RESUMO A ideia de Brasil soberano e moderno, tão marcante no ensaísmo, na pesquisa acadêmica e no imaginário coletivo, designa um vasto horizonte de aspirações comuns que propôs ciclicamente promessas de um futuro de prosperidade, até ser confrontado pela complexidade dos desafios atuais, às vésperas do segundo centenário da Independência. O artigo interroga as revisões das ideias de soberania e modernização no ensaísmo e no pensamento histórico-econômico.

ABSTRACT The idea of a sovereign and modern Brazil, so prominent in essay-writing, academic research and the collective imagination, comprises a vast horizon of common aspirations that has cyclically promised a prosperous future, until being confronted by the complexity of today’s challenges, on the eve of the second centenary of Brazil’s Independence. The article questions the revisions of the ideas of sovereignty and modernization among essay writers and in historical and economic thought.

O emprego de residuos como matéria prima é importante como estrategia governamental e para o balanço ambiental. O propósito deste trabalho foi estudar a produção de CMCase e xilanase de uma linhagem de Thermoascus aurantiacus isolado de solo brasileiro em fermentação em estado sólido (SSF) usando diferentes resíduos agrícolas (farelo de trigo, bagaço de cana, bagaço de laranja, sabugo de milho, grama verde, grama seca, serragem de eucalipto e palha de milho) como substratos sem enriquecimento dos meios e caracterizar as enzimas. O estudo das enzimas hemiceluloliticas extracelulares mostrou que o fungo T. arantiacus é mais xilanolítico do que celulolítico. Ele produziu maiores níveis das enzimas em meios contendo sabugo de milho, grama e palha de milho. Todas as enzimas foram estáveis por 24 h à temperatura ambiente numa ampla faixa de pH (3,0 - 9,0) e também foram estáveis a 60ºC por 1 h. O pH ótimo e temperatura ótima para xilanase e CMCase foram 5,0- 5,5 e 5,0 e 75ºC, respectivamente. O microrganismo cresceu muito bem estacionariamente no meio simples, de baixo custo. As enzimas estáveis secretadas extracelularmente apresentam as características necessárias para sua aplicação industrial.

The use of waste as raw material is important for government economy and natural balance. The purpose of this work was to study the production of CMCase and xylanase by a Brazilian strain of Thermoascus aurantiacus in solid state fermentation (SSF) using different agricultural residues (wheat bran, sugarcane bagasse, orange bagasse, corncob, green grass, dried grass, sawdust and corn straw) as substrates without enrichment of the medium and characterize the crude enzymes.The study of the extracellular cellulolytic and hemicellulolytic enzymes showed that T. arantiacus is more xylanolytic than cellulolytic. The highest levels of enzymes were produced in corncob, grasses and corn straw. All the enzymes were stable at room temperature by 24 h over a broad pH range (3.0-9.0) and also were stable at 60ºC for 1 h. The optimum pH and temperature for xylanase and CMCase were 5.0-5.5 and 5.0 and 75ºC, respectively. The microorganism grew quickly in stationary, simple and low cost medium. The secreted extracellular enzymes presented properties that match with those frequently required in industrial environment.

The increasing use of alcohol as an alternative fuel to gasoline or diesel can increase emission of formaldehyde, an organic gas that is irritant to the mucous membranes. The respiratory system is the major target of air pollutants and its major defense mechanism depends on the continuous activity of the cilia and the resulting constant transportation of mucous secretion. The present study was designed to evaluate the effects of formaldehyde on the ciliated epithelium through a relative large dose range around the threshold limit value adopted by the Brazilian legislation, namely 1.6 ppm (1.25 to 5 ppm). For this purpose, the isolated frog palate preparation was used as the target of toxic injury. Four groups of frog palates were exposed to diluted Ringer solution (control, N = 8) and formaldehyde diluted in Ringer solution at three different concentrations (1.25, 2.5 and 5.0 ppm, N = 10 for each group). Mucociliary clearance and ciliary beat frequency decreased significantly in contact with formaldehyde at the concentrations of 2.5 and 5.0 ppm after 60 min of exposure (P<0.05). We conclude that relatively low concentrations of formaldehyde, which is even below the Brazilian threshold limit value, are sufficient to cause short-term mucociliary impairment.