Purification and characterization of an extracellular xylanase produced by the endophytic fungus, Aspergillus terreus, grown in submerged fermentation

Aspergillus terreus produced high levels of a thermotolerant extracellular xylanase and showed low cellulase activity when cultured at 30°C for 48 h, in liquid medium supplemented with wheat bran as carbon source. Xylanase was purified 45-fold to homogeneity with a recovery yield of 67% by carboxymethyl (CM)-cellulose chromatography. The enzyme, a glycoprotein with 33% of carbohydrate content, appeared as a single protein band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gel with a molecular mass corresponding to 23 kDa. Optimal temperature and pH were 55°C and 4.5, respectively. The enzyme was thermotolerant at 45 and 50°C, with a half-life of 55 and 36 min, respectively. The Km was calculated as 22 mg/ml and Vmax as 625 mg/ml of protein using birchwood xylan as substrate. Metal ions, such as Ag+, Cu+2, Fe+2, Hg+ and Zn+2 strongly inhibited xylanase, whereas K+ and Mn+2 resulted in activation. Xylanase hydrolyzed birchwood xylan and oatspelt xylan, mostly yielding xylooligosaccharides, suggest that it is an endoxylanase (EC. 3.2.1.37).Keywords: Aspergillus terreus, endoxylanase, thermostabilit

Application of an endo-xylanase from Aspergillus japonicus in the fruit juice clarification and fruit peel waste hydrolysis.

The endo-xylanase from Aspergillus japonicus (UFMS 48.136) was purified in a single step using carboximethylcellulose chromatographic column and applied in fruit juice clarification process and fruit peel waste hydrolysis. This purification procedure resulted in 38.9-fold purification of endo-xylanase with 83.3% final yield. MALDITOF analysis confirmed the molecular mass of 32 kDa. The optimal purified endo-xylanase activity was at a range of pH from 5.0 to 6.0 and from 50 to 60 +-C, retaining more than 70% of its activity at all pH studied (3.0?8.0) for 24 h at room temperature. The A. japonicus endo-xylanolytic activity stimulation curve was assayed in the presence of different birchwood xylan concentrations (ranging from 0.02 to 0.5% w/v) and the endoxylanase activity presented a Vmax of 467.4 +- 30.38 μmol/min/mg, with a km of 2.59 +- 0.17 mg/mL, a kcat of 253.95 +- 16.51 s -1 and a kcat/km value of 98.05 +- 4.41 mL s -1 mg -1. The endo-xylanase was activated by Mn2þ (34.5%) and inhibited by Cu2þ (56.9%). The endo-xylanase was activated by β-mercaptoethanol, Triton X-100, Tween-20, Tween-80 and ferulic acid. In the clarification assay, endo-xylanase successfully clarified the juices of mango (51.11%), banana (9.99%) and tangerine (8.54%). Furthermore, the enzyme also hydrolysed all fruit peel wastes that were tested. In summary, A. japonicus endo-xylanase showed potential for applications in fruit juice clarification and in the treatment of fruit peel wastes, and it is a good candidate for the food industry due to its wide pH stability under acidic conditions

Production of cellulase-free xylanase by Aspergillus flavus: Effect of polyols on the thermostability and its application on cellulose pulp biobleaching

The production of xylanase without cellulase is required for prebleaching of pulp in pulp and paper industry. Aspergillus flavus produced high levels of xylanase on agricultural residues with wheat bran and sugarcane bagasse (4.17 U/mg), and wheat bran and corncob (2.97 U/mg). Xylanase was found to be stable at 45°C with 100% of its original activity remaining after 2 h incubation. At 50°C, xylanase was stable for the first twenty minutes, and had half-life of 50 min. The pH stability for the xylanase from A. flavus was most stable in the range of pH 3.0-8.0 retaining more that 100% activity after 1 h. The addition of 5% glycerol, mannitol or xylitol protected the xylanase from thermal inactivation at 50°C. The protective effect by glycerol, xylitol and mannitol resulted in increases of 162, 262.5 and 150% when compared with the control at 120 min, approximately. Increasing the polyols concentration up to 20% (w/v) further improved the thermostability of xylanase after 120 min at 50°C by 300% when compared with the control (no additive). The kappa number reduced 2.56 points, which corresponds to 18.34 kappa efficiency. This xylanase is an attractive enzyme for potential future application in the pulp and paper industries, since industrial application requires a cellulase-free activity, maintenance of high temperature and enzyme stability are desirable.Key words: Aspergillus flavus, polyols, xylanase, biobleaching cellulose pulp

Bioprocess and biotecnology: effect of xylanase from Aspergillus niger and Aspergillus flavus on pulp biobleaching and enzyme production using agroindustrial residues as substract

This study compares two xylanases produced by filamentous fungi such as A. niger and A. flavus using agroindustrial residues as substract and evaluated the effect of these enzymes on cellulose pulp biobleaching process. Wheat bran was the best carbon source for xylanase production by A. niger and A. flavus. The production of xylanase was 18 and 21% higher on wheat bran when we compare the xylanase production with xylan. At 50°C, the xylanase of A. niger retained over 85% activity with 2 h of incubation, and A. flavus had a half-life of more than 75 minutes. At 55°C, the xylanase produced by A. niger showed more stable than from A. flavus showing a half-life of more than 45 minutes. The xylanase activity of A. niger and A. flavus were somehow protected in the presence of glycerol 5% when compared to the control (without additives). On the biobleaching assay it was observed that the xylanase from A. flavus was more effective in comparison to A. niger. The kappa efficiency corresponded to 36.32 and 25.93, respectively. That is important to emphasize that the cellulase activity was either analyzed and significant levels were not detected, which explain why the viscosity was not significantly modified.This work was supported by grants from Conselho de Desenvolvimento Científico e Tecnológico (CNPq). This work was part of Master Dissertation of NCAG (Laboratório de Bioquímica / CCBS, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brasil). The authors gratefully for the support from the USP/Ribeirão Preto – SP, Brazil.This work was supported by grants from Conselho de Desenvolvimento Científico e Tecnológico (CNPq). This work was part of Master Dissertation of NCAG (Laboratório de Bioquímica / CCBS, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brasil). The authors gratefully for the support from the USP/Ribeirão Preto – SP, Brazil

Response to issues on GM agriculture in Africa: Are transgenic crops safe?

The controversies surrounding transgenic crops, often called Genetically Modified Organisms (GMOs), call for a need to raise the level of public awareness of Genetic Modification (GM) technology in Africa. This should be accomplished by educating the public about the potential benefits and risks that may be associated with this new technology. In the last 15 years, GM crop producing countries have benefited from adoption of this new technology in the form of improved crop productivity, food security, and quality of life. The increased income to resource-poor farmers is a key benefit at the individual level especially as most countries using this technology are in the developing world, including three African countries (South Africa, Burkina Faso and Egypt). Despite clear benefits to countries and farmers who grow GMOs, many people are concerned about suspected potential risks associated with GMOs. This sparks debate as to whether GM technology should be adopted or not. Given the concerns regarding the safety of GMO products, thorough scientific investigation of safe application of GMOs is required. The objective of this paper is to respond to the issues of GM agriculture in Africa and some of the issues surrounding the adoption of GM crops between developed and developing countries. In this article, I analyse relevant papers relating to the adoption of GM technology particularly in developing countries including the few African countries that have adopted GM crops. The issues discussed span a wide range including: safety; potential benefits and risks; disputes between the United States of America (USA) and the European Union (EU) over adoption of GM crops with a focus on Africa continent. This article is concluded by summarising the issues raised and how GM technology can be adopted for agricultural development in Africa

Biometria dos órgãos linfoides e composição físico- química da carne de frangos de crescimento lento alimentados com bagaço de mandioca e complexo enzimático / Biometry of lymphoid organs and physical-chemical composition of meat of slow growth chickens fed with cassava bagasse and enzymatic complexes

Objetivou-se no presente trabalho avaliar a biometria dos órgãos linfoides e composição físico-química da carne de frangos de crescimento lento alimentados com bagaço de mandioca com e sem complexo enzimático fúngico. Foram utilizadas 250 aves, Pescoço Pelado Vermelho, com 90 dias de idade. O delineamento experimental foi o inteiramente casualizado (DIC) em esquema fatorial (2 X 2 + 1), sendo dois níveis de inclusão do bagaço de mandioca (10 e 20%), presença e ausência do complexo enzimático e dieta controle, totalizando cinco tratamentos, cinco repetições e dez aves por unidade experimental. Foram avaliados a biometria dos órgãos linfoides (baço, bursa e timo), gordura abdominal, luminosidade (L*), coloração (a* e b*), pH, força de cisalhamento (FC), perda de peso por cozimento (PPCO), análises químicas e deposição de proteína e gordura da carne do peito. A inclusão de 10 e 20% do bagaço de mandioca com e sem complexo enzimático influenciaram (p<0,05) o peso relativo do baço e o parâmetro de cor (b*), não havendo efeito (p>0,05) sobre o peso da bursa e do timo, parâmetro de cor (a*), luminosidade (L*), pH, força de cisalhamento (FC), perda de peso por cozimento (PPCO), análises químicas, deposição de proteína e gordura da carne. Recomenda-se o uso de até 20% de bagaço de mandioca, não sendo opção tecnicamente viável a utilização do complexo enzimático fúngico, xilanase e amilase, nas dietas para frangos de crescimento lento.

Enzimas fúngicas em dietas com alimentos alternativos para frangos de crescimento lento

The feeding represents most of the total cost of production and to reduce costs and increase the profit of the producer have been researched alternative food, as the pie of babassu palm, the pie of palm and the cassava bagasse, which show potential for use in feeding the chickens for slow growth, however, with limited use, due to the different grades of fiber. Non-starch polysaccharides make it difficult for digestible enzymes to reach the food, reducing the digestibility of nutrients. To minimize this effect, exogenous enzymes have been supplemented in poultry diets. Various sources can originate these additives, most of which are acquired through fermentation processes. The temperature, pH, substrate concentration and composition of the ingredients are factors that influence the enzymatic action and consequently the availability of the nutrients. Studies show that the use of fungal enzymes can increase the nutritional value of the food and improves the digestibility of nutrients, reflecting the productive efficiency, representing savings in production costs and benefits to the environment, however, it is necessary to evaluate the use in diets with alternative foods of Regional expression. Keywords: Zootechnical additives; Enzymatic activity; Non-starch polysaccharides.Su objetivo era abordar en esta revisión sobre las enzimas fúngicas y sus efectos sobre las dietas con alimentos alternativos para los pollos de crecimiento lento. La alimentación representa la mayor parte del coste total de la producción y reducir los costes y aumentar lucre del productor se han investigado alimento alternativo, tal como la torta de babasú, la torta de palmiste y bagazo de yuca, que demuestra el potencial para su uso em la alimentación pollos cateto, sin embargo, conun uso limitado debido a los diferentes contenidos de fibra. Polisacáridos no amiláceos dificultan el acceso de las enzimas digestible acerca de los alimentos, lo que reduce la digestibilidad de los nutrientes. Para minimizar este efecto, se han complementado enzimas exógenas em las dietas de las aves. Varias fuentes pueden originate a estos aditivos, la mayoría adquirida através de los procesos de fermentación. La temperatura, pH, concentración de sustrato y la composición de los ingredientes son factores que afectan a la actividad enzimática y, por consiguiente, la disponibilidad de nutrientes. Los estudios demuestran que el uso de enzimas de fúngicas puede aumentar el valor nutritivo de los alimentos y mejorar la digestibilidad de los nutrientes, lo que refleja la eficiência productiva, lo que representa un ahorro en los costes de producción y beneficios para el medio ambiente, sin embargo, es necessário evaluarel uso de dietas con alimento alternativo expresión regional. Descriptores: Aditivos zootécnicos; La actividad enzimática; Polisacáridos no amiláceos.Objetivou-se nesta revisão abordar sobre enzimas fúngicas e seus efeitos em dietas com alimentos alternativos para frangos de crescimento lento. A alimentação representa maior parte do custo total de produção e para reduzir os gastos e aumentar o lucro do produtor têm sido pesquisados alimentos alternativos, como a torta de babaçu, a torta de dendê e o bagaço de mandioca, que demonstram potencial de utilização na alimentação de frangos caipira, no entanto, com limitação de uso, devido os diferentes teores de fibra. Os polissacarídeos não amiláceos dificultam o acesso das enzimas digestíveis sobre o alimento, diminuindo a digestibilidade dos nutrientes. Para minimizar esse efeito, têm sido suplementados enzimas exógenas nas dietas das aves. Várias fontes podem originar esses aditivos, sendo a maioria adquirida por meio dos processos fermentativos. A temperatura, o pH, a concentração do substrato e a composição dos ingredientes são fatores que influenciam a ação enzimática e, consequentemente, a disponibilidade dos nutrientes. O uso das enzimas fúngicas pode aumentar o valor nutricional do alimento e melhorar a digestibilidade dos nutrientes, refletindo na eficiência produtiva, representando economia no custo de produção e benefícios ao meio ambiente, todavia, torna-se necessário avaliar o uso em dietas com alimentos alternativos de expressão regional

Clinical approach for the classification of congenital uterine malformations

A more objective, accurate and non-invasive estimation of uterine morphology is nowadays feasible based on the use of modern imaging techniques. The validity of the current classification systems in effective categorization of the female genital malformations has been already challenged. A new clinical approach for the classification of uterine anomalies is proposed. Deviation from normal uterine anatomy is the basic characteristic used in analogy to the American Fertility Society classification. The embryological origin of the anomalies is used as a secondary parameter. Uterine anomalies are classified into the following classes: 0, normal uterus; I, dysmorphic uterus; II, septate uterus (absorption defect); III, dysfused uterus (fusion defect); IV, unilateral formed uterus (formation defect); V, aplastic or dysplastic uterus (formation defect); VI, for still unclassified cases. A subdivision of these main classes to further anatomical varieties with clinical significance is also presented. The new proposal has been designed taking into account the experience gained from the use of the currently available classification systems and intending to be as simple as possible, clear enough and accurate as well as open for further development. This proposal could be used as a starting point for a working group of experts in the field

Vaccinazioni: stato dell\u2019arte, falsi miti e prospettive. Il ruolo chiave della prevenzione.

La pratica vaccinale in Italia \ue8 organizzativamente incardinata all\u2019interno del Servizio Sanitario Nazionale (SSN) e nei Servizi Sanitari Regionali (SSR). I luoghi \u201cclassici\u201d in cui viene effettuata la procedura/prestazione vaccinale sono i servizi di vaccinazione della Aziende Sanitarie Locali (ASL) o Provinciali (ASP) delle varie Regioni

L'apport de l'électrocardiogramme foetal en cours de travail dans le cas particulier des patientes avec un utérus cicatriciel

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF