RESUMO
The fructan biosynthesis by ethanol sedimented "levan-levansucrase" complex from Zymomonas mobilis fermentation broth as well as purified levansucrase was investigated. The fructooligosaccharide (FOS) producing activity of "levan-levamsucrase" sediment was investigated in 55% sucrose syrup at 45 degrees C. It was shown that FOS in the syrup were presented by 1-kestose, 6-kestose, neokestose and nystose. The increase of gluconic acid concentration was observed in the reaction mixture during the incubation suggesting about presence of glucose/fructose oxidoreductase in "levan-levansucrase" sediment. The influence of ethanol, glycerol and NaCl on levan and fructooligosaccharide formation by "levan-levansucrase" complex and purified levansucrase was studied and the changes in the ratio between different activities of levansucrase (sucrose hydrolysis, levan biosynthesis and FOS formation) were observed. Ethanol increases the FOS biosynthesis part in total activity of purified levansucrase. The technology of the production of prebiotics containing food product--fructan syrup by "levan-levansucrase " sediment as biocatalyst was developed.
Assuntos
Hexosiltransferases/metabolismo , Zymomonas/enzimologia , Catálise , Meios de Cultura , Espaço Extracelular/enzimologia , Frutanos/metabolismo , Hexosiltransferases/isolamento & purificação , Cinética , Oxirredução , Especificidade por Substrato , Sacarose , Zymomonas/crescimento & desenvolvimentoAssuntos
Biotecnologia , Microbiologia , Pesquisadores , Universidades , Bioengenharia/educação , Bioengenharia/história , Biotecnologia/educação , Biotecnologia/história , Etanol/história , Financiamento Governamental/economia , Financiamento Governamental/história , Financiamento Governamental/legislação & jurisprudência , Tecnologia de Alimentos/educação , Tecnologia de Alimentos/história , História do Século XIX , História do Século XX , História do Século XXI , Letônia/etnologia , Pessoal de Laboratório Médico/educação , Pessoal de Laboratório Médico/história , Pessoal de Laboratório Médico/psicologia , Microbiologia/educação , Microbiologia/história , Pesquisadores/educação , Pesquisadores/história , Pesquisadores/psicologia , Universidades/históriaRESUMO
The intensification of biosynthesis of fructooligosaccharides in the presence of high salt concentrations was observed during sucrose (10%) fermentation by Zymomonas mobilis 113S. A 0.6 M NaCl concentration led to an increase of oligosaccharide productivity by 3.5-fold. Sorbitol formation was increased in the presence of 0.16 M NaCl and was inhibited at highest salt concentrations. In a medium with high (65%, w/w) sucrose content the salts gave inhibitory effects on fructooligosaccharide production by lyophilised Z. mobilis cells. Influence of salts on gluconic acid and sorbitol formation under these conditions was studied. The ratio of oligosaccharides and gluconic acid productivity (Qolig./Qglucon.) was increased approximately 2 times at 1% KCl. Sorbitol formation was not significantly influenced in the presence of KCl (up to 2%).
