01922naa a2200229 a 450000100080000000500110000800800410001902400350006010000190009524501030011426000090021752012740022665000110150065300140151165300130152570000160153870000230155470000200157770000220159770000140161977300590163319120172012-11-30       2010    bl uuuu     u00u1 u    #d7 a10.1016/j.nbt.2010.10.0012DOI1 aFARINAS, C. S.  aFinding stable cellulase and xylanasebevaluation of the synergistic effect of pH and temperature.  c2010  aEthanol fromlignocellulosic biomasshasbeenrecognizedasone of themost promising alternatives for the production of renewable and sustainable energy. However, one of the major bottlenecks holding back its commercialization is the high costs of the enzymes needed for biomass conversion. In this work, we studiedthe enzymesproducedfroma selectedstrainofAspergillusnigerunder solidstate fermentation.The cellulase and xylanase enzymatic cocktail was characterized in terms of pH and temperature by using response surface methodology. Thermostability and kinetic parameters were also determined. The statistical analysis ofpHand temperature effects on enzymatic activity showed a synergistic interaction of these two variables, thus enabling to find a pHand temperature range inwhich the enzymes have a higher activity. The results obtained allowed the construction of mathematical models used to predict endoglucanase, b-glucosidase and xylanase activities under different pH and temperature conditions. Optimumtemperature values for all three enzymes were found to be in the range between 358C and 608C, and the optimum pH range was found between 4 and 5.5. The methodology employed here was very effective in estimating enzyme behavior under different process conditions.  aEnzima  aCellulase  aXylanase1 aLOYO, M. M.1 aBARALDO JUNIOR, A.1 aTARDIOLI, P. W.1 aBERTUCCI NETO, V.1 aCOURI, S.  tNew biotechnologygv. 27, n. 6, p. 810-815, Dec. 2010.