Abstract Bacteria may be the initial cause of certain pathologies as well as a secondary agent responsible for the development of complications such as pressure ulcer infections. Pressure ulcers are a persistent health problem, especially in immunocompromised patients, and associated with infection by opportunistic microorganisms with antimicrobial resistance, such as Klebsiella pneumoniae, highlight the need for the development of new antimicrobial approaches. Thus, the aim of this study was to evaluate the antibacterial and anti-adherent activity of Origanum vulgare L. (oregano) essential oil against Klebsiella pneumoniae strains, as well as the effect of its association with synthetic antimicrobials. To this end, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) analyses were performed on microdilution plates. The assay of the Minimum Inhibitory Adherence Concentration (MIAC), with test tubes. As well as, the association study through the infusion disc method containing ampicillin (AMP), gentamicin (GEN), ciprofloxacin (CIP) and ceftriaxone (CEF). Therefore, it was possible to obtain that the essential oil of oregano presents antimicrobial and bactericidal activity, with MIC ranging between 128μg/mL and 256 μg/mL and MBC between 256 μg/mL and 512 μg/mL, on the tested K. pneumoniae strains. When used in association with ampicillin and gentamicin, oregano essential oil showed synergistic effect for some strains. Therefore, it is observed that the tested essential oil can act as a promising antibacterial in the treatment of diseases caused by K. pneumoniae.

Resumo As bactérias podem ser a causa inicial de determinadas patologias como também um agente secundário responsável pelo desenvolvimento de complicações como as infecções das lesões por pressão. As lesões por pressão configuram um problema de saúde persistente, principalmente em pacientes imunocomprometidos, e associadas a infecção por microrganismos oportunistas com resistência antimicrobiana, como por exemplo a Klebisiella pneumoniae, ressaltam a necessidade do desenvolvimento de novas abordagens antimicrobianas. Assim, o objetivo deste estudo foi avaliar a atividade antibacteriana e antiaderente do óleo essencial de Origanum vulgareL. (orégano) contra cepas da Klebisiella pneumoniae, bem como o efeito da sua associação com antimicrobianos sintéticos. Para isso foram realizadas as análises da Concentração Mínima Inibitória (CIM) e Concentração Bactericida Mínima (CBM) em placas de micro diluição. O ensaio da Concentração Mínima de Aderência (CIMA), com tubos de ensaio. Como também, o estudo de associação através do método de disco de infusão contendo ampicilina, gentamicina, ciprofloxacino e ceftriaxona. Assim sendo, foi possível obter que o óleo essencial de orégano apresenta atividade antimicrobiana e bactericida, com CIM variando entre 128μg/mL e 256 μg/mL e CBM entre 256 μg/mL e 512 μg/mL, sobre as cepas de K. pneumoniae testadas. Quando utilizado em associação com a ampicilina e gentamicina, o óleo essencial de orégano demonstrou efeito sinérgico para algumas cepas. Portanto, observa-se que o óleo essencial testado pode atuar como um promissor antibacteriano no tratamento de doenças causadas por K. pneumoniae.

ABSTRACT Anaerobic digestion (AD) stands out as a degradation pathway for the treatment of agro-industrial waste. This study aimed to evaluate the biogas production (Pb) from the co-digestion of swine (SW) and laying hen waste (LHW) under different temperature conditions (psychrophilic x mesophilic). The studies were carried out on a laboratory scale in anaerobic reactors (1.25 L) in a batch system for 60 days. Three mixtures in volumetric proportions (%) of 25/75 (P1), 50/50 (P2), and 75/25 (P3) (SW/LHW) were studied. The mixtures were characterized before and after AD in terms of TS, VS, and COD under temperatures of 18 and 36 °C, with Pb measured daily. Pb was higher at 36 °C for all mixtures compared to the psychrophilic condition (18 °C). Among the mixtures, the highest Pb value was observed for P3, reaching 0.34 and 0.60 m3 biogas kg−1 CODremoved for 18 and 36 °C, respectively. The digestate showed an increase in the contents of micro-and macronutrients for P1, P2, and P3 after AD, which indicates its use for agricultural purposes. The co-digestion of swine and laying hen waste is a promising proposal in terms of management and energy recovery of biogas, especially for mesophilic conditions in mixtures with a predominance of laying hen waste.

Abstract Low density sugarcane plantation (LDSP) has been implemented by some sugarcane producers in Brazil, aiming to save seeds and operational costs. The study was carried out in the municipality of Areia, Paraíba, Brazil. Five planting densities were used, varying from 5 to 25 m-2 of buds arranged in randomized blocks, with four replications. Data were measured annually over three cultivation cycles (2017 to 2020), during which the field was fertilized with NPK and the harvests were carried out manually without prior burning. The lower planting density presents higher productivity only in the cane plant (101.03 t ha-1) due to the higher plant height (2.37 m) and the higher number of stalks (11 stalks m-2), suggesting that these variables are due to the greater availability of light, water and photosynthate. However, there is a drastic reduction in sugarcane yield for this lower population in the 2nd ratoon by up to 65.62%, which is correlated with number of stalks per meter. We demonstrate the agronomic viability of LDSP in the population of 10 buds m-2 in relation to conventional planting of sugarcane until the 2nd ratoon. Data are important for future studies to present additional considerations for other production factors, such as the effects of mechanized harvesting and the management of nutrients and water, assessing the sustainability of this large-scale planting system.

Resumo O método de plantio de cana-de-açúcar de baixa densidade (LDSP) vem sendo implementado por alguns produtores de cana-de-açúcar no Brasil, visando economia de sementes e custos operacionais. O estudo foi realizado no município de Areia, Paraíba, Brasil. Utilizou-se cinco densidades de plantio, variando de 5 a 25 m-2 de gemas dispostas em blocos casualizados, com quatro repetições. Os dados foram medidos anualmente ao longo de três ciclos de cultivo (2017 a 2020). Menor densidade de plantio mostrou maior produtividade (101,03 t ha-1) devido à maior altura de planta (2,37 m) e ao maior número de hastes (NS) (11 hastes m-2), sugerindo que essas variáveis são devido à maior disponibilidade de luz, água e fotoassimilados. No entanto, houve redução drástica na produtividade da cana-de-açúcar para esta população menor na 2ª soca em 65,62%, estando correlacionado com o número de colmos por metro. Demonstramos a viabilidade agronômica do LDSP em uma população de 10 gemas m-2 em relação ao plantio convencional de cana-de-açúcar até a 2ª soca. Os dados são importantes para que estudos futuros apresentem considerações adicionais sobre outros fatores de produção, como os efeitos da colheita mecanizada e do manejo de nutrientes e água, avaliando a sustentabilidade desse sistema de plantio em larga escala.

ABSTRACT Technologies that improve water use efficiency (WUE) and increase crop yields are essential for the development of a responsible and productive agriculture. Therefore, the objective of this study was to evaluate economical planting beds with the use of mulching and application of different irrigation water depths as a water-saving technology, and determine the irrigation water depth that promote the optimal plant development and fruit yield and quality of two cherry tomato cultivars. The experiment was conducted at the Federal Rural University of Pernambuco, Serra Talhada, PE, Brazil. A randomized block experimental design with split-plots (5×2) was used, with plots consisting of five irrigation water depths (25%, 50%, 75%, 100%, and 125% of the crop evapotranspiration - ETc) and subplots consisting of two cherry tomato cultivars (Carolina and Yubi), with four replications, totaling 40 experimental units. The development of tomato plants was evaluated through biometric measurements of stem diameter, plant height, and canopy area. Additionally, the following variables were evaluated during fruit harvest: number of fruits, mean fruit weight, fruit diameter, fruit yield, WUE, titratable acidity, pH, and soluble solids content. The economical planting beds promoted increases in WUE. Irrigation water depths lower than 100% of ETc resulted in better plant development and higher fruit yield, number of fruits, and WUE for the evaluated cherry tomato plants. The cultivar Carolina exhibited higher production performance compared to Yubi.

RESUMO Tecnologias que promovam o aumento da eficiência do uso da água (EUA) e incremento na produtividade é indispensável para o desenvolvimento de uma agricultura responsável e produtiva. Nesse sentido, objetivou-se avaliar ‘canteiros econômicos’ com a utilização de mulching, aplicando diferentes lâminas de irrigação para consolidar o uso desses canteiros como uma tecnologia que propicia a economia de água, da mesma forma que, encontrar a lâmina de irrigação que promova o melhor desenvolvimento, rendimento produtivo e qualidade de duas cultivares de tomatecereja. A pesquisa foi conduzida na Universidade Federal Rural de Pernambuco em Serra Talhada - PE. Utilizou-se o delineamento experimental em blocos casualizados com parcelas subdivididas (5 x 2), onde foram consideradas parcelas cinco lâminas de irrigação (25, 50, 75, 100, e 125% da Evapotranspiração da cultura - ETc) e subparcelas duas cultivares de tomate-cereja (Carolina e Yubi), com quatro repetições, totalizando 40 unidades experimentais. O desenvolvimento do tomateiro foi avaliado mediante coletas biométricas de diâmetro do caule, altura da planta e área da copa. Ademais, durante a colheita foi avaliado o número de frutos, massa média dos frutos, diâmetro dos frutos, produtividade, EUA, acidez titulável, potencial hidrogeniônico e sólidos solúveis dos frutos. Os canteiros econômicos promoveram aumento da EUA. Lâminas de irrigação inferiores a 100% da ETc possibilitaram maior desenvolvimento, produtividade, número de frutos e EUA do tomatecereja. A cultivar Carolina apresentou melhor desempenho produtivo comparado a Yubi.

Considering the promising antitumor effects of compounds with dual anti-inflammatory and antiproliferative activities, thus benzophenones analogs (2-7) were evaluated on in vivo anti-inflammatory assay and molecular docking analysis. Those with the best molecular docking results were in vitro evaluated on cyclooxygenase (COX) enzymes and tested regarding antiproliferative activity. All derivatives displayed in vivo anti-inflammatory activity. Among them, the substances 2’-hydroxy-4’-benzoylphenyl-β-D-glucopyranoside (4), 4-hydroxy-4’-methoxybenzophenone (5) and 4’-(4’’-methoxybenzoyl)phenyl-β-D-glucopyranoside (7) showed the best values of Glide Score in COX-2 docking evaluation and 4 and 5 selectively inhibited COX-2 and COX-1 in vitro enzymatic assay, respectively. Thus, 4 and 5 were tested against breast cancer (MCF-7, MDA MB-231, Hs578T) and non-small-cell-lung cancer (A549) cell lines. The estrogen-positive MCF-7 cell line was more responsive compared to other tested cell lines. They induced cell cycle arrest at G1/S transition in MCF-7 cell line once there was an increase in G0/G1 population with concomitant reduction of S population. The antiproliferative activity of these substances on MCF-7 was associated with their ability to inhibit cyclin E expression, a critical regulator of G1/S transition. Taken together, the data indicate that 4 and 5 have dual anti-inflammatory and antiproliferative activities and support further studies to evaluate their antitumor potential.

Abstract This study aimed to produce soil-cement brick with wood ash incorporation coming from the textile industry. The wood ash was a partial substitute for soil and cement in the manufacture of bricks. 7 formulations were made with different proportions of substitution: 10%, 20%, and 30%. It was noticed that the substitution of cement by wood ash in 10% resulted in brick with enhanced properties, showing a 20% increase for compressive strength and a reduction of 44% for mass loss, thus, with higher durability and a reduction of water absorption of 3%, when comparing to the reference brick (soil-cement). It was shown that the reuse of wood ash in the production of soil-cement bricks is a viable and sustainable option, as it is an alternative for the destination of the waste and a reduction in the consumption of Portland cement, which generates a high volume of carbon dioxide (CO2) during its production.

Abstract Mn1-xZnxFe2O4 (0 ≤ x ≤ 0.65) nanoferrite particles were used as filler in a silicone polymer matrix in order to obtain a composite material with the purpose of absorbing electromagnetic radiation. The composite was characterized by X-ray diffraction, transmission electron microscopy and force modulation microscopy (FMM) and the electromagnetic properties by means of network and impedance analyzers. It was observed that the composite with higher concentrations of Znx (x = 0.5 and 0.65) presented the lowest dispersion, due to the size of the zinc particles. This paper provides a framework for the practical application of absorbent composite materials of MnZn nanoferrite particles combined with silicone rubber to be used in 1-10 GHz frequency bands, with reflectivity values of -24 dB in the 6 GHz frequency range.

The present work aims to evaluate the manufacturing processes of free-standing graphene oxide (GO)/reduced graphene oxide(rGO)/carbon nanotube (MWCNT) papers-like and the effect on electrical conductivities after annealing treatment. The pure GO and the hybrid papers were obtained by vacuum filtration and submitted to mild thermal annealing at 400 °C under an argon atmosphere. Analyses comparing the carbon paper-like materials before and after thermal treatment were done by thermogravimetric analysis (TGA), Raman spectroscopy, scanning electron microscopy (SEM), and electrical conductivity measurements. The characterization results show the annealing process effect on the morphology of paper materials. The GO papers and the hybrid (GO/rGO/MWCNT) exhibited good free-standing structure properties. The SEM results suggest the formation of gas void due to the thermal treatment. TGA and Raman results showed the thermal reduction and restoration of the carbon sp2 network of the graphene oxide induced by thermal treatment. The thermal treatment was responsible for changing the almost insulator characteristic of free-standing pure GO paper, achieving an electrical conductivity of 752 S/m, and improving 45% of the free-standing hybrid carbon nanomaterials papers (GO/rGO/MWCNT) electrical conductivity, achieving the value of 1020 S/m.

Resumo Megaleporinus macrocephalus é uma espécie de peixe anostomatídeo nativa da bacia do rio Paraguai, no bioma Pantanal do oeste do Brasil. No entanto, essa espécie já foi registrada em várias outras drenagens, incluindo as dos rios Alto Paraná, Uruguai, Jacuí, Doce, Mucuri e Paraíba do Sul. Este estudo apresenta dois novos registros da ocorrência de M. macrocephalus, nas bacias dos rios Itapecuru e Mearim, no estado do Maranhão, no nordeste brasileiro. O piaussu é um peixe de grande porte, de interesse comercial, amplamente criado em pisciculturas, e sua ocorrência nos rios Itapecuru e Mearim é provavelmente o resultado de indivíduos que escapam dos tanques quando transbordam durante a estação chuvosa. Análises morfológicas e sequências do gene da subunidade I do citocromo oxidase (COI) confirmaram a identificação taxonômica dos espécimes como M. macrocephalus. As sequências de COI foram 99,66% semelhantes às de M. macrocephalus depositadas no banco de dados BOLDSystems. Esses registros estendem a conhecida distribuição de M. macrocephalus às bacias dos rios Itapecuru e Mearim, no nordeste brasileiro, destacando um novo caso de introdução de espécies exóticas de peixes nas bacias hidrográficas brasileiras.

Abstract The “piaussu”, Megaleporinus macrocephalus is an anostomatid fish species native to the basin of the Paraguay River, in the Pantanal biome of western Brazil. However, this species has now been recorded in a number of other drainages, including those of the upper Paraná, Uruguay, Jacuí, Doce, Mucuri, and Paraíba do Sulrivers. This study presents two new records of the occurrence of M. macrocephalus, in the basins of the Itapecuru and Mearim rivers in the state of Maranhão, in the Brazilian Northeast. The piaussu is a large-bodied fish of commercial interest that is widely raised on fish farms, and its occurrence in the Itapecuru and Mearim rivers is likely the result of individuals escaping from fish tanks when they overflow during the rainy season. Morphological analyses and sequences of the Cytochrome Oxidase Subunit I (COI) gene confirmed the taxonomic identification of the specimens as M. macrocephalus. The COI sequences were 99.66% similar to those of M. macrocephalus deposited in the BOLDSystems database. These records extend the known distribution of M. macrocephalus to the basins of the Itapecuru and Mearim rivers in the Brazilian Northeast, highlighting a new case of introduction of exotic fish species into Brazilian river basins.

This study aimed to develop a reliable stability-indicating method (SIM) for amoxicillin 500 mg capsules (DP-drug product). A literature review addressing amoxicillin (AMX; DS-drug substance) forced degradation studies and the existing SIMs was conducted to verify the most significant outcomes. Subsequently, the forced degradation of DP and DS was carried out following the Brazilian Health Surveillance Agency (ANVISA) guidelines, including thermal degradation (dry and wet heat), acidic and alkaline hydrolyses, hydrogen peroxide oxidation, reaction with copper, and photodegradation. Both DS and DP were more susceptible to 0.015 M NaOH, resulting in approximately 50% degradation. AMX DS and DP were not significantly photodegraded, but some degradation products (PDegs) showed susceptibility to light exposure. Thermodegraded samples showing ≥ 10% degradation exhibited modified profiles in thermogravimetric (TG) and differential scanning calorimetric (DSC) analyses. The X-ray powder diffraction patterns (XRPD) of DS samples exposed to dry and wet heat displayed complete amorphization of AMX, attesting to the occurrence of physical degradation concomitantly with chemical degradation, which can alter the drug’s bioavailability. In contrast, the thermodegraded DP samples exhibited intact AMX crystals interspersed with the amorphous form, perhaps partly protected by the excipient. The validated SIM was able to detect and quantify about 80 PDegs.

Resumo O entendimento de relações ecológicas e toxicológicas envolvendo culturas geneticamente modificadas (GM) e agentes de controle biológico é de grande importância para discussões relativas à compatibilidade de culturas GM com estratégias de manejo integrado e manejo de resistência de pragas. Este trabalho avaliou o comportamento de busca e a capacidade predatória de Orius insidiosus (Say) (Hemiptera: Anthocoridae) e Doru luteipes (Scudder) (Dermaptera: Forficulidae) sobre ovos e lagartas de Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) resistente ou não à proteína Cry1F expressa em milho Bt. Para determinar o tempo de busca foi utilizado um cronômetro que foi disparado até a captura da primeira presa; a capacidade de predação foi avaliada através da contagem das presas remanescentes 24 h após infestação. Também foram avaliadas as injúrias de S. frugiperda em milho transgênico e milho convencional na presença ou ausência dos predadores. Os predadores não foram capazes de distinguir entre presas (ovos ou lagartas) resistentes e suscetíveis, considerando os comportamentos predatórios avaliados. Não houve diferença no tempo de busca e capacidade predatória sobre ovos e lagartas de S. frugiperda resistente ou suscetível entre os predadores. Na presença dos predadores, as notas de injúria de S. frugiperda resistente nas plantas de milho Bt foram menores. Conclui-se que O. insidiosus e D. luteipes não percebem a presença da proteína Cry1F na presa S. frugiperda, o que pode contribuir para o uso integrado de milho GM e controle biológico em programas de manejo integrado e manejo de resistência de pragas.

Abstract Understanding the ecological and toxicological relationship between genetically modified cultivars (GM) and biological control agents is of great importance for discussions related to the compatability of GM cultivars and integrated management strategies for pest resistance. The present study evaluated the search behavior and predatory capacity of Orius insidiosus (Say) (Hemiptera: Anthocoridae) and Doru luteipes (Scudder) (Dermaptera: Forficulidae) on eggs and caterpillars of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) resistant or not to the protein Cry1F expressed in Bt corn. To determine the search time, a stopwatch was run until the capture of the first prey, predation capacity was evaluated by counting the prey remaining after 24 hours of infestation. The injuries of S. frugiperda in genetically modified and conventional corn in the presence and absence of predators was also evaluated. The predators were not able to distinguish between resistant and susceptible prey (eggs or caterpillars), given the predatory behaviour observed. There was no difference in searching time or predatory capacity between the predators for eggs and caterpillars of either resistant or susceptible S. frugiperda. In the presence of predators, the injury scores for resistant S. frugiperda on the Bt corn plants were lower. It was concluded that O. insidiosus and D. luteipes did not notice the presence of the protein Cry1F in the prey S. frugiperda, which may facilitate the combined use of GM corn and biological control in integrated management programs and for management of pest resistance.

Resumo Nanofibras de CaFe2O4 foram sintetizadas com sucesso via solution blow spinning (SBS) e as influências do tratamento térmico nas propriedades morfológicas, microestruturais, magnéticas e óticas das nanofibras foram avaliadas. No processo de síntese, quantidades estequiométricas de nitratos de ferro e cálcio foram dissolvidos em solução aquosa contendo polivinilpirrolidona (PVP) e, em seguida, nanofibras híbridas (PVP/precursores) foram produzidas por SBS. As nanofibras híbridas foram calcinadas e depois submetidas às caracterizações microestrutural, morfológica e magnética. Os resultados evidenciaram que as nanofibras apresentaram natureza cristalina de fase única CaFe2O4, com tamanho de cristalito de 31,7 e 34,4 nm para as amostras calcinadas a 800 e 1000 °C, respectivamente. As fibras de CaFe2O4 calcinadas a 600 e 800 °C apresentaram morfologia homogênea, sem beads e com diâmetros médios de 521 e 427 nm, respectivamente. Os resultados também revelaram nanofibras com baixos gaps de energia de aproximadamente 1,98 eV e características de materiais magnéticos macios.

Abstract CaFe2O4 nanofibers were successfully synthesized via solution blow spinning (SBS), and the influences of heat-treatment on morphological, microstructural, magnetic, and optical properties of the nanofibers were evaluated. In the synthesis process, stoichiometric amounts of iron and calcium nitrates were dissolved in an aqueous solution containing polyvinylpyrrolidone (PVP) and, after that, hybrid nanofibers (PVP/precursors) were produced by SBS. The hybrid nanofibers were calcined and then subjected to microstructural, morphological, and magnetic characterizations. The results evidenced that the fibers presented the crystalline nature of the single-phase CaFe2O4, with a crystallite size of 32.7 and 34.4 nm for the samples calcined at 800 and 1000 °C, respectively. The CaFe2O4 fibers calcined at 600 and 800 °C presented a homogeneous morphology, without beads, and mean diameters of 521 and 427 nm, respectively. The results also revealed nanofibers with low band gaps of approximately 1.98 eV and characteristics of soft magnetic materials.

Agroindustrial residues, such as leaves of fruit plants, can be sources of bioactive molecules, thus adding value to co-products that are rarely explored in agroindustry. In this context, this study aimed to look into the phytochemical profiles in detail and to explore the antitumor potential of S. tuberosa and S. mombin leaves. We observed that, S. tuberosa leaf extract was cytotoxic in both tumor and healthy cells. S. mombin extracts selectively inhibited cell proliferation in the tumor cell line for prostate cancer (PC3) and did not significantly affect healthy cells. The metabolic profiles of the extracts were evaluated by gas chromatography coupled with mass spectrometry and twenty-three metabolites were identified. The correlation of metabolic profiles with cytotoxic tests indicated possible chemical markers that may be responsible for the inhibition of cell proliferation. This study revealed that the unexplored co-products in agroindustry may have great therapeutic potential, and therefore should be screened for biologically active compounds.

RESUMO A altura das garras do pneu, o lastro do trator e a cobertura do solo podem influenciar o desempenho operacional e energético do conjunto trator-escarificador. O objetivo deste estudo foi analisar o desempenho operacional e energético do conjunto trator-escarificador, em função da altura das garras do pneu, do lastro e da superfície de rolamento. O experimento foi conduzido na área experimental da Fazenda Experimental do Vale do Curu, da Universidade Federal do Ceará, em Pentecoste, CE. O experimento foi conduzido em delineamento de blocos ao acaso, em arranjo fatorial 2 × 2 × 2, com quatro repetições. Os tratamentos foram compostos por duas alturas de garras de pneu (P1-28% e P2-100%), duas lastragens (L1-100% de pesos sólidos e 75% líquidos e L2-0% de pesos sólidos e líquidos) e duas superfícies de solo (S1-solo com 4200 kg de palha ha-1 e S2-solo mobilizado). Os pneus desgastados proporcionaram menor exigência de força (12,88 kN) e potência na barra (20,06 kW) e maior capacidade de campo efetiva e operacional do conjunto trator-escarificador. Menor patinamento dos rodados dianteiro do trator foi registrado para pneu desgastado (4,81%). Para os rodados traseiros, o maior patinamento foi constatado para pneu novo (10,96%), e a maior velocidade de deslocamento foi constatada para pneu desgastado (5,54 km h-1). Menor consumo específico de combustível foi constatado para solo mobilizado (534,68 g kWh-1); além disso, o consumo horário de combustível e o consumo por área não foram afetados significativamente pelos tratamentos analisados.

ABSTRACT The heights of tire claws, tractor ballasting and soil cover can influence the operational and energy performance of the tractor-scarifier assembly. The objective of this study was to analyze the operational and energy performance of the tractor-scarifier assembly as a function of the heights of the tire claws, ballasting and rolling surface. The experiment was conducted at the experimental area of the Fazenda Experimental do Vale do Curu of the Universidade Federal do Ceará in Pentecoste municipality, CE, Brazil. The experiment was carried out in a randomized block in a 2 × 2 × 2 factorial arrangement with four repetitions. The treatments comprised two tire claw heights (T1-28% and T2-100%), two ballasts (B1-100% of solid and 75% liquid weights and B2 - 0% of solid and liquid weights), and two soil surfaces (S1 - soil with 4200 kg of straw ha-1 and S2 - mobilized soil). Worn tires provided a lower bar force (12.88 kN) and power requirement (20.06 kW) and a greater effective and operative field capacity of the tractor-scarifier assembly. The lowest slippage of the front wheels of the tractor was recorded for the worn tires (4.81%).For the rear wheels, slippages were found on the new tires (10.96%), and a higher speed of displacement was found for worn tires (5.54 km h-1). Lower specific fuel consumption was found for the mobilized soil (534.68 g kWh-1); furthermore, the hourly consumption of fuel and the consumption per area were not significantly affected by the treatments analyzed.

ABSTRACT In this study, we have optimized production of bacterial cellulose (BC) by Komagataeibacter hansenii ATCC 23769 in a static cultivation using sisal juice, an agroindustrial residue, as substrate. Optimization of fermentation parameters has been carried out using the one-variable-at-a-time method. Effect of initial sugar concentration, pH, nitrogen supplement, and cultivation time was evaluated. The influence of nitrogen source and quantity for bacterial cellulose production was studied using a central composite rotational design (CCRD).The highest production of BC (3.38 g/L) was obtained after 10 days of cultivation, using sisal juice (pH 5) at 15 g/L of sugars and supplemented with 7.5 g/L of extract yeast. The cellulose production yield in selected sisal culture conditions was three times higher than the yield in synthetic medium, indicating that sisal juice is a suitable substrate for BC production.