ABSTRACT
Background: Inulinases have been extracted and characterized from inulin-storing tissues; however, production of microbial inulinases have recently draw much attention as they offer several industrial advantages. Many microorganisms, including filamentous fungi, yeast and bacteria have been claimed as inulinase producers. These hydrolases are usually inducible and their exo-acting forms may hydrolyze fructose polymers (inulin) and oligosaccharides such as sucrose and raffinose. Fungal inulinase extracts are often produced as stable mixture of highly active fructanhydrolases. From a practical prospective, the best known inulinases to date are those produced by species of Penicillium, Aspergillus and Kluyveromyces. Results: The production of extracellular inulinase by A. kawachii in liquid cultures, using either inulin or yacon derived materials as CES as well as inulinase inducers, is reported. In addition, a partial characterization of the enzyme activity is included. Conclusions: Yacon derived products, particularly yacon juice, added to the culture medium proved to be a good CES for fungal growth as well as an inducer of enzyme synthesis. Partial characterization of the enzyme revealed that it is quite stable in a wide range of pH and temperature. In addition, characterization of the reaction products revealed that this enzyme corresponds to an exo-type. These facts are promising considering its potential application in inulin hydrolysis for the production of high fructose syrups.
Subject(s)
Aspergillus/enzymology , Glycoside Hydrolases/metabolism , Temperature , Enzyme Stability , Bioreactors , Asteraceae , Batch Cell Culture Techniques , Hydrogen-Ion Concentration , Hydrolysis , IonsABSTRACT
Pectinesterase was extracted from potato alpha cultivar, purified and partially characterized The used protocol resulted in a 58.8-fold purification (51 850.2 units/mg protein) with 15.5 percent recovery of pectinesterase activity. The purified enzyme had a molecular weight of 27 kDa and its isoelectric point was around 4.5 with pH and temperature optima of 8.0 and 60°C, respectively. The purified enzyme had a single symmetric peak of specific activity after chromatographic steps. The homogeneity of the purified pectinesterase was confirmed by gel filtration and polyacrylamide electrophoresis gel.
A pectinesterase foi extraída da batata (cultivar do alfa), purificada e parcialmente caracterizada. O protocolo usado levou a uma proteína purificada 58,8 vezes (51 850,2 units/mg da proteína) com uma recuperação de 15,5 por cento da atividade da proteína. A enzima purificada apresentou um peso molecular de 27 kDa e seu ponto isoelétrico foi ao redor 4,5. A pectinesterase exibiu pH e temperatura ótimos de respectivamente 8,0 e 60°C. A enzima purificada apresentou um único pico simétrico de atividade específica após as etapas de cromatografia. A homogeneidade da pectinesterase purificada foi confirmada por filtração em gel e por eletroforese em gel de poliacrilamida.