Recombinant protein production in heterologous hosts often seems a simpler and more effective way than its production by natural producer. The secretion of recombinant protein in Escherichia coli has many advantages comparing to than in insect or mammalian cells. The important factor for high-level recombinant protein production is the sufficient amount of E. coli biomass. Therefore, the aim of this study was to optimize the composition of propagation medium resulting in the maximum biomass yield of recombinant E. coli as the part of fermentation strategy for neuraminidase (NA) production. Three independent variables including glucose, asparagine and phosphate concentrations, and four dependent variables, such as biomass yield, residual concentrations of glucose or asparagine and pH of the propagation medium after fermentation, were chosen to the optimization by Response Surface Methodology (RSM). The optimal conditions for the maximum biomass yield expressed as dry cell weight (DCW) (16.57±0.55 g DCW.L−1) were as follows: glucose concentration of 39.37 mM, asparagine concentration of 62.68 mM and phosphate concentration of 14.80 mM. For this model, the predicted values for the responses are close to the experimental values. The yield of desired pET15b-neu plasmid from E. coli cells cultivated in optimized propagation medium was almost 23 % higher than in commonly used Luria-Bertani (LB) medium suggesting that asparagine may be involved in the induction of plasmid amplification.
Disability can cover various areas of people’s activities, but it is primarily associated with difficulties that relate to independent movement. The possibility of free movement is one of the basic human rights. People with disabilities who cannot get to work and take employment, despite a desire to do so, assimilate with the rest of society to a worse extent, do not have the means to support themselves and do not earn national income. From this point of view, programs and activities aimed at maximising mobility and access to various types of places for people with disabilities, including those in public space, are very important. These types of places include paid parking zones in cities. Their location in city centres provides access to most offices. Due to the fact that they are located in public space, municipalities and city authorities have an impact on their management and on establishing the principles of their functioning. A very important element of this management is determining the rules for providing parking spaces in paid parking zones, particularly with regard to the amount of parking fees for disabled people. The article provides an analysis of the management of the provision of disabled parking spaces in relation to paid parking zones in all voivodeship cities in Poland.
Advances Polyphenol Oxidase (PPO) from Sorghum bicolor (white and yellow varieties) grains were investigated for optimum processing condition. The partially purified enzyme was obtained from two varieties of Sorghum bicolor by step-wise separation through ion-exchange and size-exclusion chromatography. The final purification gave a yield of 7.33 % and 12.3 % for PPO from white and yellow sorghum respectively. The PPO has Vmax and Km of 2.66 U.mL−1 and 19.72 mM for white sorghum, 1.33 U.mL−1 and 12.92 mM for yellow sorghum. The optimal pH of PPO activity was found at pH 4 and pH 7 for white and pH 4 and pH 8 for yellow sorghum. The pKa 7.4 and 8.7 were obtained for PPO from white sorghum, and pKa 5.4, 7.4 and 8.5 for yellow sorghum. The PPO residual activity were above 70 % at 5 hours of incubation within the neutral pH ranges for white sorghum, while those of yellow sorghum were below 40 %. The optimum temperature of 40 ºC and 30 ºC for white and yellow sorghum PPO respectively. The average value of enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG) obtained at 20 min of incubation and temperature 50 – 80 °C were respectively 49.03 kJ.mol−1, - 129.52 J.mol−1.K−1, and 92.81 kJ.mol−1 for white sorghum PPO, and 90.1 kJ.mol−1, - 9.29 J.mol−1.K−1, and 93.37 kJ.mol−1 for yellow sorghum PPO. Zn2+, Fe2+ and ascorbic acid inhibited PPO while Cu2+, Na+ and K+ activated the enzyme. The results suggest the processing parameters for controlling PPO in potential industrial application of white and yellow sorghum grains.
The problems of process costs and pollution of residual waters in the textile industry require increasing attention due to the new ecological regulations and also those resulting from an economic point of view. Hence, the behavior of non-isothermal fixed-bed reactor applied for hydrogen peroxide decomposition by immobilized Terminox Ultra catalase attached onto the outer surface of glass beads was studied to determine the operational conditions at which hydrogen peroxide decomposition is most effectively. A dispersion model for bioreactor applied in this work, and verified experimentally, took into account the coupled mass and heat balances as well as the rate equation for parallel enzyme deactivation. The effect of feed temperature, feed flow rate, feed hydrogen peroxide concentration, and diffusional resistances were analysed. In the calculations the global effectiveness factor based on the external mass-transfer model developed previously was employed to properly predict the real bioreactor behavior.
The sliding strip of the current collector (pantograph) of a rail vehicle is an element directly cooperating with the catenary and is exposed to abrasion, electric discharge and various types of damage. It is therefore the most frequently replaced element. However, often sliding strips are exchanged before exceeding the limit thickness value, which increases the costs related to technical maintenance. Because the wear process is dependent on many factors, heuristic methods are necessary to predict the thickness of the sliding strip. Knowing the predicted thickness value, it will be possible to adapt the maintenance cycle. In the article, the results of simulations carried out based on the developed structure of the artificial neural network are also presented.
To examine the efficiency of La and Ce recycling processes from the sludge, two major methods were used, namely leaching and precipitation. The findings suggest that 12% of La and 24.2% of Ce were contained in the sludge. The sludge was leached in an optimum condition of 6N HCl at a temperature of 70°C with a 3g/50 mL solid/liquid ratio for 3 h to obtain a 100% leaching recovery of La and Ce. After pH adjustment of the obtained La and Ce optimum leaching solution to 6 with NH4OH and a simultaneous addition of H2O2 in a ratio of 1:1, Ce precipitated out with 65.9% recovery. On the other hand, La was not precipitated. The results obtained in this study reveal that leaching and pH adjustment method could be used to recover the valuable REE of La and Ce from glass polishing sludge in order to reach the goals of resource recycling.
The paper focuses attention on the problem of increased risks during the loading and unloading of railway tankers. To evaluate the risk which may occur during loading dangerous goods into tanker trains, the loading processes have been divided into seven stages. Based on HIRA risk analysis, for each stage of improvements, Quick Kaizen tasks were proposed. Special attention was paid to possible improvements in technical means, tools and processes. Thanks to the proposed improvements, it is possible to increase safety, not only during the loading of dangerous goods, but also in cases of loading and transportation of standard cargoes.
Hyaluronic acid (HA) has important applications in fields of health care products, cosmetics and clinical medical. However, the unique physiological properties of HA make cost of its traditional separation and extraction process relatively high. Foam separation technique has simple, gentle and efficient advantages on the separation of substances with surface activity by using bubbles as the separation medium. In this paper, natural surfactant CocamideBetaine (CAPB) was used as a foaming agent to explore the technology of microscale HA in aqueous solution by foam separation. The optimum process conditions were determined based on the recovery rate and enrichment ratio of HA by single factor and orthogonal experiment: at room temperature, pH = 7, separating air velocity (v) = 350 mL/min, HA concentration (CHA) = 50 mg/L, adding liquid volume (V) = 200 mL, collecting time (tcol) = 10 min, CAPB concentration (CCAPB) = 0.035 g/L. Under these conditions, HA enrichment ratio (E) equals 6.821 and HA recovery rate (R) equals 66.425%.
This article is aimed at providing a rationale for the need to introduce a new type of educational institution in Ukraine today, namely educational centers in the areas with challenging topography. This article identifies specific features of construction, given the difficult geographic topography and architectural environment of the educational institutions, and lists conditions impacting the volume and planning of educational facility construction. It defines how urban planning of school centers influence the areas with difficult topography and establishes their location type. The authors analyzed architectural and construction solutions for school centers in areas with challenging landscape. They have also identified form-shaping types of buildings and established the best slope ratio for each of the types.
New trends in sustainable design contribute to prevention of the deterioration of the natural environment and they are focused on the optimisation of the indoor environment for the improvement of the human life quality. There are complementary goals of sustainable design – the comfort of architecture users, proper spatial planning, and, as a priority, taking into account the needs of both contemporary and future generations. These existential needs are connected with both local and global sozological problems. These are related to the continuing growth of irreversible changes to the environment, such as climate change, the disappearance of biodiversity, and the over-exploitation of nonrenewable sources of energy as result of shortsighted economy. These imply the necessity for the sozological education in all subjects of study and transdisciplinary training focused on the solving of problems associated with sustainable development.