Resumen La investigación tuvo como objetivo la identificación del conocimiento que poseen los estudiantes sobre las PCA. El estudio se destaca por su carácter cualitativo y cuantitativo de tipo exploratorio descriptivo. La muestra se compuso por 62 alumnos de un bachillerato de 1º a 3º año de Cascavel/CE. Se elaboró un cuestionario semiestructurado en Google Docs con 3 preguntas subjetivas y 2 objetivas. Se obtuvo como resultado de la investigación el paracaidismo como la modalidad más citada entre los estudiantes seguido por el surf y el skate. Los estudiantes también expresaron que estas prácticas se repetían tanto en la escuela primaria como en la secundaria. Concluimos que las PCA son aún poco discutidas en las clases de Educación Física. Esto demuestra la necesidad de ampliar los debates y discusiones respecto de las CPA. Se torna muy importante la reflexión sobre las PCA en su contexto pedagógico para superar estos desafíos y lograr una implementación didáctico-pedagógica mayor por parte del docente.

Resumo O objetivo da pesquisa foi identificar os conhecimentos dos/as alunos/as sobre as PCA. O estudo se caracteriza de natureza quali-quantitavo do tipo descritiva exploratória. A amostra foi composta por 62 alunos/as de uma Escola de Ensino Médio do 1º ao 3ºano de Cascavel/CE. Foi elaborado um questionário semiestruturado no GoogleDocs com 3 questões subjetivas e 2 objetivas. Tivemos, como resultados da pesquisa, o paraquedismo como a modalidade mais citada pelos alunos, em seguida, o surfe e skate. Foram relatadas também pelos alunos que essas práticas se repetiram tanto no Ensino Fundamental como no Ensino Médio. Concluímos que o PCA ainda é pouco tematizado nas aulas de Educação Física. Isso demonstra a necessidade de ampliação dos debates e discussões a respeito da PCA. Torna-se muito importante refletir sobre as PCA no seu contexto pedagógico para que esses dilemas possam ser superados e que assim seja possível uma maior implementação didático-pedagógica do/a professor/a.

Abstract This paper aims to identify the knowledge that students possess about adventure physical activities (APA). The study stands out from its qualitative and quantitative character of exploratory descriptive type. The sample consisted of 62 high school students from 1st to 3rd year from Cascavel (Ceará, Brazil). A semi-structured GoogleDocs questionnaire with 3 subjective and 2 objective questions was created. As a result of the research, skydiving was identified as the most popular activity among students, followed by surfing and skateboarding. Students also reported that these practices were repeated in both elementary and high school. In conclusion, this study shows that APA are still little discussed in Physical Education classes, thus demonstrating the need to expand debates and discussions regarding APA. It becomes very important to reflect on the role of APA in their pedagogical context in order to overcome these challenges and achieve a greater didactic-pedagogical implementation by the teacher.

Abstract This paper aims to identify the knowledge that students possess about adventure physical activities (APA). The study stands out from its qualitative and quantitative character of exploratory descriptive type. The sample consisted of 62 high school students from 1st to 3rd year from Cascavel (Ceará, Brazil). A semi-structured GoogleDocs questionnaire with 3 subjective and 2 objective questions was created. As a result of the research, skydiving was identified as the most popular activity among students, followed by surfing and skateboarding. Students also reported that these practices were repeated in both elementary and high school. In conclusion, this study shows that APA are still little discussed in Physical Education classes, thus demonstrating the need to expand debates and discussions regarding APA. It becomes very important to reflect on the role of APA in their pedagogical context in order to overcome these challenges and achieve a greater didactic-pedagogical implementation by the teacher.

Resumo O objetivo da pesquisa foi identificar os conhecimentos dos/as alunos/as sobre as PCA. O estudo se caracteriza de natureza quali-quantitavo do tipo descritiva exploratória. A amostra foi composta por 62 alunos/as de uma Escola de Ensino Médio do 1º ao 3ºano de Cascavel/CE. Foi elaborado um questionário semiestruturado no GoogleDocs com 3 questões subjetivas e 2 objetivas. Tivemos, como resultados da pesquisa, o paraquedismo como a modalidade mais citada pelos alunos, em seguida, o surfe e skate. Foram relatadas também pelos alunos que essas práticas se repetiram tanto no Ensino Fundamental como no Ensino Médio. Concluímos que o PCA ainda é pouco tematizado nas aulas de Educação Física. Isso demonstra a necessidade de ampliação dos debates e discussões a respeito da PCA. Torna-se muito importante refletir sobre as PCA no seu contexto pedagógico para que esses dilemas possam ser superados e que assim seja possível uma maior implementação didático-pedagógica do/a professor/a.

Resumen La investigación tuvo como objetivo la identificación del conocimiento que poseen los estudiantes sobre las PCA. El estudio se destaca por su carácter cualitativo y cuantitativo de tipo exploratorio descriptivo. La muestra se compuso por 62 alumnos de un bachillerato de 1º a 3º año de Cascavel/CE. Se elaboró un cuestionario semiestructurado en Google Docs con 3 preguntas subjetivas y 2 objetivas. Se obtuvo como resultado de la investigación el paracaidismo como la modalidad más citada entre los estudiantes seguido por el surf y el skate. Los estudiantes también expresaron que estas prácticas se repetían tanto en la escuela primaria como en la secundaria. Concluimos que las PCA son aún poco discutidas en las clases de Educación Física. Esto demuestra la necesidad de ampliar los debates y discusiones respecto de las CPA. Se torna muy importante la reflexión sobre las PCA en su contexto pedagógico para superar estos desafíos y lograr una implementación didáctico-pedagógica mayor por parte del docente.

ABSTRACT For the implementation of cellulosic ethanol technology, the maximum use of lignocellulosic materials is important to increase efficiency and to reduce costs. In this context, appropriate use of the pentose released by hemicellulose hydrolysis could improve de economic viability of this process. Since the Saccharomyces cerevisiae is unable to ferment the pentose, the search for pentose-fermenting microorganisms could be an alternative. In this work, the isolation of yeast strains from decaying vegetal materials, flowers, fruits and insects and their application for assimilation and alcoholic fermentation of xylose were carried out. From a total of 30 isolated strains, 12 were able to assimilate 30 g L-1 of xylose in 120 h. The strain Candida tropicalis S4 produced 6 g L-1 of ethanol from 56 g L-1 of xylose, while the strain C. tropicalis E2 produced 22 g L-1 of xylitol. The strains Candida oleophila G10.1 and Metschnikowia koreensis G18 consumed significant amount of xylose in aerobic cultivation releasing non-identified metabolites. The different materials in environment were source for pentose-assimilating yeast with variable metabolic profile.

Abstract Citrus canker, caused by the Gram-negative bacterium Xanthomonas citri subsp. citri (Xac), is one of the most devastating diseases to affect citrus crops. There is no treatment for citrus canker; effective control against the spread of Xac is usually achieved by the elimination of affected plants along with that of asymptomatic neighbors. An in depth understanding of the pathogen is the keystone for understanding of the disease; to this effect we are committed to the development of strategies to ease the study of Xac. Genome sequencing and annotation of Xac revealed that ∼37% of the genome is composed of hypothetical ORFs. To start a systematic characterization of novel factors encoded by Xac, we constructed integrative-vectors for protein expression specific to this bacterium. The vectors allow for the production of TAP-tagged proteins in Xac under the regulation of the xylose promoter. In this study, we show that a TAP-expression vector, integrated into the amy locus of Xac, does not compromise its virulence. Furthermore, our results also demonstrate that the polypeptide TAP can be overproduced in Xac and purified from the soluble phase of cell extracts. Our results substantiate the use of our vectors for protein expression in Xac thus contributing a novel tool for the characterization of proteins and protein complexes generated by this bacterium in vivo.

ABSTRACT In Brazil, ethanol is obtained by fermentat of sugar cane juice using Saccharomyces cerevisiae. The cane juice extraction generates the bagasse that has been used for obtaining generation biofuel. However, the sugarcane bagasse has 30% pentose that cannot be fermented to ethanol by S. cerevisiae. Thus the aim of this study was to isolate a yeast able to ferment xylose to ethanol. Samples of cane juice and flowers were used for the isolation of 165 strains that were then screened for ethanol production using plate testing. Among them, the ethanol positive strains Wickerhamomyces anomalus, Schizosaccharomyces pombe and Starmerella meliponinorum were selected for a xylose fermentation assay, using a semi-synthetic and bagasse hydrolysate as must. S. meliponinorum and S. pombe produced 0.63 and 2.7 gL-1 of ethanol, respectively, from xylose in a semisynthetic medium. In the medium consisting of bagasse hydrolysate must, 0.67 and 1.1 gL-1 of ethanol were obtained from S. meliponinorum and S. pombe, respectively. All the yeasts produced xylitol from xylose in the semisynthetic medium and S. meliponinorum was that which produced the highest quantity (14.5 g L-1).

Twenty-seven thermophilic and thermotolerant fungal strains were isolated from soil, decaying organic matter and sugarcane piles based on their ability to grow at 45ºC on medium containing corn straw and cardboard as carbon sources. These fungi were identified in the genera Aspergillus, Thermomyces, Myceliophthora, Thermomucor and Candida. The majority of the isolated strains produced xylanase and cellulases under solid state fermentation (SSF). The highest cellulase and xylanase productions were obtained by the cultivation of the strains identified as Aspergillus fumigatus M.7.1 and Myceliophthora thermophila M.7.7. The enzymes from these strains exhibited maximum activity at pH 5.0 and at 60 and 70ºC. The endo-glucanase from A. fumigatus was stable from 40ºC to 65ºC and both endo-glucanase and xylanase from M. thermophila were stable in this temperature range when in absence of substrate. The enzymes were stable from pH 4.0 to 9.0.

In this work, tomato pomace, a waste abundantly available in the Mediterranean and other temperate climates agro-food industries, has been used as raw material for the production of some hydrolytic enzymes, including xylanase, exo-polygalacturonase (exo-PG), cellulase (CMCase) and α-amylase. The principal step of the process is the solid state fermentation (SSF) of this residue by Aspergillus awamori. In several laboratory experiments, maximum xylanase and exo-PG activities were measured during the first days of culture, reaching values around 100 and 80 IU/gds (international units of enzyme activity per gram of dried solid), respectively. For CMCase and α-amylase production remained almost constant along fermentation, with average values of 19 and 21.5 IU/gds, respectively. Experiments carried out in a plate-type bioreactor at lab scale showed a clear positive effect of aeration on xylanase and CMCase, while the opposite was observed for exo-PG and α-amylase. In general, xylanase was the enzyme produced in higher levels, thus the optimum conditions for the determination of the enzyme activity was characterized. The xylanase activity shows an optimum pH of 5 and an optimum temperature of 50 ºC. The enzyme is activated by Mg2+, but strongly inhibited by Hg2+ and Cu2+. The enzymatic activity remains quite high if the extract is preserved in a range of pH from 3 to 10 and a temperature between 30 ºC to 40 ºC.

No Brasil, muitas frutas, pouco exploradas economicamente, apresentam potencial como matéria-prima para a agroindústria. Este trabalho objetivou elaborar e determinar as características físico-químicas e sensoriais da geleia light de jambolão. Esta fruta tem uma coloração roxa intensa que conferiu às geleias, tanto padrão quanto light, aspecto visual bastante atrativo. As geleias light apresentaram características físico-químicas próximas daquelas desenvolvidas de forma convencional e, nas proporções de edulcorantes empregadas, os valores calóricos das formulações foram reduzidos na faixa de 41% a 53 %, enquadrando-se nas normas exigidas pela legislação brasileira para este tipo de produto. O perfil sensorial obtido para as 4 formulações light desenvolvidas evidenciou a preferência dos provadores pela geleia elaborada com a associação de ciclamato e sacarina. Assim, os resultados obtidos evidenciam boas perspectivas para a aplicação desta fruta na indústria de alimentos.

In Brazil, several little economically explored fruits have good potential as raw material for the agro-industry. This study aimed to produce and determine the physical-chemical and sensory characteristics of light jambolan jelly. This fruit has intense purple color, which gave the jellies - both standard and light - a quite attractive visual aspect. The light jellies exhibited similar physical-chemical characteristics to the ones developed through the conventional method and; with the proportion of sweeteners used, the caloric values of the formulations were reduced to the range of 41 to 53%, attending the requirements of the Brazilian legislation for this type of product. The sensory profile obtained for the 4 light formulations developed, clearly showed the tasters' preference for the jelly elaborated with the association of cyclamate and saccharin. Thus, the results revealed good perspectives for the application of this fruit in the food industry.

O cajá-manga (Spondias cytherea) é uma fruta com aroma intenso e sabor agridoce, sendo, por isto, bastante apreciado. Sua casca, embora mais fibrosa, é tenra e muitas vezes consumida juntamente com a polpa. A casca é uma parte do alimento normalmente desprezada, mas, muitas vezes, é rica em sabor e fibras, representando uma opção na formação de novos alimentos. Em função de não haver na literatura relato do aproveitamento da casca de cajá-manga para a elaboração de geleia, este trabalho teve por objetivo desenvolver e avaliar este produto. Através dos resultados, constatou-se que as cascas apresentaram maiores teores de proteína, lipídios, cinzas, fibra alimentar, carboidratos totais e pectina e menor teor de umidade em relação à polpa de cajá-manga. A geleia de casca e da polpa (controle) apresentaram as seguintes características físico-químicas: umidade, 29,5 e 34,2%; proteínas, 0,19 e 0,27%; lipídios, 0,11 e 0,16%; açúcares totais, 56,5 e 65,5%; e sólidos solúveis totais, 69 e 66 ºBrix, respectivamente. A análise sensorial indicou que o produto elaborado a partir da casca apresentou aceitação satisfatória para todos os atributos avaliados: aparência, cor, odor, textura, sabor e avaliação global. Conclui-se que a substituição total da polpa por cascas na formulação resulta em produto de bom valor nutricional sem prejuízos sensoriais.

Cajá-manga (Spondias cytherea) is a fruit with intense aroma and a sweet sour taste, thus being very appreciated. Its peel, in spite of being more fibrous, is tender and many times consumed with the pulp. The peel is a part of foods normally discarded, but many times, it is rich in taste and fibers, representing an option at the elaboration of new foods. Since there are no reports in the literature on the use of cajá-manga peel for jelly making, this work had the purpose of developing and evaluating this product. Based on the results, it was noted that the peels presented higher contents of protein, lipids, ashes, food fiber, total carbohydrates and pectin, and lower content of moisture, when compared to the pulp. The peel and the pulp (control) jellies presented the following physical-chemical characteristics: moisture, 29.5 and 34.2%; proteins, 0.19 and 0.27%; lipids, 0.11 and 0.16%; total sugars, 56.5 and 65.5%; and total soluble solids, 69 and 66 ºBrix, respectively. The sensory analysis indicated that the product elaborated from the peel presented satisfactory acceptance for all the assessed attributes: appearance, color, odor, texture, taste and global evaluation. It is concluded that the total substitution of the pulp by the peel in the formulation, results in a product with good nutritional value with no sensory damages.

Cajá-manga, também conhecida como maçã dourada, é uma fruta exótica nativa de Îles de la Société (French Polynesia), a qual foi introduzida no Brasil em 1985. A polpa de frutas maduras foi tratada com enzima comercial e o efeito foi avaliado no rendimento de suco, assim como nas propriedades físicas viscosidade, turbidez e cor (L*). Metodologia de superfície de resposta foi utilizada e três níveis foram adotados para variáveis independentes: temperatura (30, 40 e 50 ºC), tempo de incubação (30, 60 e 90 minutos) e concentração de enzima (0,01, 0,05, 0,09 v/v%). Delineamento estatístico de composto central foi utilizado para orientar o trabalho experimental. O tratamento enzimático aumentou o rendimento do suco (acima de 56%) e a cor (acima de 8,6%), e diminuiu significativamente a viscosidade (acima de 57,4%), clarificação (acima de 77%) e turbidez (acima de 85,5%). O tempo de incubação foi o fator de maior interação, enquanto que a temperatura foi o de menor. Análises de otimização para reduzir a concentração enzimática foram realizadas superpondo as análises de contorno das propriedades testadas, com as variáveis concentração de enzima, temperatura e tempo de incubação que foram respectivamente, 0,042%-0,068%; 47,0-49,0 ºC; e 82-90 minutos.

Cajá-manga, also known as golden apple and hog-plum, is an exotic fruit native from Îles de la Société (French Polynesia), which was first introduced in Brazil in 1985. The pulp of ripe fruit was treated with the commercial enzymatic pool and its effect was evaluated in terms of yield, as well as the physical properties viscosity, turbidity and color (L* values). Response surface methodology was used and three levels were adopted for the independent variables temperature (30, 40, and 50 ºC), incubation time (30, 60 and 90 minutes) and enzyme concentration (0.01, 0.05, 0.09 v/v%). A central composite statistical design was used to guide the experimental work. The enzyme treatment highly increased both juice yield (up to 56%) and color (up to 8.6%) and strongly decreased viscosity (up to 57.4%), clarity (up to 77%) and turbidity (up to 85.5%). Incubation time was the most interacting facto, whereas temperature was the least one. Optimization analysis was carried out to reduce enzyme concentration to a minimum by superposing the contour plots of the tested properties, and the recommended ranges of the variables enzyme concentration, process temperature and incubation time were, respectively, 0.042-0.068%, 47.0-49.0 ºC and 82-90 minutes.

Foi realizado levantamento das espécies de fungos poliporóides que ocorrem no perímetro urbano do município de São José do Rio Preto (20º49'12" S, 49º22'44" W), Estado de São Paulo, Brasil. Foram identificadas 18 espécies pertencentes a 11 gêneros de Agaricales (Schizophyllaceae), Hymenochaetales (Hymenochaetaceae) e Polyporales (Ganodermataceae, Gloeophyllaceae, Meruliaceae e Polyporaceae): Coriolopsis floccosa (Jungh.) Ryvarden, C. polyzona (Pers.) Ryvarden, Datronia caperata (Berk.) Ryvarden, D. mollis (Somf.:Fr.) Donk., Ganoderma australe (Fr.) Pat., Gloeophyllum striatum (Sw.) Murrill, Gloeoporus thelephoroides (Hook.) G. Cunn., Hexagonia hirta (P. Beauv.) Fr., H. hydnoides (Sw.) M. Fidalgo, H. papyracea Berk., Polyporus tenuiculus (P. Beauv.) Fr., Phellinus callimorphus (Lév.) Ryvarden, P. gilvus (Schwein.) Pat., P. umbrinellus (Bres.) Herrera & Bondartseva, Pycnoporus sanguineus (L.) Murrill, Schizophyllum commune Fr., S. umbrinum Berk. e Trametes modesta (Kunze:Fr.) Ryvarden. Datronia mollis é nova citação para o Estado de São Paulo. São apresentados chave de identificação, descrições e comentários para cada táxon estudado.

A survey of polyporoid fungi from forest fragments of São José do Rio Preto urban perimeter (20°49'12" S, 49°22'44" W), São Paulo state, Brazil was carried out. Eighteen taxa belonging to 11 genera of Agaricales (Schizophyllaceae), Hymenochaetales (Hymenochaetaceae) and Polyporales (Ganodermataceae, Gloeophyllaceae, Meruliaceae and Polyporaceae) were identified: Coriolopsis floccosa (Jungh.) Ryvarden, C. polyzona (Pers.) Ryvarden, Datronia caperata (Berk.) Ryvarden, D. mollis (Somf.:Fr.) Donk., Ganoderma australe (Fr.) Pat., Gloeophyllum striatum (Sw.) Murrill, Gloeoporus thelephoroides (Hook.) G. Cunn., Hexagonia hirta (P. Beauv.) Fr., H. hydnoides (Sw.) M. Fidalgo, H. papyracea Berk., Polyporus tenuiculus (P. Beauv.) Fr., Phellinus callimorphus (Lév.) Ryvarden, P. gilvus (Schwein.) Pat., P. umbrinellus (Bres.) Herrera & Bondartseva, Pycnoporus sanguineus (L.) Murrill, Schizophyllum commune Fr., S. umbrinum Berk. and Trametes modesta (Kunze:Fr.) Ryvarden. Datronia mollis is a new record for São Paulo state. Identification key, descriptions and comments of the taxa studied are provided.

Fungos decompositores de madeira, do grupo Basidiomicetes, coletados na "Estação Ecológica do Noroeste Paulista", São José do Rio Preto, São Paulo, Brasil, pertencentes a ordem Aphyllophorales e identificados como Coriolopsis byrsina SXS16, Lentinus strigellus SXS355, Lentinus sp. SXS48, Picnoporus sanguineus SXS 43 e Phellinus rimosus SXS47 foram estudados para a produção de ligninases por FES (fermentação em estado sólido) usando farelo de trigo ou palha de arroz como meio de cultura. A espécie C. byrsina produziu a maior quantidade de lacase (200 U mL-1) enquanto que Lentinus sp. foi o melhor produtor de manganês peroxidase (MnP) e lignina peroxidase (LiP) (7 e 8 U mL-1, respectivamente), quando cultivados em meio composto por farelo de trigo. A avaliação do efeito da suplementação de nitrogênio do substrato sólido lignocelulósico (palha de arroz) indicou um aumento de 3 a 4 vezes na produção de lacase. A caracterização das enzimas mostrou que as lacases apresentaram atividade ótima em pH 3,0-3,5 e foram estáveis em pH de neutro a alcalino. O pH ótimo para atividade de MnP e LiP foi de 3,5 e entre 4,5 e 6,0, respectivamente. Todas as linhagens produziram lacase com atividade ótima a 55-60°C, enquanto as peroxidases apresentaram atividades máximas entre temperaturas de 30 e 55°C. A aplicação das soluções enzimáticas brutas, obtidas pelo cultivo das linhagens em meio de farelo de trigo, em testes de descoloração de corantes sintéticos de diferentes grupos químicos levou a mais 70% de perda de cor dos corantes RBBR e de cybacron blue 3GA, em 6h de tratamento. Os dados obtidos indicaram que as soluções enzimáticas contendo ligninases produzidas pelas linhagens de basidiomicetos estudadas promoveram a descoloração de corantes sintéticos.

Wood rotting Basidiomycetes collected in the "Estação Ecológica do Noroeste Paulista", São José do Rio Preto, São Paulo State, Brazil, concerning Aphyllophorales order and identified as Coriolopsis byrsina SXS16, Lentinus strigellus SXS355, Lentinus sp SXS48, Picnoporus sanguineus SXS 43 and Phellinus rimosus SXS47 were tested for ligninases production by solid state fermentation (SSF) using wheat bran or rice straw as culture media. C. byrsina produced the highest laccase (200 U mL-1) and Lentinus sp produced the highest activities of manganese peroxidase (MnP) and lignin peroxidase (LiP) (7 and 8 U mL-1, respectively), when cultivated on wheat bran. The effect of N addition on enzyme production was studied in medium containing rice straw and the data showed an increase of 3 up to 4-fold in the laccase production compared to that obtained in SSF on wheat bran. The laccases presented optimum pH at 3.0-3.5 and were stable at neutral pH values. Optimum pH for MnP and LiP activities was at 3.5 and between 4.5 and 6.0, respectively. All the strains produced laccase with optimum activities between 55-60°C while the peroxidases presented maximum activity at temperatures of 30 to 55°C. The crude enzymes promoted decolorization of chemically different dyes with around 70% of decolorization of RBBR and cybacron blue 3GA in 6h of treatment. The data indicated that enzymes from these basidiomycetes strains are able to decolorize synthetic dyes.

O fungo termofílico Thermomyces lanuginosus TO3 foi isolado a partir de amostras de material de pilhas de compostagem, com base em sua capacidade de crescer em meio líquido contendo amido como única fonte de carbono, a 45 ºC, e produzir considerável quantidade de glucoamilase. A produção da enzima por fermentação submersa FSm foi alta, com um máximo de 13 U/mL em 168 h de fermentação. A atividade enzimática foi maior sobre amido do que sobre a maltose e maltooligosacarideos. As atividades de glucoamilase extra e intracelular variaram com o tempo de fermentação. A glucoamilase produzidas por T. lanuginosus TO3 apresentou elevada temperatura ótima de atividade (65 -70 ºC) com boa termoestabilidade em ausência de substrato, apresentando uma meia vida de 6 h a 60ºC, além de estabilidade em ampla faixa de pH. Os resultados apresentados indicam uma importante fonte alternativa de glucoamilase para uso no processamento industrial de amido.

Thermophilic Thermomyces lanuginosus strain TO3 was isolated from compost pile samples and was used for its ability to produce considerable glucoamylase activity when growing in liquid medium at 45ºC with starch as the sole carbon source. Enzyme productivity was high in submerged fermentation (SmF) with maximum activity of 13 U/mL after 168 h of fermentation. Higher quantities of glucose were released when the substrate for enzyme was soluble starch than maltose or maltooligosaccharides were used. The distribution of glucoamylase between the extracellular and cell-associated fractions varied according to fermentation time. Glucoamylase produced from T. lanuginosus TO3 had optimum activity at 65 ºC and good thermostability in the absence of substrate, with a half-life of 6 h at 60 ºC. The enzyme was stable over a wide pH range (4.0-10.0).

A glucoamilase é amplamente utilizada na indústria de alimentos no processamento do amido para a produção de xarope com alto teor de glicose e também muito empregada nos processos de fermentação para produção de cerveja e etanol. Neste trabalho a glucoamilase de Aspergillus awamori expressa em Saccharomyces cerevisiae produzida sob fermentação líquida foi avaliada quanto à produtividade em diferentes amidos e caracterizada físico-quimicamente. A enzima apresentou alta atividade específica de 13,8 U/mg proteína e de 2,9 U/mg biomassa ao final de 48 h de fermentação em meio contendo amido solúvel. A glucoamilase apresentou temperatura ótima de atividade a 55ºC, e temperatura de desnaturação térmica na ausência de substrato por 1h a 50ºC. O pH ótimo de atividade foi na faixa de 3,5 - 4,0 e a estabilidade ao pH entre os valores 5,0 e 7,0. A meia vida a 65ºC foi 30,2 min., e a energia de desnaturação foi de 234.3 KJ mol-1. A hidrólise em diferentes substratos mostrou a preferência da enzima pelos substratos com maior grau de polimerização, sendo o amido de milho gelatinizado o substrato preferencial à ação enzimática.

Glucoamylase is widely used in the food industry to produce high glucose syrup, and also in fermentation processes for production beer and ethanol. In this work the productivity of the glucoamylase of Aspergillus awamori expressed by the yeast Saccharomyces cerevisiae, produced in submerged fermentation using different starches, was evaluated and characterized physico-chemically. The enzyme presented high specific activity, 13.8 U/mgprotein or 2.9 U/mgbiomass, after 48 h of fermentation using soluble starch as substrate. Glucoamylase presented optimum activity at temperature of 55ºC, and, in the substratum absence, the thermostability was for 1h at 50ºC. The optimum pH of activity was pH 3.5 - 4.0 and the pH stability between 5.0 and 7.0. The half life at 65ºC was at 30.2 min, and the thermal energy of denaturation was 234.3 KJ mol-1. The hydrolysis of different substrate showed the enzyme's preference for the substrate with a larger polymerization degree. The gelatinized corn starch was the substratum most susceptible to the enzymatic action.

REVIEW: Living organisms encountered in hostile environments that are characterized by extreme temperatures rely on novel molecular mechanisms to enhance the thermal stability of their proteins, nucleic acids, lipids and cell membranes. Proteins isolated from thermophilic organisms usually exhibit higher intrinsic thermal stabilities than their counterparts isolated from mesophilic organisms. Although the molecular basis of protein thermostability is only partially understood, structural studies have suggested that the factors that may contribute to enhance protein thermostability mainly include hydrophobic packing, enhanced secondary structure propensity, helix dipole stabilization, absence of residues sensitive to oxidation or deamination, and increased electrostatic interactions. Thermostable enzymes such as amylases, xylanases and pectinases isolated from thermophilic organisms are potentially of interest in the optimization of industrial processes due to their enhanced stability. In the present review, an attempt is made to delineate the structural factors that increase enzyme thermostability and to document the research results in the production of these enzymes.