Midwest State University

Guarapuava, Brazil

Midwest State University

Guarapuava, Brazil
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Thomaz E.L.,Midwest State University
Scientia Agricola | Year: 2017

Fire is a key controlling factor in ecosystem dynamics worldwide, especially, in tropical areas under slash-and-burn agricultural systems. Farmers use fire as a tool to clean the land, and benefit from nutrient enrichment from ash-soil heating. However, fire can cause some detrimental effects on soil systems, such as organic carbon depletion, increased soil erodibility, and changes to aggregate stability. In this study, an experimental fire was applied to a plot of land following the local traditional practice of slash-and-burn. The fire temperature was monitored in the field, and its effect on soil aggregate stability was assessed. The fire temperature on soil surface was measured in four trenches, and it ranged from 355 to 660 °C (average 484 ± 142 °C). The fire temperature did not affect soil organic matter content. However, aggregate stability increased by 10 % in comparison to unburned soil. Moreover, the geometric mean diameter of burned soil was 20 % higher than that of unburned soil. In conclusion, high fire temperature changes soil aggregate stability in slash-and-burn agricultural systems. © 2017, Scientia Agricola. All rights reserved.

Knob A.,Midwest State University | Beitel S.M.,Midwest State University | Fortkamp D.,Midwest State University | Terrasan C.R.F.,Federal University of São Carlos | Almeida A.F.D.,São Paulo State University
BioMed Research International | Year: 2013

In recent decades, xylanases have been used in many processing industries. This study describes the xylanase production by Penicillium glabrum using brewer's spent grain as substrate. Additionally, this is the first work that reports the purification and characterization of a xylanase using this agroindustrial waste. Optimal production was obtained when P. glabrum was grown in liquid medium in pH 5.5, at 25 °C, under stationary condition for six days. The xylanase from P. glabrum was purified to homogeneity by a rapid and inexpensive procedure, using ammonium sulfate fractionation and molecular exclusion chromatography. SDS-PAGE analysis revealed one band with estimated molecular mass of 18.36 kDa. The optimum activity was observed at 60 °C, in pH 3.0. The enzyme was very stable at 50 °C, and high pH stability was verified from pH 2.5 to 5.0. The ion Mn2+ and the reducing agents β-mercaptoethanol and DTT enhanced xylanase activity, while the ions Hg2+, Zn2+, and Cu2+ as well as the detergent SDS were strong inhibitors of the enzyme. The use of brewer's spent grain as substrate for xylanase production cannot only add value and decrease the amount of this waste but also reduce the xylanase production cost. © 2013 Adriana Knob et al.

Zanette C.M.,Midwest State University | Dalla Santa O.R.,Midwest State University | Bersot L.S.,Federal University of Paraná
International Food Research Journal | Year: 2015

The objective of this study was to evaluate the effect of a bacteriocinogenic starter culture against L. monocytogenes in artificially contaminated sausages. During the maturation of sausages the following procedures were carried out: physical-chemical analysis, lactic acid bacteria counts, and enumeration of L. monocytogenes. In the treatment inoculated only with a pool of L. monocytogenes, the multiplication of the pathogen was verified during the 19 days of maturation and the increase in the pathogen population was 2.01 log CFU.g-1. In the treatments inoculated with starter cultures of bacteriocinogenic and bacteriocin-negative L. plantarum, we observed a 1.7 log CFU.g-1 reduction in levels of L. monocytogenes during the sausages maturation. However, no significant differences (P > 0.01) were observed between the treatments inoculated with starter cultures. The pH values of the control treatment remained almost constant at 6.07 during the maturation, differing significantly (P < 0.01) from treatments inoculated with starter cultures. © All Rights Reserved.

Correa C.S.,Federal University of Rio Grande do Sul | Laroche D.P.,University of New Hampshire | Cadore E.L.,Federal University of Rio Grande do Sul | Reischak-Oliveira A.,Federal University of Rio Grande do Sul | And 8 more authors.
International Journal of Sports Medicine | Year: 2012

The objective of the present study was to evaluate and compare the neuromuscular, morphological and functional adaptations of older women subjected to 3 different types of strength training. 58, healthy women (67±5 year) were randomized to experimental (EG, n=41) and control groups (CG, n=17) during the first 6 weeks when the EG group performed traditional resistance exercise for the lower extremity. Afterwards, EG was divided into three specific strength training groups; a traditional group (TG, n=14), a power group (PG, n=13) that performed the concentric phase of contraction at high speed and a rapid strength group (RG, n=14) that performed a lateral box jump exercise emphasizing the stretch-shortening-cycle (SSC). Subjects trained 2 days per week through the entire 12 weeks. Following 6 weeks of generalized strength training, significant improvements occurred in EG for knee extension one-repetition (1RM) maximum strength (+19%), knee extensor muscle thickness (MT, +15%), maximal muscle activation (+44% average) and onset latency (31% average) for vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) compared to CG (p<0.05). Following 6 more weeks of specific strength training, the 1RM increased significantly and similarly between groups (average of +21%), as did muscle thickness of the VL (+25%), and activation of VL (+44%) and VM (+26%). The onset latency of RF (TG=285±109ms, PG=252±76ms, RG=203±43ms), reaction time (TG=366±99ms, PG=274±76ms, RG=201±41ms), 30-s chair stand (TG=18±3, PG=18±1, RG=21±2) and counter movement jump (TG=8±2cm, PG=10±3cm, RG=13±2cm) was significantly improved only in RG (p<0.05). At the end of training, the rate of force development (RFD) over 150ms (TG=2.3±9.8N·s1, PG=3.3±3.2N·s1, RG=3.8±6.8N·s 1, CG=2.3±7.0N·s1) was significantly greater in RG and PG than in TG and CG (p<0.05). In conclusion, rapid strength training is more effective for the development of rapid force production of muscle than other specific types of strength training and by consequence, better develops the functional capabilities of older women. © Georg Thieme Verlag KG Stuttgart . New York.

Almeida J.M.,Midwest State University | Lima V.A.,Federal Technological University of Paraná | Giloni-Lima P.C.,Midwest State University | Knob A.,Midwest State University
Biomass and Bioenergy | Year: 2014

β-Glucosidases show great potential as catalysts for various biotechnology processes including biomass hydrolysis for bioethanol production. In this study, response surface methodology was used to evaluate the effect of some variables on β-glucosidase production by Penicillium verruculosum using passion fruit peel as substrate, and on hydrolysis of this process residue with P. verruculosum crude extract, by applying a full factorial central composite design. Process optimization resulted in a 5.7 fold increase in β-glucosidase activity. The enzymes were more active at 65°C, pH 4.5, remaining stable at 55 and 60°C and over a broad pH range. P. verruculosum crude extract hydrolyzed passion fruit peel with glucose yield of 45.54%. This article provides, for the first time, the production of remarkable yields of β-glucosidase and the achievement of expressive levels of glucose through the use of passion fruit peel, an abundant and inexpensive agro-industrial residue. © 2014 Elsevier Ltd.

de Almeida J.M.,Midwest State University | de Lima V.A.,Federal Technological University of Paraná | de Lima P.C.G.,Midwest State University | Knob A.,Midwest State University
Bioenergy Research | Year: 2016

Efficient, low-cost enzymatic hydrolysis of lignocellulosic biomass is essential for cost-effective production of bioethanol. The aim of this study was to establish a fungal fermentation-based strategy for the economic enzymatic conversion of pineapple peel into fermentable sugars. Trichoderma viride was grown on passion fruit peel in order to improve its β-glucosidase production, and a crude extract was then used to hydrolyze pineapple peel. The effects of medium pH, cultivation time, and passion fruit peel concentration on β-glucosidase production were evaluated using a central composite rotational design (CCRD) combined with response surface methodology (RSM). Optimal β-glucosidase activity of 2.40 U mL−1 was found after 6.5 days of cultivation in medium at pH 6.0, containing 2.0 % passion fruit peel. Saccharification of pineapple peel was also optimized by RSM and CCRD with respect to pH, temperature, β-glucosidase concentration, and reaction time and proceeded optimally at pH 4.0, 55 °C, with a β-glucosidase loading of 31.25 U g−1 dry feedstock and 75 h of reaction. Under these conditions, T. viride crude extract hydrolyzed pineapple peel with a glucose yield of 65.3 %. This study therefore presents passion fruit peel as an attractive raw material for the production of β-glucosidases. In addition, it describes an improved, effective, and low-cost enzymatic method for the production of fermentable sugars from pineapple peel, an abundant and inexpensive agro-industrial waste. © 2016 Springer Science+Business Media New York

PubMed | Midwest State University and Federal Technological University of Paraná
Type: Journal Article | Journal: Bioprocess and biosystems engineering | Year: 2015

-Glucosidases are important enzymes with significant prospects in the industrial biotechnology, including their use in biomass hydrolysis for bioethanol production. In this study, the use of canola meal as carbon source for -glucosidase production by a Trichoderma viride strain in submerged fermentation was evaluated by applying central composite design and response surface methodology to optimize the production process. This statistical approach was also used to improve the passion fruit peel hydrolysis by T. viride crude extract. The model developed 3.6-fold increased -glucosidase activity. The culture conditions that resulted in the highest -glucosidase levels were a substrate concentration of 2.9%, pH of medium 4.2 and cultivation time of 206h. The -glucosidases produced under optimal conditions showed attractive properties for industrial applications, such as activity at high temperatures and stability at 55C and over a wide pH range. In addition, the enzymatic hydrolysis of passion fruit peel by T. viride crude extract was very promising, resulting in glucose yields of 66.4%. This study, therefore, presents canola meal as an inexpensive and attractive substrate for the production of microbial -glucosidases.

Oliveira M.D.F.,Federal University of Technology of Parana | Grassi M.,Midwest State University | Gallina A.L.,Federal University of Technology of Parana | Paulo Rogerio Pinto Rodrigues E.,Midwest State University
Materials Science Forum | Year: 2015

Paint durability is directly linked to the efficiency of the substrate pre-treatment system. The objective to treat the carbon steel surface prior to painting is to turn the unstable metal surface into a stable surface one, an inert base to receive the paint. This is the main function of the phosphatization processes, which enables good paint adherence and prevents the development of corrosion processes. The demand for cleaner technologies, with lower residue generation, makes the phosphatization an unappealing method, and in this context the use of nanoceramics is an alternative to phosphate conversion layers. The objective of this study is to form a protection film which employs an organic molecule together with the zircon oxide, forming a layer which is able to anchor paint and increase the carbon steel resistance to corrosion. The treatment process conditions were established through the factorial planning, and the samples evaluated through the electrochemical impedance spectroscopy, scanning electronic microscopy and energy dispersive analysis. After comparing results of the electrochemical evaluation of the coating proposed with the iron and zinc phosphate coatings, it was possible to see that the film formed presented better corrosion resistance properties. © (2015) Trans Tech Publications, Switzerland.

Beitel S.M.,Midwest State University | Knob A.,Midwest State University
Industrial Biotechnology | Year: 2013

β-Glucosidases have great potential to be used in various biotechnological processes, such as those used by the food and feed industries, biomass hydrolysis for bioethanol production, and enhancing the flavor of wine, tea, and fruit juice. This work describes β-glucosidase production by Penicillium miczynskii. The effects of pH, time, and condition of cultivation, temperature, different carbon sources, and concentration of the selected agro-industrial waste on extracellular β-glucosidase production were studied in submerged fermentation. Additionally, the enzyme produced was biochemically characterized. The best conditions for P. miczynskii β-glucosidase production were 3% pineapple peel as carbon source, under stationary conditions, for 9 days, at pH 5.5 and temperature of 20 C, which yielded 2.82 U/mL. The enzyme showed best activity at pH 4.5-5.0, and 65 C. It was stable at 55 C and 60 C, with a half-life of 50 min and 40 min, respectively. The β-glucosidase was slightly activated in the presence of β-mercaptoethanol, Ca2+, and Co2+, and strongly inhibited by sodium dodecylsulfate (SDS), Zn2+, and Hg2+. Also, sodium citrate, NH4 +, and Ba2+ were able to inhibit this enzyme, especially at 10 mM concentration. The enzyme presented high glucose tolerance, with a Ki of 760 mM. This study describes a novel β-glucosidase that presents favorable industrial properties, such as low inhibition rate by glucose, and production on pineapple peel, an inexpensive and abundant agro-industrial waste. © 2013, Mary Ann Liebert, Inc.

Cunha M.T.,Midwest State University | Rodrigues P.R.P.,Midwest State University
Materials Science Forum | Year: 2015

The main aim of this paper is to study copper ions electroplating, evaluating the cathodic current efficacy, from cyanide ion free alkaline baths, stabilized by different complexant agents for the Cu2+ ions. The cathodic current efficacy was assessed through quartz microbalance measurements, employing different current modulations. Results revealed that the pulsed current application has great influence on the cathodic current efficacy during electroplating in the baths under study. © (2015) Trans Tech Publications, Switzerland.

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