to homogeneity through fractional acetone precipitation and size exclusion chromatography. SDS-PAGE and native PAGE analyses revealed that, purified AmyC was an approximately 172 kDa tetramer of four 42 kDa subunits. AmyC was also noted to display the same NH2-terminal amino acid sequence residues and approximately the same physico-chemical properties of AmyA and AmyB, to exhibit maximum activity at pH 5.6 and 60 °C, and to produce maltose and maltotriose as major starch hydrolysis end-products. Soyabean meal was the best substitute to yeast extract compared to fish powder waste and wheat gluten waste. AmyC production was optimized under SSF using statistical design methodology. Moisture content of 76.25%, C/N substrate ratio of 0.62, and inoculum size of 10(6.87) spores allowed maximum activity of 22118.34 U/g of dried substrate, which was 33 times higher than the one obtained before the application of the central composite design (CCD). PMID:25617840

  8. Improved Candida methylica formate dehydrogenase fermentation through statistical optimization of low-cost culture media.

    PubMed

    Kahraman, Mustafa; Ordu, Emel Bıçakçı; Yeşiladalı, Koray; Karagüler, Nevin Gül; Tamerler, Candan

    2012-01-01

    NAD⁺-dependent formate dehydrogenase (FDH, EC 1.2.1.2) is of use in the regeneration of NAD(P)H coenzymes, and therefore has strong potential for practical application in chemical and medical industries. A low-cost production of recombinant Escherichia coli (E. coli) containing FDH from Candida methylica (cmFDH) was optimized in molasses-based medium by using response surface methodology (RSM) based on central composite design (CCD). The beet molasses as a sole carbon source, (NH₄)₂HPO₄ as a nitrogen and phosphorus source, KH₂PO₄ as a buffer agent, and Mg₂SO₄ · 7H₂O as a magnesium and sulfur source were used as variables in the medium. The optimum medium composition was found to be 34.694 g L⁻¹ of reducing sugar (equivalent to molasses solution), 8.536 g L⁻¹ of (NH₄)₂HPO₄, 3.073 g L⁻¹ of KH₂PO₄, and 1.707 g L⁻¹ of Mg₂SO₄ · 7H₂O. Molasses-based culture medium increased the yield of cmFDH about three times compared to LB medium. The currently developed media has the potential to be used in industrial bioprocesses with low-cost production.

  9. Optimization strategies accounting for the additive in preparative chiral liquid chromatography.

    PubMed

    Forssén, Patrik; Edström, Lena; Lämmerhofer, Michael; Samuelsson, Jörgen; Karlsson, Anders; Lindner, Wolfgang; Fornstedt, Torgny

    2012-12-21

    This study is an in-depth investigation on how numerical optimization strategies that also account for the additive type and concentration, in preparative batch chromatography, should be performed. As a model system, the separation of Z-(R,S)-2-aminobutyric acid enantiomers on a quinidine carbamate-based chiral stationary phase in polar organic mode was used, with different additive strengths of acetic acid or hexanoic acid in methanol. The inverse method was used to determine the competitive adsorption isotherm parameters for the enantiomers and the additives. Three different optimization strategies were examined: (1) injection volume optimization, (2) optimization of injection volume and additive concentration, and (3) full optimization including injection volume, additive concentration, sample concentration and flow rate. It was concluded that (i) it is important to incorporate the additive concentration in the optimization procedure to achieve the highest production rates, (ii) the full optimization strategy had the overall best results, and (iii) the selection of additive is very important (here acetic acid additive was superior to the hexanoic acid additive). By including the additive in the adsorption model and in the numerical optimization it is not only possible to achieve higher production rates but also to properly select the additive that is most advantageous for the specific separation problem.

  10. Automated Gravimetric Calibration to Optimize the Accuracy and Precision of TECAN Freedom EVO Liquid Handler.

    PubMed

    Bessemans, Laurent; Jully, Vanessa; de Raikem, Caroline; Albanese, Mathieu; Moniotte, Nicolas; Silversmet, Pascal; Lemoine, Dominique

    2016-10-01

    High-throughput screening technologies are increasingly integrated into the formulation development process of biopharmaceuticals. The performance of liquid handling systems is dependent on the ability to deliver accurate and precise volumes of specific reagents to ensure process quality. We have developed an automated gravimetric calibration procedure to adjust the accuracy and evaluate the precision of the TECAN Freedom EVO liquid handling system. Volumes from 3 to 900 µL using calibrated syringes and fixed tips were evaluated with various solutions, including aluminum hydroxide and phosphate adjuvants, β-casein, sucrose, sodium chloride, and phosphate-buffered saline. The methodology to set up liquid class pipetting parameters for each solution was to split the process in three steps: (1) screening of predefined liquid class, including different pipetting parameters; (2) adjustment of accuracy parameters based on a calibration curve; and (3) confirmation of the adjustment. The run of appropriate pipetting scripts, data acquisition, and reports until the creation of a new liquid class in EVOware was fully automated. The calibration and confirmation of the robotic system was simple, efficient, and precise and could accelerate data acquisition for a wide range of biopharmaceutical applications. PMID:26905719

  11. Automated Gravimetric Calibration to Optimize the Accuracy and Precision of TECAN Freedom EVO Liquid Handler

    PubMed Central

    Bessemans, Laurent; Jully, Vanessa; de Raikem, Caroline; Albanese, Mathieu; Moniotte, Nicolas; Silversmet, Pascal; Lemoine, Dominique

    2016-01-01

    High-throughput screening technologies are increasingly integrated into the formulation development process of biopharmaceuticals. The performance of liquid handling systems is dependent on the ability to deliver accurate and precise volumes of specific reagents to ensure process quality. We have developed an automated gravimetric calibration procedure to adjust the accuracy and evaluate the precision of the TECAN Freedom EVO liquid handling system. Volumes from 3 to 900 µL using calibrated syringes and fixed tips were evaluated with various solutions, including aluminum hydroxide and phosphate adjuvants, β-casein, sucrose, sodium chloride, and phosphate-buffered saline. The methodology to set up liquid class pipetting parameters for each solution was to split the process in three steps: (1) screening of predefined liquid class, including different pipetting parameters; (2) adjustment of accuracy parameters based on a calibration curve; and (3) confirmation of the adjustment. The run of appropriate pipetting scripts, data acquisition, and reports until the creation of a new liquid class in EVOware was fully automated. The calibration and confirmation of the robotic system was simple, efficient, and precise and could accelerate data acquisition for a wide range of biopharmaceutical applications. PMID:26905719

  12. Application and optimization of microwave-assisted extraction and dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for sensitive determination of polyamines in turkey breast meat samples.

    PubMed

    Bashiry, Moein; Mohammadi, Abdorreza; Hosseini, Hedayat; Kamankesh, Marzieh; Aeenehvand, Saeed; Mohammadi, Zaniar

    2016-01-01

    A novel method based on microwave-assisted extraction and dispersive liquid-liquid microextraction (MAE-DLLME) followed by high-performance liquid chromatography (HPLC) was developed for the determination of three polyamines from turkey breast meat samples. Response surface methodology (RSM) based on central composite design (CCD) was used to optimize the effective factors in DLLME process. The optimum microextraction efficiency was obtained under optimized conditions. The calibration graphs of the proposed method were linear in the range of 20-200 ng g(-1), with the coefficient determination (R(2)) higher than 0.9914. The relative standard deviations were 6.72-7.30% (n = 7). The limits of detection were in the range of 0.8-1.4 ng g(-1). The recoveries of these compounds in spiked turkey breast meat samples were from 95% to 105%. The increased sensitivity in using the MAE-DLLME-HPLC-UV has been demonstrated. Compared with previous methods, the proposed method is an accurate, rapid and reliable sample-pretreatment method.

  13. Microwave-assisted of dispersive liquid-liquid microextraction and spectrophotometric determination of uranium after optimization based on Box-Behnken design and chemometrics methods

    NASA Astrophysics Data System (ADS)

    Niazi, Ali; Khorshidi, Neda; Ghaemmaghami, Pegah

    2015-01-01

    In this study an analytical procedure based on microwave-assisted dispersive liquid-liquid microextraction (MA-DLLME) and spectrophotometric coupled with chemometrics methods is proposed to determine uranium. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (24) based on an analysis of variance demonstrated that the pH, concentration of PAR, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, concentration of PAR, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 20.0-350.0 ng mL-1 with detection limit of 6.7 ng mL-1 (3δB/slope) and the enrichment factor of this method for uranium reached at 135. The relative standard deviation (R.S.D.) is 1.64% (n = 7, c = 50 ng mL-1). The partial least squares (PLS) modeling was used for multivariate calibration of the spectrophotometric data. The orthogonal signal correction (OSC) was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. MA-DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction (RMSEP) for uranium determination using PLS and OSC-PLS models were 4.63 and 0.98, respectively. This procedure allows the determination of uranium synthesis and real samples such as waste water with good reliability of the determination.

  14. Microwave-assisted of dispersive liquid-liquid microextraction and spectrophotometric determination of uranium after optimization based on Box-Behnken design and chemometrics methods.

    PubMed

    Niazi, Ali; Khorshidi, Neda; Ghaemmaghami, Pegah

    2015-01-25

    In this study an analytical procedure based on microwave-assisted dispersive liquid-liquid microextraction (MA-DLLME) and spectrophotometric coupled with chemometrics methods is proposed to determine uranium. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (2(4)) based on an analysis of variance demonstrated that the pH, concentration of PAR, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, concentration of PAR, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 20.0-350.0 ng mL(-1) with detection limit of 6.7 ng mL(-1) (3δB/slope) and the enrichment factor of this method for uranium reached at 135. The relative standard deviation (R.S.D.) is 1.64% (n=7, c=50 ng mL(-1)). The partial least squares (PLS) modeling was used for multivariate calibration of the spectrophotometric data. The orthogonal signal correction (OSC) was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. MA-DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction (RMSEP) for uranium determination using PLS and OSC-PLS models were 4.63 and 0.98, respectively. This procedure allows the determination of uranium synthesis and real samples such as waste water with good reliability of the determination. PMID:25062051

  15. Optimized nested Markov chain Monte Carlo sampling: application to the liquid nitrogen Hugoniot using density functional theory

    SciTech Connect

    Shaw, Milton Sam; Coe, Joshua D; Sewell, Thomas D

    2009-01-01

    An optimized version of the Nested Markov Chain Monte Carlo sampling method is applied to the calculation of the Hugoniot for liquid nitrogen. The 'full' system of interest is calculated using density functional theory (DFT) with a 6-31 G* basis set for the configurational energies. The 'reference' system is given by a model potential fit to the anisotropic pair interaction of two nitrogen molecules from DFT calculations. The EOS is sampled in the isobaric-isothermal (NPT) ensemble with a trial move constructed from many Monte Carlo steps in the reference system. The trial move is then accepted with a probability chosen to give the full system distribution. The P's and T's of the reference and full systems are chosen separately to optimize the computational time required to produce the full system EOS. The method is numerically very efficient and predicts a Hugoniot in excellent agreement with experimental data.

  16. Panax ginseng Adventitious Root Suspension Culture: Protocol for Biomass Production and Analysis of Ginsenosides by High Pressure Liquid Chromatography.

    PubMed

    Murthy, Hosakatte Niranjana; Paek, Kee Yoeup

    2016-01-01

    Panax ginseng C.A. Meyer (Korean ginseng) is a popular herbal medicine. It has been used in Chinese and Oriental medicines since thousands of years. Ginseng products are generally used as a tonic and an adaptogen to resist the adverse influence of a wide range of physical, chemical and biological factors, and to restore homeostasis. Ginsenosides or ginseng saponins are the principal active ingredients of ginseng. Since ginseng cultivation process is very slow and needs specific environment for field cultivation, cell and tissue cultures are sought as alternatives for the production of ginseng biomass and bioactive compounds. In this chapter, we focus on methods of induction of adventitious roots from ginseng roots, establishment of adventitious root suspension cultures using bioreactors, procedures for processing of adventitious roots, and analysis of ginsenosides by high pressure liquid chromatography. PMID:27108314

  17. Panax ginseng Adventitious Root Suspension Culture: Protocol for Biomass Production and Analysis of Ginsenosides by High Pressure Liquid Chromatography.

    PubMed

    Murthy, Hosakatte Niranjana; Paek, Kee Yoeup

    2016-01-01

    Panax ginseng C.A. Meyer (Korean ginseng) is a popular herbal medicine. It has been used in Chinese and Oriental medicines since thousands of years. Ginseng products are generally used as a tonic and an adaptogen to resist the adverse influence of a wide range of physical, chemical and biological factors, and to restore homeostasis. Ginsenosides or ginseng saponins are the principal active ingredients of ginseng. Since ginseng cultivation process is very slow and needs specific environment for field cultivation, cell and tissue cultures are sought as alternatives for the production of ginseng biomass and bioactive compounds. In this chapter, we focus on methods of induction of adventitious roots from ginseng roots, establishment of adventitious root suspension cultures using bioreactors, procedures for processing of adventitious roots, and analysis of ginsenosides by high pressure liquid chromatography.

  18. Optimization of a phase separation based magnetic-stirring salt-induced liquid-liquid microextraction method for determination of fluoroquinolones in food.

    PubMed

    Gao, Ming; Wang, Huili; Ma, Meiping; Zhang, Yuna; Yin, Xiaohan; Dahlgren, Randy A; Du, Dongli; Wang, Xuedong

    2015-05-15

    Herein, we developed a novel integrated apparatus to perform phase separation based on magnetic-stirring, salt-induced, liquid-liquid microextraction for determination of five fluoroquinolones in animal-based foods by HPLC analysis. The novel integrated apparatus consisted of three simple HDPE (high density polyethylene) parts that were used to separate the solvent from the aqueous solution prior to retrieving the extractant. The extraction parameters were optimized using the response surface method based on central composite design: 791 μL of acetone solvent, 2.5 g of Na2SO4, pH 1.7, 3.0 min of stir time, and 5.5 min centrifugation. The limits of detection were 0.07-0.53 μg kg(-1) and recoveries were 91.6-105.0% for the five fluoroquinolones from milk, eggs and honey. This method is easily constructed from inexpensive materials, extraction efficiency is high, and the approach is compatible with HPLC analysis. Thus, it has excellent prospects for sample pre-treatment and analysis of fluoroquinolones in animal-based foods. PMID:25577068

  19. Optimization of a phase separation based magnetic-stirring salt-induced liquid-liquid microextraction method for determination of fluoroquinolones in food.

    PubMed

    Gao, Ming; Wang, Huili; Ma, Meiping; Zhang, Yuna; Yin, Xiaohan; Dahlgren, Randy A; Du, Dongli; Wang, Xuedong

    2015-05-15

    Herein, we developed a novel integrated apparatus to perform phase separation based on magnetic-stirring, salt-induced, liquid-liquid microextraction for determination of five fluoroquinolones in animal-based foods by HPLC analysis. The novel integrated apparatus consisted of three simple HDPE (high density polyethylene) parts that were used to separate the solvent from the aqueous solution prior to retrieving the extractant. The extraction parameters were optimized using the response surface method based on central composite design: 791 μL of acetone solvent, 2.5 g of Na2SO4, pH 1.7, 3.0 min of stir time, and 5.5 min centrifugation. The limits of detection were 0.07-0.53 μg kg(-1) and recoveries were 91.6-105.0% for the five fluoroquinolones from milk, eggs and honey. This method is easily constructed from inexpensive materials, extraction efficiency is high, and the approach is compatible with HPLC analysis. Thus, it has excellent prospects for sample pre-treatment and analysis of fluoroquinolones in animal-based foods.

  20. A strategy for the systematic development of a liquid chromatographic mass spectrometric screening method for polymer electrolyte membrane degradation products using isocratic and gradient phase optimized liquid chromatography.

    PubMed

    Zedda, M; Tuerk, J; Teutenberg, T; Peil, S; Schmidt, T C

    2009-12-18

    Within the scope of research for target and non-target LC-MS/MS analysis of membrane degradation products of polymer electrolyte membrane fuel cells, a systematic method development for the separation of structurally similar compounds was performed by phase optimized liquid chromatography. Five different stationary phases with different selectivities were used. Isocratic separation for 4-hydroxybenzoic acid, isophthalic acid, terephthalic acid, 4-hydroxybenzaldehyde and 4-formylbenzoic acid was achieved on a C18 and a Phenyl phase. Using the PRISMA model the separation efficiency was optimized. This was achieved on a serially connected mixed stationary phase composed of 30 mm C18, 150 mm Phenyl and 60 mm C30. For the LC-MS screening of unknown degradation products from polymer electrolyte membranes in the product water of a fuel cell, a solvent gradient is mandatory for less polar or later eluting compounds. By means of 4-mercaptobenzoic acid it could be shown that a solvent gradient can be applied in order to elute later eluting compounds in a short time. The adaptability of this method for the qualitative analysis by target and non-target LC-MS/MS screening has been shown by means of 4-hydroxybenzoic acid. The combination of solvent gradient and isocratic conditions makes this approach attractive for the purpose of a screening method for known and unknown analytes in a water sample.

  1. High Quality Liquid Crystal Tunable Lenses and Optimization with Floating Electrodes

    ERIC Educational Resources Information Center

    Li, Liwei

    2013-01-01

    In addition to the display application, Liquid Crystals (LC) can be very useful in other applications such as beam steering, tunable lenses, etc. Electro-optical LC tunable lenses have been considered as an alternative to conventional glass lenses because of their ability to change their focal length with the application of a control voltage, as…

  2. Coaxial electrospray of liquid core-hydrogel shell microcapsules for encapsulation and miniaturized 3D culture of pluripotent stem cells

    PubMed Central

    Zhao, Shuting; Agarwal, Pranay; Rao, Wei; Huang, Haishui; Zhang, Renliang; Liu, Zhenguo; Yu, Jianhua; Weisleder, Noah; Zhang, Wujie; He, Xiaoming

    2014-01-01

    A novel coaxial electrospray technology is developed to generate microcapsules with a hydrogel shell of alginate and an aqueous liquid core of living cells using two aqueous fluids in one step. Approximately 50 murine embryonic stem (ES) cells encapsulated in the core with high viability (92.3 ± 2.9%) can proliferate to form a single ES cell aggregate of 128.9 ± 17.4 μm in each microcapsule within 7 days. Quantitative analyses of gene and protein expression indicate that ES cells cultured in the miniaturized 3D liquid core of the core-shell microcapsules have significantly higher pluripotency on average than the cells cultured on 2D substrate or in the conventional 3D alginate hydrogel microbeads without a core-shell architecture. The higher pluripotency is further suggested by their significantly higher capability of differentiation into beating cardiomyocytes and higher expression of cardiomyocyte specific gene markers on average after directed differentiation under the same conditions. Considering its wide availability, easiness to set up and operate, reusability, and high production rate, the novel coaxial electrospray technology together with the microcapsule system is of importance for mass production of ES cells with high pluripotency to facilitate translation of the emerging pluripotent stem cell-based regenerative medicine into the clinic. PMID:25036382

  3. Immuno-electron microscopy of primary cell cultures from genetically modified animals in liquid by atmospheric scanning electron microscopy.

    PubMed

    Kinoshita, Takaaki; Mori, Yosio; Hirano, Kazumi; Sugimoto, Shinya; Okuda, Ken-ichi; Matsumoto, Shunsuke; Namiki, Takeshi; Ebihara, Tatsuhiko; Kawata, Masaaki; Nishiyama, Hidetoshi; Sato, Mari; Suga, Mitsuo; Higashiyama, Kenichi; Sonomoto, Kenji; Mizunoe, Yoshimitsu; Nishihara, Shoko; Sato, Chikara

    2014-04-01

    High-throughput immuno-electron microscopy is required to capture the protein-protein interactions realizing physiological functions. Atmospheric scanning electron microscopy (ASEM) allows in situ correlative light and electron microscopy of samples in liquid in an open atmospheric environment. Cells are cultured in a few milliliters of medium directly in the ASEM dish, which can be coated and transferred to an incubator as required. Here, cells were imaged by optical or fluorescence microscopy, and at high resolution by gold-labeled immuno-ASEM, sometimes with additional metal staining. Axonal partitioning of neurons was correlated with specific cytoskeletal structures, including microtubules, using primary-culture neurons from wild type Drosophila, and the involvement of ankyrin in the formation of the intra-axonal segmentation boundary was studied using neurons from an ankyrin-deficient mutant. Rubella virus replication producing anti-double-stranded RNA was captured at the host cell's plasma membrane. Fas receptosome formation was associated with clathrin internalization near the surface of primitive endoderm cells. Positively charged Nanogold clearly revealed the cell outlines of primitive endoderm cells, and the cell division of lactic acid bacteria. Based on these experiments, ASEM promises to allow the study of protein interactions in various complexes in a natural environment of aqueous liquid in the near future. PMID:24564988

  4. How to Optimize the Use of Blood Cultures for the Diagnosis of Bloodstream Infections? A State-of-the Art

    PubMed Central

    Lamy, Brigitte; Dargère, Sylvie; Arendrup, Maiken C.; Parienti, Jean-Jacques; Tattevin, Pierre

    2016-01-01

    Bloodstream infection (BSI) is a major cause of death in developed countries and the detection of microorganisms is essential in managing patients. Despite major progress has been made to improve identification of microorganisms, blood culture (BC) remains the gold standard and the first line tool for detecting BSIs. Consensus guidelines are available to ensure optimal BSI procedures, but BC practices often deviate from the recommendations. This review provides an update on clinical and technical issues related to blood collection and to BC performance, with a special focus on the blood sample strategy to optimize the sensitivity and specificity of BCs. PMID:27242721

  5. Fast Filtration of Bacterial or Mammalian Suspension Cell Cultures for Optimal Metabolomics Results

    PubMed Central

    Bordag, Natalie; Janakiraman, Vijay; Nachtigall, Jonny; González Maldonado, Sandra; Bethan, Bianca; Laine, Jean-Philippe; Fux, Elie

    2016-01-01

    The metabolome offers real time detection of the adaptive, multi-parametric response of the organisms to environmental changes, pathophysiological stimuli or genetic modifications and thus rationalizes the optimization of cell cultures in bioprocessing. In bioprocessing the measurement of physiological intracellular metabolite levels is imperative for successful applications. However, a sampling method applicable to all cell types with little to no validation effort which simultaneously offers high recovery rates, high metabolite coverage and sufficient removal of extracellular contaminations is still missing. Here, quenching, centrifugation and fast filtration were compared and fast filtration in combination with a stabilizing washing solution was identified as the most promising sampling method. Different influencing factors such as filter type, vacuum pressure, washing solutions were comprehensively tested. The improved fast filtration method (MxP® FastQuench) followed by routine lipid/polar extraction delivers a broad metabolite coverage and recovery reflecting well physiological intracellular metabolite levels for different cell types, such as bacteria (Escherichia coli) as well as mammalian cells chinese hamster ovary (CHO) and mouse myeloma cells (NS0).The proposed MxP® FastQuench allows sampling, i.e. separation of cells from medium with washing and quenching, in less than 30 seconds and is robustly designed to be applicable to all cell types. The washing solution contains the carbon source respectively the 13C-labeled carbon source to avoid nutritional stress during sampling. This method is also compatible with automation which would further reduce sampling times and the variability of metabolite profiling data. PMID:27438065

  6. Proliferation and colony-forming ability of peritoneal exudate cells in liquid culture.

    PubMed

    Stewart, C C; Lin, H S; Adles, C

    1975-05-01

    Peritoneal exudate cells, obtained from mice injected with thioglycollate medium and cultured in medium containing L-cell-conditioned medium, will proliferate in an exponential fashion for 18 days with a doubling time of 68 h. After a 2 h pulse of tritiated thymidine, labeled adherent cells increased to a maximum of 22-34% during the 1st and 2nd wk of culture. Increasing the cell concentration from 2 times 10-3 to 2 times 10-5 cells/culture reduced exponential growth to 10 days and the doubling time was increased to 81.6 h. Under these culture conditions, peritoneal exudate cells were shown to form colonies on the surface of culture dishes when plated at low density. The cells within the colony were shown to be macrophages using yeast and antibody-coated sheep erythrocytes as a test for phagocytic function. The plating efficiolonies arose from a single precursor cell. The adherent cell population contains the colony-forming precursors. These precursors can be stimulated to form colonies for at least 2 wk by the addition of conditioned medium to cultures at various times after plating. While very few colony-forming cells could be demonstrated in the unstimulated peritoneal lavage, their numbers begin to increase in the exudate 4 h after injection of thioglycollate medium and reach a maximum by day 3 and then decrease. Isolated colonies may be useful in studying the function of macrophages. PMID:1092793

  7. Improvement of zinc bioaccumulation and biomass yield in the mycelia and fruiting bodies of Pleurotus florida cultured on liquid media.

    PubMed

    Poursaeid, Nasser; Azadbakht, Abas; Balali, Gholam Reza

    2015-04-01

    The effect of different concentrations of zinc on the bioaccumulation of zinc and biomass yield in both mycelium and fruiting body of Pleurotus florida cultivated in liquid medium was studied. The results showed that the optimum yield of mycelia (11.33 ± 0.44 g/L) and fruiting bodies (7.70 ± 0.19 g/L) dry biomass was obtained in a liquid medium containing 100 mg/L of zinc. At a zinc concentration of 200 mg/L, the highest concentration of zinc in the mycelia and fruiting bodies reached 1.869 ± 0.115 and 0.151 ± 0.008 mg/g dry weight, respectively. The addition of zinc to the culture media significantly reduced zinc bioaccumulation factor in mycelia (from 24.64 ± 0.52 to 3.35 ± 0.24) and fruiting bodies (from 36.71 ± 0.30 to 0.49 ± 0.02) dry weight. Our findings indicated that the ability of zinc bioaccumulation in the mycelia is much higher than in the fruiting bodies. The fundamental information obtained in this study will be useful for the improvement of zinc bioaccumulation and biomass yield in mycelia and fruiting bodies of P. florida cultivated in liquid media to obtain maximum zinc-enriched biomass.

  8. Acanthamoeba Encephalitis: Isolation of Genotype T1 in Mycobacterial Liquid Culture Medium

    PubMed Central

    Azzam, Rula; Badenoch, Paul R.; Francis, Michelle J.; Fernandez, Charles; Adamson, Penelope J.; Dendle, Claire; Woolley, Ian; Robson, Jenny; Korman, Tony M.

    2014-01-01

    We report a case of Acanthamoeba encephalitis diagnosed from an antemortem brain biopsy specimen, where the organism was first isolated in mycobacterial liquid medium and first identified by using a sequence generated by a commercial panfungal sequencing assay. We correlate susceptibility results with clinical outcome. PMID:25502534

  9. Production of microsclerotia by brazilian strains of metarhizium spp. using submerged liquid culture fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the potential production and desiccation tolerance of microsclerotia (MS) by Brazilian strains of Metarhizium. anisopliae [Ma], M. acridum [Mc] and M. robertsii [Mr]. These fungi were grown in a liquid medium containing 16 g carbon l-1 with a carbon:nitrogen ratio of 50:1. One hundre...

  10. Bioavailability of benzo[a]pyrene during NAPL-enhanced biodegradation in soil and in liquid culture.

    PubMed

    Kanaly, R A; Watanabe, K; Matsui, S

    2006-01-01

    The high molecular weight polycyclic aromatic hydrocarbon (HMW PAH) benzo[a]pyrene is generally persistent in the environment and its persistence may be due to bioavailability limitations. However, the presence of degradation-capable microorganisms and a suitable cosubstrate are also necessary. This is especially the case for benzo[a]pyrene because it may only be degraded by fortuitous metabolism. Non-aqueous phase liquid (NAPL)-enhanced benzo[a]pyrene biodegradation and indicators of bioavailability were measured in soil and liquid culture. In soil, 14CO2 from 7-[14C]benzo[a]pyrene mineralisation and overall CO2 production were monitored for 83 d after treatment with different types of NAPLs in biometer flasks. Monitoring was followed by soil extraction and measurement of 14C residues and of the remaining NAPL by gravimetry. In liquid culture, 7-[14C]benzo[a]pyrene mineralisation was monitored after treatment with different NAPLs and followed by a radiocarbon mass balance of 14C residues. Results indicated that although benzo[a]pyrene may have been bioavailable in both media types, benzo[a]pyrene mineralisation only occurred when a suitable NAPL cosubstrate was present to facilitate biodegradation. In soil, rapid increases in the rate and onset of benzo[a]pyrene mineralisation were shown to occur in benzo[a]pyrene-contaminated soils that were treated with mineral oil, which was a relatively non-biodegradable NAPL cosolvent, plus a hexane fraction-NAPL which was biodegradable and contained suitable cosubstrate(s).

  11. [Influence of different gelatin concentration and lymphocyte isolation liquid on primary culture of umbilical cord blood derived adhesive cells].

    PubMed

    Zhang, Cheng; Chen, Xing-Hua; Zhang, Xi; Gao, Lei; Kong, Pei-Yan; Liu, Hong; Liang, Xue; Peng, Xian-Gui; Wang, Qing-Yu

    2008-12-01

    In order to study the influence of different gelatin concentrations, and lymphocyte isolation liquid on primary culture of umbilical cord blood-derived adhesive cells (hCBACs), the red blood cells of umbilical cord blood was separated by 3% and 6 % gelatin for detecting the effectiveness of sedimentation, then the adhesion rate at 48 hours, the day of initial expansion and the rate of culture success were detected for hCBACs cultured with CD34(+) cells after the mononuclear cells were separated by 6% gelatin followed by Ficoll and Percoll, and the morphological characteristics and growth status were observed by invert microscopy. Cytochemistry stain for nonspecific esterase stain (NSE), peroxidase (POX), periodic acid Schiff reaction (PAS) and alkali phosphatase (ALP) and immunocytochemistry labeling for CD31, CD45, CD68 and fibronectin (Fn) were detected. The results showed that 6 % gelatin was better than that 3% gelatin for red blood sedimentation. The Percoll was predominant over Ficoll in adhesion rate at 48 hours, the day of initial expansion, the time of initial formation of adhesive cell colony units, the time of maximal numbers of adhesive cell colony units, the the cell fusion time and ratio of culture success. 60% fibroblast-liked cells, 36% macrophage liked cells and 4% small-round cells were observed in cells isolated by both isolated methods. The cytochemistry stain for NSE, POX, PAS and ALP was similar in two groups, the difference was not statistically significant between these two groups. The immunocytochemistry labeling for CD31, CD45, CD68 and Fn was also similar in both groups and the difference was also not statistically significant between these two groups. It is concluded that the combination of 6% gelatin with Percoll is an ideal separation method for primary culture of hCBACs, which provides basic information for clinical application.

  12. Lytic enzyme production optimization using low-cost substrates and its application in the clarification of xanthan gum culture broth

    PubMed Central

    da Silva, Cíntia Reis; Silva, Marilia Lordelo Cardoso; Kamida, Helio Mitoshi; Goes-Neto, Aristoteles; Koblitz, Maria Gabriela Bello

    2014-01-01

    Lytic enzymes are widely used in industrial biotechnology as they are able to hydrolyze the bacterial cell wall. One application of these enzymes is the clarification of the culture broth for the production of xanthan gum, because of its viability in viscous media and high specificity. The screening process for filamentous fungi producing lytic enzymes, the optimization of production of these enzymes by the selected microorganism, and the optimization of the application of the enzymes produced in the clarification of culture broth are presented in this article. Eleven fungal isolates were tested for their ability to produce enzymes able to increase the transmittance of the culture broth containing cells of Xanthomonas campestris. To optimize the secretion of lytic enzymes by the selected microorganism the following variables were tested: solid substrate, initial pH, incubation temperature, and addition of inducer (gelatin). Thereafter, secretion of the enzymes over time of incubation was assessed. To optimize the clarification process a central composite rotational design was applied in which the pH of the reaction medium, the dilution of the broth, and the reaction temperature were evaluated. The isolate identified as Aspergillus tamarii was selected for increasing the transmittance of the broth from 2.1% to 54.8%. The best conditions for cultivation of this microorganism were: use of coconut husk as solid substrate, with 90% moisture, at 30°C for 20 days. The lytic enzymes produced thereby were able to increase the transmittance of the culture broth from 2.1% to 70.6% at 65°C, without dilution and without pH adjustment. PMID:25473487

  13. Insights into large-scale cell-culture reactors: I. Liquid mixing and oxygen supply.

    PubMed

    Sieblist, Christian; Jenzsch, Marco; Pohlscheidt, Michael; Lübbert, Andreas

    2011-12-01

    In the pharmaceutical industry, it is state of the art to produce recombinant proteins and antibodies with animal-cell cultures using bioreactors with volumes of up to 20 m(3) . Recent guidelines and position papers for the industry by the US FDA and the European Medicines Agency stress the necessity of mechanistic insights into large-scale bioreactors. A detailed mechanistic view of their practically relevant subsystems is required as well as their mutual interactions, i.e., mixing or homogenization of the culture broth and sufficient mass and heat transfer. In large-scale bioreactors for animal-cell cultures, different agitation systems are employed. Here, we discuss details of the flows induced in stirred tank reactors relevant for animal-cell cultures. In addition, solutions of the governing fluid dynamic equations obtained with the so-called computational fluid dynamics are presented. Experimental data obtained with improved measurement techniques are shown. The results are compared to previous studies and it is found that they support current hypotheses or models. Progress in improving insights requires continuous interactions between more accurate measurements and physical models. The paper aims at promoting the basic mechanistic understanding of transport phenomena that are crucial for large-scale animal-cell culture reactors.

  14. Insights into large-scale cell-culture reactors: I. Liquid mixing and oxygen supply.

    PubMed

    Sieblist, Christian; Jenzsch, Marco; Pohlscheidt, Michael; Lübbert, Andreas

    2011-12-01

    In the pharmaceutical industry, it is state of the art to produce recombinant proteins and antibodies with animal-cell cultures using bioreactors with volumes of up to 20 m(3) . Recent guidelines and position papers for the industry by the US FDA and the European Medicines Agency stress the necessity of mechanistic insights into large-scale bioreactors. A detailed mechanistic view of their practically relevant subsystems is required as well as their mutual interactions, i.e., mixing or homogenization of the culture broth and sufficient mass and heat transfer. In large-scale bioreactors for animal-cell cultures, different agitation systems are employed. Here, we discuss details of the flows induced in stirred tank reactors relevant for animal-cell cultures. In addition, solutions of the governing fluid dynamic equations obtained with the so-called computational fluid dynamics are presented. Experimental data obtained with improved measurement techniques are shown. The results are compared to previous studies and it is found that they support current hypotheses or models. Progress in improving insights requires continuous interactions between more accurate measurements and physical models. The paper aims at promoting the basic mechanistic understanding of transport phenomena that are crucial for large-scale animal-cell culture reactors. PMID:21818860

  15. Trade-off between learning and exploitation: the Pareto-optimal versus evolutionarily stable learning schedule in cumulative cultural evolution.

    PubMed

    Wakano, Joe Yuichiro; Miura, Chiaki

    2014-02-01

    Inheritance of culture is achieved by social learning and improvement is achieved by individual learning. To realize cumulative cultural evolution, social and individual learning should be performed in this order in one's life. However, it is not clear whether such a learning schedule can evolve by the maximization of individual fitness. Here we study optimal allocation of lifetime to learning and exploitation in a two-stage life history model under a constant environment. We show that the learning schedule by which high cultural level is achieved through cumulative cultural evolution is unlikely to evolve as a result of the maximization of individual fitness, if there exists a trade-off between the time spent in learning and the time spent in exploiting the knowledge that has been learned in earlier stages of one's life. Collapse of a fully developed culture is predicted by a game-theoretical analysis where individuals behave selfishly, e.g., less learning and more exploiting. The present study suggests that such factors as group selection, the ability of learning-while-working ("on the job training"), or environmental fluctuation might be important in the realization of rapid and cumulative cultural evolution that is observed in humans. PMID:24044982

  16. Trade-off between learning and exploitation: the Pareto-optimal versus evolutionarily stable learning schedule in cumulative cultural evolution.

    PubMed

    Wakano, Joe Yuichiro; Miura, Chiaki

    2014-02-01

    Inheritance of culture is achieved by social learning and improvement is achieved by individual learning. To realize cumulative cultural evolution, social and individual learning should be performed in this order in one's life. However, it is not clear whether such a learning schedule can evolve by the maximization of individual fitness. Here we study optimal allocation of lifetime to learning and exploitation in a two-stage life history model under a constant environment. We show that the learning schedule by which high cultural level is achieved through cumulative cultural evolution is unlikely to evolve as a result of the maximization of individual fitness, if there exists a trade-off between the time spent in learning and the time spent in exploiting the knowledge that has been learned in earlier stages of one's life. Collapse of a fully developed culture is predicted by a game-theoretical analysis where individuals behave selfishly, e.g., less learning and more exploiting. The present study suggests that such factors as group selection, the ability of learning-while-working ("on the job training"), or environmental fluctuation might be important in the realization of rapid and cumulative cultural evolution that is observed in humans.

  17. Multivariable optimization of the micellar system for the ionic liquid-modified MEKC separation of phenolic acids.

    PubMed

    Liu, Lei; Wu, Bin; Liu, Ke; Li, Chao-Ran; Zhou, Xu; Li, Ping; Yang, Hua

    2016-07-15

    An ionic liquid (IL)-modified micellar electrokinetic chromatography (MEKC) method was proposed for the separation and determination of eight phenolic acids. In order to increase separation efficiency and selectivity, the micelle system consisting of aqueous mixtures of ILs, Tween 20 and borate was optimized using a D-optimal design. A 16-run experimental plan was carried out. The results indicated that the addition of ILs in background electrolyte could significantly alter the electrophoretic behavior and improve the resolution of target analytes. By evaluating the electropherograms obtained, a satisfactory separation condition for all analytes was achieved in 10min with optimized buffer composed of 0.70% (w/w) 1-butyl-3-methylimidazolium tetrafluoroborate, 8.1% (w/w) polyoxyethylene sorbitan monolaurate (Tween 20) and 10mM sodium borate at pH 9.2. Under these conditions, all calibration curves showed good linearity (r(2)>0.9969), and accuracy (recoveries ranging from 94.71 to 106.85%). Finally, the proposed method was successfully applied to determine the phenolic acids in a Chinese medicine compound, compound danshen dripping pills. PMID:27136281

  18. Shape optimization of a sheet swimming over a thin liquid layer

    NASA Astrophysics Data System (ADS)

    Wilkening, Jon; Hosoi, A. E.

    Motivated by the propulsion mechanisms adopted by gastropods, annelids and other invertebrates, we consider shape optimization of a flexible sheet that moves by propagating deformation waves along its body. The self-propelled sheet is separated from a rigid substrate by a thin layer of viscous Newtonian fluid. We use a lubrication approximation to model the dynamics and derive the relevant Euler-Lagrange equations to simultaneously optimize swimming speed, efficiency and fluid loss. We find that as the parameters controlling these quantities approach critical values, the optimal solutions become singular in a self-similar fashion and sometimes leave the realm of validity of the lubrication model. We explore these singular limits by computing higher-order corrections to the zeroth order theory and find that wave profiles that develop cusp-like singularities are appropriately penalized, yielding non-singular optimal solutions. These corrections are themselves validated by comparison with finite element solutions of the full Stokes equations, and, to the extent possible, using recent rigorous a priori error bounds.

  19. Shape optimization of a sheet swimming over a thin liquid layer

    SciTech Connect

    Wilkening, J.; Hosoi, A.E.

    2008-12-10

    Motivated by the propulsion mechanisms adopted by gastropods, annelids and other invertebrates, we consider shape optimization of a flexible sheet that moves by propagating deformation waves along its body. The self-propelled sheet is separated from a rigid substrate by a thin layer of viscous Newtonian fluid. We use a lubrication approximation to model the dynamics and derive the relevant Euler-Lagrange equations to simultaneously optimize swimming speed, efficiency and fluid loss. We find that as the parameters controlling these quantities approach critical values, the optimal solutions become singular in a self-similar fashion and sometimes leave the realm of validity of the lubrication model. We explore these singular limits by computing higher order corrections to the zeroth order theory and find that wave profiles that develop cusp-like singularities are appropriately penalized, yielding non-singular optimal solutions. These corrections are themselves validated by comparison with finite element solutions of the full Stokes equations, and, to the extent possible, using recent rigorous a-priori error bounds.

  20. Nozzle extraction geometry of a liquid metal atomizer optimized by computer simulation of electric fields

    SciTech Connect

    Cvetkovic, S.R.; Balachandran, W.; Arnold, P.G.; Kleveland, B.; Wilson, F.G.; Zhao, A.P.

    1996-07-01

    Experimental measurements are compared with results obtained using a dedicated computer program for finite element modeling of electric fields in the vicinity of a liquid metal atomizer nozzle/tip. Good agreement between the experiment and the computer model has been achieved for two different nozzle geometries (Taylor cone and rounded tip), while paying particular attention to accuracy of the numerical solution near the tip (for equipotentials as well as derived values of field strength). In addition, the potential distribution has been calculated for several different positions of extractor voltage observed for each case. Finally, the assessment of suitability of the computer technique for qualitative consideration of the atomization process itself is presented.

  1. Optimization of solid-phase extraction and liquid chromatography-tandem mass spectrometry for the determination of domoic acid in seawater, phytoplankton, and mammalian fluids and tissues.

    PubMed

    Wang, Zhihong; Maucher-Fuquay, Jennifer; Fire, Spencer E; Mikulski, Christina M; Haynes, Bennie; Doucette, Gregory J; Ramsdell, John S

    2012-02-17

    We previously reported a solid-phase extraction (SPE) method for determination of the neurotoxin domoic acid (DA) in both seawater and phytoplankton by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with the purpose of sample desalting without DA pre-concentration. In the present study, we optimized the SPE procedure with seawater and phytoplankton samples directly acidified with aqueous formic acid without addition of organic solvents, which allowed sample desalting and also 20-fold pre-concentration of DA in seawater and phytoplankton samples. In order to reduce MS contamination, a diverter valve was installed between LC and MS to send the LC eluant to waste, except for the 6-min elution window bracketing the DA retention time, which was sent to the MS. Reduction of the MS turbo gas temperature also helped to maintain the long-term stability of MS signal. Recoveries exceeded 90% for the DA-negative seawater and the DA-positive cultured phytoplankton samples spiked with DA. The SPE method for DA extraction and sample clean-up in seawater was extended to mammalian fluids and tissues with modification in order to accommodate the fluid samples with limited available volumes and the tissue extracts in aqueous methanol. Recoveries of DA from DA-exposed laboratory mammalian samples (amniotic fluid, cerebrospinal fluid, plasma, placenta, and brain) were above 85%. Recoveries of DA from samples (urine, feces, intestinal contents, and gastric contents) collected from field stranded marine mammals showed large variations and were affected by the sample status. The optimized SPE-LC-MS method allows determination of DA at trace levels (low pg mL(-1)) in seawater with/without the presence of phytoplankton. The application of SPE clean-up to mammalian fluids and tissue extracts greatly reduced the LC column degradation and MS contamination, which allowed routine screening of marine mammalian samples for confirmation of DA exposure and determination of fluid and

  2. Use of a glass bead-containing liquid medium for efficient production of a soil-free culture with polychlorinated biphenyl-dechlorination activity.

    PubMed

    Suzuki, Daisuke; Baba, Daisuke; Satheeja Santhi, Velayudhan; Jebakumar Solomon, Robinson David; Katayama, Arata

    2013-08-01

    We established a soil-free culture capable of dechlorinating polychlorinated biphenyls (PCBs) in Kanechlor-300 and Kanechlor-400 by establishing a PCB-dechlorinating soil culture in liquid medium containing 0.5 mm glass beads. PCB-dechlorination activity in liquid cultures with glass beads appeared to depend on the size of the glass beads, and soil-free cultures with 0.05-, 1.0- or 2.0 mm glass beads did not dechlorinate PCBs. Soil-free culture without glass beads also failed to dechlorinate PCBs. The soil-free culture containing 0.5 mm glass beads dechlorinated 42.6 ± 12.0 mol% in total PCBs. This soil-free culture was more effective than soil culture for dechlorinating PCBs ranging from dichlorinated PCBs to tetrachlorinated PCBs. Clone analysis of the 16S rRNA gene sequences showed that one of the predominant groups of microorganisms in the soil-free culture comprised heat-tolerant and spore-forming bacteria from the phylum Firmicutes. Heat treatment (100 °C, 10 min) did not destroy the PCB-dechlorination activity of the soil-free culture with glass beads. These results suggest that unknown species of the phylum Firmicutes were involved in PCB dechlorination in the soil-free culture. In this study, we succeeded in using a liquid medium containing glass beads as an inorganic soil substitute and showed that such a medium enhances PCB-dechlorination activity. Our study provides valuable information for developing PCB-bioremediation techniques using dechlorinating bacteria in anoxic contaminated soils and sediments.

  3. Layered Plant-Growth Media for Optimizing Gaseous, Liquid and Nutrient Requirements: Modeling, Design and Monitoring

    NASA Astrophysics Data System (ADS)

    Heinse, R.; Jones, S. B.; Bingham, G.; Bugbee, B.

    2006-12-01

    Rigorous management of restricted root zones utilizing coarse-textured porous media greatly benefits from optimizing the gas-water balance within plant-growth media. Geophysical techniques can help to quantify root- zone parameters like water content, air-filled porosity, temperature and nutrient concentration to better address the root systems performance. The efficiency of plant growth amid high root densities and limited volumes is critically linked to maintaining a favorable water content/air-filled porosity balance while considering adequate fluxes to replenish water at decreasing hydraulic conductivities during uptake. Volumes adjacent to roots also need to be optimized to provide adequate nutrients throughout the plant's life cycle while avoiding excessive salt concentrations. Our objectives were to (1) design and model an optimized root zone system using optimized porous media layers, (2) verify our design by monitoring the water content distribution and tracking nutrient release and transport, and (3) mimic water and nutrient uptake using plants or wicks to draw water from the root system. We developed a unique root-zone system using layered Ottawa sands promoting vertically uniform water contents and air-filled porosities. Watering was achieved by maintaining a shallow saturated layer at the bottom of the column and allowing capillarity to draw water upward, where coarser particle sizes formed the bottom layers with finer particles sizes forming the layers above. The depth of each layer was designed to optimize water content based on measurements and modeling of the wetting water retention curves. Layer boundaries were chosen to retain saturation between 50 and 85 percent. The saturation distribution was verified by dual-probe heat-pulse water-content sensors. The nutrient experiment involved embedding slow release fertilizer in the porous media in order to detect variations in electrical resistivity versus time during the release, diffusion and uptake of

  4. Optimization of pressurized liquid extraction of inositols from pine nuts (Pinus pinea L.).

    PubMed

    Ruiz-Aceituno, L; Rodríguez-Sánchez, S; Sanz, J; Sanz, M L; Ramos, L

    2014-06-15

    Pressurized liquid extraction (PLE) has been used for the first time to extract bioactive inositols from pine nuts. The influence of extraction time, temperature and cycles of extraction in the yield and composition of the extract was studied. A quadratic lineal model using multiple linear regression in the stepwise mode was used to evaluate possible trends in the process. Under optimised PLE conditions (50°C, 18 min, 3 cycles of 1.5 mL water each one) at 10 MPa, a noticeable reduction in extraction time and solvent volume, compared with solid-liquid extraction (SLE; room temperature, 2h, 2 cycles of 5 mL water each one) was achieved; 5.7 mg/g inositols were extracted by PLE, whereas yields of only 3.7 mg/g were obtained by SLE. Subsequent incubation of PLE extracts with Saccharomyces cerevisiae (37°C, 5h) allowed the removal of other co-extracted low molecular weight carbohydrates which may interfere in the bioactivity of inositols.

  5. Optimization of process parameters for pilot-scale liquid-state bioconversion of sewage sludge by mixed fungal inoculation.

    PubMed

    Rahman, Roshanida A; Molla, Abul Hossain; Barghash, Hind F A; Fakhru'l-Razi, Ahmadun

    2016-01-01

    Liquid-state bioconversion (LSB) technique has great potential for application in bioremediation of sewage sludge. The purpose of this study is to determine the optimum level of LSB process of sewage sludge treatment by mixed fungal (Aspergillus niger and Penicillium corylophilum) inoculation in a pilot-scale bioreactor. The optimization of process factors was investigated using response surface methodology based on Box-Behnken design considering hydraulic retention time (HRT) and substrate influent concentration (S0) on nine responses for optimizing and fitted to the regression model. The optimum region was successfully depicted by optimized conditions, which was identified as the best fit for convenient multiple responses. The results from process verification were in close agreement with those obtained through predictions. Considering five runs of different conditions of HRT (low, medium and high 3.62, 6.13 and 8.27 days, respectively) with the range of S0 value (the highest 12.56 and the lowest 7.85 g L(-1)), it was monitored as the lower HRT was considered as the best option because it required minimum days of treatment than the others with influent concentration around 10 g L(-1). Therefore, optimum process factors of 3.62 days for HRT and 10.12 g L(-1) for S0 were identified as the best fit for LSB process and its performance was deviated by less than 5% in most of the cases compared to the predicted values. The recorded optimized results address a dynamic development in commercial-scale biological treatment of wastewater for safe and environment-friendly disposal in near future.

  6. Improved detection of multiple environmental antibiotics through an optimized sample extraction strategy in liquid chromatography-mass spectrometry analysis.

    PubMed

    Yi, Xinzhu; Bayen, Stéphane; Kelly, Barry C; Li, Xu; Zhou, Zhi

    2015-12-01

    A solid-phase extraction/liquid chromatography/electrospray ionization/multi-stage mass spectrometry (SPE-LC-ESI-MS/MS) method was optimized in this study for sensitive and simultaneous detection of multiple antibiotics in urban surface waters and soils. Among the seven classes of tested antibiotics, extraction efficiencies of macrolides, lincosamide, chloramphenicol, and polyether antibiotics were significantly improved under optimized sample extraction pH. Instead of only using acidic extraction in many existing studies, the results indicated that antibiotics with low pK a values (<7) were extracted more efficiently under acidic conditions and antibiotics with high pK a values (>7) were extracted more efficiently under neutral conditions. The effects of pH were more obvious on polar compounds than those on non-polar compounds. Optimization of extraction pH resulted in significantly improved sample recovery and better detection limits. Compared with reported values in the literature, the average reduction of minimal detection limits obtained in this study was 87.6% in surface waters (0.06-2.28 ng/L) and 67.1% in soils (0.01-18.16 ng/g dry wt). This method was subsequently applied to detect antibiotics in environmental samples in a heavily populated urban city, and macrolides, sulfonamides, and lincomycin were frequently detected. Antibiotics with highest detected concentrations were sulfamethazine (82.5 ng/L) in surface waters and erythromycin (6.6 ng/g dry wt) in soils. The optimized sample extraction strategy can be used to improve the detection of a variety of antibiotics in environmental surface waters and soils.

  7. Optimization of process parameters for pilot-scale liquid-state bioconversion of sewage sludge by mixed fungal inoculation.

    PubMed

    Rahman, Roshanida A; Molla, Abul Hossain; Barghash, Hind F A; Fakhru'l-Razi, Ahmadun

    2016-01-01

    Liquid-state bioconversion (LSB) technique has great potential for application in bioremediation of sewage sludge. The purpose of this study is to determine the optimum level of LSB process of sewage sludge treatment by mixed fungal (Aspergillus niger and Penicillium corylophilum) inoculation in a pilot-scale bioreactor. The optimization of process factors was investigated using response surface methodology based on Box-Behnken design considering hydraulic retention time (HRT) and substrate influent concentration (S0) on nine responses for optimizing and fitted to the regression model. The optimum region was successfully depicted by optimized conditions, which was identified as the best fit for convenient multiple responses. The results from process verification were in close agreement with those obtained through predictions. Considering five runs of different conditions of HRT (low, medium and high 3.62, 6.13 and 8.27 days, respectively) with the range of S0 value (the highest 12.56 and the lowest 7.85 g L(-1)), it was monitored as the lower HRT was considered as the best option because it required minimum days of treatment than the others with influent concentration around 10 g L(-1). Therefore, optimum process factors of 3.62 days for HRT and 10.12 g L(-1) for S0 were identified as the best fit for LSB process and its performance was deviated by less than 5% in most of the cases compared to the predicted values. The recorded optimized results address a dynamic development in commercial-scale biological treatment of wastewater for safe and environment-friendly disposal in near future. PMID:26111620

  8. Optimizing immobilized enzyme performance in cell-free environments to produce liquid fuels.

    SciTech Connect

    Kumar, Sanat

    2015-02-05

    The overall goal of this project was to optimize enzyme performance for the production of bio-diesel fuel. Enzyme immobilization has attracted much attention as a means to increase productivity. Mesorporous silica materials have been known to be best suited for immobilizing enzymes. A major challenge is to ensure that the enzymatic activity is retained after immobilization. Two major factors which drive enzymatic deactivation are protein-surface and inter-protein interactions. Previously, we studied protein stability inside pores and how to optimize protein-surface interactions to minimize protein denaturation. In this work we studied eh effect of surface curvature and chemistry on inter-protein interactions. Our goal was to find suitable immobilization supports which minimize these inter-protein interactions. Our studies carried out in the frame work of Hydrophobic-Polar (HP) model showed that enzymes immobilized inside hydrophobic pores of optimal sizes are best suited to minimize these inter-protein interactions. Besides, this study is also of biological importance to understand the role of chaperonins in protein disaggregation. Both of these aspects profited immensely with collaborations with our experimental colleague, Prof. Georges Belfort (RPI), who performed the experimental analog of our theoretical works.

  9. Retention prediction and separation optimization under multilinear gradient elution in liquid chromatography with Microsoft Excel macros.

    PubMed

    Fasoula, S; Zisi, Ch; Gika, H; Pappa-Louisi, A; Nikitas, P

    2015-05-22

    A package of Excel VBA macros have been developed for modeling multilinear gradient retention data obtained in single or double gradient elution mode by changing organic modifier(s) content and/or eluent pH. For this purpose, ten chromatographic models were used and four methods were adopted for their application. The methods were based on (a) the analytical expression of the retention time, provided that this expression is available, (b) the retention times estimated using the Nikitas-Pappa approach, (c) the stepwise approximation, and (d) a simple numerical approximation involving the trapezoid rule for integration of the fundamental equation for gradient elution. For all these methods, Excel VBA macros have been written and implemented using two different platforms; the fitting and the optimization platform. The fitting platform calculates not only the adjustable parameters of the chromatographic models, but also the significance of these parameters and furthermore predicts the analyte elution times. The optimization platform determines the gradient conditions that lead to the optimum separation of a mixture of analytes by using the Solver evolutionary mode, provided that proper constraints are set in order to obtain the optimum gradient profile in the minimum gradient time. The performance of the two platforms was tested using experimental and artificial data. It was found that using the proposed spreadsheets, fitting, prediction, and optimization can be performed easily and effectively under all conditions. Overall, the best performance is exhibited by the analytical and Nikitas-Pappa's methods, although the former cannot be used under all circumstances.

  10. HEK293 cell culture media study towards bioprocess optimization: Animal derived component free and animal derived component containing platforms.

    PubMed

    Liste-Calleja, Leticia; Lecina, Martí; Cairó, Jordi Joan

    2014-04-01

    The increasing demand for biopharmaceuticals produced in mammalian cells has lead industries to enhance bioprocess volumetric productivity through different strategies. Among those strategies, cell culture media development is of major interest. In the present work, several commercially available culture media for Human Embryonic Kidney cells (HEK293) were evaluated in terms of maximal specific growth rate and maximal viable cell concentration supported. The main objective was to provide different cell culture platforms which are suitable for a wide range of applications depending on the type and the final use of the product obtained. Performing simple media supplementations with and without animal derived components, an enhancement of cell concentration from 2 × 10(6) cell/mL to 17 × 10(6) cell/mL was achieved in batch mode operation. Additionally, the media were evaluated for adenovirus production as a specific application case of HEK293 cells. None of the supplements interfered significantly with the adenovirus infection although some differences were encountered in viral productivity. To the best of our knowledge, the high cell density achieved in the work presented has never been reported before in HEK293 batch cell cultures and thus, our results are greatly promising to further study cell culture strategies in bioreactor towards bioprocess optimization.

  11. Optimism

    PubMed Central

    Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.

    2010-01-01

    Optimism is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of optimism have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, optimism has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that optimism is associated with taking proactive steps to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, optimism is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that optimism relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which optimism fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998

  12. Impedance magnitude optimization of the regenerator in Stirling pulse tube cryocoolers working at liquid-helium temperatures

    NASA Astrophysics Data System (ADS)

    Cao, Q.; Qiu, L. M.; Zhi, X. Q.; Han, L.; Gan, Z. H.; Zhang, X. B.; Zhang, X. J.; Sun, D. M.

    2013-12-01

    The impedance magnitude is important for the design and operation of a Stirling pulse tube cryocooler (SPTC). However, the influence of the impedance magnitude on the SPTC working at liquid-helium temperatures is still not clear due to the complexity of refrigeration mechanism at this temperature range. In this study, the influence of the impedance magnitude on the viscous and thermal losses has been investigated, which contributes to the overall refrigeration efficiency. Different from the previous study at liquid nitrogen temperatures, it has been found and verified experimentally that a higher impedance magnitude may result in a larger mass flow rate accompanied with larger losses in the warmer region, hence the refrigeration efficiency is lowered. Numerical simulation is carried out in SPTCs of different geometry dimensions and working parameters, and the experimental study is carried out in a three-stage SPTC. A minimum no-load refrigeration temperature is achieved with an appropriate impedance magnitude that is determined by the combination of frequency and precooling temperature. A lowest temperature of 4.76 K is achieved at 28 Hz and a precooling temperature of 22.6 K, which is the lowest temperature ever achieved with He-4 for SPTCs. Impedance magnitude optimization is clearly an important consideration for the design of a 4 K SPTC.

  13. Optimization of magnetic amplification by flow constraints in turbulent liquid sodium

    SciTech Connect

    Nornberg, M. D. Taylor, N. Z.; Forest, C. B.; Rahbarnia, K.; Kaplan, E.

    2014-05-15

    Direct measurements of the vector turbulent emf in a driven two-vortex flow of liquid sodium were performed in the Madison Dynamo Experiment [K. Rahbarnia et al., Astrophys. J. 759, 80 (2012)]. The measured turbulent emf is anti-parallel with the mean current and is almost entirely described by an enhanced resistivity, which increases the threshold for a kinematic dynamo. We have demonstrated that this enhanced resistivity can be mitigated by eliminating the largest-scale eddies through the introduction of baffles. By tailoring the flow to reduce large-scale components and control the helical pitch, we have reduced the power required to drive the impellers, doubled the magnetic flux generated by differential rotation, and increased the decay time of externally applied magnetic fields. Despite these improvements, the flows remain sub-critical to the dynamo instability due to the reemergence of turbulent fluctuations at high flow speeds.

  14. Modeling optimal process conditions for UV-heat inactivation of foodborne pathogens in liquid foods.

    PubMed

    Gayán, Elisa; Serrano, María Jesús; Álvarez, Ignacio; Condón, Santiago

    2016-12-01

    The combination of ultraviolet radiation and heat (UV-H treatment) has been demonstrated as a promising strategy to overcome the limited UV germicidal effect in fruit juices. Nonetheless, there are so far no data regarding the efficacy of the combined process for the inactivation of bacterial foodborne pathogens in other liquid foods with different pH and composition. In this investigation, the optimum UV-H processing conditions for the inactivation of Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and S. aureus in chicken and vegetable broth, in addition to juices, were determined. From these data models that accurately predict the most advantageous UV-H treatment temperature and the expected synergistic lethal effect from UV and heat resistance data separately were constructed. Equations demonstrated that the optimum UV-H treatment temperature mostly depended on heat resistance, whereas the maximum synergistic lethal effect also was affected by the UV resistance of the microorganism of concern in a particular food.

  15. Modeling optimal process conditions for UV-heat inactivation of foodborne pathogens in liquid foods.

    PubMed

    Gayán, Elisa; Serrano, María Jesús; Álvarez, Ignacio; Condón, Santiago

    2016-12-01

    The combination of ultraviolet radiation and heat (UV-H treatment) has been demonstrated as a promising strategy to overcome the limited UV germicidal effect in fruit juices. Nonetheless, there are so far no data regarding the efficacy of the combined process for the inactivation of bacterial foodborne pathogens in other liquid foods with different pH and composition. In this investigation, the optimum UV-H processing conditions for the inactivation of Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and S. aureus in chicken and vegetable broth, in addition to juices, were determined. From these data models that accurately predict the most advantageous UV-H treatment temperature and the expected synergistic lethal effect from UV and heat resistance data separately were constructed. Equations demonstrated that the optimum UV-H treatment temperature mostly depended on heat resistance, whereas the maximum synergistic lethal effect also was affected by the UV resistance of the microorganism of concern in a particular food. PMID:27554141

  16. Optimization of drug viscosity used in gas-powered liquid jet injectors.

    PubMed

    Portaro, Rocco; Nakayama, Haruka; Ng, Hoi Dick

    2015-01-01

    This paper describes the effect of drug viscosity on the performance of gas powered liquid jet injectors. The analysis is accomplished utilizing a Computational Fluid Dynamics (CFD) model that obtains the stagnation pressure at the nozzle outlet. The technique is based on previous work used to predict gas power driven injector piston velocity with time. The results depict the variation in average and peak injector stagnation pressure for three different driven pressures; driving injections which vary from 0.2 cP to 87 cP in viscosity. Furthermore, a numerical representation of jet shape is also obtained to verify the effect of viscosity on jet geometry. These results demonstrate that increasing viscosity by 10 times that of water produces only a slight decrease in injector stagnation pressure and produces jets with greater confinement, which will display better characteristics for puncturing the skin.

  17. Lab on a chip-based hepatic sinusoidal system simulator for optimal primary hepatocyte culture.

    PubMed

    Choi, Yoon Young; Kim, Jaehyung; Lee, Sang-Hoon; Kim, Dong-Sik

    2016-08-01

    Primary hepatocyte cultures have been used in studies on liver disease, physiology, and pharmacology. While they are an important tool for in vitro liver studies, maintaining liver-specific characteristics of hepatocytes in vitro is difficult, as these cells rapidly lose their unique characteristics and functions. Portal flow is an important condition to preserve primary hepatocyte functions and liver regeneration in vivo. We have developed a microfluidic chip that does not require bulky peripheral devices or an external power source to investigate the relationship between hepatocyte functional maintenance and flow rates. In our culture system, two types of microfluidic devices were used as scaffolds: a monolayer- and a concave chamber-based device. Under flow conditions, our chips improved albumin and urea secretion rates after 13 days compared to that of the static chips. Reverse transcription polymerase chain reaction demonstrated that hepatocyte-specific gene expression was significantly higher at 13 days under flow conditions than when using static chips. For both two-dimensional and three-dimensional culture on the chips, flow resulted in the best performance of the hepatocyte culture in vitro. We demonstrated that flow improves the viability and efficiency of long-term culture of primary hepatocytes and plays a key role in hepatocyte function. These results suggest that this flow system has the potential for long-term hepatocyte cultures as well as a technique for three-dimensional culture. PMID:27334878

  18. Culture.

    ERIC Educational Resources Information Center

    1997

    Twelve conference papers on cultural aspects of second language instruction include: "Towards True Multiculturalism: Ideas for Teachers" (Brian McVeigh); Comparing Cultures Through Critical Thinking: Development and Interpretations of Meaningful Observations" (Laurel D. Kamada); "Authority and Individualism in Japan and the USA" (Alisa Woodring);…

  19. Comparative study of hydrophilic and hydrophobic ionic liquids for observing cultured human cells by scanning electron microscopy.

    PubMed

    Ishigaki, Yasuhito; Nakamura, Yuka; Takehara, Teruaki; Kurihara, Takayuki; Koga, Hironori; Takegami, Tsutomu; Nakagawa, Hideaki; Nemoto, Noriko; Tomosugi, Naohisa; Kuwabata, Susumu; Miyazawa, Shichiro

    2011-12-01

    An ionic liquid (IL) is a salt that remains in the liquid state at room temperature. It does not vaporize under vacuum and imparts electrical conductivity to samples for observation by scanning electron microscopy (SEM). Recently, the usefulness of ILs has been widely recognized. In our previous study, one of the ILs 1-ethyl-3-methylimidazolium tetrafluoroborate (EtMelm(+) BF(4)(-)) was used for SEM analysis of biological samples. In comparison with the conventional method, samples prepared using EtMelm(+) BF(4)(-) provided more detailed SEM images of the cell ultrastructure, enabling the observation of protrusions. In addition, the IL treatment is a less time consuming and simple method that does not include dehydration, drying, and conductivity treatments, which are an essential parts of the conventional method. In this study, we compared the usefulness of four hydrophobic and three hydrophilic ILs for SEM to observe fixed cultured human A549 cells. All ILs worked well to prevent "charge-up" effect for SEM observation. However, the hydrophilic ILs tended to provide clearer images than the hydrophobic ILs. We concluded that various ILs can be used for SEM sample preparation and their application to a wide range of fields is anticipated in future.

  20. Aerosol generation and characterization of multi-walled carbon nanotubes exposed to cells cultured at the air-liquid interface.

    PubMed

    Polk, William W; Sharma, Monita; Sayes, Christie M; Hotchkiss, Jon A; Clippinger, Amy J

    2016-04-23

    Aerosol generation and characterization are critical components in the assessment of the inhalation hazards of engineered nanomaterials (NMs). An extensive review was conducted on aerosol generation and exposure apparatus as part of an international expert workshop convened to discuss the design of an in vitro testing strategy to assess pulmonary toxicity following exposure to aerosolized particles. More specifically, this workshop focused on the design of an in vitro method to predict the development of pulmonary fibrosis in humans following exposure to multi-walled carbon nanotubes (MWCNTs). Aerosol generators, for dry or liquid particle suspension aerosolization, and exposure chambers, including both commercially available systems and those developed by independent researchers, were evaluated. Additionally, characterization methods that can be used and the time points at which characterization can be conducted in order to interpret in vitro exposure results were assessed. Summarized below is the information presented and discussed regarding the relevance of various aerosol generation and characterization techniques specific to aerosolized MWCNTs exposed to cells cultured at the air-liquid interface (ALI). The generation of MWCNT aerosols relevant to human exposures and their characterization throughout exposure in an ALI system is critical for extrapolation of in vitro results to toxicological outcomes in humans.

  1. Antibacterial activity of the enniatin B, produced by Fusarium tricinctum in liquid culture, and cytotoxic effects on Caco-2 cells.

    PubMed

    Meca, Giuseppe; Sospedra, Isabel; Valero, María Adela; Mañes, Jordi; Font, Guillermina; Ruiz, María José

    2011-09-01

    The enniatins (ENs) are bioactive compounds of hexadepsipeptidic structure produced by several strains of Fusarium sp. The EN B was purified from extracts of Fusarium tricinctum growth on liquid culture of potato dextrose broth (PDB), using a semipreparative liquid chromatography (LC) followed by an analytical LC. The purity and the structure of the isolated compound were confirmed by the determination of the extinction coefficient and with electrospray ionization-mass spectrometry (ESI-MS) study. The pure fraction of EN B was utilized to determine the antibiotic effects on several bacterial strains that are considered normally pathogens of the intestinal tract: Escherichia coli, Enterococcus faecium, Salmonella enterica, Shigella dysenteriae, Listeria monocytogenes, Yersinia enterocolitica, Clostridium perfringens, Pseudomonas aeruginosa, and Staphylococcus aureus, and to study the cytotoxic effects on Caco-2 differentiated and undifferentiated cells. The results obtained demonstrated that in several antibiograms, EN B induced the inhibition of the grown microorganisms tested and no significant differences over control were detected when Caco-2 cells were exposed to EN B, at any of the concentrations used.

  2. Rational optimization of culture conditions for the most efficient ethanol production in Scheffersomyces stipitis using design of experiments.

    PubMed

    Unrean, Pornkamol; Nguyen, Nhung H A

    2012-01-01

    Optimization of culture parameters for achieving the most efficient ethanol fermentation is challenging due to multiple variables involved. Here we presented a rationalized methodology for multi-variables optimization through the design of experiments DoE approach. Three critical parameters, pH, temperature, and agitation speed, affecting ethanol fermentation in S. stipitis was investigated. A predictive model showed that agitation speed significantly affected ethanol synthesis. Reducing pH and temperature also improved ethanol production. The model identified the optimum culture conditions for the most efficient ethanol production with the yield and productivity of 0.46 g/g and 0.28 g/l h, respectively, which is consistent with experimental observation. The results also indicated the scalability of the model from shake flask to bioreactor. Thus, DoE is a promising tool permitting the rapid establishment of culture conditions for the most efficient ethanol fermentation in S. stipitis. The approach could be useful to reduce process development time in lignocellulosic ethanol industry.

  3. Optimization of culturing condition and medium composition for the production of alginate lyase by a marine Vibrio sp. YKW-34

    NASA Astrophysics Data System (ADS)

    Fu, Xiaoting; Lin, Hong; Kim, Sang Moo

    2008-02-01

    Carbohydrases secreted by marine Vibrio sp. YKW-34 with strong Laminaria cell wall degrading ability were screened, and among them alginate lyase was found to be dominant. The effects of medium composition and culturing condition on the production of alginate lyase by marine Vibrio sp. YKW-34 in flask were investigated in this study. In the culture medium of marine broth, no alginate lyase was produced. The activity of the alginate lyase, after being induced, reached 5 UmL-1. The best inoculum volume and inoculum age were 10% and 12 h, respectively. The optimal temperature for alginate lyase production was 25°C. The fermentation medium was composed of 0.5% of Laminaria powder and 0.2% of KNO3 with an initial acidity of pH 8.0. Alginate could induce alginate lyase production but not as efficiently as Laminaria powder did. The addition of fucoidan, cellulose and glucose had negative effect on the alginate lyase production. Other kinds of nitrogen sources, such as yeast extract, beef extract and peptone, had positive effect on the growth of the microorganism and negative effect on alginate lyase production. In addition, the time course of alginate lyase production under the optimized condition was described. The optimal harvest time was 48 h.

  4. The protective effect of Agaricus blazei Murrill, submerged culture using the optimized medium composition, on alcohol-induced liver injury.

    PubMed

    Wang, Hang; Li, Gang; Zhang, Wenyu; Han, Chunchao; Xu, Xin; Li, Yong-Ping

    2014-01-01

    Agaricus blazei Murrill (ABM), an edible mushroom native to Brazil, is widely used for nonprescript and medicinal purposes. Alcohol liver disease (ALD) is considered as a leading cause for a liver injury in modern dietary life, which can be developed by a prolonged or large intake of alcohol. In this study, the medium composition of ABM was optimized using response surface methodology for maximum mycelial biomass and extracellular polysaccharide (EPS) production. The model predicts to gain a maximal mycelial biomass and extracellular polysaccharide at 1.047 g/100 mL, and 0.367 g/100 mL, respectively, when the potato is 29.88 g/100 mL, the glucose is 1.01 g/100 mL, and the bran is 1.02 g/100 mL. The verified experiments showed that the model was significantly consistent with the model prediction and that the trends of mycelial biomass and extracellular polysaccharide were predicted by artificial neural network. After that, the optimized medium was used for the submerged culture of ABM. Then, alcohol-induced liver injury in mice model was used to examine the protective effect of ABM cultured using the optimized medium on the liver. And the hepatic histopathological observations showed that ABM had a relatively significant role in mice model, which had alcoholic liver damage.

  5. Optimizing the culture environment and embryo manipulation to help maintain embryo developmental potential.

    PubMed

    Swain, Jason E; Carrell, Doug; Cobo, Ana; Meseguer, Marcos; Rubio, Carmen; Smith, Gary D

    2016-03-01

    With increased use of comprehensive chromosome screening (CCS), the question remains as to why some practices do not experience the same high levels of clinical success after implementation of the approach. Indeed, the debate surrounding the efficacy and usefulness of blastocyst biopsy and CCS continues. Importantly, several variables impact the success of an assisted reproductive technology cycle. Transfer of a euploid embryo is but one factor in an intricate system that requires numerous steps to occur successfully. Certainly, the culture environment and the manipulations of the embryo during its time in the laboratory can impact its reproductive potential. Environmental stressors ranging from culture media to culture conditions and even culture platform can impact biochemical, metabolic, and epigenetic patterns that can affect the developing cell independent of chromosome number. Furthermore, accompanying procedures, such as biopsy and vitrification, are complex and, when performed improperly, can negatively impact embryo quality. These are areas that likely still carry room for improvement within the IVF laboratory.

  6. Optimized low-level liquid scintillation spectroscopy of 35S for atmospheric and biogeochemical chemistry applications

    PubMed Central

    Brothers, Lauren A.; Dominguez, Gerardo; Abramian, Anna; Corbin, Antoinette; Bluen, Ben; Thiemens, Mark H.

    2010-01-01

    Anthropogenic activities, dominated by emissions of sulfur dioxide (SO2), have perturbed the global sulfur (S) cycle. Uncertainties in timescales of S transport and chemistry in the atmosphere lead to uncertainties in the predicted impact of S emissions. Measurements of cosmogenic 35S may potentially be used to resolve existing uncertainties in the photochemical and chemical transformation of S in the environment. The lack of a simple, effective, and highly sensitive technique to measure 35S activity in samples with low activities may explain the scarcity of published measurements. We present a set of new sample handling and measurement procedures optimized for the measurement of 35S in natural samples with activities as low as 0.20 dpm above background (2σ, integration time = 2 hr). We also report simultaneous measurements of aerosol () and gas phase () collected at inland and coastal locations; the range of observed activities corresponds to SO2 residence lifetimes of 0.2 ± 0.04 (coastal) - 22.3 d ± 0.04 (inland). These optimized techniques offer the potential for resolving atmospheric processes that occur on 6–12-hour timescales as well as resolving transport phenomena such as stratospheric mixing into the troposphere. PMID:20212141

  7. Simultaneous optimization of dense non-aqueous phase liquid (DNAPL) source and contaminant plume remediation.

    PubMed

    Mayer, Alex; Endres, Karen L

    2007-05-14

    A framework is developed for simultaneous, optimal design of groundwater contaminant source removal and plume remediation strategies. The framework allows for varying degrees of effort and cost to be dedicated to source removal versus plume remediation. We have accounted for the presence of physical heterogeneity in the DNAPL source, since source heterogeneity controls mass release into the plume and the efficiency of source removal efforts. We considered high and low estimates of capital and operating costs for chemical flushing removal of the source, since these are expected to vary form site to site. Using the lower chemical flushing cost estimates, it is found that the optimal allocation of funds to source removal or plume remediation is sensitive to the degree of heterogeneity in the source. When the time elapsed between the source release and the implementation of remediation was varied, it was found that, except for the longest elapsed time (50,000 days), a combination of partial source removal and plume remediation was most efficient. When first-order, dissolved contaminant degradation was allowed, source removal was found to be unnecessary for the cases where the degradation rate exceeded intermediate values of the first-order rate constant. Finally, it was found that source removal became more necessary as the degree of aquifer heterogeneity increased.

  8. Combined column-mobile phase mixture statistical design optimization of high-performance liquid chromatographic analysis of multicomponent systems.

    PubMed

    Breitkreitz, Márcia C; Jardim, Isabel C S F; Bruns, Roy E

    2009-02-27

    A statistical approach for the simultaneous optimization of the mobile and stationary phases used in reversed-phase liquid chromatography is presented. Mixture designs using aqueous mixtures of acetonitrile (ACN), methanol (MeOH) and tetrahydrofuran (THF) organic modifiers were performed simultaneously with column type optimization, according to a split-plot design, to achieve the best separation of compounds in two sample sets: one containing 10 neutral compounds with similar retention factors and another containing 11 pesticides. Combined models were obtained by multiplying a linear model for column type, C8 or C18, by quadratic or special cubic mixture models. Instead of using an objective response function, combined models were built for elementary chromatographic criteria (retention factors, resolution and relative retention) of each solute or pair of solutes and, after their validation, the global separation was accomplished by means of Derringer's desirability functions. For neutral compounds a 37:12:8:43 (v/v/v/v) percentage mixture of ACN:MeOH:THF:H2O with the C18 column and for pesticides a 15:15:70 (v/v/v) ACN:THF:H2O mixture with the C8 column provide excellent resolution of all peaks.

  9. Optimization of continuous hydrogen production from co-fermenting molasses with liquid swine manure in an anaerobic sequencing batch reactor.

    PubMed

    Wu, Xiao; Lin, Hongjian; Zhu, Jun

    2013-05-01

    This study investigated and optimized the operational conditions for continuous hydrogen production from sugar beet molasses, co-fermented with liquid swine manure in an anaerobic sequencing batch reactor. Results indicated that pH, HRT and total solids content in the swine manure (TS) had significant impact on all the responses such as biogas production rate (BPR), hydrogen content (HC), hydrogen production rate (HPR), and hydrogen yield (HY), although the highest level of each response was achieved at different combination of the three variables. The maximum BPR, HC, HPR and HY of 32.21 L/d, 30.51%, 2.23 L/d/L and 1.57 mol-H2/mol-sugar were estimated at the optimal pH, HRT, and TS of 5.55, 15.78 h, and 0.71% for BPR; 5.22, 12.04, and 0.69 for HC; 5.32, 15.62, and 0.78% for HPR; and 5.36, 17.56, and 0.74% for HY, respectively. Good linear relationships of the predicted and tested results for all the parameters were observed.

  10. [Optimization of culture condition of a moderately thermophilic acidophilic Ferroplasma thermophilum].

    PubMed

    Zhou, Hongbo; Peng, Juanhua; Zhang, Ruiyong; Chen, Chen; Zhang, Rubing; Gu, Guohua; Qiu, Guanzhou

    2008-06-01

    The extreme microorganisms Ferroplasma spp., play an important role in bioleaching of sulphide ores at low pH value and temperatures around 50 degrees C. Without cell wall, Ferroplasma spp. is sensitive to pulp density, shearing force and heavy metal ions. Thus it is difficult to obtain their high cell density cultures, which limits the large-scale industrial application. In this paper, the optimum culture conditions of Ferroplasma thermophilum were studied by shaking culture. The results showed that the optimum culture conditions are as follows: 50 degrees C, initial pH 0.5, 50 mL working volume in 250 mL shaking-flask, inorganic nitrogen source (NH4)2SO4. The optimum combination of FeSO4.7H2O, yeast extract and peptone was determined by orthogonal experiments, including FeSO4.7H2O 40 g/L, yeast extract 0.3 g/L, peptone 0.2 g/L. Under the optimum culture conditions, the cell density was up to 6.3 x 10(7) cell/mL, and the oxidation of 40 g/L ferrous sulfate heptahydrate was finished in less than 72 hours. The results might provide information for scale-up of archaeon culture as well as its industrial application.

  11. [Determination of exogenous hormones in plant tissue culture media by reversed-phase high performance liquid chromatography].

    PubMed

    Chen, Yongbo; Zhao, Qinghua; Jiang, Qiaolong; Teng, Jianxun

    2008-01-01

    A method of high performance liquid chromatography coupled with photodiode array detector (PAD) was established for the determination of the content ratio and type of 6 exogenous hormones in plant tissue culture media. The column was a microBondaPak C18 (3.9 mm x 300 mm, 10 microm, Waters), the mobile phase was 140 mmol/L sodium acetate in triethyl amine buffer (pH 4.95)-acetonitrile (75:25, v/v), and the flow rate was 1.0 mL/min. The column temperature was 37 degrees C, and the detection wavelength was 285 nm. The six hormones reached the baseline separation in 9 minutes. The linear relationship was very good in the range of 4-200 ng (r2 > 0.9995). The exogenous hormones in the medium were extracted by methanol after vacuum dried. The average recoveries of the exogenous hormones were more than 85%. The method can be used for the analysis of exogenous hormones of plant tissue culture media, or of unknown hormone ratio and the type of media.

  12. Mycobacterial DNA extraction for whole-genome sequencing from early positive liquid (MGIT) cultures.

    PubMed

    Votintseva, Antonina A; Pankhurst, Louise J; Anson, Luke W; Morgan, Marcus R; Gascoyne-Binzi, Deborah; Walker, Timothy M; Quan, T Phuong; Wyllie, David H; Del Ojo Elias, Carlos; Wilcox, Mark; Walker, A Sarah; Peto, Tim E A; Crook, Derrick W

    2015-04-01

    We developed a low-cost and reliable method of DNA extraction from as little as 1 ml of early positive mycobacterial growth indicator tube (MGIT) cultures that is suitable for whole-genome sequencing to identify mycobacterial species and predict antibiotic resistance in clinical samples. The DNA extraction method is based on ethanol precipitation supplemented by pretreatment steps with a MolYsis kit or saline wash for the removal of human DNA and a final DNA cleanup step with solid-phase reversible immobilization beads. The protocol yielded ≥0.2 ng/μl of DNA for 90% (MolYsis kit) and 83% (saline wash) of positive MGIT cultures. A total of 144 (94%) of the 154 samples sequenced on the MiSeq platform (Illumina) achieved the target of 1 million reads, with <5% of reads derived from human or nasopharyngeal flora for 88% and 91% of samples, respectively. A total of 59 (98%) of 60 samples that were identified by the national mycobacterial reference laboratory (NMRL) as Mycobacterium tuberculosis were successfully mapped to the H37Rv reference, with >90% coverage achieved. The DNA extraction protocol, therefore, will facilitate fast and accurate identification of mycobacterial species and resistance using a range of bioinformatics tools.

  13. Differentiation of macrophages from normal human bone marrow in liquid culture. Electron microscopy and cytochemistry.

    PubMed Central

    Bainton, D R; Golde, D W

    1978-01-01

    To study the various stages of human mononuclear phagocyte maturation, we cultivated bone marrow in an in vitro diffusion chamber with the cells growing in suspension and upon a dialysis membrane. At 2, 7, and 14 days, the cultured cells were examined by electron microscopy and cytochemical techniques for peroxidase and for more limited analysis of acid phosphatase and arylsulfatase. Peroxidase was being synthesized in promonocytes of 2- and 7-day cultures, as evidenced by reaction product in the rough-surfaced endoplasmic reticulum, Golgi complex, and storage granules. Peroxidase synthesis had ceased in monocytes and the enzyme appeared only in some granules. By 7 days, large macrophages predominated, containing numerous peroxidase-positive storage granules, and heterophagy of dying cells was evident. By 14 days, the most prevalent cell type was the large peroxidase-negative macrophage. Thus, peroxidase is present in high concentrations in immature cells but absent at later stages, presumably a result of degranulation of peroxidase-positive storage granules. Clusters of peroxidase-negative macrophages with indistinct borders (epithelioid cells), as well as obvious multinucleated giant cells, were noted. Frequently, the interdigitating plasma membranes of neighboring macrophages showed a modification resembling a septate junction--to our knowledge, representing the first documentation of this specialized cell contact between normal macrophages. We suggest that such junctions may serve as zones of adhesion between epithelioid cells. Images PMID:659615

  14. Plant defense responses in opium poppy cell cultures revealed by liquid chromatography-tandem mass spectrometry proteomics.

    PubMed

    Zulak, Katherine G; Khan, Morgan F; Alcantara, Joenel; Schriemer, David C; Facchini, Peter J

    2009-01-01

    Opium poppy (Papaver somniferum) produces a diverse array of bioactive benzylisoquinoline alkaloids, including the narcotic analgesic morphine and the antimicrobial agent sanguinarine. In contrast to the plant, cell cultures of opium poppy do not accumulate alkaloids constitutively but produce sanguinarine in response to treatment with certain fungal-derived elicitors. The induction of sanguinarine biosynthesis provides a model platform to characterize the regulation of benzylisoquinoline alkaloid pathways and other defense responses. Proteome analysis of elicitor-treated opium poppy cell cultures by two-dimensional denaturing-polyacrylamide gel electrophoresis coupled with liquid chromatography-tandem mass spectrometry facilitated the identification of 219 of 340 protein spots based on peptide fragment fingerprint searches of a combination of databases. Of the 219 hits, 129 were identified through pre-existing plant proteome databases, 63 were identified by matching predicted translation products in opium poppy-expressed sequence tag databases, and the remainder shared evidence from both databases. Metabolic enzymes represented the largest category of proteins and included S-adenosylmethionine synthetase, several glycolytic, and a nearly complete set of tricarboxylic acid cycle enzymes, one alkaloid, and several other secondary metabolic enzymes. The abundance of chaperones, heat shock proteins, protein degradation factors, and pathogenesis-related proteins provided a comprehensive proteomics view on the coordination of plant defense responses. Qualitative comparison of protein abundance in control and elicitor-treated cell cultures allowed the separation of induced and constitutive or suppressed proteins. DNA microarrays were used to corroborate increases in protein abundance with a corresponding induction in cognate transcript levels.

  15. Optimization of the open-loop liquid crystal adaptive optics retinal imaging system

    NASA Astrophysics Data System (ADS)

    Kong, Ningning; Li, Chao; Xia, Mingliang; Li, Dayu; Qi, Yue; Xuan, Li

    2012-02-01

    An open-loop adaptive optics (AO) system for retinal imaging was constructed using a liquid crystal spatial light modulator (LC-SLM) as the wavefront compensator. Due to the dispersion of the LC-SLM, there was only one illumination source for both aberration detection and retinal imaging in this system. To increase the field of view (FOV) for retinal imaging, a modified mechanical shutter was integrated into the illumination channel to control the size of the illumination spot on the fundus. The AO loop was operated in a pulsing mode, and the fundus was illuminated twice by two laser impulses in a single AO correction loop. As a result, the FOV for retinal imaging was increased to 1.7-deg without compromising the aberration detection accuracy. The correction precision of the open-loop AO system was evaluated in a closed-loop configuration; the residual error is approximately 0.0909λ (root-mean-square, RMS), and the Strehl ratio ranges to 0.7217. Two subjects with differing rates of myopia (-3D and -5D) were tested. High-resolution images of capillaries and photoreceptors were obtained.

  16. Economic on-line optimization for liquids extraction and treating in gas processing plants

    SciTech Connect

    Berkowitz, P.N.; Gamez, J.P.

    1995-11-01

    Significant changes in the gas processing industry are driving processors to become more dependent on their ability to adapt plant operations to respond to changing third party contracts, wide variability of inlet conditions, plus the volatile market pricing of NGL`s and residue gas in order to remain competitive and profitable. The need for flexible operations at each facility requires an on-line, real time supervisory controller/optimizer that manipulates the process to achieve its economic optimum. Economic optimum does not equal process optimum and the traditional approach of only meeting the control objectives is insufficient for today`s gas plant operations. Because gas plants have no storage of products or residue gas, lost opportunity is immediate with no means to regain lost profitability. The nonlinear characteristics of the process makes typical available control technologies unacceptable for these applications. A new solution that incorporates economics, process dynamics and the economic arrangements of the gas processor has been developed with the cooperation of industry, the Gas Research Institute (GRI) and Continental Controls, Inc. (CCI). The objective function of this software solution is the maximization of profit for the plant and its co-owners. Thus, the optimum set of controlled variables is also dynamic, dependent on product price margins, variability of the inlet gas, and the cost of utilities. This simultaneous control and optimization solution has produced benefits that have paid for the project in as little as two and one half months and typically four to seven months depending on the gas throughput and its richness.

  17. [Experimental study on the optimal treatment schedule for combination of BRM (immunostimulators, cultured killer cells or interleukin-2) and chemotherapy].

    PubMed

    Kan, N; Okino, T; Satoh, K; Mise, K; Teramura, Y; Yamasaki, S; Harada, T; Ohgaki, K; Tobe, T

    1990-08-01

    In the present study we tried to reevaluate the optimal combination timing in the experimental treatment with BRM and chemotherapeutic agents. BALB/c mice with advanced malignant ascites tumor (MOPC 104 E) were treated with cyclophosphamide (CPA, 2 mg/kg) and BRM such as immunostimulator (OK-432, Lentinan or Bestatin), interleukin-2 (IL 2) or cultured killer cells. The survival of mice was prolonged when immunostimulators were given before CPA. However, no combined effect was seen when immunostimulators were administered after CPA. Treatment with cultured killer cells and in vivo IL 2 after immunochemotherapy (immunostimulator followed by CPA) was the most effective protocol in which immunostimulator, chemotherapy, killer cells and IL 2 respectively seemed to induce, regulate, supplement and amplify anti-tumor effector cells.

  18. Optimization of Caco-2 and HT29 co-culture in vitro cell models for permeability studies.

    PubMed

    Pan, Fengguang; Han, Lu; Zhang, Yan; Yu, Yiding; Liu, Jingbo

    2015-01-01

    The purpose of this study was to investigate the appropriate proportion of Caco-2 and HT29 co-culture in vitro cell models for permeability studies. The results showed that the transepithelial electrical resistance values of 9:1 and 1:0 groups (263 ± 3.61 and 300 ± 7.55) after 21-day culture were >250 Ω cm(2), which were suitable for further experiments. The confocal laser microscopy showed that the group of 9:1 (Caco-2:HT29) had the highest integrity, whereas the group of 0:1 (Caco-2:HT29) exhibited the lowest. The staining study confirmed that mucus was successfully produced by HT29 cells, and it was also produced in co-cultures with Caco-2 cells model, but the Caco-2 monocultures did not have any blue staining, which made us affirm that mucus is only produced in the presence of HT29 cells. The real-time PCR results showed that the total highest expression level of ALPi and MUC5AC was the ratio of 9:1 (Caco-2:HT29) and lowest is 1:1 (Caco-2:HT29). So we concluded that 9:1 (Caco-2:HT29) is the optimal Caco-2 to HT29 ratio in the in vitro model co-culture for permeability studies. PMID:26299896

  19. Liquid culture production of microsclerotia and submerged conidia by Trichoderma harzianum active against damping-off disease caused by Rhizoctonia solani.

    PubMed

    Kobori, Nilce N; Mascarin, Gabriel M; Jackson, Mark A; Schisler, David A

    2015-04-01

    Media and culturing protocols were identified that supported the formation of submerged conidia and microsclerotia (MS) by Trichoderma harzianum Rifai strain T-22 using liquid culture fermentation. Liquid media with a higher carbon concentration (36 g L(-1)) promoted MS formation at all C:N ratios tested. Hyphae aggregated to form MS after 2 d growth and after 7 d MS were fully melanized. This is the first report of MS formation by T. harzianum or any species of Trichoderma. Furthermore, submerged conidia formation was induced by liquid culture media, but yields, desiccation tolerance, and storage stability varied with C:N ratio and carbon rate. Air-dried MS granules (<4% moisture) retained excellent shelf life under cool and unrefrigerated storage conditions with no loss in conidial production. A low-cost complex nitrogen source based on cottonseed flour effectively supported high MS yields. Amending potting mix with dried MS formulations reduced or eliminated damping-off of melon seedlings caused by Rhizoctonia solani. Together, the results provide insights into the liquid culture production, stabilization process, and bioefficacy of the hitherto unreported MS of T. harzianum as a potential biofungicide for use in integrated management programs against soilborne diseases. PMID:25813507

  20. Elm tree (Ulmus parvifolia) bark bioprocessed with Mycelia of Shiitake (Lentinus edodes) mushrooms in liquid Culture: Composition and mechanism of protection against allergic asthma in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present study investigated the antiasthma effect of a bioprocessed Ulmus parvifolia bark extract (BPUBE) from Lentinus edodes liquid mycelia culture against allergic asthma biomarkers in U266B1 leukemia cells and OVA-sensitized/challenged mice. BPUBE suppressed total IgE release from U266B1 cel...

  1. Liquid culture production of microsclerotia and submerged conidia by Trichoderma harzianum active against damping-off disease caused by Rhizoctonia solani.

    PubMed

    Kobori, Nilce N; Mascarin, Gabriel M; Jackson, Mark A; Schisler, David A

    2015-04-01

    Media and culturing protocols were identified that supported the formation of submerged conidia and microsclerotia (MS) by Trichoderma harzianum Rifai strain T-22 using liquid culture fermentation. Liquid media with a higher carbon concentration (36 g L(-1)) promoted MS formation at all C:N ratios tested. Hyphae aggregated to form MS after 2 d growth and after 7 d MS were fully melanized. This is the first report of MS formation by T. harzianum or any species of Trichoderma. Furthermore, submerged conidia formation was induced by liquid culture media, but yields, desiccation tolerance, and storage stability varied with C:N ratio and carbon rate. Air-dried MS granules (<4% moisture) retained excellent shelf life under cool and unrefrigerated storage conditions with no loss in conidial production. A low-cost complex nitrogen source based on cottonseed flour effectively supported high MS yields. Amending potting mix with dried MS formulations reduced or eliminated damping-off of melon seedlings caused by Rhizoctonia solani. Together, the results provide insights into the liquid culture production, stabilization process, and bioefficacy of the hitherto unreported MS of T. harzianum as a potential biofungicide for use in integrated management programs against soilborne diseases.

  2. Optimized Dispersive Liquid-Liquid Microextraction Method and High Performance Liquid Chromatography with Ultraviolet Detection for Simultaneous Determination of Sorbic and Benzoic Acids and Evaluation of Contamination of These Preservatives in Iranian Foods.

    PubMed

    Javanmardi, Fardin; Arefhosseini, Seyyed Rafie; Ansarin, Masood; Nemati, Mahboob

    2015-01-01

    A rapid, simple, and sensitive dispersive liquid-liquid microextraction procedure followed by HPLC-UV was applied to determine the benzoate and sorbate in foods. The method was optimized for some variables including extraction solvent type and volume, dispersing solvent type and volume, and the effects of salt and pH. Optimum conditions were determined as follows: sample volume, 5 mL; extraction solvent (chloroform) volume, 250 μL; disperser solvent (acetone) volume, 1.2 mL; NaCl amount, 0.75 g/5 mL at pH 4. Sixty samples were analyzed, including 15 doogh, 15 fruit juice, 15 cookie, and 15 tomato paste; benzoic acid was detected in 57 samples (95%) at levels up to 448.1 μg/mL and sorbic acid in 31 samples (51.6%) at levels up to 1369 μg/mL. Under the optimum experimental conditions, the LOD and LOQ were determined as 0.1 and 0.5 μg/mL for benzoate and 0.08 and 0.3 μg/mL for sorbate, respectively. The results showed that these preservatives are commonly used at high levels in yogurt drinks (dooghs) and cookies. Also, the concentration of benzoic acid that was detected in the tomato paste and fruit juice samples was low but may affect children and sensitive persons.

  3. Development of optimal medium content for bioelements accumulation in Bacopa monnieri (L.) in vitro culture.

    PubMed

    Łojewski, Maciej; Muszyńska, Bożena; Smalec, Agata; Reczyński, Witold; Opoka, Włodzimierz; Sułkowska-Ziaja, Katarzyna

    2014-10-01

    Bacopa monnieri is one of the most interesting plants from the Ayurveda system. The aims of present research were, basing on in vitro shoot culture of B. monnieri, to determine content and to evaluate the influence of physiologically important metabolites on the selected bioelements accumulation in biomass. The most significant increase in biomass production was observed in the culture medium enriched with 0.5 mg/L of anthranilic acid. In this medium also, the highest accumulation of Mg was noted. The highest concentration of iron was determined in B. monnieri in vitro culture enriched with 0.25 g/L of serine. The addition of L-tryptophan, magnesium sulfate, and zinc hydroaspartate caused only a small increase in the accumulation of copper in B. monnieri. Increase in Zn accumulation was obtained in biomass from in vitro culture of B. monnieri with the addition of magnesium sulfate and zinc hydroaspartate. In the case of Na, the maximum level of this element was in biomass from medium enriched with zinc hydroaspartate. Twofold increase in K concentration was obtained in biomass from cultures on medium with addition of serine and magnesium sulfate. The concentrations of Ca in biomass of all studied media were at the similar level.

  4. Innovative use of Mucuna monosperma (Wight) callus cultures for continuous production of melanin by using statistically optimized biotransformation medium.

    PubMed

    Inamdar, Shrirang; Joshi, Swati; Bapat, Vishwas; Jadhav, Jyoti

    2014-01-20

    Melanins are predominantly indolic polymers which are having extensive applications in cosmetics, agriculture and medicine. In the present study, optimization of nutritional parameters influencing melanin production by Mucuna monosperma callus cultures was attempted using the response surface methodology (RSM). Standardization of four factors was carried out using the Box-Behnken design. The optimized levels of factors predicted by the model include tyrosine 0.978gL(-1), pH 5.85, SDS 34.55mgL(-1)and copper sulphate 21.14mgL(-1) tyrosine, which resulted in highest melanin yield of 0.887gL(-1). The optimization of medium using RSM resulted in a 3.06-fold increase in the yield of melanin. The ANOVA analysis showed a significant R(2)-value (0.9995), model F-value (1917.72) and probability (0.0001), with insignificant lack of fit. Optimized medium was used in the laboratory scale column reactor for the continuous production of melanin. Uninterrupted flow column exhibited maximum melanin production rate of 250mgL(-1)h(-1) which is the highest value ever reported using plant as a biotransformation source. Melanin production was confirmed by spectrophotometric and chemical analysis. Thus, this study demonstrates the production of melanin by M. monosperma callus, using a laboratory scale column reactor.

  5. Innovative use of Mucuna monosperma (Wight) callus cultures for continuous production of melanin by using statistically optimized biotransformation medium.

    PubMed

    Inamdar, Shrirang; Joshi, Swati; Bapat, Vishwas; Jadhav, Jyoti

    2014-01-20

    Melanins are predominantly indolic polymers which are having extensive applications in cosmetics, agriculture and medicine. In the present study, optimization of nutritional parameters influencing melanin production by Mucuna monosperma callus cultures was attempted using the response surface methodology (RSM). Standardization of four factors was carried out using the Box-Behnken design. The optimized levels of factors predicted by the model include tyrosine 0.978gL(-1), pH 5.85, SDS 34.55mgL(-1)and copper sulphate 21.14mgL(-1) tyrosine, which resulted in highest melanin yield of 0.887gL(-1). The optimization of medium using RSM resulted in a 3.06-fold increase in the yield of melanin. The ANOVA analysis showed a significant R(2)-value (0.9995), model F-value (1917.72) and probability (0.0001), with insignificant lack of fit. Optimized medium was used in the laboratory scale column reactor for the continuous production of melanin. Uninterrupted flow column exhibited maximum melanin production rate of 250mgL(-1)h(-1) which is the highest value ever reported using plant as a biotransformation source. Melanin production was confirmed by spectrophotometric and chemical analysis. Thus, this study demonstrates the production of melanin by M. monosperma callus, using a laboratory scale column reactor. PMID:24291190

  6. Finite-difference time-domain analysis of a complete transverse electromagnetic cell loaded with liquid biological media in culture dishes.

    PubMed

    Popović, M; Hagness, S C; Taflove, A

    1998-08-01

    Transverse electromagnetic (TEM) cells can be used for exposing biological culture specimens to electromagnetic fields and observing possible anomalous effects. The uniformity of field exposure is critical to quantifying the biological response versus the electromagnetic dose. Standing waves and other electromagnetic field nonuniformities can cause nonuniform exposure. This paper reports the results of high-resolution three-dimensional finite-difference time-domain (FDTD) simulations of a complete TEM cell designed for operation at 837 MHz. Several different cases were studied in which the number of culture dishes, the depth of the culture liquid, and the orientation of the culture dishes were varied. Further, the effect of the culture-dish glass bottom thickness and the meniscus of the liquid medium were examined. The FDTD results show that there is a significant nonuniform field and specific absorption rate (SAR) distribution within the culture medium for each case examined. Hence, biological dose-response experiments using the TEM cells should account for the possibility of strong localized SAR peaking in the culture media to provide useful data in setting exposure standards for wireless communications.

  7. Isolation and analysis of differentially expressed genes during asexual sporulation in liquid static culture of Ganoderma lucidum by suppression subtractive hybridization.

    PubMed

    Xu, Jun-Wei; Zhao, Wei; Xu, Yi-Ning; Zhong, Jian-Jiang

    2012-04-01

    Ganoderma lucidum differentiates in liquid static culture by forming aerial mycelia and asexual spores, and this differentiation process is accompanied by higher production of anti-tumor compounds ganoderic acids. To gain an insight into the molecular events during asexual sporulation of G. lucidum, comparative transcriptome analysis using suppression subtractive hybridization (SSH) technique was performed to identify preferentially expressed genes in liquid static culture vs. in traditional shaking culture. After macroarray analysis of 1920 cDNAs from SSH library, 147 unigenes which exhibited high expression in static culture were identified. Among these sequences, putative translations of 88 unigenes possessed much similarity to known proteins involved in cell organization, signal transduction, cell metabolism, protein biosynthesis and transcription regulation; 13 had significant similarity to hypothetical proteins; the remaining 46 showed little or no similarity to GenBank sequences. RT-qPCR analysis confirmed increases in transcripts of selected genes under liquid static culture condition. The results of this study present the useful application of EST analysis on G. lucidum and provide preliminary indication of gene expression putatively involved in asexual sporulation process.

  8. Optimizing carbon dioxide and light levels during in vitro culture of Theobroma cacao

    SciTech Connect

    Figueira, A.; Janick, J. . Dept. of Horticulture)

    1994-07-01

    In vitro culture of axillary cotyledonary shoots of Theobroma cacao L. (cacao) under increasing CO[sub 2] concentration from ambient to 24,000 ppm (culture tube levels) significantly increased total shoot elongation, number of leaves, leaf area per explant, and shoot dry and fresh weight. Although light was necessary for the CO[sub 2] response, the effect of various photon fluxes was not significant for the measured growth parameters. Net photosynthesis estimated on the basis of CO[sub 2] depletion in culture tubes increased 3.5 times from 463 to 2639 ppm CO[sub 2], and increased 1.5 times from 2,639 to 14,849 ppm CO[sub 2], but declined from 14,849 to 24,015 ppm CO[sub 2]. Ethylene concentration in culture vessels increased under enriched CO[sub 2] conditions. Depletion of nutrients (fructose, K, Ca, Mg, and P) from the medium was increased under enriched CO[sub 2] conditions.

  9. Optimization of in vitro inhibition of HT-29 colon cancer cell cultures by Solanum tuberosum L. extracts.

    PubMed

    Zuber, T; Holm, D; Byrne, P; Ducreux, L; Taylor, M; Kaiser, M; Stushnoff, C

    2015-01-01

    Secondary metabolites in potato have been reported to possess bioactive properties, including growth inhibition of cancer cells. Because potatoes are widely consumed globally, potential health benefits may have broad application. Thus we investigated growth inhibition of HT-29 colon cancer cell cultures by extracts from 13 diverse genetic breeding clones. Extracts from three pigmented selections (CO97226-2R/R, CO97216-1P/P, CO04058-3RW/RW) inhibited growth of in vitro HT-29 cell cultures more effectively than other clones tested. While inhibition was highest from pigmented selections and pigmented tuber tissue sectors, not all pigmented breeding lines tested had appreciable inhibitory properties. Thus, inhibition was not uniquely linked to pigmentation. Immature tubers had the highest inhibitory properties, and in most cases mature tubers retained very low inhibition properties. Flowers and skins inhibited strongly at lower extract concentrations. An extract consisting of 7.2 mg mL⁻¹ cell culture medium was the lowest effective concentration. While raw tuber extracts inhibited most effectively, a few clones at higher concentrations retained inhibition after cooking. Heated whole tubers retained higher inhibition than heated aqueous extracts. While all aqueous extracts from the two tuber selections (CO97216-1P/P and CO97226-2R/R) inhibited HT-29 cell cultures, inhibition was significantly enhanced in purple pigmented tubers of CO97216-1P/P prepared cryogenically as liquid nitrogen powders compared to extracts from freeze dried samples. Upregulation of caspase-3 protease activity, indicative of apoptosis, was highest among the most inhibitory clone samples. The unique sectorial red pigment expressing selection (CO04058-3RW/RW) provided a model system that isolated expression in pigmented sectors, and thus eliminated developmental, environmental and genetic confounding. PMID:25338312

  10. Optimization of in vitro inhibition of HT-29 colon cancer cell cultures by Solanum tuberosum L. extracts.

    PubMed

    Zuber, T; Holm, D; Byrne, P; Ducreux, L; Taylor, M; Kaiser, M; Stushnoff, C

    2015-01-01

    Secondary metabolites in potato have been reported to possess bioactive properties, including growth inhibition of cancer cells. Because potatoes are widely consumed globally, potential health benefits may have broad application. Thus we investigated growth inhibition of HT-29 colon cancer cell cultures by extracts from 13 diverse genetic breeding clones. Extracts from three pigmented selections (CO97226-2R/R, CO97216-1P/P, CO04058-3RW/RW) inhibited growth of in vitro HT-29 cell cultures more effectively than other clones tested. While inhibition was highest from pigmented selections and pigmented tuber tissue sectors, not all pigmented breeding lines tested had appreciable inhibitory properties. Thus, inhibition was not uniquely linked to pigmentation. Immature tubers had the highest inhibitory properties, and in most cases mature tubers retained very low inhibition properties. Flowers and skins inhibited strongly at lower extract concentrations. An extract consisting of 7.2 mg mL⁻¹ cell culture medium was the lowest effective concentration. While raw tuber extracts inhibited most effectively, a few clones at higher concentrations retained inhibition after cooking. Heated whole tubers retained higher inhibition than heated aqueous extracts. While all aqueous extracts from the two tuber selections (CO97216-1P/P and CO97226-2R/R) inhibited HT-29 cell cultures, inhibition was significantly enhanced in purple pigmented tubers of CO97216-1P/P prepared cryogenically as liquid nitrogen powders compared to extracts from freeze dried samples. Upregulation of caspase-3 protease activity, indicative of apoptosis, was highest among the most inhibitory clone samples. The unique sectorial red pigment expressing selection (CO04058-3RW/RW) provided a model system that isolated expression in pigmented sectors, and thus eliminated developmental, environmental and genetic confounding.

  11. Optimization of a 3D Dynamic Culturing System for In Vitro Modeling of Frontotemporal Neurodegeneration-Relevant Pathologic Features.

    PubMed

    Tunesi, Marta; Fusco, Federica; Fiordaliso, Fabio; Corbelli, Alessandro; Biella, Gloria; Raimondi, Manuela T

    2016-01-01

    Frontotemporal lobar degeneration (FTLD) is a severe neurodegenerative disorder that is diagnosed with increasing frequency in clinical setting. Currently, no therapy is available and in addition the molecular basis of the disease are far from being elucidated. Consequently, it is of pivotal importance to develop reliable and cost-effective in vitro models for basic research purposes and drug screening. To this respect, recent results in the field of Alzheimer's disease have suggested that a tridimensional (3D) environment is an added value to better model key pathologic features of the disease. Here, we have tried to add complexity to the 3D cell culturing concept by using a microfluidic bioreactor, where cells are cultured under a continuous flow of medium, thus mimicking the interstitial fluid movement that actually perfuses the body tissues, including the brain. We have implemented this model using a neuronal-like cell line (SH-SY5Y), a widely exploited cell model for neurodegenerative disorders that shows some basic features relevant for FTLD modeling, such as the release of the FTLD-related protein progranulin (PRGN) in specific vesicles (exosomes). We have efficiently seeded the cells on 3D scaffolds, optimized a disease-relevant oxidative stress experiment (by targeting mitochondrial function that is one of the possible FTLD-involved pathological mechanisms) and evaluated cell metabolic activity in dynamic culture in comparison to static conditions, finding that SH-SY5Y cells cultured in 3D scaffold are susceptible to the oxidative damage triggered by a mitochondrial-targeting toxin (6-OHDA) and that the same cells cultured in dynamic conditions kept their basic capacity to secrete PRGN in exosomes once recovered from the bioreactor and plated in standard 2D conditions. We think that a further improvement of our microfluidic system may help in providing a full device where assessing basic FTLD-related features (including PRGN dynamic secretion) that may be

  12. Optimization of a 3D Dynamic Culturing System for In Vitro Modeling of Frontotemporal Neurodegeneration-Relevant Pathologic Features.

    PubMed

    Tunesi, Marta; Fusco, Federica; Fiordaliso, Fabio; Corbelli, Alessandro; Biella, Gloria; Raimondi, Manuela T

    2016-01-01

    Frontotemporal lobar degeneration (FTLD) is a severe neurodegenerative disorder that is diagnosed with increasing frequency in clinical setting. Currently, no therapy is available and in addition the molecular basis of the disease are far from being elucidated. Consequently, it is of pivotal importance to develop reliable and cost-effective in vitro models for basic research purposes and drug screening. To this respect, recent results in the field of Alzheimer's disease have suggested that a tridimensional (3D) environment is an added value to better model key pathologic features of the disease. Here, we have tried to add complexity to the 3D cell culturing concept by using a microfluidic bioreactor, where cells are cultured under a continuous flow of medium, thus mimicking the interstitial fluid movement that actually perfuses the body tissues, including the brain. We have implemented this model using a neuronal-like cell line (SH-SY5Y), a widely exploited cell model for neurodegenerative disorders that shows some basic features relevant for FTLD modeling, such as the release of the FTLD-related protein progranulin (PRGN) in specific vesicles (exosomes). We have efficiently seeded the cells on 3D scaffolds, optimized a disease-relevant oxidative stress experiment (by targeting mitochondrial function that is one of the possible FTLD-involved pathological mechanisms) and evaluated cell metabolic activity in dynamic culture in comparison to static conditions, finding that SH-SY5Y cells cultured in 3D scaffold are susceptible to the oxidative damage triggered by a mitochondrial-targeting toxin (6-OHDA) and that the same cells cultured in dynamic conditions kept their basic capacity to secrete PRGN in exosomes once recovered from the bioreactor and plated in standard 2D conditions. We think that a further improvement of our microfluidic system may help in providing a full device where assessing basic FTLD-related features (including PRGN dynamic secretion) that may be

  13. Statistical analysis of optimal culture conditions for Gluconacetobacter hansenii cellulose production

    SciTech Connect

    Hutchens, Stacy A; Leon, R. V.; O'Neill, Hugh Michael; Evans, Barbara R

    2007-01-01

    The purpose of this study was to analyze the effects of different culture parameters on Gluconacetobacter hansenii (ATCC 10821) to determine which conditions provided optimum cellulose growth. Five culture factors were investigated: carbon source, addition of ethanol, inoculation ratio, pH and temperature. JMP Software (SAS, Cary, NC, USA) was used to design this experiment using a fractional factorial design. After 22 days of static culture, the cellulose produced by the bacteria was harvested, purified and dried to compare the cellulose yields. The results were analyzed by fitting the data to a first-order model with two-factor interactions. The study confirmed that carbon source, addition of ethanol, and temperature were significant factors in the production of cellulose of this G. hansenii strain. While pH alone does not significantly affect average cellulose production, cellulose yields are affected by pH interaction with the carbon source. Culturing the bacteria on glucose at pH 6-5 produces more cellulose than at pH 5-5, while using mannitol at pH 5-5 produces more cellulose than at pH 6-5. The bacteria produced the most cellulose when cultured on mannitol, at pH 5-5, without ethanol, at 20 C. Inoculation ratio was not found to be a significant factor or involved in any significant two-factor interaction. These findings give insight into the conditions necessary to maximize cellulose production from this G. hansenii strain. In addition, this work demonstrates how the fractional factorial design can be used to test a large number of factors using an abbreviated set of experiments. Fitting a statistical model determined the significant factors as well as the significant two-factor interactions.

  14. Principal Leadership: Creating a Culture of Academic Optimism to Improve Achievement for All Students

    ERIC Educational Resources Information Center

    McGuigan, Leigh; Hoy, Wayne K.

    2006-01-01

    Since the Coleman Report (1966), educational researchers have tried to identify school properties that make a difference in student achievement and overcome the negative influence of low socioeconomic status. We theorized that academic optimism was a latent construct that enhanced student achievement and that enabling school structure provided a…

  15. Optimization of hexadecylpyridinium chloride decontamination for culture of Mycobacterium avium subsp. paratuberculosis from milk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cows in advanced stages of Johne’s disease shed Mycobacterium avium subsp. paratuberculosis (MAP) into both their milk and feces, allowing for transmission of the bacteria between animals. The objective of this study was to formulate an optimized protocol for the isolation of MAP from milk and colos...

  16. A novel Fe(III) dependent bioflocculant from Klebsiella oxytoca GS-4-08: culture conditions optimization and flocculation mechanism

    PubMed Central

    Yu, Lei; Tang, Qing-wen; Zhang, Yu-jia; Chen, Rong-ping; Liu, Xin; Qiao, Wei-chuan; Li, Wen-wei; Ruan, Hong-hua; Song, Xin

    2016-01-01

    In this work, the effect of cultivation factors on the flocculation efficiency (FE) of bioflocculant P-GS408 from Klebsiella oxytoca was optimized by the response surface methodology. The most significant factor, i.e. culture time, was determined by gray relational analysis. A total of 240 mg of purified P-GS408 was prepared from 1 liter of culture solution under the optimal conditions. GC-MS analysis results indicated that the polysaccharide of P-GS408 mainly contains Rhamnose and Galactose, and the existence of abundant hydroxyl, carboxyl and amino groups was evidenced by FTIR and XPS analyses. With the aid of Fe3+, the FE of kaolin solution by P-GS408 could achieve 99.48% in ten minutes. Functional groups of polysaccharide were involved in the first adsorption step and the zeta potential of kaolin solution changed from −39.0 mV to 43.4 mV in the presence of Fe3+ and P-GS408. Three-dimensional excitation-emission (EEM) fluorescence spectra demonstrates that the trivalent Fe3+ and Al3+ can bind efficiently with P-GS408, while those univalent and divalent cations cannot. With the help of SEM images, FTIR, zeta potential and EEM spectra, we proposed the P-GS408 flocculation mechanism, which consists of coordination bond combination, charge neutrality, adsorption and bridging, and net catching. PMID:27713559

  17. Selection and optimization of transfection enhancer additives for increased virus-like particle production in HEK293 suspension cell cultures.

    PubMed

    Cervera, Laura; Fuenmayor, Javier; González-Domínguez, Irene; Gutiérrez-Granados, Sonia; Segura, Maria Mercedes; Gòdia, Francesc

    2015-12-01

    The manufacturing of biopharmaceuticals in mammalian cells typically relies on the use of stable producer cell lines. However, in recent years, transient gene expression has emerged as a suitable technology for rapid production of biopharmaceuticals. Transient gene expression is particularly well suited for early developmental phases, where several potential therapeutic targets need to be produced and tested in vivo. As a relatively new bioprocessing modality, a number of opportunities exist for improving cell culture productivity upon transient transfection. For instance, several compounds have shown positive effects on transient gene expression. These transfection enhancers either facilitate entry of PEI/DNA transfection complexes into the cell or nucleus or increase levels of gene expression. In this work, the potential of combining transfection enhancers to increase Gag-based virus-like particle production levels upon transfection of suspension-growing HEK 293 cells is evaluated. Using Plackett-Burman design of experiments, it is first tested the effect of eight transfection enhancers: trichostatin A, valproic acid, sodium butyrate, dimethyl sulfoxide (DMSO), lithium acetate, caffeine, hydroxyurea, and nocodazole. An optimal combination of compounds exhibiting the highest effect on gene expression levels was subsequently identified using a surface response experimental design. The optimal consisted on the addition of 20 mM lithium acetate, 3.36 mM valproic acid, and 5.04 mM caffeine which increased VLP production levels 3.8-fold, while maintaining cell culture viability at 94%. PMID:26278533

  18. Final report-passive safety optimization in liquid sodium-cooled reactors.

    SciTech Connect

    Cahalana, J. E.; Hahn, D.; Nuclear Engineering Division; Korea Atomic Energy Research Inst.

    2007-08-13

    This report summarizes the results of a three-year collaboration between Argonne National Laboratory (ANL) and the Korea Atomic Energy Research Institute (KAERI) to identify and quantify the performance of innovative design features in metallic-fueled, sodium-cooled fast reactor designs. The objective of the work was to establish the reliability and safety margin enhancements provided by design innovations offering significant potential for construction, maintenance, and operating cost reductions. The project goal was accomplished with a combination of advanced model development (Task 1), analysis of innovative design and safety features (Tasks 2 and 3), and planning of key safety experiments (Task 4). Task 1--Computational Methods for Analysis of Passive Safety Design Features: An advanced three-dimensional subassembly thermal-hydraulic model was developed jointly and implemented in ANL and KAERI computer codes. The objective of the model development effort was to provide a high-accuracy capability to predict fuel, cladding, coolant, and structural temperatures in reactor fuel subassemblies, and thereby reduce the uncertainties associated with lower fidelity models previously used for safety and design analysis. The project included model formulation, implementation, and verification by application to available reactor tests performed at EBR-II. Task 2--Comparative Analysis and Evaluation of Innovative Design Features: Integrated safety assessments of innovative liquid metal reactor designs were performed to quantify the performance of inherent safety features. The objective of the analysis effort was to identify the potential safety margin enhancements possible in a sodium-cooled, metal-fueled reactor design by use of passive safety mechanisms to mitigate low-probability accident consequences. The project included baseline analyses using state-of-the-art computational models and advanced analyses using the new model developed in Task 1. Task 3--Safety

  19. Statistically optimized biotransformation protocol for continuous production of L-DOPA using Mucuna monosperma callus culture.

    PubMed

    Inamdar, Shrirang Appasaheb; Surwase, Shripad Nagnath; Jadhav, Shekhar Bhagwan; Bapat, Vishwas Anant; Jadhav, Jyoti Prafull

    2013-01-01

    L-DOPA (3,4-dihydroxyphenyl-L-alanine), a modified amino acid, is an expansively used drug for the Parkinson's disease treatment. In the present study, optimization of nutritional parameters influencing L-DOPA production was attempted using the response surface methodology (RSM) from Mucuna monosperma callus. Optimization of the four factors was carried out using the Box-Behnken design. The optimized levels of factors predicted by the model include tyrosine 0.894 g l(-1), pH 4.99, ascorbic acid 31.62 mg l(-1)and copper sulphate 23.92 mg l(-1), which resulted in highest L-DOPA yield of 0.309 g l(-1). The optimization of medium using RSM resulted in a 3.45-fold increase in the yield of L-DOPA. The ANOVA analysis showed a significant R (2) value (0.9912), model F-value (112.465) and probability (0.0001), with insignificant lack of fit. Optimized medium was used in the laboratory scale column reactor for continuous production of L-DOPA. Uninterrupted flow column exhibited maximum L-DOPA production rate of 200 mg L(-1) h(-1) which is one of the highest values ever reported using plant as a biotransformation source. L-DOPA production was confirmed by HPTLC and HPLC analysis. This study demonstrates the synthesis of L- DOPA using Mucuna monosperma callus using a laboratory scale column reactor. PMID:25674405

  20. Robust optimization for nonlinear time-delay dynamical system of dha regulon with cost sensitivity constraint in batch culture

    NASA Astrophysics Data System (ADS)

    Yuan, Jinlong; Zhang, Xu; Liu, Chongyang; Chang, Liang; Xie, Jun; Feng, Enmin; Yin, Hongchao; Xiu, Zhilong

    2016-09-01

    Time-delay dynamical systems, which depend on both the current state of the system and the state at delayed times, have been an active area of research in many real-world applications. In this paper, we consider a nonlinear time-delay dynamical system of dha-regulonwith unknown time-delays in batch culture of glycerol bioconversion to 1,3-propanediol induced by Klebsiella pneumonia. Some important properties and strong positive invariance are discussed. Because of the difficulty in accurately measuring the concentrations of intracellular substances and the absence of equilibrium points for the time-delay system, a quantitative biological robustness for the concentrations of intracellular substances is defined by penalizing a weighted sum of the expectation and variance of the relative deviation between system outputs before and after the time-delays are perturbed. Our goal is to determine optimal values of the time-delays. To this end, we formulate an optimization problem in which the time delays are decision variables and the cost function is to minimize the biological robustness. This optimization problem is subject to the time-delay system, parameter constraints, continuous state inequality constraints for ensuring that the concentrations of extracellular and intracellular substances lie within specified limits, a quality constraint to reflect operational requirements and a cost sensitivity constraint for ensuring that an acceptable level of the system performance is achieved. It is approximated as a sequence of nonlinear programming sub-problems through the application of constraint transcription and local smoothing approximation techniques. Due to the highly complex nature of this optimization problem, the computational cost is high. Thus, a parallel algorithm is proposed to solve these nonlinear programming sub-problems based on the filled function method. Finally, it is observed that the obtained optimal estimates for the time-delays are highly satisfactory

  1. Optimization of signal versus background in liquid xenon detectors used for dark matter direct detection experiments

    NASA Astrophysics Data System (ADS)

    D'Arcangelo, Francesca D.

    2010-02-01

    The discovery of cosmic acceleration twelve years ago implies that our universe is dominated by dark energy, which is either a tiny cosmological constant or a mysterious fluid with large negative pressure, or that Einstein's successful theory of gravity needs to be modified at large scales/low energies. Since then, independent evidence of a number of cosmological probes has firmly established the picture of a universe where dark energy (or the effective contribution from a modification of gravity) makes up about 72% of the total energy density. Whichever of the options mentioned above will turn out to be the right one, a satisfying explanation for cosmic acceleration will likely lead to important new insights in fundamental physics. The question of the physics behind cosmic acceleration is thus one of the most intriguing open questions in modern physics. In this thesis, we calculate current constraints on dark energy and study how to optimally use the cosmological tools at our disposal to learn about its nature. We will first present constraints from a host of recent data on the dark energy sound speed and equation of state for different dark energy models including early dark energy. We then study the observational properties of purely kinetic k-essence models and show how they can in principle be straightforwardly distinguished from quintessence models by their equation of state behavior. We next consider a large, representative set of dark energy and modified gravity models and show that they can be divided into a small set of observationally distinct classes. We also find that all non-early dark energy models we consider can be modeled extremely well by a simple linear equation of state form. We will then go on to discuss a number of alternative, model independent parametrizations of dark energy properties. Among other things, we find that principal component analysis is not as model-independent as one would like it to be and that assuming a fixed value for the

  2. Optimization of fermentation parameters to study the behavior of selected lactic cultures on soy solid state fermentation.

    PubMed

    Rodríguez de Olmos, A; Bru, E; Garro, M S

    2015-03-01

    The use of solid fermentation substrate (SSF) has been appreciated by the demand for natural and healthy products. Lactic acid bacteria and bifidobacteria play a leading role in the production of novel functional foods and their behavior is practically unknown in these systems. Soy is an excellent substrate for the production of functional foods for their low cost and nutritional value. The aim of this work was to optimize different parameters involved in solid state fermentation (SSF) using selected lactic cultures to improve soybean substrate as a possible strategy for the elaboration of new soy food with enhanced functional and nutritional properties. Soy flour and selected lactic cultures were used under different conditions to optimize the soy SSF. The measured responses were bacterial growth, free amino acids and β-glucosidase activity, which were analyzed by applying response surface methodology. Based on the proposed statistical model, different fermentation conditions were raised by varying the moisture content (50-80%) of the soy substrate and temperature of incubation (31-43°C). The effect of inoculum amount was also investigated. These studies demonstrated the ability of selected strains (Lactobacillus paracasei subsp. paracasei and Bifidobacterium longum) to grow with strain-dependent behavior on the SSF system. β-Glucosidase activity was evident in both strains and L. paracasei subsp. paracasei was able to increase the free amino acids at the end of fermentation under assayed conditions. The used statistical model has allowed the optimization of fermentation parameters on soy SSF by selected lactic strains. Besides, the possibility to work with lower initial bacterial amounts to obtain results with significant technological impact was demonstrated.

  3. Optimization of culture conditions and medium composition for the marine algicidal bacterium Alteromonas sp. DH46 by uniform design

    NASA Astrophysics Data System (ADS)

    Lin, Jing; Zheng, Wei; Tian, Yun; Wang, Guizhong; Zheng, Tianling

    2013-09-01

    Harmful algal blooms (HABs) have led to extensive ecological and environmental issues and huge economic losses. Various HAB control techniques have been developed, and biological methods have been paid more attention. Algicidal bacteria is a general designation for bacteria which inhibit algal growth in a direct or indirect manner, and kill or damage the algal cells. A metabolite which is strongly toxic to the dinoflagellate Alexandrium tamarense was produced by strain DH46 of the alga-lysing bacterium Alteromonas sp. The culture conditions were optimized using a single-factor test method. Factors including carbon source, nitrogen source, temperature, initial pH value, rotational speed and salinity were studied. The results showed that the cultivation of the bacteria at 28°C and 180 r min-1 with initial pH 7 and 30 salt contcentration favored both the cell growth and the lysing effect of strain DH46. The optimal medium composition for strain DH46 was determined by means of uniform design experimentation, and the most important components influencing the cell density were tryptone, yeast extract, soluble starch, NaNO3 and MgSO4. When the following culture medium was used (tryptone 14.0g, yeast extract 1.63g, soluble starch 5.0 g, NaNO3 1.6 g, MgSO4 2.3 g in 1L), the largest bacterial dry weight (7.36 g L-1) was obtained, which was an enhancement of 107% compared to the initial medium; and the algal lysis rate was as high as 98.4% which increased nearly 10% after optimization.

  4. Optimization of fermentation parameters to study the behavior of selected lactic cultures on soy solid state fermentation.

    PubMed

    Rodríguez de Olmos, A; Bru, E; Garro, M S

    2015-03-01

    The use of solid fermentation substrate (SSF) has been appreciated by the demand for natural and healthy products. Lactic acid bacteria and bifidobacteria play a leading role in the production of novel functional foods and their behavior is practically unknown in these systems. Soy is an excellent substrate for the production of functional foods for their low cost and nutritional value. The aim of this work was to optimize different parameters involved in solid state fermentation (SSF) using selected lactic cultures to improve soybean substrate as a possible strategy for the elaboration of new soy food with enhanced functional and nutritional properties. Soy flour and selected lactic cultures were used under different conditions to optimize the soy SSF. The measured responses were bacterial growth, free amino acids and β-glucosidase activity, which were analyzed by applying response surface methodology. Based on the proposed statistical model, different fermentation conditions were raised by varying the moisture content (50-80%) of the soy substrate and temperature of incubation (31-43°C). The effect of inoculum amount was also investigated. These studies demonstrated the ability of selected strains (Lactobacillus paracasei subsp. paracasei and Bifidobacterium longum) to grow with strain-dependent behavior on the SSF system. β-Glucosidase activity was evident in both strains and L. paracasei subsp. paracasei was able to increase the free amino acids at the end of fermentation under assayed conditions. The used statistical model has allowed the optimization of fermentation parameters on soy SSF by selected lactic strains. Besides, the possibility to work with lower initial bacterial amounts to obtain results with significant technological impact was demonstrated. PMID:25498472

  5. Efficient, validated method for detection of mycobacterial growth in liquid culture media by use of bead beating, magnetic-particle-based nucleic acid isolation, and quantitative PCR.

    PubMed

    Plain, Karren M; Waldron, Anna M; Begg, Douglas J; de Silva, Kumudika; Purdie, Auriol C; Whittington, Richard J

    2015-04-01

    Pathogenic mycobacteria are difficult to culture, requiring specialized media and a long incubation time, and have complex and exceedingly robust cell walls. Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of Johne's disease, a chronic wasting disease of ruminants, is a typical example. Culture of MAP from the feces and intestinal tissues is a commonly used test for confirmation of infection. Liquid medium offers greater sensitivity than solid medium for detection of MAP; however, support for the BD Bactec 460 system commonly used for this purpose has been discontinued. We previously developed a new liquid culture medium, M7H9C, to replace it, with confirmation of growth reliant on PCR. Here, we report an efficient DNA isolation and quantitative PCR methodology for the specific detection and confirmation of MAP growth in liquid culture media containing egg yolk. The analytical sensitivity was at least 10(4)-fold higher than a commonly used method involving ethanol precipitation of DNA and conventional PCR; this may be partly due to the addition of a bead-beating step to manually disrupt the cell wall of the mycobacteria. The limit of detection, determined using pure cultures of two different MAP strains, was 100 to 1,000 MAP organisms/ml. The diagnostic accuracy was confirmed using a panel of cattle fecal (n=54) and sheep fecal and tissue (n=90) culture samples. This technique is directly relevant for diagnostic laboratories that perform MAP cultures but may also be applicable to the detection of other species, including M. avium and M. tuberculosis.

  6. Benefits and limitations of modeling for optimization of Porphyridium cruentum cultures in an annular photobioreactor.

    PubMed

    Muller-Feuga, Arnaud; Le Guédes, Roland; Pruvost, Jérémy

    2003-06-26

    A deterministic Markov process was developed to estimate the efficiency of a fully controlled photobioreactor by calculating the growth of the Rhodophyte Porphyridium cruentum. It was assumed that microalgal growth, in strictly controlled and non-nutrient-limited conditions, is a function of the amount of light energy received. The light sources delivered a continuous 206 microE m(-2) s(-1) average photon flux density to cultures reaching concentrations of 3 g l(-1) in batch and 0.7 g l(-1) in chemostat. The concentration time-courses calculated compared satisfactorily with measured results for both batch and continuous cultures. The quality of simulation in these two cases validated the hypotheses made, especially for the linearity of light bioconversion, and allowed the model to be used for further exploration of the photobioreactor-operating domain. Distribution of the specific growth rate as a function of time and radial position was compared for the two simulated cases. The use of an initial batch of several days prior to the dilution of a continuous culture proved theoretically beneficial for overall production. The influence of the dilution rate and of light-path length on surface productivity and concentration at steady state were demonstrated.

  7. Optimizing the selection process of yeast starter cultures by preselecting strains dominating spontaneous fermentations.

    PubMed

    Pulvirenti, Andrea; Rainieri, Sandra; Boveri, Silvio; Giudici, Paolo

    2009-03-01

    We propose an efficient and time-saving strategy for starter culture selection. Our approach is based on the accomplishment of 3 phases: (i) the selection of yeast strains dominating spontaneous fermentations, (ii) the selection among the dominant strains of those showing the best technological characteristics, and (iii) the final selection among good technological strains of those showing the desired qualitative traits. We applied this approach to wine fermentations, even though the same strategy has the potential to be employed for the selection of any type of starter culture. We isolated and identified yeast strains at the mid- and final stages of 6 spontaneous fermentations carried out in 3 different Spanish wineries. We identified all strains as Saccharomyces cerevisiae by restriction fragment length polymorphism of the ribosomal DNA internal transcribed spacer region, and subsequently distinguished each strain by analyzing the polymorphism of the inter-delta regions. Strains that were detected both at the mid- and final stages of the fermentation were considered dominant. Four dominant strains were finally selected and tested in pilot-scale fermentation, and their performance was compared with that of a commercial wine strain. All dominant strains showed good fitness and resulted suitable to be employed as starter cultures. One of the dominant strains isolated in this study is currently commercialized.

  8. The Optimization of an Ionic Liquid-Based TALSPEAK-Like Process for Rare Earth Ions Separation

    SciTech Connect

    Dai, Sheng; Sun, Xiaoqi; Luo, Huimin

    2014-01-01

    Five new functionalized ionic liquids (FILs), tetraethylammonium di(2-ethylhexyl)phosphate ([N2222][DEHP]), tetraethylammonium bis(2,4,4-trimethylpentyl)phosphinite ([N2222][BTMPP]), tetraethylammonium bis(2,4,4-trimethylpentyl)dithiophosphinite ([N2222][BTMPDTP]), tetrahexylammonium di(2-ethylhexyl)phosphate ([N6666][DEHP]), and tetraoctylammonium di(2-ethylhexyl)phosphate ([N8888][DEHP]) were synthesized and characterized. These ILs along with two previously synthesized FILs ([N4444][DEHP] & [N1888][DEHP]) were used as ionic extractants and investigated for rare earth elements (REEs) separation in 1-decyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide/bis(perfluoroethanesulfonyl)imide ([C10mim][NTf2]/[BETI]). These FILs as ionic extractants were miscible with [C10mim][NTf2]/[BETI]. We herein report the applications of these FILs in an IL-based TALSPEAK-like process and the optimization of the process by adjusting the cations and anions of the FILs, concentrations of the FILs as ionic extractants in the IL phase, concentrations of diethylenetriamine pentaacetic acid (DTPA) in the aqueous phase, and acidities of the aqueous phase.

  9. Optimized ultra performance liquid chromatography tandem high resolution mass spectrometry method for the quantification of paraquat in plasma and urine.

    PubMed

    Lu, Haihua; Yu, Jing; Wu, Linlin; Xing, Jingjing; Wang, Jun; Huang, Peipei; Zhang, Jinsong; Xiao, Hang; Gao, Rong

    2016-08-01

    A simple, sensitive and specific ultra performance liquid chromatography coupled to electrospray tandem high resolution mass spectrometry (UPLC-ESI-HRMS/MS) method has been developed and validated for quantification of paraquat in plasma and urine. The sample preparation was carried out by one-step protein precipitation with acetonitrile. The paraquat was separated with a HILIC column in 10min. Detection was performed using Q Exactive Orbitrap mass spectrometer by Targeted-MS/MS scan mode. Methodological parameters, such as ammonium formate concentration, formic acid concentration, spray voltage, capillary temperature, heater temperature and normalized collision energy were optimized to achieve the highest sensitivity. The calibration curve was linear over the concentration range of LOQ-1000ng/mL. LOD was 0.1 and 0.3ng/mL, LOQ was 0.3 and 0.8ng/mL for urine and plasma, respectively. The intra- and inter-day precisions were <7.97% and 4.78% for plasma and urine. The accuracies were within the range 93.51-100.90%. The plasma and urine matrices had negligible relative matrix effect in this study. This method was successfully applied to determine paraquat concentration in plasma samples with hemoperfusion from 5 suspected paraquat poisoning patients. PMID:27270261

  10. Development of optimal liquid based cytology sample processing methods for HPV testing: minimising the 'inadequate' test result.

    PubMed

    Peevor, R; Jones, J; Fiander, A N; Hibbitts, S

    2011-05-01

    Incorporation of HPV testing into cervical screening is anticipated and robust methods for DNA extraction from liquid based cytology (LBC) samples are required. This study compared QIAamp extraction with Proteinase K digestion and developed methods to address DNA extraction failure (β-globin PCR negative) from clinical specimens. Proteinase K and QIAamp extraction methods in paired LBC samples were comparable with adequate DNA retrieved from 93.3% of clinical specimens. An HPV prevalence cohort (n=10,000) found 7% (n=676) LBC samples tested negative for β-globin, and were classified as inadequate. This 'failure' rate is unsuitable for population screening, particularly as the sampling method is intrusive. 379/676 samples were assessed to determine the cause of test failure. Re-testing confirmed adequate DNA in 21.6% of the original extracts; re-extraction from stored material identified 56.2% samples contained adequate material; dilution to overcome sample inhibition (1:10) resolved 51.7% cases in original extracts and 28% in new extracts. A standardised approach to HPV testing with an optimal DNA concentration input rather than standard volume input is recommended. Samples failing initial DNA extraction should be repeat extracted and assessed for sample inhibition to reduce the 7% of HPV tests being reported as inadequate and reduce the need for retesting of those women to <1%.

  11. Statistical optimization of culture medium for production of exopolysaccharide from endophytic fungus Bionectria ochroleuca and its antitumor effect in vitro

    PubMed Central

    Li, Yun; Guo, Shoujun; Zhu, Hui

    2016-01-01

    Endophytic fungi have been recognized as possible useful sources of bioactive metabolites. However, exopolysaccharide (EPS) production from endophytic fungi and its antitumor activity have been less explored. In the present study, endophtic fungus Bionectria ochroleuca M21 was exploited for the production of EPS in submerged culture. Among tested medium components, glucose, yeast extract, MgSO4 and Tween80 were found to be effective and significant on EPS production. Response surface methodology (RSM) was employed to optimize medium composition. The results showed that the significant factors were glucose, yeast extract and Tween80. The optimal medium was observed at the composition of glucose 55.7 g/L, yeast extract 6.04 g/L, MgSO4 0.25g/L and Tween80 0.1 % (v/v). Using the optimized medium, EPS production was achieve at 2.65 ± 0.16 g/L after 4 days fermentation in a 5L bioreactor. Examination of cytotoxicity showed that the EPS from B. ochroleuca M21 did not have cytotoxic activity on human liver HL-7702 cells at concentration 0.025-1.6 mg/mL. In contrast, the EPS exhibited antiproliferative activities against cell lines of liver cancer (HepG2), gastric cancer (SGC-7901) and colon cancer (HT29) in a dose- and time-dependent manner in the concentration ranges of 0.1-0.45 mg/mL. PMID:27330527

  12. Response surface optimization of culture medium for enhanced docosahexaenoic acid production by a Malaysian thraustochytrid

    PubMed Central

    Manikan, Vidyah; Kalil, Mohd Sahaid; Hamid, Aidil Abdul

    2015-01-01

    Docosahexaenoic acid (DHA, C22:6n-3) plays a vital role in the enhancement of human health, particularly for cognitive, neurological, and visual functions. Marine microalgae, such as members of the genus Aurantiochytrium, are rich in DHA and represent a promising source of omega-3 fatty acids. In this study, levels of glucose, yeast extract, sodium glutamate and sea salt were optimized for enhanced lipid and DHA production by a Malaysian isolate of thraustochytrid, Aurantiochytrium sp. SW1, using response surface methodology (RSM). The optimized medium contained 60 g/L glucose, 2 g/L yeast extract, 24 g/L sodium glutamate and 6 g/L sea salt. This combination produced 17.8 g/L biomass containing 53.9% lipid (9.6 g/L) which contained 44.07% DHA (4.23 g/L). The optimized medium was used in a scale-up run, where a 5 L bench-top bioreactor was employed to verify the applicability of the medium at larger scale. This produced 24.46 g/L biomass containing 38.43% lipid (9.4 g/L), of which 47.87% was DHA (4.5 g/L). The total amount of DHA produced was 25% higher than that produced in the original medium prior to optimization. This result suggests that Aurantiochytrium sp. SW1 could be developed for industrial application as a commercial DHA-producing microorganism. PMID:25721623

  13. Optimization of an accelerated solvent extraction dispersive liquid-liquid microextraction method for the separation and determination of essential oil from Ligusticum chuanxiong Hort by gas chromatography with mass spectrometry.

    PubMed

    Yang, Guang; Sun, Qiushi; Hu, Zhiyan; Liu, Hua; Zhou, Tingting; Fan, Guorong

    2015-10-01

    In this study, an accelerated solvent extraction dispersive liquid-liquid microextraction coupled with gas chromatography and mass spectrometry was established and employed for the extraction, concentration and analysis of essential oil constituents from Ligusticum chuanxiong Hort. Response surface methodology was performed to optimize the key parameters in accelerated solvent extraction on the extraction efficiency, and key parameters in dispersive liquid-liquid microextraction were discussed as well. Two representative constituents in Ligusticum chuanxiong Hort, (Z)-ligustilide and n-butylphthalide, were quantitatively analyzed. It was shown that the qualitative result of the accelerated solvent extraction dispersive liquid-liquid microextraction approach was in good agreement with that of hydro-distillation, whereas the proposed approach took far less extraction time (30 min), consumed less plant material (usually <1 g, 0.01 g for this study) and solvent (<20 mL) than the conventional system. To sum up, the proposed method could be recommended as a new approach in the extraction and analysis of essential oil. PMID:26304788

  14. Optimization of an accelerated solvent extraction dispersive liquid-liquid microextraction method for the separation and determination of essential oil from Ligusticum chuanxiong Hort by gas chromatography with mass spectrometry.

    PubMed

    Yang, Guang; Sun, Qiushi; Hu, Zhiyan; Liu, Hua; Zhou, Tingting; Fan, Guorong

    2015-10-01

    In this study, an accelerated solvent extraction dispersive liquid-liquid microextraction coupled with gas chromatography and mass spectrometry was established and employed for the extraction, concentration and analysis of essential oil constituents from Ligusticum chuanxiong Hort. Response surface methodology was performed to optimize the key parameters in accelerated solvent extraction on the extraction efficiency, and key parameters in dispersive liquid-liquid microextraction were discussed as well. Two representative constituents in Ligusticum chuanxiong Hort, (Z)-ligustilide and n-butylphthalide, were quantitatively analyzed. It was shown that the qualitative result of the accelerated solvent extraction dispersive liquid-liquid microextraction approach was in good agreement with that of hydro-distillation, whereas the proposed approach took far less extraction time (30 min), consumed less plant material (usually <1 g, 0.01 g for this study) and solvent (<20 mL) than the conventional system. To sum up, the proposed method could be recommended as a new approach in the extraction and analysis of essential oil.

  15. Evidence for the involvement of nematocidal toxins of Purpureocillium lilacinum 6029 cultured on Karanja deoiled cake liquid medium.

    PubMed

    Sharma, Abhishek; Sharma, Satyawati; Mittal, Aditya; Naik, S N

    2016-05-01

    In present study, in vitro nematocidal bioassays, FT-IR and HPLC analysis were employed to demonstrate the involvement of toxins of Purpureocillium lilacinum in killing root-knot nematodes (Meloidogyne incognita). During growth study, maximum mycelial biomass (10.52 g/l) in de-oiled Karanja cake medium was achieved on 8th day while complete mortality of nematodes was obtained by 6th day filtrate (FKSM). Maximum production of crude nematocidal toxin was recorded on 7th day suggesting that the toxin production was paralleled with growth of the fungus. The median lethal concentration (LC50) determined for the crude toxin from 6th day to 10th day ranged from 89.41 to 43.21 ppm. The median lethal time (LT50) for the crude toxin of FKSM was found to be 1.46 h. This is the first report of implementing a comparative infra-red spectroscopy coupled with HPLC analysis to predict the presence of nematocidal toxin in the fungal filtrate cultured on Karanja deoiled cake liquid medium.

  16. Proteomic mapping of bezafibrate-treated human hepatocytes in primary culture using two-dimensional liquid chromatography.

    PubMed

    Alvergnas, M; Rouleau, A; Lucchi, G; Heyd, B; Ducoroy, P; Richert, L; Martin, H

    2011-03-01

    Peroxisome proliferators have been extensively studied in rodents and are known to induce liver tumors, whereas the effects of these compounds are not very clearly identified in humans when they are widely exposed to herbicides, plasticizers, solvents or drugs such as the lipid-lowering fibrate bezafibrate (BEZA). We assessed the effect of BEZA on human hepatocyte proteome. Hepatocyte proteins, including those membrane-associated, were successfully extracted and separated using 2D-liquid chromatography (PF2D, Beckman coulter). Proteins that were regulated by ≥ 1.5 fold compared to controls were identified by mass spectrometry (MALDI-TOF, Bruker Daltonics) and SwissProt bank search. BEZA modified the expression of proteins involved in various metabolic pathways as well as in cell homeostasis. No marker of peroxisome proliferation was obtained but surprisingly the expression of proteins involved in liver carcinogenicity was modulated. The co-treatment of cultures with N-acetylcysteine modified the set of proteins regulated by BEZA, either by a potentiation or an inhibition of the effects. Our study points out that the hepatocellular redox environment has to be taken into account when using fibrates in therapeutics.

  17. Degradation of Chlorobenzenes at Nanomolar Concentrations by Burkholderia sp. Strain PS14 in Liquid Cultures and in Soil

    PubMed Central

    Rapp, Peter; Timmis, Kenneth N.

    1999-01-01

    The utilization of 1,2,4,5-tetrachloro-, 1,2,4-trichloro-, the three isomeric dichlorobenzenes and fructose as the sole carbon and energy sources at nanomolar concentrations was studied in batch experiments with Burkholderia sp. strain PS14. In liquid culture, all chlorobenzenes were metabolized within 1 h from their initial concentration of 500 nM to below their detection limits of 0.5 nM for 1,2,4,5-tetrachloro- and 1,2,4-trichlorobenzene and 7.5 nM for the three dichlorobenzene isomers, with 63% mineralization of the tetra- and trichloroisomers. Fructose at the same initial concentration was, in contrast, metabolized over a 4-h incubation period down to a residual concentration of approximately 125 nM with 38% mineralization during this time. In soil microcosms, Burkholderia sp. strain PS14 metabolized tetrachlorobenzene present at 64.8 ppb and trichlorobenzene present at 54.4 ppb over a 72-h incubation period to below the detection limits of 0.108 and 0.09 ppb, respectively, with approximately 80% mineralization. A high sorptive capacity of Burkholderia sp. strain PS14 for 1,2,4,5-tetrachlorobenzene was found at very low cell density. The results demonstrate that Burkholderia sp. strain PS14 exhibits a very high affinity for chlorobenzenes at nanomolar concentrations. PMID:10347041

  18. Inhibition of aflatoxin metabolism and growth of Aspergillus flavus in liquid culture by a DNA methylation inhibitor.

    PubMed

    Yang, Kunlong; Zhuang, Zhenhong; Zhang, Feng; Song, Fengqin; Zhong, Hong; Ran, Fanlei; Yu, Song; Xu, Gaopo; Lan, Faxiu; Wang, Shihua

    2015-01-01

    Aflatoxins (AFs) are a group of highly oxygenated polyketidese-derived toxins mainly produced by Aspergillus flavus and A. parasiticus, whose biosynthesis mechanisms are extremely sophisticated. Methylation is known as the major form of epigenetic regulation, which is correlated with gene expression. As the DNA methylation inhibitor 5-azacytidine (5-AC) blocks AF production, we studied AFB1 metabolism and morphological changes of A. flavus by treatment with 5-AC in liquid culture. The results show that 5-AC caused a decrease in AF production and concurrent changes in morphology. In addition, we isolated a non-aflatoxigenic mutant of A. flavus, showing a significant reduction in pigment production, after 5-AC treatment. This mutant showed significant reduction in the expression of genes in the AF biosynthesis pathway, and conidia formation. Furthermore, as AF biosynthesis and oxidative stress are intimately related events, we assessed the viability of A. flavus to oxidative stress after treatment with 5-AC, which showed that the mutant was more sensitive to the strong oxidant hydrogen peroxide. We found that the non-aflatoxigenic mutant showed a decrease in reactive oxygen species (ROS) and metabolites indicative of oxidative stress, which may be caused by the disruption of the defence system against excessive ROS formation after 5-AC treatment. These data indicate that 5-AC, as an inactivator of DNA methyltransferase, plays a very important role in AFB1 metabolism and the development of A. flavus, which might provide an effective strategy to pre- or post-harvest control of AFs. PMID:25312249

  19. Magnetic Nanodrug Delivery Through the Mucus Layer of Air-Liquid Interface Cultured Primary Normal Human Tracheobronchial Epithelial Cells

    PubMed Central

    Economou, E. C.; Marinelli, S.; Smith, M. C.; Routt, A. A.; Kravets, V. V.; Chu, H. W.; Spendier, K.; Celinski, Z. J.

    2016-01-01

    Superparamagnetic iron oxide (Fe3O4) and highly anisotropic barium hexaferrite (BaFe12O19) nanoparticles were coated with an anti-inflammatory drug and magnetically transported through mucus produced by primary human airway epithelial cells. Using wet planetary ball milling, dl-2-amino-3-phosphonopropionic acid-coated BaFe12O19 nano-particles (BaNPs) of 1–100 nm in diameter were prepared in water. BaNPs and conventional 20–30-nm Fe3O4 nanoparticles (FeNPs) were then encased in a polymer (PLGA) loaded with dexamethasone (Dex) and tagged for imaging. PLGA-Dex-coated BaNPs and FeNPs were characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), and superconducting quantum interference device (SQUID) magnetometry. Both PLGA-Dex-coated BaNPs and FeNPs were transferred to the surface of a ~100-μm thick mucus layer of air-liquid interface cultured primary normal human tracheobronchial epithelial (NHTE) cells. Within 30 min, the nanoparticles were pulled successfully through the mucus layer by a permanent neodymium magnet. The penetration time of the nanomedicine was monitored using confocal microscopy and tailored by varying the thickness of the PLGA-Dex coating around the particles. PMID:27774374

  20. A novel method to optimize culture conditions for biomass and sporulation of the entomopathogenic fungus Beauveria bassiana IBC1201

    PubMed Central

    Gao, Li

    2011-01-01

    Biomass yields and sporulation of Beauveria bassiana was concerned on culture conditions, environmental factors and cultivation method. We optimized the best culture conditions for biomass yields of B. bassiana IBC1201 with the novel “two-stage” cultivation method as well as orthogonal matrix method. Firstly, we cultured spore suspension on the basal medium (sucrose 19.00 g, soy peptone 4.06 g, K2HPO4 1.00 g, KCl 0.50 g, MgSO4 0.50 g, FeSO4 0.10 g and 17.00 g Bactor) for the first stage culture of 4 days under room condition. Then, we transferred them to another defined medium (Cellobiose 9.52 g, urea 1.70 g, ZnSO4•7H2O 0.05 g/L, MnSO4•H2O 0.005 g/L, CaCl2 1.00 g/L, CuSO4•5H2O 0.05 g/L and 17.00 g Bactor) for more 4 days cultivation with the environmental factors combination of water potential -1.2 MPa /pH 3 /12 h light cycle/23 ℃ for biomass yields, and with the environmental factors combination of water potential -0.8 MPa /pH 3 /24 h light cycle/23 ℃ for spore yields. These results provided important information for mass production (including biomass and spore yields) of this great potential biocontrol fungus. PMID:24031792

  1. Air-liquid interface cultures enhance the oxygen supply and trigger the structural and functional differentiation of intestinal porcine epithelial cells (IPEC).

    PubMed

    Nossol, Constanze; Diesing, A-K; Walk, N; Faber-Zuschratter, H; Hartig, R; Post, A; Kluess, J; Rothkötter, H-J; Kahlert, S

    2011-07-01

    The specific function of the epithelium as critical barrier between the intestinal lumen and the organism's internal microenvironment is reflected by permanent maintenance of intercellular junctions and cellular polarity. The intestinal epithelial cells are responsible for absorption of nutritional components, facing mechanical stress and a changing oxygen supplementation via blood stream. Oxygen itself can regulate the barrier and the absorptive function of the epithelium. Therefore, we compared the dish cell culture, the transwell-like membrane culture and the oxygen enriched air-liquid interface (ALI) culture. We demonstrated strong influence of the different culture conditions on morphology and function of intestinal porcine epithelial cell lines in vitro. ALI culture resulted in a significant increase in cell number, epithelial cell layer thickness and expression as well as apical localisation of the microvilli-associated protein villin. Remarkable similarities regarding the morphological parameters were observed between ALI cultures and intestinal epithelial cells in vivo. Furthermore, the functional analysis of protein uptake and degradation by the epithelial cells demonstrated the necessity of sufficient oxygen supply as achieved in ALI cultures. Our study is the first report providing marked evidence that optimised oxygen supply using ALI cultures directly affects the morphological differentiation and functional properties of intestinal epithelial cells in vitro.

  2. Characterization of eight terpenoids from tissue cultures of the Chinese herbal plant, Tripterygium wilfordii, by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

    PubMed

    Su, Ping; Cheng, Qiqing; Wang, Xiujuan; Cheng, Xiaoqing; Zhang, Meng; Tong, Yuru; Li, Fei; Gao, Wei; Huang, Luqi

    2014-09-01

    In this study, a reliable method for analysis and identification of eight terpenoids in tissue cultures of Tripterygium wilfordii has been established using high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC-ESI-MS). Our study indicated that sterile seedlings, callus cultures and cell-suspension cultures can rapidly increase the amount of biological materials. HPLC-ESI-MS was used to identify terpenoids from the extracts of these tissue cultures. Triptolide, triptophenolide, celastrol and wilforlide A were unambiguously determined by comparing the retention times, UV spectral data, and mass fragmentation behaviors with those of the reference compounds. Another four compounds were tentatively identified as triptonoterpenol, triptonoterpene, 22β-hydroxy-3-oxoolean-12-en-29-oic acid and wilforlide B, based on their UV and mass spectrometry spectra. The quantitative analysis showed that all three materials contain triptolide, triptophenolide, celastrol, wilforlide A, and the contents of the four compounds in the cell-suspension cultures were 53.1, 240, 129 and 964 µg/g, respectively, which were at least 2.0-fold higher than these in the sterile seedlings and callus cultures. Considering the known pharmacological activity of triptolide and celastrol, we recommend the cell-suspension cultures as biological materials for future studies, such as clinical and toxicological studies. The developed method was validated by the evaluation of its precision, linearity, detection limits and recovery, and it was successfully used to identify and quantify the terpenoids in the tissue cultures.

  3. Biological upgrading of coal liquids. Final report

    SciTech Connect

    1995-02-01

    A large number of bacterial enrichments have been developed for their ability to utilize nitrogen and sulfur in coal liquids and the model compound naphtha. These bacteria include the original aerobic bacteria isolated from natural sources which utilize heteroatom compounds in the presence of rich media, aerobic nitrogen-utilizing bacteria and denitrifying bacteria. The most promising isolates include Mix M, a mixture of aerobic bacteria; ER15, a pyridine-utilizing isolate; ERI6, an aniline-utilizing isolate and a sewage sludge isolate. Culture optimization experiments have led to these bacteria being able to remove up to 40 percent of the sulfur and nitrogen in naphtha and coal liquids in batch culture. Continuous culture experiments showed that the coal liquid is too toxic to the bacteria to be fed without dilution or extraction. Thus either semi-batch operation must be employed with continuous gas sparging into a batch of liquid, or acid extracted coal liquid must be employed in continuous reactor studies with continuous liquid flow. Isolate EN-1, a chemical waste isolate, removed 27 percent of the sulfur and 19 percent of the nitrogen in fed batch experiments. Isolate ERI5 removed 28 percent of the nitrogen in coal liquid in 10 days in fed batch culture. The sewage sludge isolate removed 22.5 percent of the sulfur and 6.5 percent of the nitrogen from extracted coal liquid in continuous culture, and Mix M removed 17.5 percent of the nitrogen from medium containing extracted coal liquid. An economic evaluation has been prepared for the removal of nitrogen heteroatom compounds from Wilsonville coal liquid using acid extraction followed by fermentation. Similar technology can be developed for sulfur removal. The evaluation indicates that the nitrogen heteroatom compounds can be removed for $0.09/lb of coal liquid treated.

  4. Inhibition of Listeria monocytogenes and Escherichia coli O157:H7 in liquid broth medium and during processing of fermented sausage using autochthonous starter cultures.

    PubMed

    Pragalaki, T; Bloukas, J G; Kotzekidou, P

    2013-11-01

    The antimicrobial effect of two autochthonous starter cultures of Lactobacillus sakei was evaluated in vitro (in liquid broth medium) and in situ assays. The inactivation of foodborne pathogens Listeria monocytogenes (serotype 4ab No 10) and Escherichia coli O157:H7 ATCC 43888 was investigated during the production of fermented sausage according to a typical Greek recipe using L. sakei strains as starter cultures. The inactivation kinetics were modeled using GInaFiT, a freeware tool to assess microbial survival curves. By the end of the ripening period, the inhibition of L. monocytogenes was significant in treatments with L. sakei 8416 and L. sakei 4413 compared to the control treatment. A 2.2-log reduction of the population of E. coli O157:H7 resulted from the autochthonous starter culture L. sakei 4413 during sausage processing. The use of the autochthonous starter cultures constitutes an additional improvement to the microbial safety by reducing foodborne pathogens. PMID:23793080

  5. Inhibition of Listeria monocytogenes and Escherichia coli O157:H7 in liquid broth medium and during processing of fermented sausage using autochthonous starter cultures.

    PubMed

    Pragalaki, T; Bloukas, J G; Kotzekidou, P

    2013-11-01

    The antimicrobial effect of two autochthonous starter cultures of Lactobacillus sakei was evaluated in vitro (in liquid broth medium) and in situ assays. The inactivation of foodborne pathogens Listeria monocytogenes (serotype 4ab No 10) and Escherichia coli O157:H7 ATCC 43888 was investigated during the production of fermented sausage according to a typical Greek recipe using L. sakei strains as starter cultures. The inactivation kinetics were modeled using GInaFiT, a freeware tool to assess microbial survival curves. By the end of the ripening period, the inhibition of L. monocytogenes was significant in treatments with L. sakei 8416 and L. sakei 4413 compared to the control treatment. A 2.2-log reduction of the population of E. coli O157:H7 resulted from the autochthonous starter culture L. sakei 4413 during sausage processing. The use of the autochthonous starter cultures constitutes an additional improvement to the microbial safety by reducing foodborne pathogens.

  6. Optimization of polyhydroxybutyrate production by mixed cultures submitted to aerobic dynamic feeding conditions.

    PubMed

    Serafim, Luísa S; Lemos, Paulo C; Oliveira, Rui; Reis, Maria A M

    2004-07-20

    Activated sludge submitted to aerobic dynamic feeding conditions showed a good and stable capacity to store polyhydroxybutyrate (PHB). The system, working for 2 years, selected a microbial population with a high PHB storage capacity. The influence of carbon and nitrogen concentrations on the PHB accumulation yield was studied in a range of 15-180 Cmmol/l for acetate and 0-2.8 Nmmol/l for ammonia. Low ammonia concentrations favored PHB accumulation. The maximum PHB content, 67.5%, was obtained for 180 Cmmol/l of acetate supplied in one pulse. However, such high substrate concentration proved to be inhibitory for the storage mechanism, causing a slowdown of the specific PHB storage rate. In order to avoid substrate inhibition, 180 Cmmol/l of acetate was supplied in different ways: continuously fed and in three pulses of 60 Cmmol/l each. In both cases the specific PHB storage rate increased and the PHB content obtained were 56.2% and 78.5%, respectively. The latter value of PHB content is similar to that obtained by pure cultures and was never reported for mixed cultures. Addition of acetate by pulses controlled by the oxygen concentration was kept for 16 days, the PHB content being always above 70% of cell dry weight.

  7. Production and optimization of L-glutaminase enzyme from Hypocrea jecorina pure culture.

    PubMed

    Bülbül, Dilara; Karakuş, Emine

    2013-01-01

    L-Glutaminase (L-glutamine amidohydrolase, EC 3.5.1.2) is the important enzyme that catalyzes the deamination of L-glutamine to L-glutamic acid and ammonium ions. Recently, L-glutaminase has received much attention with respect to its therapeutic and industrial applications. It acts as a potent antileukemic agent and shows flavor-enhancing capacity in the production of fermented foods. Glutaminase activity is widely distributed in plants, animal tissues, and microorganisms, including bacteria, yeasts, and fungi. This study presents microbial production of glutaminase enzyme from Hypocrea jecorina pure culture and determination of optimum conditions and calculation of kinetic parameters of the produced enzyme. The optimum values were determined by using sa Nesslerization reaction for our produced glutaminase enzyme. The optimum pH value was determined as 8.0 and optimum temperature as 50°C for the glutaminase enzyme. The Km and Vmax values, the kinetic parameters, of enzyme produced from Hypocrea jecorina, pure culture were determined as 0.491 mM for Km and 13.86 U/L for Vmax by plotted Lineweaver-Burk graphing, respectively. The glutaminase enzyme from H. jecorina microorganism has very high thermal and storage stability.

  8. [Is it possible to "cancel" aging process of cell cultures under optimal conditions for cultivation?].

    PubMed

    Bozhkov, A I; Kovaleva, M K; Menzianova, N G

    2011-01-01

    The characteristics of the cells epigenotypes Dunaliella viridis Teod. in the process of chronological and replicative aging were investigated. By 40th day of accumulative cultivation (which coincided with the stationary growth phase) DNA content in the cells of Dunaliella viridis increased 2 times, triacylglycerides 3 times, beta-carotene and carbonyl proteins 2 times, RNA content decreased in comparison with cells in exponential growth phase, i. e., the 40th day of growth of culture forms the age-related epigenotype. 4 received subcultures were being transplanted during 2 years in mid-logarithmic growth phase (subculture-10), early stationary phase of growth (subculture-20), in the mid-stationary growth phase (subculture-30), and late stationary growth phase (subculture-40). It is shown that epigenotype of subculture-10 remained unchanged over 2 years of cultivation, i. e., it does not manifest replicative aging. At the same time, the subculture-20, although long enough (at least 40 passages), maintained epigenotype characteristic of young cultures, and showed age-related changes. Pronounced age-dependent changes of epigenotype in the course of cultivation were identified for subculture-30, and subculture-40 was characterized by unstable epigenotype. Thus, cultivation conditions determine the intensity of replicative aging in Dunaliella viridis.

  9. Application of response surface methodology to optimize pressurized liquid extraction of antioxidant compounds from sage (Salvia officinalis L.), basil (Ocimum basilicum L.) and thyme (Thymus vulgaris L.).

    PubMed

    Hossain, M B; Brunton, N P; Martin-Diana, A B; Barry-Ryan, C

    2010-12-01

    The present study optimized pressurized liquid extraction (PLE) conditions using Dionex ASE® 200, USA to maximize the antioxidant activity [Ferric ion Reducing Antioxidant Power (FRAP)] and total polyphenol content (TP) of the extracts from three spices of Lamiaceae family (sage, basil and thyme). Optimal conditions with regard to extraction temperature (66-129 °C) and solvent concentration (32-88% methanol) were identified using response surface methodology (RSM). For all three spices, results showed that 129 °C was the optimum temperature with regard to antioxidant activity. Optimal methanol concentrations with respect to the antioxidant activity of sage and basil extracts were 58% and 60% respectively. Thyme showed a different trend with regard to methanol concentration and was optimally extracted at 33%. Antioxidant activity yields of the optimal PLE were significantly (p < 0.05) higher than solid/liquid extracts. Predicted models were highly significant (p < 0.05) for both total phenol (TP) and FRAP values in all the spices with high regression coefficients (R(2)) ranging from 0.651 to 0.999.

  10. Optimization of critical factors to enhance polyhydroxyalkanoates (PHA) synthesis by mixed culture using Taguchi design of experimental methodology.

    PubMed

    Venkata Mohan, S; Venkateswar Reddy, M

    2013-01-01

    Optimizing different factors is crucial for enhancement of mixed culture bioplastics (polyhydroxyalkanoates (PHA)) production. Design of experimental (DOE) methodology using Taguchi orthogonal array (OA) was applied to evaluate the influence and specific function of eight important factors (iron, glucose concentration, VFA concentration, VFA composition, nitrogen concentration, phosphorous concentration, pH, and microenvironment) on the bioplastics production. Three levels of factor (2(1) × 3(7)) variation were considered with symbolic arrays of experimental matrix [L(18)-18 experimental trails]. All the factors were assigned with three levels except iron concentration (2(1)). Among all the factors, microenvironment influenced bioplastics production substantially (contributing 81%), followed by pH (11%) and glucose concentration (2.5%). Validation experiments were performed with the obtained optimum conditions which resulted in improved PHA production. Good substrate degradation (as COD) of 68% was registered during PHA production. Dehydrogenase and phosphatase enzymatic activities were monitored during process operation. PMID:23201522

  11. Molecular characterization of forest soil based Paenibacillus elgii and optimization of various culture conditions for its improved antimicrobial activity.

    PubMed

    Kumar, S N; Jacob, Jubi; Reshma, U R; Rajesh, R O; Kumar, B S D

    2015-01-01

    Microorganisms have provided a bounty of bioactive secondary metabolites with very exciting biological activities such as antibacterial, antifungal antiviral, and anticancer, etc. The present study aims at the optimization of culture conditions for improved antimicrobial production of Paenibacillus elgii obtained from Wayanad forest of Western Ghats region of Kerala, India. A bacterial strain isolated from the Western Ghats forest soil of Wayanad, Kerala, India was identified as P. elgii by 16S rRNA gene sequencing. P. elgii recorded significant board spectrum activity against all human and plant pathogenic microorganism tested except Candida albicans. It has been well known that even minor variations in the fermentation medium may impact not only the quantity of desired bioactive metabolites but also the general metabolic profile of the producing microorganisms. Thus, further studies were carried out to assess the impact of medium components on the antimicrobial production of P. elgii and to optimize an ideal fermentation medium to maximize its antimicrobial production. Out of three media [nutrient broth (NA), Luria broth (LB) and Trypticase soy broth (TSB)] used for fermentation, TSB medium recorded significant activity. Glucose and meat peptone were identified as the best carbon and nitrogen sources, which significantly affected the antibiotic production when supplemented with TSB medium. Next the effect of various fermentation conditions such as temperature, pH, and incubation time on the production of antimicrobial compounds was studied on TSB + glucose + meat peptone and an initial pH of 7 and a temperature of 30°C for 3 days were found to be optimum for maximum antimicrobial production. The results indicate that medium composition in the fermentation media along with cultural parameters plays a vital role in the enhanced production of antimicrobial substances.

  12. Molecular characterization of forest soil based Paenibacillus elgii and optimization of various culture conditions for its improved antimicrobial activity.

    PubMed

    Kumar, S N; Jacob, Jubi; Reshma, U R; Rajesh, R O; Kumar, B S D

    2015-01-01

    Microorganisms have provided a bounty of bioactive secondary metabolites with very exciting biological activities such as antibacterial, antifungal antiviral, and anticancer, etc. The present study aims at the optimization of culture conditions for improved antimicrobial production of Paenibacillus elgii obtained from Wayanad forest of Western Ghats region of Kerala, India. A bacterial strain isolated from the Western Ghats forest soil of Wayanad, Kerala, India was identified as P. elgii by 16S rRNA gene sequencing. P. elgii recorded significant board spectrum activity against all human and plant pathogenic microorganism tested except Candida albicans. It has been well known that even minor variations in the fermentation medium may impact not only the quantity of desired bioactive metabolites but also the general metabolic profile of the producing microorganisms. Thus, further studies were carried out to assess the impact of medium components on the antimicrobial production of P. elgii and to optimize an ideal fermentation medium to maximize its antimicrobial production. Out of three media [nutrient broth (NA), Luria broth (LB) and Trypticase soy broth (TSB)] used for fermentation, TSB medium recorded significant activity. Glucose and meat peptone were identified as the best carbon and nitrogen sources, which significantly affected the antibiotic production when supplemented with TSB medium. Next the effect of various fermentation conditions such as temperature, pH, and incubation time on the production of antimicrobial compounds was studied on TSB + glucose + meat peptone and an initial pH of 7 and a temperature of 30°C for 3 days were found to be optimum for maximum antimicrobial production. The results indicate that medium composition in the fermentation media along with cultural parameters plays a vital role in the enhanced production of antimicrobial substances. PMID:26539188

  13. Molecular characterization of forest soil based Paenibacillus elgii and optimization of various culture conditions for its improved antimicrobial activity

    PubMed Central

    Kumar, S. N.; Jacob, Jubi; Reshma, U. R.; Rajesh, R. O.; Kumar, B. S. D.

    2015-01-01

    Microorganisms have provided a bounty of bioactive secondary metabolites with very exciting biological activities such as antibacterial, antifungal antiviral, and anticancer, etc. The present study aims at the optimization of culture conditions for improved antimicrobial production of Paenibacillus elgii obtained from Wayanad forest of Western Ghats region of Kerala, India. A bacterial strain isolated from the Western Ghats forest soil of Wayanad, Kerala, India was identified as P. elgii by 16S rRNA gene sequencing. P. elgii recorded significant board spectrum activity against all human and plant pathogenic microorganism tested except Candida albicans. It has been well known that even minor variations in the fermentation medium may impact not only the quantity of desired bioactive metabolites but also the general metabolic profile of the producing microorganisms. Thus, further studies were carried out to assess the impact of medium components on the antimicrobial production of P. elgii and to optimize an ideal fermentation medium to maximize its antimicrobial production. Out of three media [nutrient broth (NA), Luria broth (LB) and Trypticase soy broth (TSB)] used for fermentation, TSB medium recorded significant activity. Glucose and meat peptone were identified as the best carbon and nitrogen sources, which significantly affected the antibiotic production when supplemented with TSB medium. Next the effect of various fermentation conditions such as temperature, pH, and incubation time on the production of antimicrobial compounds was studied on TSB + glucose + meat peptone and an initial pH of 7 and a temperature of 30°C for 3 days were found to be optimum for maximum antimicrobial production. The results indicate that medium composition in the fermentation media along with cultural parameters plays a vital role in the enhanced production of antimicrobial substances. PMID:26539188

  14. Screening of phenylpyruvic acid producers and optimization of culture conditions in bench scale bioreactors.

    PubMed

    Coban, Hasan B; Demirci, Ali; Patterson, Paul H; Elias, Ryan J

    2014-11-01

    Alpha keto acids are deaminated forms of amino acids that have received significant attention as feed and food additives in the agriculture and medical industries. To date, their production has been commonly performed at shake-flask scale with low product concentrations. In this study, production of phenylpyruvic acid (PPA), which is the alpha keto acid of phenylalanine was investigated. First, various microorganisms were screened to select the most efficient producer. Thereafter, growth parameters (temperature, pH, and aeration) were optimized in bench scale bioreactors to maximize both PPA and biomass concentration in bench scale bioreactors, using response surface methodology. Among the four different microorganisms evaluated, Proteus vulgaris was the most productive strain for PPA production. Optimum temperature, pH, and aeration conditions were determined as 34.5 °C, 5.12, and 0.5 vvm for PPA production, whereas 36.9 °C, pH 6.87, and 0.96 vvm for the biomass production. Under these optimum conditions, PPA concentration was enhanced to 1,054 mg/L, which was almost three times higher than shake-flask fermentation concentrations. Moreover, P. vulgaris biomass was produced at 3.25 g/L under optimum conditions. Overall, this study demonstrated that optimization of growth parameters improved PPA production in 1-L working volume bench-scale bioreactors compared to previous studies in the literature and was a first step to scale up the production to industrial production.

  15. Optimization of a 3D Dynamic Culturing System for In Vitro Modeling of Frontotemporal Neurodegeneration-Relevant Pathologic Features

    PubMed Central

    Tunesi, Marta; Fusco, Federica; Fiordaliso, Fabio; Corbelli, Alessandro; Biella, Gloria; Raimondi, Manuela T.

    2016-01-01

    Frontotemporal lobar degeneration (FTLD) is a severe neurodegenerative disorder that is diagnosed with increasing frequency in clinical setting. Currently, no therapy is available and in addition the molecular basis of the disease are far from being elucidated. Consequently, it is of pivotal importance to develop reliable and cost-effective in vitro models for basic research purposes and drug screening. To this respect, recent results in the field of Alzheimer’s disease have suggested that a tridimensional (3D) environment is an added value to better model key pathologic features of the disease. Here, we have tried to add complexity to the 3D cell culturing concept by using a microfluidic bioreactor, where cells are cultured under a continuous flow of medium, thus mimicking the interstitial fluid movement that actually perfuses the body tissues, including the brain. We have implemented this model using a neuronal-like cell line (SH-SY5Y), a widely exploited cell model for neurodegenerative disorders that shows some basic features relevant for FTLD modeling, such as the release of the FTLD-related protein progranulin (PRGN) in specific vesicles (exosomes). We have efficiently seeded the cells on 3D scaffolds, optimized a disease-relevant oxidative stress experiment (by targeting mitochondrial function that is one of the possible FTLD-involved pathological mechanisms) and evaluated cell metabolic activity in dynamic culture in comparison to static conditions, finding that SH-SY5Y cells cultured in 3D scaffold are susceptible to the oxidative damage triggered by a mitochondrial-targeting toxin (6-OHDA) and that the same cells cultured in dynamic conditions kept their basic capacity to secrete PRGN in exosomes once recovered from the bioreactor and plated in standard 2D conditions. We think that a further improvement of our microfluidic system may help in providing a full device where assessing basic FTLD-related features (including PRGN dynamic secretion) that may

  16. Optimization of heat and mass transfers in counterflow corrugated-plate liquid-gas exchangers used in a greenhouse dehumidifier

    NASA Astrophysics Data System (ADS)

    Bentounes, N.; Jaffrin, A.

    1998-09-01

    Heat and mass transfers occuring in a counterflow direct contact liquid-gas exchanger determine the performance of a new greenhouse air dehumidifier designed at INRA. This prototype uses triethylene glycol (TEG) as the desiccant fluid which extracts water vapor from the air. The regeneration of the TEG desiccant fluid is then performed by direct contact with combustion gas from a high efficiency boiler equipped with a condensor. The heat and mass transfers between the thin film of diluted TEG and the hot gas were simulated by a model which uses correlation formula from the literature specifically relevant to the present cross-corrugated plates geometry. A simple set of analytical solutions is first derived, which explains why some possible processes can clearly be far from optimal. Then, more exact numerical calculations confirm that some undesirable water recondensations on the upper part of the exchanger were limiting the performance of this prototype. More suitable conditions were defined for the process, which lead to a new design of the apparatus. In this second prototype, a gas-gas exchanger provides dryer and cooler gas to the basis of the regenerators, while a warmer TEG is fed on the top. A whole range of operating conditions was experimented and measured parameters were compared with numerical simulations of this new configuration: recondensation did not occur any more. As a consequence, this second prototype was able to concentrate the desiccant fluid at the desired rate of 20 kg H_{2O}/hour, under temperature and humidity conditions which correspond to the dehumidification of a 1000 m2 greenhouse heated at night during the winter season.

  17. Optimization of dynamic headspace extraction system for measurement of halogenated volatile organic compounds in liquid or viscous samples

    NASA Astrophysics Data System (ADS)

    Taniai, G.; Oda, H.; Kurihara, M.; Hashimoto, S.

    2010-12-01

    Halogenated volatile organic compounds (HVOCs) produced in the marine environment are thought to play a key role in atmospheric reactions, particularly those involved in the global radiation budget and the depression of tropospheric and stratospheric ozone. To evaluate HVOCs concentrations in the various natural samples, we developed an automated dynamic headspace extraction method for the determination of 15 HVOCs, such as chloromethane, bromomethane, bromoethane, iodomethane, iodoethane, bromochloromethane, 1-iodopropane, 2-iodopropane, dibromomethane, bromodichloromethane, chloroiodomethane, chlorodibromomethane, bromoiodomethane, tribromomethane, and diiodomethane. Dynamic headspace system (GERSTEL DHS) was used to purge the gas phase above samples and to trap HVOCs on the adsorbent column from the purge gas. We measured the HVOCs concentrations in the adsorbent column with gas chromatograph (Agilent 6890N)- mass spectrometer (Agilent 5975C). In dynamic headspace system, an glass tube containing Tenax TA or Tenax GR was used as adsorbent column for the collection of 15 HVOCs. The parameters for purge and trap extraction, such as purge flow rate (ml/min), purge volume (ml), incubation time (min), and agitator speed (rpm), were optimized. The detection limits of HVOCs in water samples were 1270 pM (chloromethane), 103 pM (bromomethane), 42.1 pM (iodomethane), and 1.4 to 10.2 pM (other HVOCs). The repeatability (relative standard deviation) for 15 HVOCs were < 9 % except chloromethane (16.2 %) and bromomethane (11.0 %). On the basis of the measurements for various samples, we concluded that this analytical method is useful for the determination of wide range of HVOCs with boiling points between - 24°C (chloromethane) and 181°C (diiodomethane) for the liquid or viscous samples.

  18. Optimization of a liquid chromatographic method for determination of malachite green and its metabolites in fish tissues

    USGS Publications Warehouse

    Plakas, S.M.; ELSaid, K.R.; Stehly, G.R.; Roybal, J.E.

    1995-01-01

    A liquid chromatographic (LC) method was adapted and optimized for the determination of malachite green and its metabolites in fish plasma and muscle, Residues in plasma were extracted with acetonitrile, the extract was evaporated to dryness, and residues were resolubilized for LC analysis, Residues in muscle were extracted with an acetonitrile-acetate buffer mixture, reextracted with acetonitrile, and partitioned into methylene chloride with final cleanup on alumina and propylsulfonic acid solid-phase extraction columns, Residue levels were determined by using an LC cyano column with a PbO2 postcolumn and visible detection (618 nm). Overall mean recoveries of parent malachite green (MG-C) and its major metabolite, leucomalachite green (MG-L), from plasma were 93 and 87%, respectively, at fortification levels ranging from 25 to 250 ppb, Overall mean recoveries of MG-C and MG-L from muscle were 85 and 95%, respectively, at fortification levels ranging from 5 to 100 ppb, Relative standard deviations (RSDs) of recoveries at all fortification levels ranged from 3.9 to 7.0% for plasma and from 2.1 to 5.2% for muscle, The method was applied to incurred residues in tissues sampled from catfish after waterborne exposure to [C-14]MG-C. Mean recoveries of total radioactive residues in plasma and muscle throughout the extraction and cleanup process were 88 and 87%, respectively, and corresponding RSDs for MG-C and MG-L were in the same range as those for fortified tissues, MG-L, was confirmed as the major metabolite of MG-C in catfish.

  19. Utility of four strains of white-rot fungi for the detoxification of 2,4,6-trinitrotoluene in liquid culture

    SciTech Connect

    Donnelly, K.C.; Chen, J.C.; Huebner, H.J.; Brown, K.W.; Autenrieth, R.L.; Bonner, J.S.

    1997-06-01

    The purpose of this study was to investigate the potential of four different strains of white-rot fungi (Phanerochaete chrysosporium, Phanerochaete sordida, Phlebia brevispora, and Cyathus stercoreus) to degrade 2,4,6-trinitrotoluene (TNT) in liquid medium. Loss of TNT from the culture medium was determined using high-performance liquid chromatography (HPLC), while the mutagenicity of the medium residues were evaluated using the Salmonella/microsome bioassay. The data indicate that within 21 d of incubation, all fungi were able to reduce the TNT concentration in the liquid medium to below detection limits. In this study, P. sordida showed a relatively high growth rate and the fastest rate of TNT degradation. The fungal treatment also produced a significant reduction of TNT mutagenicity. Treatment with C. stercoreus, P. brevispora, P. sordida, and P. chrysosporium resulted in the elimination of 94%, 90%, 87%, and 67% of the initial TNT-amended medium mutagenicity, respectively. The data also demonstrate that during incubation, TNT was eliminated from the culture medium two to eight times faster than the reduction in mutagenic potential. These results suggest that TNT disappearance alone cannot be used as the sole criterion in TNT remediation. Chemical analysis revealed that the major metabolites in the initial transformation of TNT were the monoamino-dinitrotoluenes, which were also degraded by the selected white-rot fungi. The study demonstrated that the white-rot fungi are capable of metabolizing and detoxifying TNT under aerobic conditions in nonligninolytic liquid medium.

  20. Effects of sodium sulfate on the freshwater microalga Chlamydomonas moewusii: implications for the optimization of algal culture media.

    PubMed

    Mera, Roi; Torres, Enrique; Abalde, Julio

    2016-02-01

    The study of the microalgal growth kinetics is an indispensable tool in all fields of phycology. Knowing the optimal nutrient concentration is an important issue that will help to develop efficient growth systems for these microorganisms. Although nitrogen and phosphorus are well studied for this purpose, sulfur seems to be less investigated. Sulfate is a primary sulfur source used by microalgae; moreover, the concentration of this compound is increasing in freshwater systems due to pollution. The aim of this study was to investigate the effects of different sodium sulfate concentrations in the culture medium on growth and growth kinetics of the freshwater microalga Chlamydomonas moewusii. Production of biomass, chl content, kinetic equations, and a mathematical model that describe the microalgal growth in relation with the concentration of sodium sulfate were obtained. The lowest concentration of sodium sulfate allowing optimal growth was 0.1 mM. Concentrations higher than 3 mM generated a toxic effect. This work demonstrates that this toxic effect was not directly due to the excess of sulfate ion but by the elevation of the ionic strength. An inhibition model was successfully used to simulate the relationship between specific growth rate and sodium sulfate in this microalga.

  1. Effects of sodium sulfate on the freshwater microalga Chlamydomonas moewusii: implications for the optimization of algal culture media.

    PubMed

    Mera, Roi; Torres, Enrique; Abalde, Julio

    2016-02-01

    The study of the microalgal growth kinetics is an indispensable tool in all fields of phycology. Knowing the optimal nutrient concentration is an important issue that will help to develop efficient growth systems for these microorganisms. Although nitrogen and phosphorus are well studied for this purpose, sulfur seems to be less investigated. Sulfate is a primary sulfur source used by microalgae; moreover, the concentration of this compound is increasing in freshwater systems due to pollution. The aim of this study was to investigate the effects of different sodium sulfate concentrations in the culture medium on growth and growth kinetics of the freshwater microalga Chlamydomonas moewusii. Production of biomass, chl content, kinetic equations, and a mathematical model that describe the microalgal growth in relation with the concentration of sodium sulfate were obtained. The lowest concentration of sodium sulfate allowing optimal growth was 0.1 mM. Concentrations higher than 3 mM generated a toxic effect. This work demonstrates that this toxic effect was not directly due to the excess of sulfate ion but by the elevation of the ionic strength. An inhibition model was successfully used to simulate the relationship between specific growth rate and sodium sulfate in this microalga. PMID:26987090

  2. Fumonisin production in rice cultures of Fusarium verticillioides under different incubation conditions using an optimized analytical method.

    PubMed

    Hinojo, M J; Medina, A; Valle-Algarra, F M; Gimeno-Adelantado, J V; Jiménez, M; Mateo, R

    2006-04-01

    Fumonisin B1 (FB1) and fumonisin B2 (FB2) are the main members of a family of mycotoxins produced by various fungal species belonging to the Gibberella fujikuroi complex. The present work shows the results of a comparative study of various clean-up and derivatization procedures for analysis of fumonisins in rice cultures. Fumonisins were extracted from rice with acetonitrile/water (50/50, v/v). For clean-up, three solid-phase extraction procedures were assayed (C18 cartridge, SAX cartridge, and a combination of both). Two reagents (o-phthaldialdehyde and 4-fluoro-7-nitro-benzofurazan) were studied comparatively for formation of fluorescent derivatives. The separation was carried out by LC using a fluorescence detector. The best procedure for analysis of fumonisins in rice involved clean-up with C18 cartridge and derivatization with o-phthaldialdehyde. The limit of detection was 0.010 mg kg(-1) for both toxins. In the 10-500 mg kg(-1) spiking level range, the recovery rates for FB1 and FB2 in rice varied from 94.6% to 103.6% and from 96.3% to 101.9%, respectively. The optimized analytical method for determination of fumonisins in rice was applied to the study of FB1 and FB2 production by four isolates of the G. fujikuroi species complex in rice cultures carried out at different temperatures and water activities to establish the influence of strain and environmental conditions on fumonisin production in this cereal. In general, fumonisin production was the highest at 20 degrees C and lowest at 37 degrees C. Four of the five assayed water activity (aw) values (0.97, 0.98, 0.99, and 1.0) did not affect significantly fumonisin accumulation but fumonisins were not detected in cultures when aw was 0.96.

  3. Development and validation of a liquid medium (M7H9C) for routine culture of Mycobacterium avium subsp. paratuberculosis to replace modified Bactec 12B medium.

    PubMed

    Whittington, Richard J; Whittington, Ann-Michele; Waldron, Anna; Begg, Douglas J; de Silva, Kumi; Purdie, Auriol C; Plain, Karren M

    2013-12-01

    Liquid culture of Mycobacterium avium subsp. paratuberculosis from clinical samples, such as feces, is the most sensitive antemortem test for the diagnosis of Johne's disease in ruminants. In Australia, New Zealand, the United States, and some other countries, the Bactec 460 system with modified Bactec 12B medium (Becton, Dickinson) has been the most commonly used liquid culture system, but it was discontinued in 2012. In this study, a new liquid culture medium, M7H9C, was developed. It consists of a Middlebrook 7H9 medium base with added Casitone, albumin, dextrose, catalase, egg yolk, mycobactin J, and a cocktail of antibiotics. We found that polyoxyethylene stearate (POES) was not essential for the cultivation of M. avium subsp. paratuberculosis in either the Bactec 12B or the M7H9C medium. The limit of detection determined using pure cultures of the C and S strains of M. avium subsp. paratuberculosis was 7 bacilli per 50 μl inoculum in the two media. The new medium was validated using 784 fecal and tissue samples from sheep and cattle, >25% of which contained viable M. avium subsp. paratuberculosis. Discrepant results for the clinical samples between the two media were mostly associated with samples that contained <10 viable bacilli per gram, but these results were relatively uncommon, and the performances of the two media were not significantly different. M7H9C medium was less than half the cost of the Bactec 12B medium and did not require regular examination during incubation, but a confirmatory IS900 PCR test had to be performed on every culture after the predetermined incubation period.

  4. [Optimization of culture conditions for in vitro rooting of argan (Argania spinosa L.)].

    PubMed

    Bousselmame, F; Kenny, L; Chlyah, H

    2001-11-01

    The root system produced of in vitro organ plantlets is of poor quality and not efficient for the transfer to out-door conditions. To overcome such problems, experimentation was undertaken where the effects of growth regulators, nitrogen, sugar, activated charcoal and coconut fiber were tested on root induction and elongation. Modified Murashige and Skoog with half strength salt was used as a basal medium. Root induction (85%) with a mean of 16 roots per explant was obtained when shoots were grown, under dark conditions for 14 days, with a combination of two auxins (IBA and NNA), added at equal concentrations (5 mg.L-1). Secondary roots, 10 cm long, were initiated in 12% of the cultures in presence of 5 g.L-1 activated charcoal. Further improvements in the growth of the primary and secondary roots were obtained when semi-solid medium was substituted with a substrate composed of coconut fibers (80 g) mixed with semi-solid medium (35 mL) and agar (2.5 g.L-1). PMID:11725707

  5. Isolation, culture optimization and physico-chemical characterization of laccase enzyme from Pleurotus fossulatus.

    PubMed

    Chowdhury, P; Hari, R; Chakraborty, B; Mandal, B; Naskar, S; Das, Nirmalendu

    2014-01-15

    Pleurotus fossulatus (Cooke) Sace is member of oyster mushroom can produced extracellular laccase (benzenediol: oxygen oxidoreductase; EC 1.10.3.2) in submerged fermentation. To analyze the optimum production for laccase P. fossulatus was cultured both in stationary and shaking condition in different media. Partial purification of laccase was done after 0-80% ammonium sulphate precipitation, followed by DEAE (Diethylaminoethyl) Sephadex (A-50) anion exchange chromatography. Potato-sucrose peptone (PSP) medium and Potato-dextrose (PD) medium showed highest laccase production in shaking and stationary conditions, respectively. Though the time required for optimum laccase production in stationary condition was much more than the shaking condition but the amount of laccase was about 2.75t greater in former condition. The laccase produced in stationary condition was more stable than the enzyme produced in shaking condition. The partially purified enzyme showed highest affinity towards o-dianisidine than guaiacol and ABTS (2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) as evidenced by their K(m). The physico-chemical properties of the laccase suggested the significance of this enzyme in industrial applications. PMID:24783799

  6. A new cellulose-producing bacterium, Rhodococcus sp. MI 2: screening and optimization of culture conditions.

    PubMed

    Tanskul, Somporn; Amornthatree, Korntip; Jaturonlak, Nathakan

    2013-01-30

    A total of 59 bacterial strains were isolated from ripe fruits and vegetables and tested for their ability to produce cellulose. Only one identified as Rhodococcus sp. MI 2 based on its taxonomic characteristics and 16S rDNA sequence analysis. The glucose was the only product of digestion by cellulase confirmed by TLC and reversed phase HPLC. Rhodococcus sp. MI 2 produced significantly more cellulose with the SH medium containing glucose than with the coconut juice medium. Rhodococcus sp. MI 2 initially produced 3.91 ± 0.091, 2.20 ± 0.090 and 0.19 ± 0.051 g/L/6 days cellulose under static, agitated and stirred conditions, respectively, whereas A. xylinum 998 produced 1.17 ± 0.065, 1.34 ± 0.115 and 0.12 ± 0.046 g/L/6 days cellulose under the same conditions, respectively. The optimum culture conditions for cellulose production in SH medium were room temperature (25 °C), a 5% (v/v) inoculum, peptone 0.7%, yeast extract 0.9%, and sucrose 1.5%, at a pH of 3.5. The cellulose yield was increased by adding 0.5% CaCO(3) to the SH medium with sucrose but added agar had no effect. The cellulose yield under optimum and static conditions was increased about twice, from 3.7 to 7.4 g/L/14 days.

  7. [Optimization of culture conditions for in vitro rooting of argan (Argania spinosa L.)].

    PubMed

    Bousselmame, F; Kenny, L; Chlyah, H

    2001-11-01

    The root system produced of in vitro organ plantlets is of poor quality and not efficient for the transfer to out-door conditions. To overcome such problems, experimentation was undertaken where the effects of growth regulators, nitrogen, sugar, activated charcoal and coconut fiber were tested on root induction and elongation. Modified Murashige and Skoog with half strength salt was used as a basal medium. Root induction (85%) with a mean of 16 roots per explant was obtained when shoots were grown, under dark conditions for 14 days, with a combination of two auxins (IBA and NNA), added at equal concentrations (5 mg.L-1). Secondary roots, 10 cm long, were initiated in 12% of the cultures in presence of 5 g.L-1 activated charcoal. Further improvements in the growth of the primary and secondary roots were obtained when semi-solid medium was substituted with a substrate composed of coconut fibers (80 g) mixed with semi-solid medium (35 mL) and agar (2.5 g.L-1).

  8. Optimization of the analysis of flavor volatile compounds by liquid-liquid microextraction (LLME). Application to the aroma analysis of melons, peaches, grapes, strawberries, and tomatoes.

    PubMed

    Aubert, Christophe; Baumann, Severine; Arguel, Helene

    2005-11-16

    A fast method based on liquid-liquid microextraction (LLME) has been developed for the analysis of volatile compounds in fruit and vegetable juices. The method was tested in an aqueous solution containing 49 common flavor compounds typically found in fruit aroma. Influence on extraction yield of the salts used, their levels, and the time of extraction was investigated. The efficiency of n-propyl gallate to inhibit the formation of secondary compounds from lipids during the crushing of fruit tissues was also tested. The proposed method was then applied to several authentic samples such as melons, peaches, grapes, strawberries, and tomatoes. The advantages and limitations of LLME are discussed.

  9. Optimization of culture media for large-scale lutein production by heterotrophic Chlorella vulgaris.

    PubMed

    Jeon, Jin Young; Kwon, Ji-Sue; Kang, Soon Tae; Kim, Bo-Ra; Jung, Yuchul; Han, Jae Gap; Park, Joon Hyun; Hwang, Jae Kwan

    2014-01-01

    Lutein is a carotenoid with a purported role in protecting eyes from oxidative stress, particularly the high-energy photons of blue light. Statistical optimization was performed to growth media that supports a higher production of lutein by heterotrophically cultivated Chlorella vulgaris. The effect of media composition of C. vulgaris on lutein was examined using fractional factorial design (FFD) and central composite design (CCD). The results indicated that the presence of magnesium sulfate, EDTA-2Na, and trace metal solution significantly affected lutein production. The optimum concentrations for lutein production were found to be 0.34 g/L, 0.06 g/L, and 0.4 mL/L for MgSO4 ·7H2 O, EDTA-2Na, and trace metal solution, respectively. These values were validated using a 5-L jar fermenter. Lutein concentration was increased by almost 80% (139.64 ± 12.88 mg/L to 252.75 ± 12.92 mg/L) after 4 days. Moreover, the lutein concentration was not reduced as the cultivation was scaled up to 25,000 L (260.55 ± 3.23 mg/L) and 240,000 L (263.13 ± 2.72 mg/L). These observations suggest C. vulgaris as a potential lutein source.

  10. Optimization of culture media for large-scale lutein production by heterotrophic Chlorella vulgaris.

    PubMed

    Jeon, Jin Young; Kwon, Ji-Sue; Kang, Soon Tae; Kim, Bo-Ra; Jung, Yuchul; Han, Jae Gap; Park, Joon Hyun; Hwang, Jae Kwan

    2014-01-01

    Lutein is a carotenoid with a purported role in protecting eyes from oxidative stress, particularly the high-energy photons of blue light. Statistical optimization was performed to growth media that supports a higher production of lutein by heterotrophically cultivated Chlorella vulgaris. The effect of media composition of C. vulgaris on lutein was examined using fractional factorial design (FFD) and central composite design (CCD). The results indicated that the presence of magnesium sulfate, EDTA-2Na, and trace metal solution significantly affected lutein production. The optimum concentrations for lutein production were found to be 0.34 g/L, 0.06 g/L, and 0.4 mL/L for MgSO4 ·7H2 O, EDTA-2Na, and trace metal solution, respectively. These values were validated using a 5-L jar fermenter. Lutein concentration was increased by almost 80% (139.64 ± 12.88 mg/L to 252.75 ± 12.92 mg/L) after 4 days. Moreover, the lutein concentration was not reduced as the cultivation was scaled up to 25,000 L (260.55 ± 3.23 mg/L) and 240,000 L (263.13 ± 2.72 mg/L). These observations suggest C. vulgaris as a potential lutein source. PMID:24550199

  11. Ultra-high performance liquid chromatographic determination of levofloxacin in human plasma and prostate tissue with use of experimental design optimization procedures.

    PubMed

    Szerkus, O; Jacyna, J; Wiczling, P; Gibas, A; Sieczkowski, M; Siluk, D; Matuszewski, M; Kaliszan, R; Markuszewski, M J

    2016-09-01

    Fluoroquinolones are considered as gold standard for the prevention of bacterial infections after transrectal ultrasound guided prostate biopsy. However, recent studies reported that fluoroquinolone- resistant bacterial strains are responsible for gradually increasing number of infections after transrectal prostate biopsy. In daily clinical practice, antibacterial efficacy is evaluated only in vitro, by measuring the reaction of bacteria with an antimicrobial agent in culture media (i.e. calculation of minimal inhibitory concentration). Such approach, however, has no relation to the treated tissue characteristics and might be highly misleading. Thus, the objective of this study was to develop, with the use of Design of Experiments approach, a reliable, specific and sensitive ultra-high performance liquid chromatography- diode array detection method for the quantitative analysis of levofloxacin in plasma and prostate tissue samples obtained from patients undergoing prostate biopsy. Moreover, correlation study between concentrations observed in plasma samples vs prostatic tissue samples was performed, resulting in better understanding, evaluation and optimization of the fluoroquinolone-based antimicrobial prophylaxis during transrectal ultrasound guided prostate biopsy. Box-Behnken design was employed to optimize chromatographic conditions of the isocratic elution program in order to obtain desirable retention time, peak symmetry and resolution of levofloxacine and ciprofloxacine (internal standard) peaks. Fractional Factorial design 2(4-1) with four center points was used for screening of significant factors affecting levofloxacin extraction from the prostatic tissue. Due to the limited number of tissue samples the prostatic sample preparation procedure was further optimized using Central Composite design. Design of Experiments approach was also utilized for evaluation of parameter robustness. The method was found linear over the range of 0.030-10μg/mL for human

  12. Ultra-high performance liquid chromatographic determination of levofloxacin in human plasma and prostate tissue with use of experimental design optimization procedures.

    PubMed

    Szerkus, O; Jacyna, J; Wiczling, P; Gibas, A; Sieczkowski, M; Siluk, D; Matuszewski, M; Kaliszan, R; Markuszewski, M J

    2016-09-01

    Fluoroquinolones are considered as gold standard for the prevention of bacterial infections after transrectal ultrasound guided prostate biopsy. However, recent studies reported that fluoroquinolone- resistant bacterial strains are responsible for gradually increasing number of infections after transrectal prostate biopsy. In daily clinical practice, antibacterial efficacy is evaluated only in vitro, by measuring the reaction of bacteria with an antimicrobial agent in culture media (i.e. calculation of minimal inhibitory concentration). Such approach, however, has no relation to the treated tissue characteristics and might be highly misleading. Thus, the objective of this study was to develop, with the use of Design of Experiments approach, a reliable, specific and sensitive ultra-high performance liquid chromatography- diode array detection method for the quantitative analysis of levofloxacin in plasma and prostate tissue samples obtained from patients undergoing prostate biopsy. Moreover, correlation study between concentrations observed in plasma samples vs prostatic tissue samples was performed, resulting in better understanding, evaluation and optimization of the fluoroquinolone-based antimicrobial prophylaxis during transrectal ultrasound guided prostate biopsy. Box-Behnken design was employed to optimize chromatographic conditions of the isocratic elution program in order to obtain desirable retention time, peak symmetry and resolution of levofloxacine and ciprofloxacine (internal standard) peaks. Fractional Factorial design 2(4-1) with four center points was used for screening of significant factors affecting levofloxacin extraction from the prostatic tissue. Due to the limited number of tissue samples the prostatic sample preparation procedure was further optimized using Central Composite design. Design of Experiments approach was also utilized for evaluation of parameter robustness. The method was found linear over the range of 0.030-10μg/mL for human

  13. Optimization of cultural conditions for biosurfactant production by Pleurotus djamor in solid state fermentation.

    PubMed

    Velioglu, Zulfiye; Ozturk Urek, Raziye

    2015-11-01

    Being eco-friendly, less toxic, more biodegradable and biocompatible, biological surfactants have higher activity and stability compared to synthetic ones. In spite of the fact that there are abundant benefits of biosurfactants over the synthetic congeners, the problem related with the economical and large scale production proceeds. The utilization of several industrial wastes in the production media as substrates reduces the production cost. This current study aims optimization of biosurfactant production conditions by Pleurotus djamor, grown on sunflower seed shell, grape wastes or potato peels as renewable cheap substrates in solid state fermentation. After determination of the best substrate for biosurfactant production, we indicate optimum size and amount of solid substrate, volume of medium, temperature, pH and Fe(2+) concentrations on biosurfactant production. In optimum conditions, by reducing water surface tension to 28.82 ± 0.3 mN/m and having oil displacement diameter of 3.9 ± 0.3 cm, 10.205 ± 0.5 g/l biosurfactant was produced. Moreover, chemical composition of biosurfactant produced in optimum condition was determined by FTIR. Lastly, laboratory's large-scale production was carried out in optimum conditions in a tray bioreactor designed by us and 8.9 ± 0.5 g/l biosurfactant was produced with a significant surface activity (37.74 ± 0.3 mN/m). With its economical suggestions and applicability of laboratory's large-scale production, this work indicates the possibility of using low cost agro-industrial wastes as renewable substrates for biosurfactant production. Therefore, using economically produced biosurfactant will reduce cost in several applications such as bioremediation, oil recovery and biodegradation of toxic chemicals.

  14. Optimization of cultural conditions for biosurfactant production by Pleurotus djamor in solid state fermentation.

    PubMed

    Velioglu, Zulfiye; Ozturk Urek, Raziye

    2015-11-01

    Being eco-friendly, less toxic, more biodegradable and biocompatible, biological surfactants have higher activity and stability compared to synthetic ones. In spite of the fact that there are abundant benefits of biosurfactants over the synthetic congeners, the problem related with the economical and large scale production proceeds. The utilization of several industrial wastes in the production media as substrates reduces the production cost. This current study aims optimization of biosurfactant production conditions by Pleurotus djamor, grown on sunflower seed shell, grape wastes or potato peels as renewable cheap substrates in solid state fermentation. After determination of the best substrate for biosurfactant production, we indicate optimum size and amount of solid substrate, volume of medium, temperature, pH and Fe(2+) concentrations on biosurfactant production. In optimum conditions, by reducing water surface tension to 28.82 ± 0.3 mN/m and having oil displacement diameter of 3.9 ± 0.3 cm, 10.205 ± 0.5 g/l biosurfactant was produced. Moreover, chemical composition of biosurfactant produced in optimum condition was determined by FTIR. Lastly, laboratory's large-scale production was carried out in optimum conditions in a tray bioreactor designed by us and 8.9 ± 0.5 g/l biosurfactant was produced with a significant surface activity (37.74 ± 0.3 mN/m). With its economical suggestions and applicability of laboratory's large-scale production, this work indicates the possibility of using low cost agro-industrial wastes as renewable substrates for biosurfactant production. Therefore, using economically produced biosurfactant will reduce cost in several applications such as bioremediation, oil recovery and biodegradation of toxic chemicals. PMID:25865657

  15. Screening and optimization of low-cost medium for Pseudomonas putida Rs-198 culture using RSM

    PubMed Central

    Peng, Yanjie; He, Yanhui; Wu, Zhansheng; Lu, Jianjiang; Li, Chun

    2014-01-01

    The plant growth-promoting rhizobacterial strain Pseudomonas putida Rs-198 was isolated from salinized soils from Xinjiang Province. We optimized the composition of the low-cost medium of P. putida Rs-198 based on its bacterial concentration, as well as its phosphate-dissolving and indole acetic acid (IAA)-producing capabilities using the response surface methodology (RSM), and a mathematical model was developed to show the effect of each medium component and its interactions on phosphate dissolution and IAA production. The model predicted a maximum phosphate concentration in medium containing 63.23 mg/L inorganic phosphate with 49.22 g/L corn flour, 14.63 g/L soybean meal, 2.03 g/L K2HPO4, 0.19 g/L MnSO4 and 5.00 g/L NaCl. The maximum IAA concentration (18.73 mg/L) was predicted in medium containing 52.41 g/L corn flour, 15.82 g/L soybean meal, 2.40 g/L K2HPO4, 0.17 g/L MnSO4 and 5.00 g/L NaCl. These predicted values were also verified through experiments, with a cell density of 1013 cfu/mL, phosphate dissolution of 64.33 mg/L, and IAA concentration of 18.08 mg/L. The excellent correlation between predicted and measured values of each model justifies the validity of both the response models. The study aims to provide a basis for industrialized fermentation using P. putida Rs-198. PMID:25763026

  16. Biological synthesis of very small silver nanoparticles by culture supernatant of Klebsiella pneumonia: The effects of visible-light irradiation and the liquid mixing process

    SciTech Connect

    Mokhtari, Narges; Daneshpajouh, Shahram; Seyedbagheri, Seyedali; Atashdehghan, Reza; Abdi, Khosro; Sarkar, Saeed; Minaian, Sara; Shahverdi, Hamid Reza; Shahverdi, Ahmad Reza

    2009-06-03

    This study has investigated different visible-light irradiation's effect on the formation of silver nanoparticles from silver nitrate using the culture supernatant of Klebsiella pneumonia. Our study shows that visible-light emission can significantly prompt the synthesis of silver nanoparticles. Also, the study experimentally investigated the liquid mixing process effect on silver nanoparticle synthesis by visible-light irradiation. This study successfully synthesized uniformly dispersed silver nanoparticles with a uniform size and shape in the range of 1-6 nm with an average size of 3 nm. Furthermore, the study investigated the mechanism of the reduction of silver ions by culture supernatant of K. pneumonia, and used X-ray diffraction to characterize silver chloride as an intermediate compound. Silver chloride was prepared synthetically and used as a substrate for the synthesis of silver nanoparticles by culture supernatant of K. pneumonia. The silver nanoparticles have been prepared from silver chloride during this investigation for the first time.

  17. Optimization of HEK-293S cell cultures for the production of adenoviral vectors in bioreactors using on-line OUR measurements.

    PubMed

    Gálvez, J; Lecina, M; Solà, C; Cairó, J J; Gòdia, F

    2012-01-01

    The culture of HEK-293S cells in a stirred tank bioreactor for adenoviral vectors production for gene therapy is studied. Process monitoring using oxygen uptake rate (OUR) was performed. The OUR was determined on-line by the dynamic method, providing good information of the process evolution. OUR enabled cell activity monitoring, facilitating as well the determination of the feeding rate in perfusion cultures and when to infect the culture. Batch cultures were used to validate the monitoring methodology. A cell density of 10×10(5)cell/mL was infected, producing 1.3×10(9) infectious viral particles/mL (IVP/mL). To increase cell density values maintaining cell specific productivity, perfusion cultures, based on tangential flow filtration, were studied. In this case, OUR measurements were used to optimize the dynamic culture medium feeding strategy, addressed to avoid any potential nutrient limitation. Furthermore, the infection protocol was defined in order to optimize the use of the viral inoculum, minimizing the uncontrolled release of particles through the filter unit mesh. All these developments enabled an infection at 78×10(5)cell/mL with the consequent production of 44×10(9)IVP/mL, representing a cell specific productivity 4.3 times higher than for the batch culture.

  18. Self-Regulation among Youth in Four Western Cultures: Is There an Adolescence-Specific Structure of the Selection-Optimization-Compensation (SOC) Model?

    ERIC Educational Resources Information Center

    Gestsdottir, Steinunn; Geldhof, G. John; Paus, Tomáš; Freund, Alexandra M.; Adalbjarnardottir, Sigrun; Lerner, Jacqueline V.; Lerner, Richard M.

    2015-01-01

    We address how to conceptualize and measure intentional self-regulation (ISR) among adolescents from four cultures by assessing whether ISR (conceptualized by the SOC model of Selection, Optimization, and Compensation) is represented by three factors (as with adult samples) or as one "adolescence-specific" factor. A total of 4,057 14-…

  19. The role of goal representations, cultural identity, and dispositional optimism in the depressive experiences of American Indian youth from a Northern Plains tribe.

    PubMed

    Tyser, Jason; Scott, Walter D; Readdy, Tucker; McCrea, Sean M

    2014-03-01

    American Indian researchers and scholars have emphasized the importance of identifying variables that promote resilience and protect against the development of psychopathology in American Indian youth. The present study examined the role of self-regulation, specifically goal characteristics (i.e., goal self-efficacy, goal specificity, intrinsic vs. extrinsic motivation, and goal conflict) and dispositional optimism, as well as cultural identity and self-reported academic grades in the depressive experiences of American Indian youth from a North American plains tribe. One hundred and sixty-four participants (53% female) completed measures of goal representations, cultural identity, dispositional optimism, academic performance, and depressive symptoms. Results supported a model in which higher goal self-efficacy, American Indian cultural identity, grade point average, and dispositional optimism each significantly predicted fewer depressive symptoms. Moreover, grade point average and goal self-efficacy had both direct and indirect (through dispositional optimism) relationships with depressive symptoms. Our findings underscore the importance of cognitive self-regulatory processes and cultural identity in the depressive experiences for these American Indian youth and may have implications for youth interventions attempting to increase resiliency and decrease risk for depressive symptoms.

  20. Development of a new cell culture-based method and optimized protocol for the detection of enteric viruses.

    PubMed

    Lee, Jae Ho; Lee, Gyu-Cheol; Kim, Jong Ik; Yi, Hyun Ah; Lee, Chan Hee

    2013-07-01

    The development of rapid and effective methods to detect water- and food-borne enteric viruses is important for the prevention and control of mass infection. This study represents an attempt to develop a reliable cell culture-based detection system and optimize an effective and rapid protocol for the assaying of environmental samples for the presence of infectious enteric viruses. Six enteric viruses were used in this study: poliovirus, Coxsackie virus A9, Coxsackie virus B5, human rotavirus G1, hepatitis A virus, and adenovirus type 41. Among the cell lines from humans (A549, HeLa, HEK293, and HFF) and other primates (Vero, BS-C-1, FRhK-4, BGMK, and MA104), a cytopathic effect (CPE) analysis indicated that the MA104 cell line was the most optimal for use in the detection of infectious enteric viruses. Both the sensitivity and specificity of virus detection in MA104 cells were similar to or higher than those in standard BGMK cells. Next, a method was developed for the determination of the infectiousness of enteric viruses using the colorimetric thiazolyl blue (MTT) assay. This assay utilizes 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide to yield % values based on colorimetric results. These results were compared with those from a conventional CPE-based TCID(50) assay, revealing no statistically significant difference between the two methods. The MTT% values in MA104 cells were comparable to those in BGMK cells. This MA104 cell-based MTT assay could substitute for the classical BGMK cell-based CPE assay for infectious enteric viruses.

  1. Optimized simultaneous saccharification and co-fermentation of rice straw for ethanol production by Saccharomyces cerevisiae and Scheffersomyces stipitis co-culture using design of experiments.

    PubMed

    Suriyachai, Nopparat; Weerasaia, Khatiya; Laosiripojana, Navadol; Champreda, Verawat; Unrean, Pornkamol

    2013-08-01

    Herein an ethanol production process from rice straw was optimized. Simultaneous saccharification and co-fermentation (SSCF) using Saccharomyces cerevisiae and Scheffersomyces stipitis co-culture was carried out to enhance ethanol production. The optimal saccharification solid loading was 5%. Key fermentation parameters for co-culture including cell ratio, agitation rate and temperature was rationally optimized using design of experiment (DoE). Optimized co-culture conditions for maximum ethanol production efficiency were at S. cerevisiae:S. stipitis cell ratio of 0.31, agitation rate of 116 rpm and temperature of 33.1°C. The optimized SSCF process reached ethanol titer of 15.2g/L and ethanol yield of 99% of theoretical yield, consistent with the DoE model prediction. Moreover, SSCF process under high biomass concentration resulted in high ethanol concentration of 28.6g/L. This work suggests the efficiency and scalability of the developed SSCF process which could provide an important basis for the economic feasibility of ethanol production from lignocelluloses. PMID:23735799

  2. Optimized simultaneous saccharification and co-fermentation of rice straw for ethanol production by Saccharomyces cerevisiae and Scheffersomyces stipitis co-culture using design of experiments.

    PubMed

    Suriyachai, Nopparat; Weerasaia, Khatiya; Laosiripojana, Navadol; Champreda, Verawat; Unrean, Pornkamol

    2013-08-01

    Herein an ethanol production process from rice straw was optimized. Simultaneous saccharification and co-fermentation (SSCF) using Saccharomyces cerevisiae and Scheffersomyces stipitis co-culture was carried out to enhance ethanol production. The optimal saccharification solid loading was 5%. Key fermentation parameters for co-culture including cell ratio, agitation rate and temperature was rationally optimized using design of experiment (DoE). Optimized co-culture conditions for maximum ethanol production efficiency were at S. cerevisiae:S. stipitis cell ratio of 0.31, agitation rate of 116 rpm and temperature of 33.1°C. The optimized SSCF process reached ethanol titer of 15.2g/L and ethanol yield of 99% of theoretical yield, consistent with the DoE model prediction. Moreover, SSCF process under high biomass concentration resulted in high ethanol concentration of 28.6g/L. This work suggests the efficiency and scalability of the developed SSCF process which could provide an important basis for the economic feasibility of ethanol production from lignocelluloses.

  3. Self-consistent Shaw optimized model potential: Application to the determination of structural and atomic transport properties of liquid alkali metals by molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Harchaoui, N.; Hellal, S.; Gasser, J. G.; Grosdidier, B.

    2010-03-01

    The 'first-principles' fully non-local and energy-dependent optimized model potential (OMP) derived by Shaw is developed further. In contrast to Shaw's original paper, OMP parameters are derived in a self-consistent manner that does not rely on knowledge of experimental values of the ionization and cohesive energies. To our knowledge, this is the first time that this method has been used for effective potential calculations. In an application to liquid Li, Na, and K alkali metals, we used OMP pseudopotential-based interactions between ions to carry out standard molecular dynamics simulations. In the calculations, the ionic structure for the liquid state was first checked at a temperature near the melting point. Similar accurate calculations, but for atomic transport properties, predict the temperature dependence of the self-diffusion coefficients. The theoretical results obtained are in overall agreement with available experimental measurements. Thus, one can have some confidence in the ability of the optimized model potential to give a good representation of the physical properties of these alkali ions in the liquid environment.

  4. Optimization of Ionic Liquid Based Simultaneous Ultrasonic- and Microwave-Assisted Extraction of Rutin and Quercetin from Leaves of Velvetleaf (Abutilon theophrasti) by Response Surface Methodology

    PubMed Central

    Zhao, Chunjian; Lu, Zhicheng; He, Xin; Li, Zhao; Shi, Kunming; Yang, Lei; Fu, Yujie; Zu, Yuangang

    2014-01-01

    An ionic liquids based simultaneous ultrasonic and microwave assisted extraction (ILs-UMAE) method has been proposed for the extraction of rutin (RU), quercetin (QU), from velvetleaf leaves. The influential parameters of the ILs-UMAE were optimized by the single factor and the central composite design (CCD) experiments. A 2.00 M 1-butyl-3-methylimidazolium bromide ([C4mim]Br) was used as the experimental ionic liquid, extraction temperature 60°C, extraction time 12 min, liquid-solid ratio 32 mL/g, microwave power of 534 W, and a fixed ultrasonic power of 50 W. Compared to conventional heating reflux extraction (HRE), the RU and QU extraction yields obtained by ILs-UMAE were, respectively, 5.49 mg/g and 0.27 mg/g, which increased, respectively, 2.01-fold and 2.34-fold with the recoveries that were in the range of 97.62–102.36% for RU and 97.33–102.21% for QU with RSDs lower than 3.2% under the optimized UMAE conditions. In addition, the shorter extraction time was used in ILs-UMAE, compared with HRE. Therefore, ILs-UMAE was a rapid and an efficient method for the extraction of RU and QU from the leaves of velvetleaf. PMID:25243207

  5. Evaluation of three real-time PCR assays for differential identification of Mycobacterium tuberculosis complex and nontuberculous mycobacteria species in liquid culture media.

    PubMed

    Jung, Yu Jung; Kim, Ji-Youn; Song, Dong Joon; Koh, Won-Jung; Huh, Hee Jae; Ki, Chang-Seok; Lee, Nam Yong

    2016-06-01

    We evaluated the analytical performance of M. tuberculosis complex (MTBC)/nontuberculous mycobacteria (NTM) PCR assays for differential identification of MTBC and NTM using culture-positive liquid media. Eighty-five type strains and 100 consecutive mycobacterial liquid media cultures (MGIT 960 system) were analyzed by a conventional PCR assay (MTB-ID(®) V3) and three real-time PCR assays (AdvanSure™ TB/NTM real-time PCR, AdvanSure; GENEDIA(®) MTB/NTM Detection Kit, Genedia; Real-Q MTB & NTM kit, Real-Q). The accuracy rates for reference strains were 89.4%, 100%, 98.8%, and 98.8% for the MTB-ID V3, AdvanSure, Genedia, and Real-Q assays, respectively. Cross-reactivity in the MTB-ID V3 assay was mainly attributable to non-mycobacterium Corynebacterineae species. The diagnostic performance was determined using clinical isolates grown in liquid media, and the overall sensitivities for all PCR assays were higher than 95%. In conclusion, the three real-time PCR assays showed better performance in discriminating mycobacterium species and non-mycobacterium Corynebacterineae species than the conventional PCR assay.

  6. A testing scheme for the detection of Mycobacterium avium subsp. paratuberculosis in bovine feces utilizing the ESP para-JEM liquid culture system.

    PubMed

    Rajeev, Sreekumari; Shulaw, William; Berghaus, Roy; Zhang, Yan; Byrum, Beverly

    2006-11-01

    A testing scheme for the detection of Mycobacterium avium subsp. paratuberculosis (MAP) in broth cultures of bovine fecal samples carried out in ESP para-JEM System was evaluated. The scheme included acid-fast staining (on signal-positive and signal-negative samples), and confirmation by PCR for 2 MAP-specific targets and subculture of all acid-fast positive PCR-negative samples. Two hundred and fifty bovine fecal samples were evaluated for the presence of MAP using this scheme. Thirty-seven (15%) of 250 fecal samples had a positive culture result when the proposed testing scheme was used, compared to 14 (6%) positive results when using the standard ESP para-JEM protocol (requiring samples to have a positive signal from the system, a positive acid-fast stain, and a positive IS900 PCR result), and 20 (8%) positives when conventional culture was performed on Herrold egg yolk (HEY) media. A preliminary comparison of real-time and conventional PCR on DNA extracted from 15 MAP-positive broth cultures by 3 different protocols suggested that conventional PCR may be a better choice for the confirmation of the presence of MAP in the liquid cultures than real-time PCR.

  7. Optimization of pressurized liquid extraction using a multivariate chemometric approach and comparison of solid-phase extraction cleanup steps for the determination of polycyclic aromatic hydrocarbons in mosses.

    PubMed

    Foan, L; Simon, V

    2012-09-21

    A factorial design was used to optimize the extraction of polycyclic aromatic hydrocarbons (PAHs) from mosses, plants used as biomonitors of air pollution. The analytical procedure consists of pressurized liquid extraction (PLE) followed by solid-phase extraction (SPE) cleanup, in association with analysis by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). For method development, homogeneous samples were prepared with large quantities of the mosses Isothecium myosuroides Brid. and Hypnum cupressiforme Hedw., collected from a Spanish Nature Reserve. A factorial design was used to identify the optimal PLE operational conditions: 2 static cycles of 5 min at 80 °C. The analytical procedure performed with PLE showed similar recoveries (∼70%) and total PAH concentrations (∼200 ng g(-1)) as found using Soxtec extraction, with the advantage of reducing solvent consumption by 3 (30 mL against 100mL per sample), and taking a fifth of the time (24 samples extracted automatically in 8h against 2 samples in 3.5h). The performance of SPE normal phases (NH(2), Florisil, silica and activated aluminium) generally used for organic matrix cleanup was also compared. Florisil appeared to be the most selective phase and ensured the highest PAH recoveries. The optimal analytical procedure was validated with a reference material and applied to moss samples from a remote Spanish site in order to determine spatial and inter-species variability.

  8. Optimization of pressurized liquid extraction using a multivariate chemometric approach and comparison of solid-phase extraction cleanup steps for the determination of polycyclic aromatic hydrocarbons in mosses.

    PubMed

    Foan, L; Simon, V

    2012-09-21

    A factorial design was used to optimize the extraction of polycyclic aromatic hydrocarbons (PAHs) from mosses, plants used as biomonitors of air pollution. The analytical procedure consists of pressurized liquid extraction (PLE) followed by solid-phase extraction (SPE) cleanup, in association with analysis by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). For method development, homogeneous samples were prepared with large quantities of the mosses Isothecium myosuroides Brid. and Hypnum cupressiforme Hedw., collected from a Spanish Nature Reserve. A factorial design was used to identify the optimal PLE operational conditions: 2 static cycles of 5 min at 80 °C. The analytical procedure performed with PLE showed similar recoveries (∼70%) and total PAH concentrations (∼200 ng g(-1)) as found using Soxtec extraction, with the advantage of reducing solvent consumption by 3 (30 mL against 100mL per sample), and taking a fifth of the time (24 samples extracted automatically in 8h against 2 samples in 3.5h). The performance of SPE normal phases (NH(2), Florisil, silica and activated aluminium) generally used for organic matrix cleanup was also compared. Florisil appeared to be the most selective phase and ensured the highest PAH recoveries. The optimal analytical procedure was validated with a reference material and applied to moss samples from a remote Spanish site in order to determine spatial and inter-species variability. PMID:22885040

  9. Development of a fast extraction method and optimization of liquid chromatography-mass spectrometry for the analysis of phenolic compounds in lentil seed coats.

    PubMed

    Mirali, Mahla; Ambrose, Stephen J; Wood, Stephen A; Vandenberg, Albert; Purves, Randy W

    2014-10-15

    A systematic set of optimization experiments was conducted to design an efficient extraction and analysis protocol for screening six different sub-classes of phenolic compounds in the seed coat of various lentil (Lens culinaris Medik.) genotypes. Different compounds from anthocyanidins, flavan-3-ols, proanthocyanidins, flavanones, flavones, and flavonols sub-classes were first optimized for use as standards for liquid chromatography mass spectrometry (LC-MS) with UV detection. The effect of maceration duration, reconstitution solvent, and extraction solvent were investigated using lentil genotype CDC Maxim. Chromatographic conditions were optimized by examining column separation efficiencies, organic composition, and solvent gradient. The results showed that a 1h maceration step was sufficient and that non-acidified solvents were more appropriate; a 70:30 acetone: water (v/v) solvent was ultimately selected. Using a Kinetex PFP column, the organic concentration, gradient, and flow rate were optimized to maximize the resolution of phenolic compounds in a short 30-min analysis time. The optimized method was applied to three lentil genotypes with different phenolic compound profiles to provide information of value to breeding programs.

  10. Metabolome analysis of Saccharomyces cerevisiae and optimization of culture medium for S-adenosyl-L-methionine production.

    PubMed

    Hayakawa, Kenshi; Matsuda, Fumio; Shimizu, Hiroshi

    2016-12-01

    S-Adenosyl-L-methionine (SAM) is a fine chemical used as a nutritional supplement and a prescription drug. It is industrially produced using Saccharomyces cerevisiae owing to its high SAM content. To investigate the optimization of culture medium components for higher SAM production, metabolome analysis was conducted to compare the intracellular metabolite concentrations between Kyokai no. 6 (high SAM-producing) and laboratory yeast S288C (control) under different SAM production conditions. Metabolome analysis and the result of principal component analysis showed that the rate-limiting step for SAM production was ATP supply and the levels of degradation products of adenosine nucleotides were higher in Kyokai 6 strain than in the S288C strain under the L-methionine supplemented condition. Analysis of ATP accumulation showed that the levels of intracellular ATP in the Kyokai 6 strain were also higher compared to those in the S288C strain. Furthermore, as expected from metabolome analysis, the SAM content of Kyokai 6 strain cultivated in the medium without yeast extract increased by 2.5-fold compared to that in the additional condition, by increasing intracellular ATP level with inhibited cell growth. These results suggest that high SAM production is attributed to the enhanced ATP supply with L-methionine condition and high efficiency of intracellular ATP consumption.

  11. Enhancing isomaltulose production by recombinant Escherichia coli producing sucrose isomerase: culture medium optimization containing agricultural wastes and cell immobilization.

    PubMed

    Li, Sha; Xu, Hong; Yu, Jianguang; Wang, Yanyuan; Feng, Xiaohai; Ouyang, Pingkai

    2013-10-01

    Isomaltulose is a structural isomer of sucrose commercially used in food industries. In this work, recombinant Escherichia coli producing sucrose isomerase (SIase) was used to convert sucrose into isomaltulose. To develop an economical industrial medium, untreated cane molasses (10.63 g l⁻¹), yeast extract (25.93 g l⁻¹), and corn steep liquor (10.45 g l⁻¹) were used as main culture compositions for SIase production. The relatively high SIase activity (14.50 ± 0.11 U mg DCW⁻¹) was obtained by the recombinant cells. To the best of our knowledge, this is the first investigation on SIase production by engineered E. coli using untreated cane molasses. The recombinant E. coli cells expressing the SIase gene were immobilized in calcium alginate gel in order to improve the efficiency of recycling. The immobilization was most effective with 2 % (w/v) sodium alginate and 3 % (w/v) calcium chloride. The optimal initial biomass for immobilization was 20 % (w/v, wet wt.), with a hardening time of 8 h for cell immobilization. The immobilized E. coli cells exhibited good stability for 30 batches with the productivity of 0.45 g isomaltulose g pellet⁻¹ h⁻¹. A continuous isomaltulose formation process using a column reactor remained stable for 40 days with 83 ± 2 % isomaltulose yield, which would be beneficial for economical production of isomaltulose. PMID:23300051

  12. Optimization of Culture Conditions for Some Identified Fungal Species and Stability Profile of α-Galactosidase Produced

    PubMed Central

    Chauhan, A. S.; Srivastava, N.; Kehri, H. K.; Sharma, B.

    2013-01-01

    Microbial α-galactosidase preparations have implications in medicine and in the modification of various agricultural products as well. In this paper, four isolated fungal strains such as AL-3, WF-3, WP-4 and CL-4 from rhizospheric soil identified as Penicillium glabrum (AL-3), Trichoderma evansii (WF-3), Lasiodiplodia theobromae (WP-4) and Penicillium flavus (CL-4) based on their morphology and microscopic examinations, are screened for their potential towards α-galactosidases production. The culture conditions have been optimized and supplemented with specific carbon substrates (1%, w/v) by using galactose-containing polysaccharides like guar gum (GG), soya casein (SC) and wheat straw (WS). All strains significantly released galactose from GG, showing maximum production of enzyme at 7th day of incubation in rotary shaker (120 rpm) that is 190.3, 174.5, 93.9 and 28.8 U/mL, respectively, followed by SC and WS. The enzyme activity was stable up to 7days at −20°C, then after it declines. This investigation reveals that AL-3 show optimum enzyme activity in guar gum media, whereas WF-3 exhibited greater enzyme stability. Results indicated that the secretion of proteins, enzyme and the stability of enzyme activity varied not only from one strain to another but also differed in their preferences of utilization of different substrates. PMID:23424684

  13. Enhancing isomaltulose production by recombinant Escherichia coli producing sucrose isomerase: culture medium optimization containing agricultural wastes and cell immobilization.

    PubMed

    Li, Sha; Xu, Hong; Yu, Jianguang; Wang, Yanyuan; Feng, Xiaohai; Ouyang, Pingkai

    2013-10-01

    Isomaltulose is a structural isomer of sucrose commercially used in food industries. In this work, recombinant Escherichia coli producing sucrose isomerase (SIase) was used to convert sucrose into isomaltulose. To develop an economical industrial medium, untreated cane molasses (10.63 g l⁻¹), yeast extract (25.93 g l⁻¹), and corn steep liquor (10.45 g l⁻¹) were used as main culture compositions for SIase production. The relatively high SIase activity (14.50 ± 0.11 U mg DCW⁻¹) was obtained by the recombinant cells. To the best of our knowledge, this is the first investigation on SIase production by engineered E. coli using untreated cane molasses. The recombinant E. coli cells expressing the SIase gene were immobilized in calcium alginate gel in order to improve the efficiency of recycling. The immobilization was most effective with 2 % (w/v) sodium alginate and 3 % (w/v) calcium chloride. The optimal initial biomass for immobilization was 20 % (w/v, wet wt.), with a hardening time of 8 h for cell immobilization. The immobilized E. coli cells exhibited good stability for 30 batches with the productivity of 0.45 g isomaltulose g pellet⁻¹ h⁻¹. A continuous isomaltulose formation process using a column reactor remained stable for 40 days with 83 ± 2 % isomaltulose yield, which would be beneficial for economical production of isomaltulose.

  14. Optimization of Culture Conditions for Some Identified Fungal Species and Stability Profile of α-Galactosidase Produced.

    PubMed

    Chauhan, A S; Srivastava, N; Kehri, H K; Sharma, B

    2013-01-01

    Microbial α-galactosidase preparations have implications in medicine and in the modification of various agricultural products as well. In this paper, four isolated fungal strains such as AL-3, WF-3, WP-4 and CL-4 from rhizospheric soil identified as Penicillium glabrum (AL-3), Trichoderma evansii (WF-3), Lasiodiplodia theobromae (WP-4) and Penicillium flavus (CL-4) based on their morphology and microscopic examinations, are screened for their potential towards α-galactosidases production. The culture conditions have been optimized and supplemented with specific carbon substrates (1%, w/v) by using galactose-containing polysaccharides like guar gum (GG), soya casein (SC) and wheat straw (WS). All strains significantly released galactose from GG, showing maximum production of enzyme at 7th day of incubation in rotary shaker (120 rpm) that is 190.3, 174.5, 93.9 and 28.8 U/mL, respectively, followed by SC and WS. The enzyme activity was stable up to 7days at -20°C, then after it declines. This investigation reveals that AL-3 show optimum enzyme activity in guar gum media, whereas WF-3 exhibited greater enzyme stability. Results indicated that the secretion of proteins, enzyme and the stability of enzyme activity varied not only from one strain to another but also differed in their preferences of utilization of different substrates. PMID:23424684

  15. Organic solvent-free air-assisted liquid-liquid microextraction for optimized extraction of illegal azo-based dyes and their main metabolite from spices, cosmetics and human bio-fluid samples in one step.

    PubMed

    Barfi, Behruz; Asghari, Alireza; Rajabi, Maryam; Sabzalian, Sedigheh

    2015-08-15

    Air-assisted liquid-liquid microextraction (AALLME) has unique capabilities to develop as an organic solvent-free and one-step microextraction method, applying ionic-liquids as extraction solvent and avoiding centrifugation step. Herein, a novel and simple eco-friendly method, termed one-step air-assisted liquid-liquid microextraction (OS-AALLME), was developed to extract some illegal azo-based dyes (including Sudan I to IV, and Orange G) from food and cosmetic products. A series of experiments were investigated to achieve the most favorable conditions (including extraction solvent: 77μL of 1-Hexyl-3-methylimidazolium hexafluorophosphate; sample pH 6.3, without salt addition; and extraction cycles: 25 during 100s of sonication) using a central composite design strategy. Under these conditions, limits of detection, linear dynamic ranges, enrichment factors and consumptive indices were in the range of 3.9-84.8ngmL(-1), 0.013-3.1μgmL(-1), 33-39, and 0.13-0.15, respectively. The results showed that -as well as its simplicity, fastness, and use of no hazardous disperser and extraction solvents- OS-AALLME is an enough sensitive and efficient method for the extraction of these dyes from complex matrices. After optimization and validation, OS-AALLME was applied to estimate the concentration of 1-amino-2-naphthol in human bio-fluids as a main reductive metabolite of selected dyes. Levels of 1-amino-2-naphthol in plasma and urinary excretion suggested that this compound may be used as a new potential biomarker of these dyes in human body. PMID:26149246

  16. Organic solvent-free air-assisted liquid-liquid microextraction for optimized extraction of illegal azo-based dyes and their main metabolite from spices, cosmetics and human bio-fluid samples in one step.

    PubMed

    Barfi, Behruz; Asghari, Alireza; Rajabi, Maryam; Sabzalian, Sedigheh

    2015-08-15

    Air-assisted liquid-liquid microextraction (AALLME) has unique capabilities to develop as an organic solvent-free and one-step microextraction method, applying ionic-liquids as extraction solvent and avoiding centrifugation step. Herein, a novel and simple eco-friendly method, termed one-step air-assisted liquid-liquid microextraction (OS-AALLME), was developed to extract some illegal azo-based dyes (including Sudan I to IV, and Orange G) from food and cosmetic products. A series of experiments were investigated to achieve the most favorable conditions (including extraction solvent: 77μL of 1-Hexyl-3-methylimidazolium hexafluorophosphate; sample pH 6.3, without salt addition; and extraction cycles: 25 during 100s of sonication) using a central composite design strategy. Under these conditions, limits of detection, linear dynamic ranges, enrichment factors and consumptive indices were in the range of 3.9-84.8ngmL(-1), 0.013-3.1μgmL(-1), 33-39, and 0.13-0.15, respectively. The results showed that -as well as its simplicity, fastness, and use of no hazardous disperser and extraction solvents- OS-AALLME is an enough sensitive and efficient method for the extraction of these dyes from complex matrices. After optimization and validation, OS-AALLME was applied to estimate the concentration of 1-amino-2-naphthol in human bio-fluids as a main reductive metabolite of selected dyes. Levels of 1-amino-2-naphthol in plasma and urinary excretion suggested that this compound may be used as a new potential biomarker of these dyes in human body.

  17. Sparging and agitation-induced injury of cultured animals cells: Do cell-to-bubble interactions in the bulk liquid injure cells?

    PubMed

    Michaels, J D; Mallik, A K; Papoutsakis, E T

    1996-08-20

    It has been established that the forces resulting from bubbles rupturing at the free air (gas)/liquid surface injure animal cells in agitated and/or sparged bioreactors. Although it has been suggested that bubble coalescence and breakup within agitated and sparged bioreactors (i.e., away from the free liquid surface) can be a source of cell injury as well, the evidence has been indirect. We have carried out experiments to examine this issue. The free air/liquid surface in a sparged and agitated bioractor was eliminated by completely filling the 2-L reactor and allowing sparged bubbles to escape through an outlet tube. Two identical bioreactors were run in parallel to make comparisons between cultures that were oxygenated via direct air sparging and the control culture in which silicone tubing was used for bubble-free oxygenation. Thus, cell damage from cell-to-bubble interactions due to processes (bubble coalescence and breakup) occurring in the bulk liquid could be isolated by eliminating damage due to bubbles rupturing at the free air/liquid surface of the bioreactor. We found that Chinese hamster ovary (CHO) cells grown in medium that does not contain shear-protecting additives can be agitated at rates up to 600 rpm without being damaged extensively by cell-to bubble interactions in the bulk of the bioreactor. We verified this using both batch and high-density perfusion cultures. We tested two impeller designs (pitched blade and Rushton) and found them not to affect cell damage under similar operational conditions. Sparger location (above vs. below the impeller) had no effect on cell damage at higher agitation rates but may affect the injury process at lower agitation intensities (here, below 250 rpm). In the absence of a headspace, we found less cell damage at higher agitation intensities (400 and 600 rpm), and we suggest that this nonintuitive finding derives from the important effect of bubble size and foam stability on the cell damage process. (c) 1996 John

  18. Theoretical searches and spectral computations of preferred conformations of various absolute configurations for a cyclodipeptide, cordycedipeptide A from the culture liquid of Cordyceps sinensis

    NASA Astrophysics Data System (ADS)

    Mang, Chao-Yong; Liu, Cai-Ping; Liu, Guang-Ming; Jiang, Bei; Lan, Hai; Wu, Ke-Chen; Yan, Ya; Li, Hai-Fei; Yang, Ming-Hui; Zhao, Yu

    2015-02-01

    A cyclic dipeptide often has the multiple configurations and the abundant conformations. The density functional theory (DFT) method is used to search the preferred conformation of the most probable configuration for cordycedipeptide A isolated from the culture liquid of Cordyceps sinensis. The time-dependent DFT approach is exploited to describe the profile of electronic circular dichroism (CD). The calculated results show that the most probable configuration is 3S6R7S, whose preferred conformation has a negative optical rotation and a positive lowest energy electronic CD band.

  19. Theoretical searches and spectral computations of preferred conformations of various absolute configurations for a cyclodipeptide, cordycedipeptide A from the culture liquid of Cordyceps sinensis.

    PubMed

    Mang, Chao-Yong; Liu, Cai-Ping; Liu, Guang-Ming; Jiang, Bei; Lan, Hai; Wu, Ke-Chen; Yan, Ya; Li, Hai-Fei; Yang, Ming-Hui; Zhao, Yu

    2015-02-01

    A cyclic dipeptide often has the multiple configurations and the abundant conformations. The density functional theory (DFT) method is used to search the preferred conformation of the most probable configuration for cordycedipeptide A isolated from the culture liquid of Cordyceps sinensis. The time-dependent DFT approach is exploited to describe the profile of electronic circular dichroism (CD). The calculated results show that the most probable configuration is 3S6R7S, whose preferred conformation has a negative optical rotation and a positive lowest energy electronic CD band. PMID:25459699

  20. 132 Characterization of 2 Epithelial Cell Air-Liquid Interface (ALI) Culture Models for Human Healthy Nasal Mucosa and Nasal Polyps

    PubMed Central

    de Borja Callejas, Fco; Martínez-Antón, Asunción; Roca-Ferrer, Jordi; Cortijo, Julio; Picado, César; Mullol, Joaquim

    2012-01-01

    Background Primary human airway epithelial cells, when submerged in culture, undergo a dedifferentiation with loss of many features of the in vivo airway epithelium. However, when cultured in an air-liquid interface (ALI), cells develop a well-differentiated, polarized, and pseudostratified epithelium. The aim of the current study was to characterize the mucociliary differentiation of human nasal mucosa and polyp epithelial cells cultured using an ALI system. Methods Nasal mucosa (NM, n = 3) and nasal polyps (NP, n = 3) were obtained from patients undergoing nasal corrective surgery and endoscopic sinus surgery, respectively. Epithelial cells were obtained from the explant method, and differentiated in ALI culture during 28 days. Cultures were studied at different time points (0, 7, 14, 21, and 28 days): tissue ultrastructure by scanning electron microscopy (SEM) and transmission electron microscopy (TEM); mucous (MUC5AC, MUC5B) and serous (lactoferrin) cell secretion by ELISA; and cytokeratin 18 (epithelial marker), β-tubulin IV (cilia marker), MUC5AC (goblet cell marker), and p63 (basal cell marker) expression by immunocytochemistry. Results In both NM and NP ALI cultures and at days 14 and 28, a pseudostratified epithelium with ciliated, mucus-secreting and basal cells was observed, and expression of cytokeratin 18, b-tubulin IV, MUC5AC and p63 was detected. In NP cultures, both MUC5AC (day 14: 2.2 ± 0.1-folds; day 28: 3.6-fold ± 0.7-fold) and MUC5B (day 14: 3.2-fold ± 0.6-fold; day 28: 3.1-fold ± 1-fold) increased over time compared to day 0 (P < 0.05). In NM cultures, only MUC5B (day 14: 3.9-fold ± 0.9-fold; day 28: 3.4-fold ± 0.4-fold; P < 0.05) but not MUC5AC increased over time compared to day 0 (P < 0.05). Secretion of lactoferrin was present but showed no changes over time in either NM or NP ALI cultures. Conclusions Epithelial cell ALI cultures provide a well-differentiated human nasal mucosa and polyp tissues that may be used as an in vitro model

  1. Optimization of the culture medium composition to improve the production of hyoscyamine in elicited Datura stramonium L. hairy roots using the Response Surface Methodology (RSM).

    PubMed

    Ryad, Amdoun; Lakhdar, Khelifi; Majda, Khelifi-Slaoui; Samia, Amroune; Mark, Asch; Corinne, Assaf-Ducrocq; Eric, Gontier

    2010-11-18

    Traditionally, optimization in biological analyses has been carried out by monitoring the influence of one factor at a time; this technique is called one-variable-at-a-time. The disadvantage of this technique is that it does not include any interactive effects among the variables studied and requires a large number of experiments. Therefore, in recent years, the Response Surface Methodology (RSM) has become the most popular optimization method. It is an effective mathematical and statistical technique which has been widely used in optimization studies with minimal experimental trials where interactive factors may be involved. This present study follows on from our previous work, where RSM was used to optimize the B5 medium composition in [NO(3-)], [Ca(2+)] and sucrose to attain the best production of hyoscyamine (HS) from the hairy roots (HRs) of Datura stramonium elicited by Jasmonic Acid (JA). The present paper focuses on the use of the RSM in biological studies, such as plant material, to establish a predictive model with the planning of experiments, analysis of the model, diagnostics and adjustment for the accuracy of the model. With the RSM, only 20 experiments were necessary to determine optimal concentrations. The model could be employed to carry out interpolations and predict the response to elicitation. Applying this model, the optimization of the HS level was 212.7% for the elicited HRs of Datura stramonium, cultured in B5-OP medium (optimized), in comparison with elicited HRs cultured in B5 medium (control). The optimal concentrations, under experimental conditions, were determined to be: 79.1 mM [NO(3-)], 11.4 mM [Ca(2+)] and 42.9 mg/L of sucrose.

  2. Statistical optimization of medium composition and culture condition for the production of recombinant anti-lipopolysaccharide factor of Eriocheir sinensis in Escherichia coli

    NASA Astrophysics Data System (ADS)

    Jiang, Shan; Liu, Mei; Wang, Baojie; Jiang, Keyong; Wang, Lei

    2011-11-01

    Anti-lipopolysaccharide factors (ALFs) are important antimicrobial peptides that are isolated from some aquatic species. In a previous study, we isolated ALF genes from Chinese mitten crab, Eriocheir sinensis. In this study, we optimized the production of a recombinant ALF by expressing E. sinensis ALF genes in Escherichia coli maintained in shake-flasks. In particular, we focused on optimization of both the medium composition and the culture condition. Various medium components were analyzed by the Plackett-Burman design, and two significant screened factors, (NH4)2SO4 and KH2PO4, were further optimized via the central composite design (CCD). Based on the CCD analysis, we investigated the induction start-up time, the isopropylthio-D-galactoside (IPTG) concentration, the post-induction time, and the temperature by response surface methodology. We found that the highest level of ALF fusion protein was achieved in the medium containing 1.89 g/L (NH4)2SO4 and 3.18 g/L KH2PO4, with a cell optical density of 0.8 at 600 nm before induction, an IPTG concentration of 0.5 mmol/L, a post-induction temperature of 32.7°C, and a post-induction time of 4 h. Applying the whole optimization strategy using all optimal factors improved the target protein content from 6.1% (without optimization) to 13.2%. We further applied the optimized medium and conditions in high cell density cultivation, and determined that the soluble target protein constituted 10.5% of the total protein. Our identification of the economic medium composition, optimal culture conditions, and details of the fermentation process should facilitate the potential application of ALF for further research.

  3. Adjoint-based shape optimization of fin geometry for enhanced solid/liquid phase-change process

    NASA Astrophysics Data System (ADS)

    Morimoto, Kenichi; Suzuki, Yuji

    2015-11-01

    In recent years, the control of heat transfer processes, which play a critical role in various engineering devices/systems, has gained renewed attention. The present study aims to establish an adjoint-based shape optimization method for high-performance heat transfer processes involving phase-change phenomena. A possible example includes the application to the thermal management technique using phase-change material. Adjoint-based shape optimization scheme is useful to optimal shape design and optimal control of systems, for which the base function of the solution is unknown and the solution includes an infinite number of degrees of freedom. Here we formulate the shape-optimization scheme based on adjoint heat conduction analyses, focusing on the shape optimization of fin geometry. In the computation of the developed scheme, a meshless local Petrov-Galerkin (MLPG) method that is suited for dealing with complex boundary geometry is employed, and the enthalpy method is adopted for analyzing the motion of the phase-change interface. We examine in detail the effect of the initial geometry and the node distribution in the MLPG analysis upon the final solution of the shape optimization. Also, we present a new strategy for the computation using bubble mesh.

  4. Development of three-dimensional lung multicellular spheroids in air- and liquid-interface culture for the evaluation of anticancer therapeutics.

    PubMed

    Meenach, Samantha A; Tsoras, Alexandra N; McGarry, Ronald C; Mansour, Heidi M; Hilt, J Zach; Anderson, Kimberly W

    2016-04-01

    Three-dimensional (3D) lung multicellular spheroids (MCS) in liquid-covered culture (LCC) and air-interface culture (AIC) conditions have both been developed for the evaluation of aerosol anticancer therapeutics in solution and aerosols, respectively. The MCS were formed by seeding lung cancer cells on top of collagen where they formed spheroids due to the prevalence of cell-to-cell interactions. LCC MCS were exposed to paclitaxel (PTX) in media whereas AIC MCS were exposed to dry powder PEGylated phospholipid aerosol microparticles containing paclitaxel. The difference in viability for 2D versus 3D culture for both LCC and AIC was evaluated along with the effects of the particles on lung epithelium via transepithelial electrical resistance (TEER) measurements. For LCC and AIC conditions, the 3D spheroids were more resistant to treatment with higher IC50 values for A549 and H358 cell lines. TEER results initially indicated a decrease in resistance upon drug or particle exposure, however, these values increased over the course of several days indicating the ability of the cells to recover. Overall, these studies offer a comprehensive in vitro evaluation of aerosol particles used in the treatment of lung cancer while introducing a new method for culturing lung cancer MCS in both LCC and AIC conditions.

  5. Newborn pig trachea cell line cultured in air-liquid interface conditions allows a partial in vitro representation of the porcine upper airway tissue

    PubMed Central

    2014-01-01

    Background The domestic pig is an excellent animal model to study human microbial diseases due to its similarity to humans in terms of anatomy, physiology, and genetics. We assessed the suitability of an in vitro air-liquid interface (ALI) culture system for newborn pig trachea (NPTr) cells as a practical tool for analyzing the immune response of respiratory epithelial cells to aggressors. This cell line offers a wide microbial susceptibility spectrum to both viruses and bacteria. The purpose of our study was to evaluate and characterize diverse aspects of cell differentiation using different culture media. After the NPTr cells reached confluence, the apical medium was removed and the cells were fed by medium from the basal side. Results We assessed the cellular layer’s capacity to polarize and differentiate in ALI conditions. Using immunofluorescence and electronic microscopy we evaluated the presence of goblet and ciliated cells, the epithelial junction organization, and the transepithelial electrical resistance. We found that the cellular layer develops a variable density of mucus producing cells and acquires a transepithelial resistance. We also identified increased development of cellular junctions over the culture period. Finally, we observed variable expression of transcripts associated to proteins such as keratin 8, mucins (MUC1, MUC2, and MUC4), occludin, and villin 1. Conclusions The culture of NPTr cells in ALI conditions allows a partial in vitro representation of porcine upper airway tissue that could be used to investigate some aspects of host/respiratory pathogen interactions. PMID:24885012

  6. Development of three-dimensional lung multicellular spheroids in air- and liquid-interface culture for the evaluation of anticancer therapeutics

    PubMed Central

    MEENACH, SAMANTHA A.; TSORAS, ALEXANDRA N.; McGARRY, RONALD C.; MANSOUR, HEIDI M.; HILT, J. ZACH; ANDERSON, KIMBERLY W.

    2016-01-01

    Three-dimensional (3D) lung multicellular spheroids (MCS) in liquid-covered culture (LCC) and air-interface culture (AIC) conditions have both been developed for the evaluation of aerosol anticancer therapeutics in solution and aerosols, respectively. The MCS were formed by seeding lung cancer cells on top of collagen where they formed spheroids due to the prevalence of cell-to-cell interactions. LCC MCS were exposed to paclitaxel (PTX) in media whereas AIC MCS were exposed to dry powder PEGylated phospholipid aerosol microparticles containing paclitaxel. The difference in viability for 2D versus 3D culture for both LCC and AIC was evaluated along with the effects of the particles on lung epithelium via transepithelial electrical resistance (TEER) measurements. For LCC and AIC conditions, the 3D spheroids were more resistant to treatment with higher IC50 values for A549 and H358 cell lines. TEER results initially indicated a decrease in resistance upon drug or particle exposure, however, these values increased over the course of several days indicating the ability of the cells to recover. Overall, these studies offer a comprehensive in vitro evaluation of aerosol particles used in the treatment of lung cancer while introducing a new method for culturing lung cancer MCS in both LCC and AIC conditions. PMID:26846376

  7. Determination of microcystins in natural blooms and cyanobacterial strain cultures by matrix solid-phase dispersion and liquid chromatography-mass spectrometry.

    PubMed

    Cameán, Ana; Moreno, Isabel M; Ruiz, María J; Picó, Yolanda

    2004-10-01

    An analytical procedure based on matrix solid-phase dispersion (MSPD) and liquid chromatography-mass spectrometry (LC-MS) was developed for determining three microcystins (MCs) in natural water blooms and cyanobacteria strain cultures. The procedure involves sample homogenization with C(18), washed with dichloromethane to eliminate interfering compounds, and elution with acidic methanol. Results were compared to those achieved by using an organic solvent standard method. Mean recoveries of MCs with MSPD were 85-92% with intra-day relative standard deviation (RSDs) of 9-19%, whereas organic solvent extraction resulted in recovery rates of 92-105% with intra-day RSDs ranging from 8 to 18%. Limits of quantification (LOQs) were 1 microg g(-1) dry weight for the MCs either by MSPD or organic solvent extraction. The two analytical methods tested were specific and sensitive to the extraction of MCs and were applied to the detection of MCs in water blooms and culture strains. The concentration of MCs varied from 7 to 3,330 microg g(-1) of lyophilized cells with MC-LR always showing the highest concentration. MCs levels were higher in culture strains than in water blooms, except for MC-LR, whose concentration in blooms was slightly superior to that determined in culture strains.

  8. Optimization of modified carbon paste electrode with multiwalled carbon nanotube/ionic liquid/cauliflower-like gold nanostructures for simultaneous determination of ascorbic acid, dopamine and uric acid.

    PubMed

    Afraz, Ahmadreza; Rafati, Amir Abbas; Najafi, Mojgan

    2014-11-01

    We describe the modification of a carbon paste electrode (CPE) with multiwalled carbon nanotubes (MWCNTs) and an ionic liquid (IL). Electrochemical studies by using a D-optimal mixture design in Design-Expert software revealed an optimized composition of 60% graphite, 14.2% paraffin, 10.8% MWCNT and 15% IL. The optimal modified CPE shows good electrochemical properties that are well matched with model prediction parameters. In the next step, the optimized CPE was modified with gold nanostructures by applying a double-pulse electrochemical technique. The resulting electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and electrochemical impedance spectroscopy. It gives three sharp and well-separated oxidation peaks for ascorbic acid (AA), dopamine (DA), and uric acid (UA). The sensor enables simultaneous determination of AA, DA and UA with linear responses from 0.3 to 285, 0.08 to 200, and 0.1 to 450 μM, respectively, and with 120, 30 and 30 nM detection limits (at an S/N of 3). The method was successfully applied to the determination of AA, DA, and UA in spiked samples of human serum and urine.

  9. Development of response surface methodology for optimization of extraction parameters and quantitative estimation of embelin from Embelia ribes Burm by high performance liquid chromatography

    PubMed Central

    Alam, Md. Shamsir; Damanhouri, Zoheir A.; Ahmad, Aftab; Abidin, Lubna; Amir, Mohd; Aqil, Mohd; Khan, Shah Alam; Mujeeb, Mohd

    2015-01-01

    Background: Embelia ribes Burm is widely used medicinal plant for the treatment of different types of disorders in the Indian traditional systems of medicine. Objective: The present work was aimed to optimize the extraction parameters of embelin from E. ribes fruits and also to quantify embelin content in different extracts of the plant. Materials and Methods: Optimization of extraction parameters such as solvent: drug ratio, temperature and time were carried out by response surface methodology (RSM). Quantitative estimation of embelin in different extracts of E. ribes fruits was done through high performance liquid chromatography. Results: The optimal conditions determined for extraction of embelin through RSM were; extraction time (27.50 min), extraction temperature 45°C and solvent: drug ratio (8:1). Under the optimized conditions, the embelin yield (32.71%) was equitable to the expected yield (31.07%, P > 0.05). These results showed that the developed model is satisfactory and suitable for the extraction process of embelin. The analysis of variance showed a high goodness of model fit and the accomplishment of the RSM method for improving embelin extraction from the fruits of E. ribes. Conclusion: It is concluded that this may be a useful method for the extraction and quantitative estimation of embelin from the fruits of E. ribes. PMID:26109763

  10. Optimization of a liquid chromatography ion mobility-mass spectrometry method for untargeted metabolomics using experimental design and multivariate data analysis.

    PubMed

    Tebani, Abdellah; Schmitz-Afonso, Isabelle; Rutledge, Douglas N; Gonzalez, Bruno J; Bekri, Soumeya; Afonso, Carlos

    2016-03-24

    High-resolution mass spectrometry coupled with pattern recognition techniques is an established tool to perform comprehensive metabolite profiling of biological datasets. This paves the way for new, powerful and innovative diagnostic approaches in the post-genomic era and molecular medicine. However, interpreting untargeted metabolomic data requires robust, reproducible and reliable analytical methods to translate results into biologically relevant and actionable knowledge. The analyses of biological samples were developed based on ultra-high performance liquid chromatography (UHPLC) coupled to ion mobility - mass spectrometry (IM-MS). A strategy for optimizing the analytical conditions for untargeted UHPLC-IM-MS methods is proposed using an experimental design approach. Optimization experiments were conducted through a screening process designed to identify the factors that have significant effects on the selected responses (total number of peaks and number of reliable peaks). For this purpose, full and fractional factorial designs were used while partial least squares regression was used for experimental design modeling and optimization of parameter values. The total number of peaks yielded the best predictive model and is used for optimization of parameters setting.

  11. Use of Response Surface Methodology to Optimize Culture Conditions for Hydrogen Production by an Anaerobic Bacterial Strain from Soluble Starch

    NASA Astrophysics Data System (ADS)

    Kieu, Hoa Thi Quynh; Nguyen, Yen Thi; Dang, Yen Thi; Nguyen, Binh Thanh

    2016-05-01

    Biohydrogen is a clean source of energy that produces no harmful byproducts during combustion, being a potential sustainable energy carrier for the future. Therefore, biohydrogen produced by anaerobic bacteria via dark fermentation has attracted attention worldwide as a renewable energy source. However, the hydrogen production capability of these bacteria depends on major factors such as substrate, iron-containing hydrogenase, reduction agent, pH, and temperature. In this study, the response surface methodology (RSM) with central composite design (CCD) was employed to improve the hydrogen production by an anaerobic bacterial strain isolated from animal waste in Phu Linh, Soc Son, Vietnam (PL strain). The hydrogen production process was investigated as a function of three critical factors: soluble starch concentration (8 g L-1 to 12 g L-1), ferrous iron concentration (100 mg L-1 to 200 mg L-1), and l-cysteine concentration (300 mg L-1 to 500 mg L-1). RSM analysis showed that all three factors significantly influenced hydrogen production. Among them, the ferrous iron concentration presented the greatest influence. The optimum hydrogen concentration of 1030 mL L-1 medium was obtained with 10 g L-1 soluble starch, 150 mg L-1 ferrous iron, and 400 mg L-1 l-cysteine after 48 h of anaerobic fermentation. The hydrogen concentration produced by the PL strain was doubled after using RSM. The obtained results indicate that RSM with CCD can be used as a technique to optimize culture conditions for enhancement of hydrogen production by the selected anaerobic bacterial strain. Hydrogen production from low-cost organic substrates such as soluble starch using anaerobic fermentation methods may be one of the most promising approaches.

  12. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source.

    PubMed

    Mauro, N A; Vogt, A J; Derendorf, K S; Johnson, M L; Rustan, G E; Quirinale, D G; Kreyssig, A; Lokshin, K A; Neuefeind, J C; An, Ke; Wang, Xun-Li; Goldman, A I; Egami, T; Kelton, K F

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. However, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample (∼100 mg).

  13. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source

    SciTech Connect

    Mauro, N. A.; Vogt, A. J.; Derendorf, K. S.; Johnson, M. L.; Rustan, G. E.; Quirinale, D. G.; Kreyssig, A.; Lokshin, K. A.; Neuefeind, J. C.; An, Ke; Wang, Xun-Li; Goldman, A. I.; Egami, T.; Kelton, K. F.

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. But, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. Furthermore, to demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample ( 100 mg).

  14. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source.

    PubMed

    Mauro, N A; Vogt, A J; Derendorf, K S; Johnson, M L; Rustan, G E; Quirinale, D G; Kreyssig, A; Lokshin, K A; Neuefeind, J C; An, Ke; Wang, Xun-Li; Goldman, A I; Egami, T; Kelton, K F

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. However, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample (∼100 mg). PMID:26827330

  15. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source

    NASA Astrophysics Data System (ADS)

    Mauro, N. A.; Vogt, A. J.; Derendorf, K. S.; Johnson, M. L.; Rustan, G. E.; Quirinale, D. G.; Kreyssig, A.; Lokshin, K. A.; Neuefeind, J. C.; An, Ke; Wang, Xun-Li; Goldman, A. I.; Egami, T.; Kelton, K. F.

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. However, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample (˜100 mg).

  16. Electrostatic levitation facility optimized for neutron diffraction studies of high temperature liquids at a spallation neutron source

    DOE PAGESBeta

    Mauro, N. A.; Vogt, A. J.; Derendorf, K. S.; Johnson, M. L.; Rustan, G. E.; Quirinale, D. G.; Kreyssig, A.; Lokshin, K. A.; Neuefeind, J. C.; An, Ke; et al

    2016-01-01

    Neutron diffraction studies of metallic liquids provide valuable information about inherent topological and chemical ordering on multiple length scales as well as insight into dynamical processes at the level of a few atoms. But, there exist very few facilities in the world that allow such studies to be made of reactive metallic liquids in a containerless environment, and these are designed for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elasticmore » and inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum chamber, external and internal neutron collimation optics, and a sample exchange mechanism that allows up to 30 samples to be processed between chamber openings. Two heating lasers allow excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated temperature control system allows isothermal measurements to be conducted for times approaching 2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. Furthermore, to demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at the SNS after only 30 min of acquisition time for a small sample ( 100 mg).« less

  17. A highly modular beamline electrostatic levitation facility, optimized for in situ high-energy x-ray scattering studies of equilibrium and supercooled liquids.

    PubMed

    Mauro, N A; Kelton, K F

    2011-03-01

    High-energy x-ray diffraction studies of metallic liquids provide valuable information about structural evolution on the atomic length scale, leading to insights into the origin of the nucleation barrier and the processes of supercooling and glass formation. The containerless processing of the beamline electrostatic levitation (BESL) facility allows coordinated thermophysical and structural studies of equilibrium and supercooled liquids to be made in a contamination-free, high-vacuum (∼10(-8) Torr) environment. To date, the incorporation of electrostatic levitation facilities into synchrotron beamlines has been difficult due to the large footprint of the apparatus and the difficulties associated with its transportation and implementation. Here, we describe a modular levitation facility that is optimized for diffraction studies of high-temperature liquids at high-energy synchrotron beamlines. The modular approach used in the apparatus design allows it to be easily transported and quickly setup. Unlike most previous electrostatic levitation facilities, BESL can be operated by a single user instead of a user team. PMID:21456796

  18. A highly modular beamline electrostatic levitation facility, optimized for in situ high-energy x-ray scattering studies of equilibrium and supercooled liquids

    SciTech Connect

    Mauro, N.A.; Kelton, K.F.

    2011-10-27

    High-energy x-ray diffraction studies of metallic liquids provide valuable information about structural evolution on the atomic length scale, leading to insights into the origin of the nucleation barrier and the processes of supercooling and glass formation. The containerless processing of the beamline electrostatic levitation (BESL) facility allows coordinated thermophysical and structural studies of equilibrium and supercooled liquids to be made in a contamination-free, high-vacuum ({approx}10{sup -8} Torr) environment. To date, the incorporation of electrostatic levitation facilities into synchrotron beamlines has been difficult due to the large footprint of the apparatus and the difficulties associated with its transportation and implementation. Here, we describe a modular levitation facility that is optimized for diffraction studies of high-temperature liquids at high-energy synchrotron beamlines. The modular approach used in the apparatus design allows it to be easily transported and quickly setup. Unlike most previous electrostatic levitation facilities, BESL can be operated by a single user instead of a user team.

  19. Optimization of biological and instrumental detection of explosives and ignitable liquid residues including canines, SPME/ITMS and GC/MSn

    NASA Astrophysics Data System (ADS)

    Furton, Kenneth G.; Harper, Ross J.; Perr, Jeannette M.; Almirall, Jose R.

    2003-09-01

    A comprehensive study and comparison is underway using biological detectors and instrumental methods for the rapid detection of ignitable liquid residues (ILR) and high explosives. Headspace solid phase microextraction (SPME) has been demonstrated to be an effective sampling method helping to identify active odor signature chemicals used by detector dogs to locate forensic specimens as well as a rapid pre-concentration technique prior to instrumental detection. Common ignitable liquids and common military and industrial explosives have been studied including trinitrotoluene, tetryl, RDX, HMX, EGDN, PETN and nitroglycerine. This study focuses on identifying volatile odor signature chemicals present, which can be used to enhance the level and reliability of detection of ILR and explosives by canines and instrumental methods. While most instrumental methods currently in use focus on particles and on parent organic compounds, which are often involatile, characteristic volatile organics are generally also present and can be exploited to enhance detection particularly for well-concealed devices. Specific examples include the volatile odor chemicals 2-ethyl-1-hexanol and cyclohexanone, which are readily available in the headspace of the high explosive composition C-4; whereas, the active chemical cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) is not. The analysis and identification of these headspace 'fingerprint' organics is followed by double-blind dog trials of the individual components using certified teams in an attempt to isolate and understand the target compounds to which dogs are sensitive. Studies to compare commonly used training aids with the actual target explosive have also been undertaken to determine their suitability and effectiveness. The optimization of solid phase microextraction (SPME) combined with ion trap mobility spectrometry (ITMS) and gas chromatography/mass spectrometry/mass spectrometry (GC/MSn) is detailed including interface development

  20. Recovery of culturable of Escherichia coli O157:H7 during operation of a liquid-based bioaerosol sampler

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Collection fluids used in liquid-based bioaerosol samplers can influence the viability of microorganisms. In this study we determined the recovery efficiency of vegetative E. coli O157:H7 cells that were spiked into low viscosity evaporating collection fluids during operation of a BioSampler™ for up...

  1. Liquid Ventilation

    PubMed Central

    Tawfic, Qutaiba A.; Kausalya, Rajini

    2011-01-01

    Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV) is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. The potential for multiple clinical applications for liquid-assisted ventilation will be clarified and optimized in future. PMID:22043370

  2. Statistical optimization of culture conditions for milk-clotting enzyme production by bacillus amyloliquefaciens using wheat bran-an agro-industry waste.

    PubMed

    Zhang, Weibing; He, Xiaoling; Liu, Hongna; Guo, Huiyuan; Ren, Fazheng; Wen, Pengcheng

    2013-12-01

    In order to improve the production of the milk-clotting enzyme under submerged fermentation, two statistical methods were applied to optimize the culture conditions of Bacillus amyloliquefaciens D4 using wheat bran as nutrient source. First, initial pH, agitation speed, and fermentation time were shown to have significant effects on D4 enzyme production using the Plackett-Burman experimental design. Subsequently, optimal conditions were obtained using the Box-Behnken method, which were as follows: initial pH 7.57, agitation speed 241 rpm, fermentation time 53.3 h. Under these conditions, the milk-clotting enzyme production was remarkably enhanced. The milk-clotting enzyme activity reached 1996.9 SU/mL, which was 2.92-fold higher than that of the initial culture conditions, showing that the Plackett-Burman design and Box-Behnken response surface method are effective to optimize culture conditions. The research can provide a reference for full utilization of wheat bran and the production of milk-clotting enzyme by B. amyloliquefaciens D4 under submerged fermentation.

  3. Effect of Sample Preparation on the Discrimination of Bacterial Isolates Cultured in Liquid Nutrient Media Using Laser-Induced Breakdown Spectroscopy (LIBS).

    PubMed

    Gamble, Gary R; Park, Bosoon; Yoon, Seung-Chul; Lawrence, Kurt C

    2016-03-01

    Laser-induced breakdown spectroscopy (LIBS) is used as the basis for discrimination between two genera of gram-negative bacteria and two genera of gram-positive bacteria representing pathogenic threats commonly found in poultry processing rinse waters. Because LIBS-based discrimination relies primarily upon the relative proportions of inorganic cell components including Na, K, Mg, and Ca, this study aims to determine the effects of trace mineral content and pH found in the water source used to isolate the bacteria upon the reliability of the resulting discriminant analysis. All four genera were cultured using tryptic soy agar (TSA) as the nutrient medium, and were grown under identical environmental conditions. The only variable introduced is the source water used to isolate the cultured bacteria. Cultures of each bacterium were produced using deionized (DI) water under two atmosphere conditions, reverse osmosis (RO) water, tap water, phosphate buffered saline (PBS) water, and TRIS buffered water. After 3 days of culture growth, the bacteria were centrifuged and washed three times in the same water source. Bacteria were then freeze dried, mixed with microcrystalline cellulose, and a pellet was made for LIBS analysis. Principal component analysis (PCA) was used to extract related variations in LIBS spectral data among the four bacteria genera and six water types used to isolate the bacteria, and Mahalanobis discriminant analysis (MDA) was used for classification. Results indicate not only that the four genera can be discriminated from each other in each water type, but that each genus can be discriminated by water type used for isolation. It is concluded that in order for LIBS to be a reliable and repeatable method for discrimination of bacteria grown in liquid nutrient media, care must be taken to insure that the water source used in purification of the culture be precisely controlled regarding pH, ionic strength, and proportionate amounts of mineral cations

  4. Optimization and characterization of an in vitro bovine mammary cell culture system to study regulation of milk protein synthesis and mammary differentiation

    SciTech Connect

    Talhouk, R.S.

    1988-01-01

    A long term bovine mammary cell culture system that maintains normal mammary cell function was established and optimized to study milk protein synthesis and secretion and mammary differentiation. This culture system used bovine mammary acini isolated from developing or lactating mammary gland by enzymatic dissociation, and cryopreserved until thawed and plated for growth in vitro for these studies. Cells in M199 with lactogenic hormones {plus minus} fetal calf serum (FCS) were cultured on plastic, 100ul and 500ul type I collagen, and Matrigel, or embedded within type I collagen. Cell morphology, cell number, and total TCA-precipitable {sup 35}S-labelled proteins were monitored. Milk protein ({alpha}{sub s,1}-casein, lactoferrin (LF), {alpha}-lactalbumin, and {beta}-lactoglobulin) secretion and intracellular levels were determined by an ELISA assay.

  5. Statistical optimization of a culture medium for biomass and poly(3-hydroxybutyrate) production by a recombinant Escherichia coli strain using agroindustrial byproducts.

    PubMed

    Nikel, Pablo I; Pettinari, M Julia; Méndez, Beatriz S; Galvagno, Miguel A

    2005-12-01

    A statistically based Plackett-Burman screening design identified milk whey and corn steep liquor concentrations as well as ionic strength (based on phosphate buffer concentration) as the three main independent components of the culture medium that significantly (p < 0.05) influenced biomass and poly(3-hydroxybutyrate) (PHB) production in recombinant cells of Escherichia coli. This strain carries a plasmid encoding phb genes from a natural isolate of Azotobacter sp. Response surface methodology, using a central composite rotatable design, demonstrated that the optimal concentrations of the three components, defined as those yielding maximal biomass and PHB production in shaken flasks, were 37.96 g deproteinated milk whey powder/l, 29.39 g corn steep liquor/l, and 23.76 g phosphates/l (r2 = 0.957). The model was validated by culturing the recombinant cells in medium containing these optimal concentrations, which yielded 9.41 g biomass/l and 6.12 g PHB/l in the culture broth. Similar amounts of PHB were obtained following batch fermentations in a bioreactor. These results show that PHB can be produced efficiently by culturing the recombinant strain in medium containing cheap carbon and nitrogen sources.

  6. Evaluation of in vitro bone resorption: high-performance liquid chromatography measurement of the pyridinolines released in osteoclast cultures.

    PubMed

    Lorget, F; Mentaverri, R; Meddah, B; Cayrolle, G; Wattel, A; Morel, A; Schecroun, N; Maamer, M; de Vernejoul, M C; Kamel, S; Brazier, M

    2000-09-10

    None of the currently used methods to evaluate bone resorption by osteoclasts cultured on bone substrate measures directly the amounts of degraded bone collagen, which is a direct reflection of the osteoclast "work done." We therefore propose a reliable biochemical method to evaluate the in vitro collagenolysis process. Bone-resorbing activity was evaluated, after HPLC separation, by fluorimetric measurement of hydroxylysylpyridinoline (HP), a collagen cross-link molecule, released in culture supernatants. We first confirm previous data reporting that HP is released in the culture medium in a peptide-conjugated form. After acid hydrolysis, we show that HP is highly correlated with the lacunae area (r = 0.68, P<0.0001) and with the amounts of antigenic collagen fragments (Cross-laps for culture) released in culture medium (r = 0.77, P<0.0002). Using a cysteine protease inhibitor, we observed that lacunae areas are dramatically less inhibited (35% inhibition) than the release of bone-degraded products, including HP and antigenic collagen fragments (96 and 92% inhibition, respectively). Coupled to the resorbed area measurement, biochemical evaluations offer both quantitative and qualitative complementary measurements of the osteoclastic bone-resorbing process.

  7. Optimization of the cell seeding density and modeling of cell growth and metabolism using the modified Gompertz model for microencapsulated animal cell culture.

    PubMed

    Wen-tao, Qi; Ying, Zhang; Juan, Ma; Xin, Guo; Yu-bing, Xie; Wei, Wang; Xiaojun, Ma

    2006-04-01

    Cell microencapsulation is one of the promising strategies for the in vitro production of proteins or in vivo delivery of therapeutic products. In order to design and fabricate the optimized microencapsulated cell system, the Gompertz model was applied and modified to describe the growth and metabolism of microencapsulated cell, including substrate consumption and product formation. The Gompertz model successfully described the cell growth kinetics and the modified Gompertz models fitted the substrate consumption and product formation well. It was demonstrated that the optimal initial cell seeding density was about 4-5 x 10(6) cells/mL of microcapsule, in terms of the maximum specific growth rate, the glucose consumption potential and the product formation potential calculated by the Gompertz and modified Gompertz models. Modeling of cell growth and metabolism in microcapsules provides a guideline for optimizing the culture of microencapsulated cells.

  8. Characterization of the Early Events Leading to Totipotency in an Arabidopsis Protoplast Liquid Culture by Temporal Transcript Profiling[W][OPEN

    PubMed Central

    Chupeau, Marie-Christine; Granier, Fabienne; Pichon, Olivier; Renou, Jean-Pierre; Gaudin, Valérie; Chupeau, Yves

    2013-01-01

    The molecular mechanisms underlying plant cell totipotency are largely unknown. Here, we present a protocol for the efficient regeneration of plants from Arabidopsis thaliana protoplasts. The specific liquid medium used in our study leads to a high rate of reentry into the cell cycle of most cell types, providing a powerful system to study dedifferentiation/regeneration processes in independent somatic cells. To identify the early events in the establishment of totipotency, we monitored the genome-wide transcript profiles of plantlets and protoplast-derived cells (PdCs) during the first week of culture. Plant cells rapidly dedifferentiated. Then, we observed the reinitiation and reorientation of protein synthesis, accompanied by the reinitiation of cell division and de novo cell wall synthesis. Marked changes in the expression of chromatin-associated genes, especially of those in the histone variant family, were observed during protoplast culture. Surprisingly, the epigenetic status of PdCs and well-established cell cultures differed, with PdCs exhibiting rare reactivated transposons and epigenetic changes. The differentially expressed genes identified in this study are interesting candidates for investigating the molecular mechanisms underlying plant cell plasticity and totipotency. One of these genes, the plant-specific transcription factor ABERRANT LATERAL ROOT FORMATION4, is required for the initiation of protoplast division. PMID:23903317

  9. Optimization of Liquid Fermentation Medium for Production of Inonotus sanghuang (Higher Basidiomycetes) Mycelia and Evaluation of their Mycochemical Contents and Antioxidant Activities.

    PubMed

    Tian, Xue-Mei; Dai, Yu-Cheng; Song, Ai-Rong; Xu, Kun; Ng, Lean Teik

    2015-01-01

    Inonotus sanghuang, an authentic "Sanghuang" mushroom used in traditional Chinese medicine, is known to possess important pharmacological activities. In this study, we aimed to optimize the liquid fermentation medium for I. sanghuang mycelial production and to determine the effects of two-stage cultivation (shake and static) on the yield of total flavonoids, total phenolics, and polysaccharides, as well as the antioxidant activities of I. sanghuang mycelial extracts (ISME). Under an optimized medium composition (38.96 g/L of corn flour, 4.15 g/L of yeast extract, 20.55 g/L of bran and pH 6.39), the predicted and experimental optimal mycelial biomasses were 17.60 g/L and 18.33±0.86 g/L, respectively. The results of two-stage cultivation showed that contents of total flavonoids and total phenolics in mycelia increased by 37.92% and 77.27%, respectively. However, irregular polysaccharide contents were noted throughout the experimental period. Antioxidant assays showed that ISME possessed good free-radical scavenging activity, which is mainly contributed by polyphenolic-type metabolites.

  10. Self-assembled liquid crystalline nanoparticles as an ophthalmic drug delivery system. Part II: optimization of formulation variables using experimental design.

    PubMed

    Achouri, Djamila; Sergent, Michelle; Tonetto, Alain; Piccerelle, Philippe; Andrieu, Véronique; Hornebecq, Virginie

    2015-03-01

    In the field of keratoconus treatment, a lipid-based liquid crystal nanoparticles system has been developed to improve the preocular retention and ocular bioavailability of riboflavin, a water-soluble drug. The formulation of this ophthalmic drug delivery system was optimized by a simplex lattice experimental design. The delivery system is composed of three main components that are mono acyl glycerol (monoolein), poloxamer 407 and water and two secondary components that are riboflavin and glycerol (added to adjust the osmotic pressure). The amounts of these three main components were selected as the factors to systematically optimize the dependent variables that are the encapsulation efficiency and the particle size. In this way, 12 formulas describing experimental domain of interest were prepared. Results obtained using small angle X-rays scattering (SAXS) and cryo-transmission electron microscopy (cryo-TEM) evidenced the presence of nano-objects with either sponge or hexagonal inverted structure. In the zone of interest, the percentage of each component was determined to obtain both high encapsulation efficiency and small size of particles. Two optimized formulations were found: F7 and F1. They are very close in the ternary phase diagram as they contain 6.83% of poloxamer 407; 44.18% and 42.03% of monoolein; 46.29% and 48.44% of water for F7 and F11, respectively. These formulations displayed a good compromise between inputs and outputs investigated.

  11. Optimization of Liquid Fermentation Medium for Production of Inonotus sanghuang (Higher Basidiomycetes) Mycelia and Evaluation of their Mycochemical Contents and Antioxidant Activities.

    PubMed

    Tian, Xue-Mei; Dai, Yu-Cheng; Song, Ai-Rong; Xu, Kun; Ng, Lean Teik

    2015-01-01

    Inonotus sanghuang, an authentic "Sanghuang" mushroom used in traditional Chinese medicine, is known to possess important pharmacological activities. In this study, we aimed to optimize the liquid fermentation medium for I. sanghuang mycelial production and to determine the effects of two-stage cultivation (shake and static) on the yield of total flavonoids, total phenolics, and polysaccharides, as well as the antioxidant activities of I. sanghuang mycelial extracts (ISME). Under an optimized medium composition (38.96 g/L of corn flour, 4.15 g/L of yeast extract, 20.55 g/L of bran and pH 6.39), the predicted and experimental optimal mycelial biomasses were 17.60 g/L and 18.33±0.86 g/L, respectively. The results of two-stage cultivation showed that contents of total flavonoids and total phenolics in mycelia increased by 37.92% and 77.27%, respectively. However, irregular polysaccharide contents were noted throughout the experimental period. Antioxidant assays showed that ISME possessed good free-radical scavenging activity, which is mainly contributed by polyphenolic-type metabolites. PMID:26559702

  12. Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria

    PubMed Central

    Maia, Margarida R. G.; Marques, Sara; Cabrita, Ana R. J.; Wallace, R. John; Thompson, Gertrude; Fonseca, António J. M.; Oliveira, Hugo M.

    2016-01-01

    Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.

  13. Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria.

    PubMed

    Maia, Margarida R G; Marques, Sara; Cabrita, Ana R J; Wallace, R John; Thompson, Gertrude; Fonseca, António J M; Oliveira, Hugo M

    2016-01-01

    Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.

  14. Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria.

    PubMed

    Maia, Margarida R G; Marques, Sara; Cabrita, Ana R J; Wallace, R John; Thompson, Gertrude; Fonseca, António J M; Oliveira, Hugo M

    2016-01-01

    Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells. PMID:27630632

  15. Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria

    PubMed Central

    Maia, Margarida R. G.; Marques, Sara; Cabrita, Ana R. J.; Wallace, R. John; Thompson, Gertrude; Fonseca, António J. M.; Oliveira, Hugo M.

    2016-01-01

    Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells. PMID:27630632

  16. Response surface methodology based on central composite design as a chemometric tool for optimization of dispersive-solidification liquid-liquid microextraction for speciation of inorganic arsenic in environmental water samples.

    PubMed

    Asadollahzadeh, Mehdi; Tavakoli, Hamed; Torab-Mostaedi, Meisam; Hosseini, Ghaffar; Hemmati, Alireza

    2014-06-01

    Dispersive-solidification liquid-liquid microextraction (DSLLME) coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed for preconcentration and determination of inorganic arsenic (III, V) in water samples. At pH=1, As(III) formed complex with ammonium pyrrolidine dithiocarbamate (APDC) and extracted into the fine droplets of 1-dodecanol (extraction solvent) which were dispersed with ethanol (disperser solvent) into the water sample solution. After extraction, the organic phase was separated by centrifugation, and was solidified by transferring into an ice bath. The solidified solvent was transferred to a conical vial and melted quickly at room temperature. As(III) was determined in the melted organic phase while As(V) remained in the aqueous layer. Total inorganic As was determined after the reduction of the pentavalent forms of arsenic with sodium thiosulphate and potassium iodide. As(V) was calculated by difference between the concentration of total inorganic As and As(III). The variable of interest in the DSLLME method, such as the volume of extraction solvent and disperser solvent, pH, concentration of APDC (chelating agent), extraction time and salt effect, was optimized with the aid of chemometric approaches. First, in screening experiments, fractional factorial design (FFD) was used for selecting the variables which significantly affected the extraction procedure. Afterwards, the significant variables were optimized using response surface methodology (RSM) based on central composite design (CCD). In the optimum conditions, the proposed method has been successfully applied to the determination of inorganic arsenic in different environmental water samples and certified reference material (NIST RSM 1643e). PMID:24725860

  17. Response surface methodology based on central composite design as a chemometric tool for optimization of dispersive-solidification liquid-liquid microextraction for speciation of inorganic arsenic in environmental water samples.

    PubMed

    Asadollahzadeh, Mehdi; Tavakoli, Hamed; Torab-Mostaedi, Meisam; Hosseini, Ghaffar; Hemmati, Alireza

    2014-06-01

    Dispersive-solidification liquid-liquid microextraction (DSLLME) coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed for preconcentration and determination of inorganic arsenic (III, V) in water samples. At pH=1, As(III) formed complex with ammonium pyrrolidine dithiocarbamate (APDC) and extracted into the fine droplets of 1-dodecanol (extraction solvent) which were dispersed with ethanol (disperser solvent) into the water sample solution. After extraction, the organic phase was separated by centrifugation, and was solidified by transferring into an ice bath. The solidified solvent was transferred to a conical vial and melted quickly at room temperature. As(III) was determined in the melted organic phase while As(V) remained in the aqueous layer. Total inorganic As was determined after the reduction of the pentavalent forms of arsenic with sodium thiosulphate and potassium iodide. As(V) was calculated by difference between the concentration of total inorganic As and As(III). The variable of interest in the DSLLME method, such as the volume of extraction solvent and disperser solvent, pH, concentration of APDC (chelating agent), extraction time and salt effect, was optimized with the aid of chemometric approaches. First, in screening experiments, fractional factorial design (FFD) was used for selecting the variables which significantly affected the extraction procedure. Afterwards, the significant variables were optimized using response surface methodology (RSM) based on central composite design (CCD). In the optimum conditions, the proposed method has been successfully applied to the determination of inorganic arsenic in different environmental water samples and certified reference material (NIST RSM 1643e).

  18. Optimization of two methods for the analysis of hydrogen peroxide: high performance liquid chromatography with fluorescence detection and high performance liquid chromatography with electrochemical detection in direct current mode.

    PubMed

    Tarvin, Megan; McCord, Bruce; Mount, Kelly; Sherlach, Katy; Miller, Mark L

    2010-11-26

    Two complementary methods were optimized for the separation and detection of trace levels of hydrogen peroxide. The first method utilized reversed-phase high-performance liquid chromatography with fluorescence detection (HPLC-FD). With this approach, hydrogen peroxide was detected based upon its participation in the hemin-catalyzed oxidation of p-hydroxyphenylacetic acid to yield the fluorescent dimer. The second method utilized high performance liquid chromatography with electrochemical detection (HPLC-ED). With this approach, hydrogen peroxide was detected based upon its oxidation at a gold working electrode at an applied potential of 400 mV vs. hydrogen reference electrode (Pd/H(2)). Both methods were linear across the range of 15-300 μM, and the electrochemical method was linear across a wider range of 7.4-15,000 μM. The limit of detection for hydrogen peroxide was 6 μM by HPLC/FD, and 0.6 μM by HPLC/ED. A series of organic peroxides and inorganic ions were evaluated for their potential to interfere with the detection of hydrogen peroxide. Studies investigating the recovery of hydrogen peroxide with three different extraction protocols were also performed. Post-blast debris from the detonation of a mixture of concentrated hydrogen peroxide with nitromethane was analyzed on both systems. Hydrogen peroxide residues were successfully detected on this post-blast debris.

  19. Optimizing Culture Medium Composition to Improve Oligodendrocyte Progenitor Cell Yields In Vitro from Subventricular Zone-Derived Neural Progenitor Cell Neurospheres

    PubMed Central

    Franco, Paula G.; Pasquini, Juana M.; Silvestroff, Lucas

    2015-01-01

    Neural Stem and Progenitor Cells (NSC/NPC) are gathering tangible recognition for their uses in cell therapy and cell replacement therapies for human disease, as well as a model system to continue research on overall neural developmental processes in vitro. The Subventricular Zone is one of the largest NSC/NPC niches in the developing mammalian Central Nervous System, and persists through to adulthood. Oligodendrocyte progenitor cell (OPC) enriched cultures are usefull tools for in vitro studies as well as for cell replacement therapies for treating demyelination diseases. We used Subventricular Zone-derived NSC/NPC primary cultures from newborn mice and compared the effects of different growth factor combinations on cell proliferation and OPC yield. The Platelet Derived Growth Factor-AA and BB homodimers had a positive and significant impact on OPC generation. Furthermore, heparin addition to the culture media contributed to further increase overall culture yields. The OPC generated by this protocol were able to mature into Myelin Basic Protein-expressing cells and to interact with neurons in an in vitro co-culture system. As a whole, we describe an optimized in vitro method for increasing OPC. PMID:25837625

  20. Different Culture Metabolites of the Red Sea Fungus Fusarium equiseti Optimize the Inhibition of Hepatitis C Virus NS3/4A Protease (HCV PR)

    PubMed Central

    Hawas, Usama W.; Al-Farawati, Radwan; Abou El-Kassem, Lamia T.; Turki, Adnan J.

    2016-01-01

    The endophytic fungus Fusarium equiseti was isolated from the brown alga Padina pavonica, collected from the Red Sea. The fungus was identified by its morphology and 18S rDNA. Cultivation of this fungal strain in biomalt-peptone medium led to isolation of 12 known metabolites of diketopeprazines and anthraquinones. The organic extract and isolated compounds were screened for their inhibition of hepatitis C virus NS3/4A protease (HCV PR). As a result, the fungal metabolites showed inhibition of HCV protease (IC50 from 19 to 77 μM), and the fungus was subjected to culture on Czapek’s (Cz) media, with a yield of nine metabolites with potent HCV protease inhibition ranging from IC50 10 to 37 μM. The Cz culture extract exhibited high-level inhibition of HCV protease (IC50 27.6 μg/mL) compared to the biomalt culture extract (IC50 56 μg/mL), and the most potent HCV PR isolated compound (Griseoxanthone C, IC50 19.8 μM) from the bio-malt culture extract showed less of an inhibitory effect compared to isolated ω-hydroxyemodin (IC50 10.7 μM) from the optimized Cz culture extract. Both HCV PR active inhibitors ω-hydroxyemodin and griseoxanthone C were considered as the lowest selective safe constituents against Trypsin inhibitory effect with IC50 48.5 and 51.3 μM, respectively. PMID:27775589

  1. Glucose concentration alters dissolved oxygen levels in liquid cultures of Beauveria bassiana and affects formation and bioefficacy of blastospores

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beauveria bassiana is a ubiquitous dimorphic entomopathogenic fungus commonly used for controlling numerous insect pests worldwide. The goal of the present study was to optimize the production of B. bassiana to achieve high yields of the preferred morphology, a yeast-like blastospore, rather than my...

  2. Analysis of steroids in yeast-mediated cell culture by on-line solid-phase extraction coupled high-performance liquid chromatography electrospray-ionization/mass spectrometry and novel continuous postcolumn infusion of internal standard technique.

    PubMed

    Cheng, Cheanyeh; Tsai, Hsiang-Rong

    2008-08-15

    The reduction of 17-ketosteroid estrone or androstenedione to corresponding 17alpha- and 17beta-estradiol or testosterone and epitestosterone has been performed with Saccharomyces cerevisiae. In the analysis of the cell culture, the solid-phase extraction (SPE) method was on-line coupled to high-performance liquid chromatography electrospray-ionization/mass spectrometry (HPLC-ESI/MS) for sample pretreatment to eliminate the complicated matrix interference and preconcentrate of the analytes before chromatographic separation. A novel quantification method with the continuous postcolumn infusion of internal standard was developed for the determination of substrate and products. This novel quantitative method can stabilize and enhance the ionization of all analytes during analysis. The HPLC-ESI/MS analysis of estrone, 17alpha-, and 17beta-estradiol was operated with a negative ion mode and the analysis of androstenedione, testosterone, and epitestosterone was operated with a positive ion mode. The optimal concentration of the internal standard progesterone with the continuous postcolumn infusion technique was 3 microg mL(-1) for estrogen analysis and 1 ng mL(-1) for androgen analysis and both were at a constant infusion rate of 0.5 microL min(-1). All of the linear correlation coefficients of the standard calibration curves were over 0.99 and had a linear range from 0 to 50 ng mL(-1). The limit of detections (LODs) and the limit of quantitations (LOQs) for steroids analyzed were from 0.12 to 0.36 ng mL(-1) and from 0.4 to 1.2 ng mL(-1), respectively. The analysis accuracies and precisions were better than 94% and lower than 8.8% R.S.D., respectively. The developed method for the analysis of steroids in the cell culture was successful.

  3. Optimizing Photovoltaic Response by Tuning Light-Harvesting Nanocrystal Shape Synthesized Using a Quick Liquid-Gas Phase Reaction.

    PubMed

    Mazumdar, Sayantan; Tamilselvan, Muthusamy; Bhattacharyya, Aninda J

    2015-12-30

    The electron recombination lifetime in a sensitized semiconductor assembly is greatly influenced by the crystal structure and geometric form of the light-harvesting semiconductor nanocrystal. When such light harvesters with varying structural characteristics are configured in a photoanode, its interface with the electrolyte becomes equally important and directly influences the photovoltaic efficiency. We have systematically probed here the influence of nanocrystal crystallographic structure and shape on the electron recombination lifetime and its eventual influence on the light to electricity conversion efficiency of a liquid junction semiconductor sensitized solar cell. The light-harvesting cadmium sulfide (CdS) nanocrystals of distinctly different and controlled shapes are obtained using a novel and simple liquid-gas phase synthesis method performed at different temperatures involving very short reaction times. High-resolution synchrotron X-ray diffraction and spectroscopic studies respectively exhibit different crystallographic phase content and optical properties. When assembled on a mesoscopic TiO2 film by a linker molecule, they exhibit remarkable variation in electron recombination lifetime by 1 order of magnitude, as determined by ac-impedance spectroscopy. This also drastically affects the photovoltaic efficiency of the differently shaped nanocrystal sensitized solar cells.

  4. Optimization of Sample Preparation for the Identification and Quantification of Saxitoxin in Proficiency Test Mussel Sample using Liquid Chromatography-Tandem Mass Spectrometry.

    PubMed

    Harju, Kirsi; Rapinoja, Marja-Leena; Avondet, Marc-André; Arnold, Werner; Schär, Martin; Burrell, Stephen; Luginbühl, Werner; Vanninen, Paula

    2015-11-25

    Saxitoxin (STX) and some selected paralytic shellfish poisoning (PSP) analogues in mussel samples were identified and quantified with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample extraction and purification methods of mussel sample were optimized for LC-MS/MS analysis. The developed method was applied to the analysis of the homogenized mussel samples in the proficiency test (PT) within the EQuATox project (Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk). Ten laboratories from eight countries participated in the STX PT. Identification of PSP toxins in naturally contaminated mussel samples was performed by comparison of product ion spectra and retention times with those of reference standards. The quantitative results were obtained with LC-MS/MS by spiking reference standards in toxic mussel extracts. The results were within the z-score of ±1 when compared to the results measured with the official AOAC (Association of Official Analytical Chemists) method 2005.06, pre-column oxidation high-performance liquid chromatography with fluorescence detection (HPLC-FLD).

  5. Optimization of an analytical methodology for the simultaneous determination of different classes of ultraviolet filters in cosmetics by pressurized liquid extraction-gas chromatography tandem mass spectrometry.

    PubMed

    Vila, Marlene; Lamas, J Pablo; Garcia-Jares, Carmen; Dagnac, Thierry; Llompart, Maria

    2015-07-31

    A methodology based on pressurized liquid extraction (PLE) followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) has been developed for the simultaneous analysis of different classes of UV filters including methoxycinnamates, benzophenones, salicylates, p-aminobenzoic acid derivatives, and others in cosmetic products. The extractions were carried out in 1mL extraction cells and the amount of sample extracted was only 100mg. The experimental conditions, including the acetylation of the PLE extracts to improve GC performance, were optimized by means of experimental design tools. The two main factors affecting the PLE procedure such as solvent type and extraction temperature were assessed. The use of a matrix matched approach consisting of the addition of 10μL of diluted commercial cosmetic oil avoided matrix effects. Good linearity (R(2)>0.9970), quantitative recoveries (>80% for most of compounds, excluding three banned benzophenones) and satisfactory precision (RSD<10% in most cases) were achieved under the optimal conditions. The validated methodology was successfully applied to the analysis of different types of cosmetic formulations including sunscreens, hair products, nail polish, and lipsticks, amongst others. PMID:26091782

  6. Optimization of an analytical methodology for the simultaneous determination of different classes of ultraviolet filters in cosmetics by pressurized liquid extraction-gas chromatography tandem mass spectrometry.

    PubMed

    Vila, Marlene; Lamas, J Pablo; Garcia-Jares, Carmen; Dagnac, Thierry; Llompart, Maria

    2015-07-31

    A methodology based on pressurized liquid extraction (PLE) followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) has been developed for the simultaneous analysis of different classes of UV filters including methoxycinnamates, benzophenones, salicylates, p-aminobenzoic acid derivatives, and others in cosmetic products. The extractions were carried out in 1mL extraction cells and the amount of sample extracted was only 100mg. The experimental conditions, including the acetylation of the PLE extracts to improve GC performance, were optimized by means of experimental design tools. The two main factors affecting the PLE procedure such as solvent type and extraction temperature were assessed. The use of a matrix matched approach consisting of the addition of 10μL of diluted commercial cosmetic oil avoided matrix effects. Good linearity (R(2)>0.9970), quantitative recoveries (>80% for most of compounds, excluding three banned benzophenones) and satisfactory precision (RSD<10% in most cases) were achieved under the optimal conditions. The validated methodology was successfully applied to the analysis of different types of cosmetic formulations including sunscreens, hair products, nail polish, and lipsticks, amongst others.

  7. Quality by design based optimization of a high performance liquid chromatography method for assay determination of low concentration preservatives in complex nasal formulations.

    PubMed

    Zakrajšek, Jure; Stojić, Vladimir; Bohanec, Simona; Urleb, Uroš

    2015-01-01

    The effects of seven different chromatographic parameters and five sample preparation parameters in a high performance liquid chromatography (HPLC) method for assay determination of benzalkonium chloride (BKC) in a nasal formulation were evaluated using two fractional factorial experimental designs. The design space of the analytical method was modeled using Umetrics Modde software and the optimal method conditions were predicted. The optimum HPLC chromatographic conditions were obtained using a Luna CN column (150 x 4.6 mm, 3 µm). The results show that mobile phase pH, amount of acetonitrile in the mobile phase and column temperature are the most important factors in obtaining good separation of BKC homologs from an interfering peak. In the sample preparation step, the use of an aqueous solution for dissolving the samples was the most important factor since it eliminated the interfering effect of the active compound. The optimal method was validated for linearity, accuracy and precision. The use of experimental designs enables obtaining the maximum amount of information with the least possible number of experiments. Such designs are an economical manner in evaluating a variety of different factors and their interactions.

  8. Mycotoxin production in liquid culture and on plants infected with Alternaria spp. isolated from rocket and cabbage.

    PubMed

    Siciliano, Ilenia; Ortu, Giuseppe; Gilardi, Giovanna; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-03-05

    Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower). A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions.

  9. A new computer-controlled air-liquid interface cultivation system for the generation of differentiated cell cultures of the airway epithelium.

    PubMed

    Aufderheide, Michaela; Förster, Christine; Beschay, Morris; Branscheid, Detlev; Emura, Makito

    2016-01-01

    The increased application of in vitro systems in pharmacology and toxicology requires cell culture systems that facilitate the cultivation process and ensure stable, reproducible and controllable cultivation conditions. Up to now, some devices have been developed for the cultivation of cells under submersed conditions. However, systems meeting the requirements of an air-liquid interface (ALI) cultivation for the special needs of bronchial epithelial cells for example are still lacking. In order to obtain in vivo like organization and differentiation of these cells they need to be cultivated under ALI conditions on microporous membranes in direct contact with the environmental atmosphere. For this purpose, a Long-Term-Cultivation system was developed (CULTEX(®) LTC-C system) for the computer-controlled cultivation of such cells. The transwell inserts are placed in an incubator module (24 inserts), which can be adjusted for the medium level (ultrasonic pulse-echosensor), time and volume-dependent medium exchange, and frequency for mixing the medium with a rotating disc for homogeneous distribution of medium and secretion components. Normal primary freshly isolated bronchial epithelial cells were cultivated for up to 38 days to show the efficiency of such a cultivation procedure for generating 3D cultures exhibiting in vivo-like pseudostratified organization of the cells as well as differentiation characteristics like mucus-producing and cilia-forming cells.

  10. Optimization of the basal medium for improving production and secretion of taxanes from suspension cell culture of Taxus baccata L

    PubMed Central

    2012-01-01

    Background and purpose of the study Taxol is one of the most effective anticancer drugs that isolated from Taxus sp. due to the slow growth of Taxus trees and low concentration of Taxol in the tissues, the biotechnological approaches especially plant cell culture have been considered to produce Taxol in commercial scale. Methods We investigated the effects of basal medium type used in culture media on production of Taxol and other taxane compounds from cell suspension culture of T. baccata L. Briefly, five commonly basal media including Gamborg, Murashige and Skoog, Woody Plant, Schenk and Hildebrandt, and Driver and Kuniyuki medium were used for preparing separate suspension culture media. The intra- and extra-cellular yields of taxanes were analyzed by using HPLC after 21 days period of culturing. Results The yields of taxanes were significantly different for the cultures prepared by different basal media. Moreover, the effects of basal medium on the yield of products differed for varius taxane compounds. Maximum yields of Baccatin III (10.03 mgl-1) and 10-deacetyl baccatin III (4.2 mgl-1) were achieved from the DKW basal media, but the yield of Taxol was maximum (16.58 mgl-1) in the WPM basal media. Furthermore, the secretion of taxanes from the cells into medium was also considerably affected by the type of basal medium. The maximum extra-cellular yield of Taxol (7.81 mgl-1), Baccatin III (5.0 mgl-1), and 10-deacetyl baccatin III (1.45 mgl-1) were also obtained by using DKW basal medium that were significantly higher than those obtained from other culture media. PMID:23352123

  11. Optimization of culture conditions for osteogenically-induced mesenchymal stem cells in β-tricalcium phosphate ceramics with large interconnected channels.

    PubMed

    Bernhardt, Anne; Lode, Anja; Peters, Fabian; Gelinsky, Michael

    2011-06-01

    The aim of this study was to optimize culture conditions for human mesenchymal stem cells (hMSCs) in β-tricalcium phosphate ceramics with large interconnected channels. Fully interconnected macrochannels comprising pore diameters of 750 µm and 1400 µm were inserted into microporous β-tricalcium phosphate (β-TCP) scaffolds by milling. Human bone marrow-derived MSCs were seeded into the scaffolds and cultivated for up to 3 weeks in both static and perfusion culture in the presence of osteogenic supplements (dexamethasone, β-glycerophosphate, ascorbate). It was confirmed by scanning electron microscopic investigations and histological staining that the perfusion culture resulted in uniform distribution of cells inside the whole channel network, whereas the statically cultivated cells were primarily found at the surface of the ceramic samples. It was also determined that perfusion with standard medium containing 10% fetal calf serum (FCS) led to a strong increase (seven-fold) of cell numbers compared with static cultivation observed after 3 weeks. Perfusion with low-serum medium (2% FCS) resulted in moderate proliferation rates which were comparable to those achieved in static culture, although the specific alkaline phosphatase (ALP) activity increased by a factor of more than 3 compared to static cultivation. Gene expression analysis of the ALP gene also revealed higher levels of ALP mRNA in low-serum perfused samples compared to statically cultivated constructs. In contrast, gene expression of the late osteogenic marker bone sialoprotein II (BSPII) was decreased for perfused samples compared to statically cultivated samples.

  12. Ferulic acid, an efficient inhibitor of type B trichothecene biosynthesis and Tri gene expression in Fusarium liquid cultures.

    PubMed

    Boutigny, Anne-Laure; Barreau, Christian; Atanasova-Penichon, Vessela; Verdal-Bonnin, Marie-Noëlle; Pinson-Gadais, Laëtitia; Richard-Forget, Florence

    2009-01-01

    The effect of ferulic acid, the most abundant phenolic acid in wheat bran, was studied in vitro on type B trichothecene biosynthesis by Fusarium. It was demonstrated that ferulic acid is an efficient inhibitor of mycotoxin production by all strains of Fusarium tested, including different chemotypes and species. To analyse the mechanism of toxin biosynthesis inhibition by ferulic acid, expression of representative Tri genes, involved in the trichothecene biosynthesis pathway, was monitored by real-time RT-PCR. A decrease in the level of Tri gene expression was measured, suggesting that inhibition of toxin synthesis by ferulic acid could be regulated at the transcriptional level. Moreover, toxin production was shown to be reduced proportionally to the initial amount of ferulic acid added in the culture medium. Addition of ferulic acid either at the spore germination step or to a mycelial culture resulted in the same final inhibitory effect on mycotoxin accumulation. A cumulative inhibitory effect on trichothecene biosynthesis was even observed with successive supplementation of ferulic acid. Ferulic acid, which content varies among wheat varieties, could then play an important role in modulating trichothecene biosynthesis by Fusarium in some wheat varieties.

  13. Numerical fluid-dynamic optimization of microchannel-provided porous scaffolds for the co-culture of adherent and non-adherent cells.

    PubMed

    Cantini, Marco; Fiore, Gianfranco B; Redaelli, Alberto; Soncini, Monica

    2009-03-01

    Computational fluid dynamic (CFD) techniques were used to optimize the microenvironment inside scaffolds for hematopoietic stem cell (HSC) culture in a perfusion bioreactor. These matrices are meant to be seeded with adherent bone marrow stromal cells and then co-cultivated with HSCs; the scaffold micro-architecture and the fluid-dynamic conditions have to be optimized to avoid non-adherent stem cells being dragged away while ensuring adequate nutrient supply. The insertion of longitudinal microchannels was tested as a tool to improve perfusion in a homogeneous porous scaffold. Models of microchannel-provided scaffolds, characterized by different values of geometric parameters concerning pores and channels, were built, and numerical fluid-dynamic and oxygen-transfer analyses were carried out. The results of the computations indicated that the microchannels created preferential paths for culture medium flow, causing low shear stresses and drag forces within the pores; meanwhile, they improved oxygen delivery by forcing its penetration into the scaffold bulk. In particular, an 85% porous, 3-mm-thick scaffold with 175-microm-diameter pores was considered; at a constant average drag force guaranteeing stem cell suspension inside this porous bulk, the addition of approximately 260-microm-diameter, 700-microm-spaced channels resulted in 34% higher oxygen partial pressure at the exit (approximately 135 vs 101 mmHg), maintaining a wall shear stress median value of approximately 0.14 mPa. The present work demonstrates the capacity of microchannel-provided scaffolds to ensure suitable conditions for HSC culture and shows that CFD methods are a valuable tool to retrieve significant clues for the design of the culture environment.

  14. Optimization of metabolite extraction of human vein tissue for ultra performance liquid chromatography-mass spectrometry and nuclear magnetic resonance-based untargeted metabolic profiling.

    PubMed

    Anwar, Muzaffar A; Vorkas, Panagiotis A; Li, Jia V; Shalhoub, Joseph; Want, Elizabeth J; Davies, Alun H; Holmes, Elaine

    2015-11-21

    Human vein tissue is an important matrix to examine when investigating vascular diseases with respect to understanding underlying disease mechanisms. Here, we report the development of an extraction protocol for multi-platform metabolic profiling of human vein tissue. For the first stage of the optimization, two different ratios of methanol/water and 5 organic solvents--namely dichloromethane, chloroform, isopropanol, hexane and methyl tert-butyl ether (MTBE) solutions with methanol--were tested for polar and organic compound extraction, respectively. The extraction output was assessed using (1)H Nuclear Magnetic Resonance (NMR) spectroscopy and a panel of Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS) methodologies. On the basis of the reproducibility of extraction replicates and metabolic coverage, the optimal aqueous (methanol/water) and organic (MTBE/methanol) solvents identified from the first stage were used in a sequential approach for metabolite extraction, altering the order of solvent-mixture addition. The combination of organic metabolite extraction with MTBE/methanol (3 : 1) followed by extraction of polar compounds with methanol/water (1 : 1) was shown to be the best method for extracting metabolites from human vein tissue in terms of reproducibility and number of signals detected and could be used as a single extraction procedure to serve both NMR and UPLC-MS analyses. Molecular classes such as triacylglycerols, phosphatidylcholines, phosphatidylethanolamines, sphingolipids, purines, and pyrimidines were reproducibly extracted. This study enabled an optimal extraction protocol for robust and more comprehensive metabolome coverage for human vein tissue. Many of the physiological and pathological processes affecting the composition of human vein tissue are common to other tissues and hence the extraction method developed in this study can be generically applied.

  15. Culture of neural cells of the eyestalk of a mangrove crab is optimized on poly-L-ornithine substrate.

    PubMed

    Wajsenzon, Inês Júlia Ribas; de Carvalho, Litia Alves; Biancalana, Adriano; da Silva, Wagner Antönio Barbosa; Dos Santos Mermelstein, Claudia; de Araujo, Elizabeth Giestal; Allodi, Silvana

    2016-10-01

    Although there is a considerable demand for cell culture protocols from invertebrates for both basic and applied research, few attempts have been made to culture neural cells of crustaceans. We describe an in vitro method that permits the proliferation, growth and characterization of neural cells from the visual system of an adult decapod crustacean. We explain the coating of the culture plates with different adhesive substrates, and the adaptation of the medium to maintain viable neural cells for up to 7 days. Scanning electron microscopy allowed us to monitor the conditioned culture medium to assess cell morphology and cell damage. We quantified cells in the different substrates and performed statistical analyses. Of the most commonly used substrates, poly-L-ornithine was found to be the best for maintaining neural cells for 7 days. We characterized glial cells and neurons, and observed cell proliferation using immunocytochemical reactions with specific markers. This protocol was designed to aid in conducting investigations of adult crustacean neural cells in culture. We believe that an advantage of this method is the potential for adaptation to neural cells from other arthropods and even other groups of invertebrates.

  16. Optimization and scale-up of cell culture and purification processes for production of an adenovirus-vectored tuberculosis vaccine candidate.

    PubMed

    Shen, Chun Fang; Jacob, Danielle; Zhu, Tao; Bernier, Alice; Shao, Zhongqi; Yu, Xuefeng; Patel, Mehul; Lanthier, Stephane; Kamen, Amine

    2016-06-17

    Tuberculosis (TB) is the second leading cause of death by infectious disease worldwide. The only available TB vaccine is the Bacille Calmette-Guerin (BCG). However, parenterally administered Mycobacterium bovis BCG vaccine confers only limited immune protection from pulmonary tuberculosis in humans. There is a need for developing effective boosting vaccination strategies. AdAg85A, an adenoviral vector expressing the mycobacterial protein Ag85A, is a new tuberculosis vaccine candidate, and has shown promising results in pre-clinical studies and phase I trial. This adenovirus vectored vaccine is produced using HEK 293 cell culture. Here we report on the optimization of cell culture conditions, scale-up of production and purification of the AdAg85A at different scales. Four commercial serum-free media were evaluated under various conditions for supporting the growth of HEK293 cell and production of AdAg85A. A culturing strategy was employed to take advantages of two culture media with respective strengths in supporting the cell growth and virus production, which enabled to maintain virus productivity at higher cell densities and resulted in more than two folds of increases in culture titer. The production of AdAg85A was successfully scaled up and validated at 60L bioreactor under the optimal conditions. The AdAg85A generated from the 3L and 60L bioreactor runs was purified through several purification steps. More than 98% of total cellular proteins was removed, over 60% of viral particles was recovered after the purification process, and purity of AdAg85A was similar to that of the ATCC VR-1516 Ad5 standard. Vaccination of mice with the purified AdAg85A demonstrated a very good level of Ag85A-specific antibody responses. The optimized production and purification conditions were transferred to a GMP facility for manufacturing of AdAg85A for generation of clinical grade material to support clinical trials. PMID:27154390

  17. Optimization study for metabolomics analysis of human sweat by liquid chromatography-tandem mass spectrometry in high resolution mode.

    PubMed

    Calderón-Santiago, M; Priego-Capote, F; Jurado-Gámez, B; Luque de Castro, M D

    2014-03-14

    Sweat has recently gained popularity as a potential tool for diagnostics and biomarker monitoring as it is a non-invasive biofluid the composition of which could be modified by certain pathologies, as is the case with cystic fibrosis, which increases chloride levels in sweat. The aim of the present study was to develop an analytical method for analysis of human sweat by liquid chromatography-mass spectrometry (LC-Q-TOF MS/MS) in high resolution mode. Thus, different sample preparation strategies and different chromatographic modes (HILIC and C18 reverse modes) were compared to check their effect on the profile of sweat metabolites. Forty-one compounds were identified by the MS/MS information obtained with a mass tolerance window below 4 ppm. Amino acids, dicarboxylic acids and other interesting metabolites such as inosine, choline, uric acid and tyramine were identified. Among the tested protocols, direct analysis after dilution was a suited option to obtain a representative snapshot of sweat metabolome. In addition, sample clean up by C18 SpinColumn SPE cartridges improved the sensitivity of most identified compounds and reduced the number of interferents. As most of the identified metabolites are involved in key biochemical pathways, this study opens new possibilities to the use of sweat as a source of metabolite biomarkers of specific disorders.

  18. An optimized capillary electrophoresis method for the simultaneous analysis of biomass degradation products in ionic liquid containing samples.

    PubMed

    Aid, Tiina; Paist, Loore; Lopp, Margus; Kaljurand, Mihkel; Vaher, Merike

    2016-05-20

    An indirect capillary electrophoresis method for a quantitative determination of mono-, di- and oligosaccharides was developed to investigate biomass degradation, the isomerization of glucose into fructose and conversion of fructose to 5-hydroxymethylfurfural (5-HMF) in ionic liquids (ILs). Three chromophores, namely 2,6-pyridinedicarboxylic acid (PDC), maleic acid and phthalic acid, were used to perform indirect detection. The electroosmotic flow (EOF) was reversed to reduce analysis time, using 1-tetradecyl-3-methylimidazolium chloride (C14MImCl). The simultaneous separation of the underivatized mono-, di- and oligosaccharides was performed using four cellodextrin oligomers (cellotriose, cellotetraose, cellopentaose, cellohexaose), eight carbohydrates (xylose, fructose, glucose, galactose, lactose, cellobiose, raffinose, sucrose), two organic acids (acetic acid, levulinic acid) and 5-HMF. The best performance was obtained using background electrolyte (BGE) composed of 138.2mM NaOH, 40mM maleic acid and 5mMC14MImCl, the applied voltage was -21.7kV. The linear ranges for analyzed compounds were following: organic acids, raffinose and sucrose from 0.20 to 7mM, cellodextrin oligomers from 0.25 to 5mM, other analyzed carbohydrates from 0.25 to 7mM and 5-HMF from 0.05 to 7mM. The relative standard deviations (RSD) of peak areas varied from 3.47 to 9.62% during a 5-day analysis period and 0.58-5.29% during one day. PMID:27095128

  19. An all-at-once factorial method to optimize dip-pen deposition of liquid protein inks

    NASA Astrophysics Data System (ADS)

    Henning, A. K.; Rozhok, S.; Fragala, J.; Shile, R.; Ouyang, K.

    2013-03-01

    An all-at-once factorial method is presented, which optimizes protein ink deposition using microfabricated pens by identifying the pen design which writes the greatest number of uniform-size spots or droplets without re-inking. Pen features associated with capillary ink transport are varied according to statistical design-of-experiment (SDOE) principles, and evaluated using a special 1D pen array of twelve pens. Variable parameter pens are bracketed by control pens. Each pen array element embodies one component of the SDOE matrix. All parameters are evaluated simultaneously with a single droplet writing pass. Results can also be evaluated simultaneously, leading to rapid choice of those pen parameters which deliver the greatest number of printed features having the smallest coefficient of variation.

  20. Enhanced production of α-amylase by Penicillium chrysogenum in liquid culture by modifying the process parameters.

    PubMed

    Dar, Gowhar H; Kamili, Azra N; Nazir, Ruqeya; Bandh, Suhaib A; Jan, Tariq R; Chishti, Mohammad Z

    2015-11-01

    In this paper, we have assessed the role of changing physicochemical parameters and substrate types on the production of α-amylase enzyme from Penicillium chrysogenum, with a view to determining the optimal conditions required for its maximum production. The findings of this research revealed that, at pH 6 using linseed oil cake as substratum, α-amylase enzyme production was maximum (550.0 U/mL), when the fungi was incubated for 6 days at 30 °C in 0.1 M acetate buffer. Further, reasonably good production of the α-amylase enzyme was also observed at pH 9 with all the experimented carbon sources as substrates. Moreover, statistical analysis, using analysis of variance (ANOVA) carried out to study the impact of different studied parameters on the α-amylase enzyme production revealed that incubation period of 6-18 days is highly significant (p = 0.01) factor in amylotic activity of the P. chrysogenum. Under the researched out optimal conditions, P. chrysogenum is an economically viable option for the industrial and biotechnological production of α-amylase enzyme.

  1. Assessing the optimal liquid volume to be sprayed on isolated olive trees according to their canopy volumes.

    PubMed

    Miranda-Fuentes, A; Llorens, J; Rodríguez-Lizana, A; Cuenca, A; Gil, E; Blanco-Roldán, G L; Gil-Ribes, J A

    2016-10-15

    The application of pesticides to traditional and intensive olive orchards in Southern Spain has led to environmental problems. More specifically, the lack of an accurate, useful criterion to regulate the spray volume in relation to canopy characteristics has led to spray drift and runoff, which are threats to local ecosystems. The aim of this study was to determine the optimal relationship between canopy volume and the spray application volume, called specific spray volume, CV, through laboratory and field trials. In the laboratory trial, 6 specific spray volumes (0.05, 0.08, 0.10, 0.12, 0.15, and 0.20Lm(-3)) were tested in a specially designed structure containing small, live olive trees in order to simulate an intensive plantation system. The model aimed to evaluate the coverage of pesticide application on water sensitive paper (WSP) collectors. In the field trial, the three laboratory specific spray volumes that gave the best coverage values were tested on live, intensively managed trees, whose crown volume was manually measured. Food dye E-102 was used to determine the spray deposition on artificial targets (10×10cm absorbent paper pieces), and WSP was used to evaluate spray coverage. The spray penetration and deposit homogeneity inside the canopy were also evaluated. Weather conditions during the field trial were monitored with a weather station. The results of the laboratory trial showed that the three best specific spray volumes were 0.08, 0.10, and 0.12Lm(-3), resulting in mean coverage values of approximately 30%. The ANOVA of the field trial results showed that the 0.12Lm(-3) was the optimal specific spray volume for isolated olive trees. This specific spray volume gave the highest mean deposits, the best efficiency (as measured by the greatest normalized deposit), the most favourable penetration and homogeneity, and the highest coverage values. PMID:27300563

  2. Assessing the optimal liquid volume to be sprayed on isolated olive trees according to their canopy volumes.

    PubMed

    Miranda-Fuentes, A; Llorens, J; Rodríguez-Lizana, A; Cuenca, A; Gil, E; Blanco-Roldán, G L; Gil-Ribes, J A

    2016-10-15

    The application of pesticides to traditional and intensive olive orchards in Southern Spain has led to environmental problems. More specifically, the lack of an accurate, useful criterion to regulate the spray volume in relation to canopy characteristics has led to spray drift and runoff, which are threats to local ecosystems. The aim of this study was to determine the optimal relationship between canopy volume and the spray application volume, called specific spray volume, CV, through laboratory and field trials. In the laboratory trial, 6 specific spray volumes (0.05, 0.08, 0.10, 0.12, 0.15, and 0.20Lm(-3)) were tested in a specially designed structure containing small, live olive trees in order to simulate an intensive plantation system. The model aimed to evaluate the coverage of pesticide application on water sensitive paper (WSP) collectors. In the field trial, the three laboratory specific spray volumes that gave the best coverage values were tested on live, intensively managed trees, whose crown volume was manually measured. Food dye E-102 was used to determine the spray deposition on artificial targets (10×10cm absorbent paper pieces), and WSP was used to evaluate spray coverage. The spray penetration and deposit homogeneity inside the canopy were also evaluated. Weather conditions during the field trial were monitored with a weather station. The results of the laboratory trial showed that the three best specific spray volumes were 0.08, 0.10, and 0.12Lm(-3), resulting in mean coverage values of approximately 30%. The ANOVA of the field trial results showed that the 0.12Lm(-3) was the optimal specific spray volume for isolated olive trees. This specific spray volume gave the highest mean deposits, the best efficiency (as measured by the greatest normalized deposit), the most favourable penetration and homogeneity, and the highest coverage values.

  3. A polysaccharide isolated from the liquid culture of Lentinus edodes (shiitake) mushroom mycelia containing black rice bran protects mice against Salmonellosis through up-regulation of the Th1 immune reaction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present study investigated the antibacterial effect of a bioprocessed polysaccharide (BPP) isolated from Lentinus edodes liquid mycelial culture supplemented with black rice bran against murine salmonellosis. BPP was not bactericidal in vitro, but did, however stimulate uptake of the bacteria i...

  4. The optimal period of Ca-EDTA treatment for parthenogenetic activation of porcine oocytes during maturation culture

    PubMed Central

    MORITA, Yasuhiro; TANIGUCHI, Masayasu; TANIHARA, Fuminori; ITO, Aya; NAMULA, Zhao; DO, Lanh Thi Kim; TAKAGI, Mitsuhiro; TAKEMOTO, Tatsuya; OTOI, Takeshige

    2016-01-01

    The changes triggered by sperm-induced activation of oocytes, which are required for normal oocyte development, can be mediated by other agents, thereby inducing the parthenogenesis. In this study, we exposed porcine oocytes to 1 mM Ca-EDTA, a metal-ion chelator, at various intervals during 48 hr of in vitro maturation to determine the optimum period of Ca-EDTA treatment for parthenogenetic activation. When the oocytes were cultured with or without Ca-EDTA from 36 hr (post-12), 24 hr (post-24), 12 hr (post-36) and 0 hr (post-48) after the start of maturation culture, the blastocyst formation rates were significantly higher (P<0.05) in the post-24, post-36 and post-48 groups (3.3%, 4.0% and 2.6%, respectively) than those in the control group without treatment (0%). Furthermore, when the oocytes were cultured with Ca-EDTA for 0 hr (control), 12 hr (pre-12), 24 hr (pre-24), 36 hr (pre-36) and 48 hr (pre-48) from the start of maturation culture, the oocytes formed blastocysts only in the pre-36 and pre-48 groups (0.4% or 0.8%, respectively). Pronuclei (<66.7%) were observed only when the periods of Ca-EDTA treatment were more than 12 hr during maturation culture. In the control group, no pronuclei were detected. Our findings demonstrate that porcine immature oocytes can be parthenogenetically activated by Ca-EDTA treatment for at least 24 hr to 36 hr during maturation culture, leading to pronucleus formation followed by the formation of blastocysts. PMID:26947170

  5. Application of an integrated statistical design for optimization of culture condition for ammonium removal by Nitrosomonas europaea.

    PubMed

    Bao, Yingling; Zhengfang, Ye

    2013-01-01

    Statistical methodology was applied to the optimization of the ammonium oxidation by Nitrosomonas europaea for biomass concentration (C(B)), nitrite yield (Y(N)) and ammonium removal (R(A)). Initial screening by Plackett-Burman design was performed to select major variables out of nineteen factors, among which NH4Cl concentration (C(N)), trace element solution (TES), agitation speed (AS), and fermentation time (T) were found to have significant effects. Path of steepest ascent and response surface methodology was applied to optimize the levels of the selected factors. Finally, multi-objective optimization was used to obtain optimal condition by compromise of the three desirable objectives through a combination of weighted coefficient method coupled with entropy measurement methodology. These models enabled us to identify the optimum operation conditions (C(N)= 84.1 mM; TES = 0.74 ml; AS= 100 rpm and T = 78 h), under which C(B)= 3.386×10(8) cells/ml; Y(N)= 1.98 mg/mg and R(A) = 97.76% were simultaneously obtained. The optimized conditions were shown to be feasible through verification tests.

  6. Determination of paralytic shellfish poisoning toxins in cultured microalgae by high-performance liquid chromatography with fluorescence detection.

    PubMed

    He, Hong-Zhi; Li, Hua-Bin; Jiang, Yue; Chen, Feng

    2005-11-01

    A novel method for the determination of paralytic shellfish poisoning (PSP) toxins using high-performance liquid chromatography with fluorescence detection was developed. The fluorescent derivates of neosaxitoxin (neoSTX), saxitoxin (STX), gonyautoxins 1 and 4 (GTX1+4), and gonyautoxins 2 and 3 (GTX2+3) were separated on a muBondapak NH2 column (300 mm x 3.9 mm, 10 microm) using water and acetate buffer (pH 6.5) as the mobile phase (1.00 mL min(-1)) in gradient mode with fluorescence detection at 390 nm (excitation at 330 nm). The linear ranges of neoSTX, STX, GTX1+4 and GTX2+3 were 3.31-331, 0.952-95.2, 3.78-378 and 0.124-12.4 ng mL(-1), respectively. The detection limits of neoSTX, STX, GTX1+4 and GTX2+3 were 1.10, 0.32, 1.26 and 0.041 ng mL(-1), respectively. The method was successfully applied to the determination of PSP toxins in microalgae. The recoveries ranged from 88+/-2% to 107+/-4% and the relative standard deviations were 0.16% to 4.4%. The procedure is also environmentally friendly because no organic solvent is used in the mobile phase.

  7. Producing biodiesel from cotton seed oil using Rhizopus oryzae ATTC #34612 whole cell biocatalysts: Culture media and cultivation period optimization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of culture medium composition and cultivation time on biodiesel production by Rhizopus oryzae ATCC #34612 whole cell catalysts, immobilized on novel rigid polyethylene biomass supports, was investigated. Supplementation of the medium with carbon sources led to higher lipase activity and i...

  8. Enabling School Structure, Collective Responsibility, and a Culture of Academic Optimism: Toward a Robust Model of School Performance in Taiwan

    ERIC Educational Resources Information Center

    Wu, Jason H.; Hoy, Wayne K.; Tarter, C. John

    2013-01-01

    Purpose: The purpose of this research is twofold: to test a theory of academic optimism in Taiwan elementary schools and to expand the theory by adding new variables, collective responsibility and enabling school structure, to the model. Design/methodology/approach: Structural equation modeling was used to test, refine, and expand an…

  9. Isolation, Identification and Optimal Culture Conditions of Streptomyces albidoflavus C247 Producing Antifungal Agents against Rhizoctonia solani AG2-2

    PubMed Central

    Islam, Md. Rezuanul; Jeong, Yong Tae; Ryu, Yeon Ju; Song, Chi Hyun

    2009-01-01

    Streptomyces albidoflavus C247 was isolated from the soil of the Gyeongsan golf course in Korea. Physiological, biochemical and 16S rDNA gene sequence analysis strongly suggested that the isolate belonged to Streptomyces albidoflavus. Preliminary screening revealed that the isolate was active against fungi and bacteria. Self-directing optimization was employed to determine the best combination of parameters such as carbon and nitrogen source, pH and temperature. Nutritional and culture conditions for the production of antibiotics by this organism under shake-flask conditions were also optimized. Maltose (5%) and soytone (5%) were found to be the best carbon and nitrogen sources for the production of antibiotics by S. albidoflavus C247. Additionally, 62.89% mycelial growth inhibition was achieved when the organism was cultured at 30℃ and pH 6.5. Ethyl acetate (EtOAc) was the best extraction solvent for the isolation of the antibiotics, and 100 µg/ml of EtOAc extract was found to inhibit 60.27% of the mycelial growth of Rhizoctonia solani AG2-2(IV) when the poison plate diffusion method was conducted. PMID:23983519

  10. Optimization of Culture Conditions for Production of the Anti-Leukemic Glutaminase Free L-Asparaginase by Newly Isolated Streptomyces olivaceus NEAE-119 Using Response Surface Methodology.

    PubMed

    El-Naggar, Noura El-Ahmady; Moawad, Hassan; El-Shweihy, Nancy M; El-Ewasy, Sara M

    2015-01-01

    Among the antitumor drugs, bacterial enzyme L-asparaginase has been employed as the most effective chemotherapeutic agent in pediatric oncotherapy especially for acute lymphoblastic leukemia. Glutaminase free L-asparaginase producing actinomycetes were isolated from soil samples collected from Egypt. Among them, a potential culture, strain NEAE-119, was selected and identified on the basis of morphological, cultural, physiological, and biochemical properties together with 16S rRNA sequence as Streptomyces olivaceus NEAE-119 and sequencing product (1509 bp) was deposited in the GenBank database under accession number KJ200342. The optimization of different process parameters for L-asparaginase production by Streptomyces olivaceus NEAE-119 using Plackett-Burman experimental design and response surface methodology was carried out. Fifteen variables (temperature, pH, incubation time, inoculum size, inoculum age, agitation speed, dextrose, starch, L-asparagine, KNO3, yeast extract, K2HPO4, MgSO4·7H2O, NaCl, and FeSO4·7H2O) were screened using Plackett-Burman experimental design. The most positive significant independent variables affecting enzyme production (temperature, inoculum age, and agitation speed) were further optimized by the face-centered central composite design-response surface methodology. PMID:26180806

  11. Optimization of Culture Conditions for Production of the Anti-Leukemic Glutaminase Free L-Asparaginase by Newly Isolated Streptomyces olivaceus NEAE-119 Using Response Surface Methodology

    PubMed Central

    El-Naggar, Noura El-Ahmady; Moawad, Hassan; El-Shweihy, Nancy M.; El-Ewasy, Sara M.

    2015-01-01

    Among the antitumor drugs, bacterial enzyme L-asparaginase has been employed as the most effective chemotherapeutic agent in pediatric oncotherapy especially for acute lymphoblastic leukemia. Glutaminase free L-asparaginase producing actinomycetes were isolated from soil samples collected from Egypt. Among them, a potential culture, strain NEAE-119, was selected and identified on the basis of morphological, cultural, physiological, and biochemical properties together with 16S rRNA sequence as Streptomyces olivaceus NEAE-119 and sequencing product (1509 bp) was deposited in the GenBank database under accession number KJ200342. The optimization of different process parameters for L-asparaginase production by Streptomyces olivaceus NEAE-119 using Plackett-Burman experimental design and response surface methodology was carried out. Fifteen variables (temperature, pH, incubation time, inoculum size, inoculum age, agitation speed, dextrose, starch, L-asparagine, KNO3, yeast extract, K2HPO4, MgSO4·7H2O, NaCl, and FeSO4·7H2O) were screened using Plackett-Burman experimental design. The most positive significant independent variables affecting enzyme production (temperature, inoculum age, and agitation speed) were further optimized by the face-centered central composite design-response surface methodology. PMID:26180806

  12. Optimization for speed and sensitivity in capillary high performance liquid chromatography. The importance of column diameter in online monitoring of serotonin by microdialysis.

    PubMed

    Zhang, Jing; Liu, Yansheng; Jaquins-Gerstl, Andrea; Shu, Zhan; Michael, Adrian C; Weber, Stephen G

    2012-08-17

    The speed of a separation defines the best time resolution possible in online measurements using chromatography. The desired time resolution multiplied by the flow rate of the stream of analyte being sampled defines the maximum volume of sample per injection. The best concentration sensitivity in chromatography is obtained by injecting the largest volume of sample that is consistent with achieving a satisfactory separation, and thus measurement accuracy. Taking these facts together, it is easy to understand that separation speed and concentration sensitivity are linked in this type of measurement. To address the problem of how to achieve the best sensitivity and shortest measurement time simultaneously, we have combined recent approaches to the optimization of the separation itself with an analysis of method sensitivity. This analysis leads to the column diameter becoming an important parameter in the optimization process. We use these ideas in one particular problem presented by online microdialysis sampling/liquid chromatography/electrochemical detection for measuring concentrations of serotonin in the dialysate. In this case the problem becomes the optimization of conditions to yield maximum signal for a given sample volume under the highest speed conditions with a certain required number of theoretical plates. It turns out that the observed concentration sensitivity at an electrochemical detector can be regulated by temperature, particle size, injection volume/column diameter, and void time. The theory was successfully used for optimization of neurotransmitter serotonin measurement by capillary HPLC when sampling from a microdialysis flow stream. The final conditions are: 150 μm i.d., 3.1cm long columns with 1.7 μm particle diameter working at a flow rate of 12 μL/min, an injection volume of 500 nL, and a temperature of 343 K. The retention time for serotonin is 22.7s, the analysis time is about 36 s (which allows for determination of 3-methoxytyramine), and

  13. Mushroom polysaccharides and lipids synthesized in liquid agitated and static cultures. Part I: screening various mushroom species.

    PubMed

    Diamantopoulou, Panagiota; Papanikolaou, Seraphim; Kapoti, Maria; Komaitis, Michael; Aggelis, George; Philippoussis, Antonios

    2012-06-01

    The effect of four synthetic media containing glucose (initial concentration 30 g l(-1)) on mycelial growth, exopolysaccharides (EPS) and cellular lipids production was examined in 11 mushroom species after 12 and 16 days of culture in static- and shake-flasks. Fatty acid analysis of cellular lipids produced was also performed. Agitation had a positive effect on biomass production, glucose consumption and lipid biosynthesis. Media that favoured the production of biomass were not suitable for EPS biosynthesis and vice versa. Biomass values varied from ~1.0 g l(-1) (Lentinula edodes) to ~19 g l(-1) (Pleurotus ostreatus), while the highest EPS quantity achieved ranged between 1.6 and 1.8 g l(-1) (for Ganoderma lucidum and L. edodes, respectively). Quantities of total cellular lipids varied between 2.5 and 18.5 % w/w, in dry mycelial mass for the fungi tested. Lipid in dry weight values were influenced by the medium composition. Cellular lipids presented noticeable quantities of poly-unsaturated fatty acids like linoleic acid. Compared to most of the mushrooms tested, lipids of Volvariella volvacea were more saturated. The ability of several mushroom species of our study to produce in notable quantities the above-mentioned added-value compounds renders these fungi worthy for further investigations.

  14. The preparation of Cistanche phenylethanoid glycosides liquid proliposomes: Optimized formulation, characterization and proliposome dripping pills in vitro and in vivo evaluation.

    PubMed

    Li, Meng; Li, Yunjing; Liu, Weiwei; Li, Rongli; Qin, Cuiying; Liu, Nan; Han, Jing

    2016-10-10

    Water-soluble Cistanche phenylethanoid glycosides (CPhGs) have poor permeability and low bioavailability. However, liposomes can improve the permeability of such drugs and their poor stability, and proliposomes have been used to overcome these problems. Based on this, Cistanche phenylethanoid glycoside liquid proliposomes (CPhGsP) and dripping(?) pills were prepared and optimized using response surface methodology. The properties of CPhGsP were evaluated in terms of their encapsulation efficiency, particle size, zeta potential, and morphology. The results obtained showed that the optimal formulation was drug/soybean phospholipid/poloxamer-188/sodium deoxycholate/propylene glycol 1:22.38:3.52:0.84:80 (w/w/w/w/v). This resulted in an encapsulation efficiency, particle size, and zeta potential of hydrated proliposomes with phosphate buffer solution (pH7.4) of 51.97%, 671.7nm, and -25.49mV, respectively. Stability testing of CPhGsP and CPhGs ordinary liposomes was carried out for 3months at 4±2°C, 25±2°C, 40±2°C, 75±5% RH. The results obtained showed that the stability of the proliposomes was better than that of ordinary liposomes at the same temperature, while a lower temperature of 4°C is ideal for storage. Cistanche phenylethanoid glycoside liquid proliposomes dripping pills (CPhGsPD) are efficiently released in gastrointestinal solution as shown by in vitro release experiments and the structure of the liposomes does not destroy the proliposome dripping pills by hydration. In vivo experiments showed that the areas under the plasma level-time curves and peak concentrations of CPhGsPD and hydrated proliposomes were higher than those of CPhGs. Moreover, with CPhGsPD, the pharmacokinetic parameters were similar to those with hydrated proliposomes. These results showed that CPhGsPD offer a good way to improve the oral delivery of CPhGs. PMID:27493021

  15. Optimization of the BGM cell line culture and viral assay procedures for monitoring viruses in the environment.

    PubMed Central

    Dahling, D R; Wright, B A

    1986-01-01

    An in-depth study of the continuous cell line designated BGM is described herein, and recommendations are made for standardizing cell culture and viral assay procedures. Based on data gathered from a survey of 58 laboratories using this cell line, a research plan was developed that included the study of growth media, sera, NaHCO3 levels, culture bottles, cell concentration, overlay media, agar, virus infection conditions, and cell-dissociating agents. Additionally, a comparative virus isolation study with BGM cells and nine other cell types was conducted with 37 sewage samples collected from nine different geographic areas. The results of the study indicated that the BGM cell line is superior for virus isolation when compared with the other cell types and that certain media and additives tend to increase BGM cell sensitivity to a specific group of viruses. A standardized procedure for cultivation of BGM cells is described which provides a more effective enterovirus assay system. PMID:3010860

  16. Towards Optimal Spectral and Spatial Documentation of Cultural Heritage. Cosch - AN Interdisciplinary Action in the Cost Framework

    NASA Astrophysics Data System (ADS)

    Boochs, F.; Bentkowska-Kafel, A.; Degringy, C.; Hautta-Kasari, M.; Rizvic, S.; Sitnik, R.; Tremeau, A.

    2013-07-01

    This paper introduces the aims and early activities of Colour and Space in Cultural Heritage (COSCH), an interdisciplinary European network of experts in the latest optical measuring techniques and electronic imaging applied to documentation of artefacts. COSCH is a forum open to organisations, institutions and companies interested in collaboration within the emerging field of precise spectral and spatial imaging techniques, in physical and chemical sciences applied to cultural heritage objects, as well as in research and applications to conservation and art-historical analysis of such objects. COSCH started in Nov