-The production and characterization of cellulase from thermophilic strain Bacillus sp. C1AC5507 was studied. For enzyme production, sugarcane bagasse was used as carbon source. The produced carboxymethyl cellulase (CMCase) had a molecular weight around 55 kDa and its activity varied between 0.14 and 0.37 IU mL -1 in conditions predicted by Response Surface Methodology. The optimum temperature and pH for the CMCase production were 70 °C and 7.0, respectively. The enzyme activity was inhibited mostly by Cu +2 and activated mostly by Co +2 , Mn 2+ , Ca +2 and Fe +3 . Our findings provide a contribution to the use of natural wastes such as sugarcane bagasse as substrate for growth and production of thermophilic CMCase. Further optimization to increase the production of cellulase enables the use in industrial applications.

As enzimas pectinolíticas são usadas na extração de suco de fruta e sua clarificação, tratamento de fibra têxtil e extração de óleo vegetal. O objetivo deste trabalho foi utilizar a metodologia do planejamento experimental fatorial e análise de superfície de resposta para verificar os efeitos da umidade inicial do meio, adição de sulfato de amônia e de fosfato de potássio na produção da poligalacturonase através da fermentação em estado sólido, usando como substrato o resíduo do pedúnculo de caju seco (Anacardium occidentale L.) e como agente da fermentação o microrganismo Aspergillus niger CCT0916. A melhor condição de produção da poligalacturonase foi com umidade de 40%, 1% de sulfato de amônia e sem adição do fosfato de potássio atingindo-se uma atividade da poligalacturonase de 16 U/g e 82% de redução de viscosidade com 30 horas de fermentação. Palavras-chave: Poligalacturonase, pectinases, fermentação em estado sólido, pedúnculo de caju, superfície de resposta.

AplicAção dA metodologiA de superfície de respostA no estudo dA produção e extrAção dA poligAlActuronAse sharline florentino de melo santos e gorete ribeiro de macedo Departamento de Engenharia Química, Universidade Federal do Rio Grande do Norte, Campus Universitário, Centro de Tecnologia, 59072-970 Natal -RN, Brasil flávio luiz Honorato da silva * e rosane liege Alves de souza Unidade Acadêmica de Engenharia Química, Universidade Federal de Campina Grande, Centro de Tecnologia, 58109-900 Campina Grande -PB, Brasil gustavo Adolfo saavedra pinto Embrapa Agroindústria Tropical, Rua Dra. Sara Mesquita, 2270, 60511-110 Fortaleza -CE, BrasilRecebido em 22/8/07; aceito em 20/6/08; publicado na web 10/11/08 APPLICATION OF RESPONSE SURFACE METHODOLOGY TO STUDY THE PRODUCTION AND THE EXTRACTION OF POLYGALACTURONASE. The aim of this work was to verify the effects of initial medium moisture content (U), addition of ammonium sulphate (N) and of potassium phosphate (P) in the production of the polygalacturonase through the solid-state fermentation, using cashew apple husk as substrate and Aspergillus niger CCT0916 as transformation agent. We also studied the best extraction conditions of the produced enzyme. The best condition of production was with U of 40%, 1% of N and 0% of P being reached an activity of the poligalacturonase of 10.1 U/g. The best extraction condition is an agitation system with a time of 100 min and a solvent-fermented medium volume ratio of 5 mL/g. Keywords: solid-state fermentation; cashew apple; Aspergillus niger. introduçãoO termo fermentação em estado sólido (FES), ou fermentação semi-sólida, ou fermentação em meio semi-sólido aplica-se aos processos onde existe crescimento de microrganismos sobre ou dentro de partículas em matriz sólida, onde a quantidade de líquido apresenta um nível de atividade de água que possa garantir o crescimento e metabolismo dos microrganismos, mas não exceda à máxima capacidade de ligação da água com a matriz sólida. 1 A fermentação em estado sólido apresenta diversas vantagens em relação à fermentação submersa, principalmente quando os agentes de transformação são fungos filamentosos. Uma delas é que as condições de cultivo são mais parecidas com o habitat natural dos fungos filamentosos, com isto os fungos estão mais adaptados para crescer e excretar maior quantidade de enzimas.2 A concentração dos produtos após extração é bem maior que os obtidos no processo de fermentação submersa e gera menos resíduo líquido. Este processo desperta maior interesse econômico em regiões com abundância em biomassa e resíduos agroindustriais, que representam material barato e abundante. 3A produção de pedúnculos de caju no Brasil é estimada em torno de 1,8 milhão de t/ano, concentrando-se basicamente na região Nordeste, e com aproveitamento industrial de apenas 15% do total.4 A quantidade desperdiçada apresenta elevada concentração de nutrientes que têm potencial de uso para conversão por microrganismos, na obtenção de produtos de alto valor agregado como enzimas.As enzimas pectinolíti...

Recent years have seen an increase in the use of lignocellulosic materials in the development of bioproducts. Because sisal fiber is a low cost raw material and is readily available, this work aimed to evaluate its hemicellulose fraction for the simultaneous production of xylitol and ethanol. The sisal fiber presented a higher hemicellulose content than other frequently-employed biomasses, such as sugarcane bagasse. A pretreatment with dilute acid and low temperatures was conducted in order to obtain the hemicellulose fraction. The highest xylose contents (0.132 g·g−1 of sisal fiber) were obtained at 120 °C with 2.5% (v/v) of sulfuric acid. The yeast Candida tropicalis CCT 1516 was used in the fermentation. In the sisal fiber hemicellulose hydrolysate, the maximum production of xylitol (0.32 g·g−1) and of ethanol (0.27 g·g−1) was achieved in 60 h. Thus, sisal fiber presents as a potential biomass for the production of ethanol and xylitol, creating value with the use of hemicellulosic liquor without detoxification and without the additional steps of alkaline pretreatment.

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The agro-industrial waste deposited in the environment causes problems in nature that can be solved with the use and generation of bioproducts. Thus, the objective was to study the lignocellulosic fraction of cashew (Anacardium occidentale L.) peduncle bagasse and fermentation on large scale (8-16 times) using the strain Candida guilliermondii CCT-3544 as production agent. According to the obtained results, it can be noted that the dry cashew peduncle bagasse has 21.45% of cellulose, 10.96% of hemicellulose and 35.39% of lignin. During fermentation, C. guilliermondii 3544-CAT was able to grow on medium containing hydrolysate, with maximum cell growth concentration of 3.5 g L-1. The behavior of the sugars in the fermentation process was similar in the different variables, with maximum production of ethanol and xylitol at 48 h of fermentation.

Some sugarcane varieties have high activity of polyphenoloxidase enzyme, impairing the production of lower color sugar. Polyphenoloxidase (PPO) is an enzyme from the oxidoreductases group and it is present in a greater or lesser amount depending on the sugarcane variety, climatic conditions, age, culture treatment, harvest and processing conditions. The presence of this enzyme has great impact in the food industry, as it is the main enzyme involved in the undesirable darkening of fruits and vegetables during processing and storage. It is of great importance for the food industry to study inactivation methods for this enzyme. The aim of this work was to evaluate the effect of ozone gas associated (replacement of the conventional sulphitation process), whose concentrations were 150, 300 and 450 mg/L, at the inactivation temperature of polyphenoloxidase enzyme of sugarcane variety RB 92579 for the production of lower color sugar. Treatment with ozone concentration of 150 mg·L-1 at 105 °C showed direct correlation between juice color reduction and enzyme inactivation, resulting in the production of lower color sugar.

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