Sintese de oligossacarideos por inulinase de Kluyveromyces bulgarius

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

19/02/1998

RESUMO

Oligosaccharides are a class of compounds with a great potential for application in the food industry, so that they have been studied by many researchers. The fructooligosaccharides which contains low calories, are noncariogenic, and suitable for diabetics and estimulate particularlly the production of bifidobacteria. The objective of this work is to study the characteristics of inulinases with transfructosilation activity produced by differents microrganisms. The effect of pH, temperature and time reaction in the fructooligosaccharides production were studied. The enzymes are produced by fermentation with the following microrganisms: K/uyveromyces bu/garicus ATCC 16045, K/uyveromyces /actis K/uyveromyces fragilis. During fermentation the enzymatic activity, pH, ART and dry weight are analyzed. The enzyme purification was carried out with ethanol and FPLC (Fast Protein Liquid Chromatography), using Q-Sepharose Fast Flow column chromatography. The synthesis products were identified and mesured by liquid chromatography (HPLC). It was observed that the raw enzymatic material of K. /actis and K. fragilis showed f3-fructosiltransferase and ?-fructosilhidrolase activity, as well as the production of a water insoluble polymer. Also, the enzyme produced by K. bu/garicus showed of ?-fructosiltransferase and ?-fructosilhidrolase activity, however the f3-fructosilhidrolase activity was higher than ?-fructosiltransferase. The enzyme was characterized as inulinase, with ratio S/I (S=invertase activity and I =inulinase activity) equals to 3.86. The purification was carried out by precipitation with ethanol (70% of saturation at -15°C), followed by anionic exchange chromatography. Purification factors and efficiencies were respectively 1.45 and 67.77% for the first step and 9.18 and 52.09% for second one. During the study of the transfructosilation activity it was observed that the production of oligosaccharides, which were characterized as frutooligosaccharides, identified mainly as kestose and nistose. The reaction was carried out in the following conditions: p~ of 4.0-6.0, temperature of 30-50°C, reaction time of 60 hours and sucrose concentration of 50%. The maximum concentration of frutooligosaccharides was 51.68 g/L(94% kestose and 6% nistose), obtained at pH 6.0 and temperature at 50°C

ASSUNTO(S)

oligossacarideos cromatografia liquida fermentação

ACESSO AO ARTIGO

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