Characterization of Crude and Partially Purified Lipase from Geotrichum candidum Obtained with Different Nitrogen Sources

Lipases from Geotrichum candidum were produced in two different medium: A = 12 % (w/v) clarified corn steep liquor (CCSL) + 0.6 % (w/v) soybean oil (SO) and B = 3.5 % (w/v) yeast hydrolysate (YH) + 0.7 % (w/v) SO. Lipases were partially purified from both media by hydrophobic interaction chromatography using 3.0 mol L^?1 of NaCl as mobile phase, and they were characterized in the crude and partially purified forms. The recovery of lipase activity from CCSL and YH via HIC were 96 and 94.3 %, and the purification factors were 44.3 and 86.7‐fold, respectively. All evaluated lipases had similar optimum pH (7.0–7.7), but, for the CCSL crude lipase, optimum temperature (47 °C) was 10 °C higher than others lipases evaluated. CCSL crude lipase possessed a higher thermo stability than YH crude lipase, e.g., at 37 °C (pH 7.0) the half‐life of CCSL crude lipase was 19.25 h and at pH 8.0 (30 °C) the half‐life was 48 h, which are five and ten times higher than with YH crude lipase, respectively. On the other hand, the YH crude lipase possessed a higher catalytic constant (k_cat = 2.3 min^?1) but with almost the same catalytic efficiency (K_m/k_cat = 32.12 mg mL min^?1) in relation to CCSL crude lipase. The lipases differ in biocatalytic properties between substrates, suggesting that the two lipases can be employed for different applications.     

Secondary Metabolites in Ramalina terebrata Detected by UHPLC/ESI/MS/MS and Identification of Parietin as Tau Protein Inhibitor

Liquid chromatography coupled with mass spectrometry is an outstanding methodology for fast analysis of phenolic compounds in biological samples. Twenty two compounds were quickly and accurately identified in the methanolic extract of the Antarctic lichen Ramalina terebrata for the first time using ultra high pressure liquid chromatography coupled with photodiode array detector and high resolution mass spectrometry (UHPLC-PDA-Q/Orbitrap/MS/MS). In addition, the extract and the four compounds isolated from this species were tested for the inhibitory activity of tau protein aggregation, which is a protein involved in Alzheimer’s disease (AD). All compounds showed null activity with the exception of parietin, which it was able to inhibit aggregation process of tau in a concentration range between 3 µg/mL (10 µM) to 28 µg/mL (100 µM). In addition, we show how parietin interact with tau ³⁰⁶VQIVYK³¹¹ hexapeptide inside of the microtubule binding domain (4R) with the help of molecular docking experiments. Finally, the constituents present in the methanolic extract could possibly contribute to the established anti-aggregation activity for this extract and this in-depth analysis of the chemical composition of R. terebrata could guide further research into its medicinal properties and potential uses.     

Optimization of dopamine determination based on nanowires PEDOT/polydopamine hybrid film modified electrode

Poly(3,4-ethylenedioxythiophene) nanowires (nw-PEDOT), between 6.7–13.8 nm diameter, were obtained by electrochemical methods utilizing modified electrodes with silicon oxide as a template to afford a Pt/nw-PEDOT electrode. Dopamine electro-polymerization was next accomplished upon this electrode (Pt/nw-PEDOT/PDA). The Pt/nw-PEDOT/PDA assembly is capable of hindering interfering signals such as those from ascorbic and uric acid, enabling thus the selective detection of dopamine. Amperometric determination studies allowed limit of detection and limit of quantification limits of 0.47 and 1.59 µM, respectively, to be established. These limits were lower than those obtained with the same conducting polymer but without a nanowire structure.     

Use of a new milk-clotting protease from Thermomucor indicae-seudaticae N31 as coagulant and changes during ripening of Prato cheese

Prato cheeses were manufactured using coagulant from Thermomucor indicae-seudaticae N31 or a commercial coagulant. Cheeses were characterised using the following analysis: yield; fat; acidity; moisture; ash; salt; pH; total nitrogen; total protein; NS-pH 4.6/NT*100; NS-TCA 12%/NT*100; casein electrophoresis; and RP-HPLC. The results were statistically analysed and revealed that the proteolytic indices were not significantly different throughout the 60 days of ripening of cheeses made with either coagulant. Even though there were some quantitative differences in the peptide profile of cheeses, the enzyme from T. indicae-seudaticae N31 was used in the production of good quality Prato cheese without having to change the established technological parameters of the process.     

Critical Success Factors for New Product Development in Biotechnology Companies

The development of new products has become increasingly critical for the competitiveness of companies, due to increased diversity and variety of products, the reduction of product life cycles, and, primarily, globalization of markets. Thus, the identification and prioritization of critical success factors for developing new products is important, particularly for the high degree of risk and uncertainty involved. The main objective of this article is the identification and prioritization of critical success factors in new product development projects in biotechnology companies in the state of Minas Gerais, Brazil. The research method used was a survey questionnaire, which was sent to a sample of 31 biotechnology companies in Minas Gerais state. The principal findings of this research are that interpersonal skills/relationships of the project leader and technical skills are the most critical factors for successful new product development in this industry. The implications for the biotechnology industry in general, as well as for those responsible for managing new product development, are discussed.     

Quail egg yolk (Coturnix coturnix japonica) enriched with omega-3 fatty acids

This experiment was carried out with 58-week old laying quails (Coturnix coturnix japonica) assigned to four treatment groups with eight quails per replication in six repetitions in a completely randomized design. The treatments consisted of diets with different levels of flaxseed (0, 1.5, 3.0, and 5.0%). The amounts of cholesterol and total lipids and the fatty acid composition of quail egg yolk were determined in four 21-day cycles. No difference was found in cholesterol levels between the four treatments and the four cycles. The increased ingestion of linolenic acid (LNA) in diet reduced the formation of arachidonic acid (AA) significantly. The 3.0 and 5.0% treatment groups presented a reduction in total saturated fatty acids (TSFA) with the increase in percent flaxseed in feed comparatively to the control value. The n-3 fatty acid level was high in all treatments when compared to that of the control group. The n-6/n-3 ratio decreased from 21.30 (control) to 4.52 (5.0%), which is a better value from the nutritional viewpoint.     

Comparisons Between the p--q and p--q--r Theories in Three-Phase Four-Wire Systems

This paper presents a comparative analysis between results from applications of the p-q and the p-q-r theories in shunt active power filters for three-phase four-wire systems, discussing aspects related to the influence of the system voltage in the control methods that calculate the compensating currents. It is shown that in some cases, a preprocessing of the system voltage is required if the goal is to achieve sinusoidal compensated currents. On the other hand, when the goal is to compensate zero-sequence current, the need of energy storage elements in the active filter is discussed. In this case, if zero-sequence components are present simultaneously in the system voltage and load current, they produce zero-sequence power flow, and the control methods based on both theories must contain additional calculations to allow the elimination of energy storage elements in the active filter. A control strategy based on the p-q theory is proposed to eliminate the neutral current without the need of energy storage elements, with the advantage of avoiding the extra transformation from alphabeta0 to pqr coordinates that is needed in the p-q-r theory. Simulation results are presented for the purpose of comparing the performance of both control methods.     

ISO 9001 certification in the American Continent: a statistical analysis and modelling

The ISO 9001 standard is considered as an effective tool to support a quality management system (QMS). A steady growth in the number of ISO 9001 issued certificates is observed worldwide, confirming the interest of companies in this approach. However, information regarding this behaviour over time in the American Continent is scarce. This paper presents a set of qualitative and quantitative analyses related to the ISO 9001 certification (globally and at the country level of the Americas), the use of this standard in countries that were part of the ISO Survey 2011 and modelling the ISO 9001 certification for American countries, in order to characterise through mathematical models, the evolution of the certification process and to identify factors that influence the ISO 9001 issued certificates in the various countries analysed. Based on the work developed, a positive relationship was found between the number of issued certificates in each country per 1000 inhabitants and the indicators of economic development (Gross National Income Per Capita). It is determined that the total reserves of a country is an economic variable that directly affects the number of issued certificates, a finding not observed in other forecasting models.     

Power flow solutions through tensor methods

This work deals with the application of tensor methods based on a quadratic model, to solve a set of nonlinear equations. Particular attention is given to the power flow problem, with emphasis on the modelling of the steady state electric network equations in rectangular coordinates. Two formulations of the power flow problem are used for the application of tensor methods. The first is the conventional approach based on active and reactive power mismatches. The second includes the equations of both power injection and the current injection balances. It is shown that the use of tensor models increases the robustness and can speed up the power flow iterative process if the computational effort for calculating the quadratic term is reduced. Numerical results obtained with power systems ranging from 6 to 1916 buses illustrate the application of the proposed methodology.