Production of thermostable ß-glucosidase and CMCase by Penicillium sp: LMI01 isolated from the Amazon region

Background: Cellulolytic enzymes of microbial origin have great industrial importance because of their wide application in various industrial sectors. Fungi are considered the most efficient producers of these enzymes. Bioprospecting survey to identify fungal sources of biomass-hydrolyzing enzymes from a high-diversity environment is an important approach to discover interesting strains for bioprocess uses. In this study, we evaluated the production of endoglucanase (CMCase) and ß-glucosidase, enzymes from the lignocellulolytic complex, produced by a native fungus. Penicillium sp. LMI01 was isolated from decaying plant material in the Amazon region, and its performance was compared with that of the standard isolate Trichoderma reesei QM9414 under submerged fermentation conditions. Results: The effectiveness of LMI01 was similar to that of QM9414 in volumetric enzyme activity (U/mL); however, the specific enzyme activity (U/mg) of the former was higher, corresponding to 24.170 U/mg of CMCase and 1.345 U/mg of ß-glucosidase. The enzymes produced by LMI01 had the following physicochemical properties: CMCase activity was optimal at pH 4.2 and the ß-glucosidase activity was optimal at pH 6.0. Both CMCase and ß-glucosidase had an optimum temperature at 60°C and were thermostable between 50 and 60°C. The electrophoretic profile of the proteins secreted by LMI01 indicated that this isolate produced at least two enzymes with CMCase activity, with approximate molecular masses of 50 and 35 kDa, and ß-glucosidases with molecular masses between 70 and 100 kDa. Conclusions: The effectiveness and characteristics of these enzymes indicate that LMI01 can be an alternative for the hydrolysis of lignocellulosic materials and should be tested in commercial formulations.

Sistema celulolítico de Aspergillus niger em substrato sólido de bagaço de cana-de-açúcar tratado / Cellulolitic system of Aspergillus niger obtained on a solid substrate of treated sugar cane bagasse

A produçäo em substrato sólido de celulase total, endobetaglicosidase, betaglicosidase e da xilanase de Aspergillus niger foi potencializada pelo tratamento de bagaço de cana-de-açúcar com peróxido alcalino e hidróxido de sódio. Para as exobetaglicosidase näo houve diferença significativa entre os 3 tipos de amostras. Em relaçäo à atividade de betaglicosidase os tratamentos com hidróxido de sódio e peróxido alcalino proporcionaram atividade média superior 9,0 e 7,8 vezes, respectivamente, em relaçäo à média obtida com bagaço sem tratamento. Para a xilanase, as atividades médias com o bagaço tratado com hidróxido de sódio e peróxido alcalino foram 3,8 e 3,5 vezes superiores respectivamente, frente à atividade do bagaço näo tratado. Os tratamentos químicos näo apresentaram efeito täo marcante nas fraçöes endobetaglicosidase, exobetaglicosidase e celulase total. Nestas fraçöes, as atividades médias foram cerca de 1,5 vezes superiores às obtidas com o bagaço näo tratado. A produçäo de todas as fraçöes celulolíticas e da xilanase foi inferior em reatores de maior porte tais como bandeja e reator rotativo do que em pequenos frascos de laboratório

Production of cellulases and beta-glucosidase by new isolate of Aspergillus niger F-92

The production of cellulase was investigated in shakes culture of a new isolate of Aspergillus niger F-92. Amongst different concentration of cellulose powder tested, concentration 1.5% [w/v] showed maximum production of enzyme after nine days incubation at 30C. The optimum initial pH for enzyme production was found to be 5.0. The production of cellulases was sensitive to nitrogen source in the medium, the optimum production was seen when soybean flour [600 mg N/L] was used as the only nitrogen source. KH2PO4 [0.2% w/v] was found to be optimum at concentration 0.3 M caused marked increase in cellulases and beta-glucosidase production. Under the optimum culture conditions the activities of FPase, CMCase and beta-glucosidase were 1.89, 4.2 and 7.82 IU/ml, respectively