Grupo de Microbiologia Aplicada e Bioprocessos, Departamento de Biotecnologia, Universidade de São Paulo-Escola de Engenharia de Lorena, Lorena, São Paulo, Brazil.
Appl Biochem Biotechnol. 2010 Nov;162(6):1558-63. doi: 10.1007/s12010-010-8937-9. Epub 2010 Apr 17.
Xylitol enzymatic production can be an alternative to chemical and microbial processes, because of advantages like higher conversion efficiency. However, for an adequate conversion, it is necessary to investigate the effect of many parameters, such as buffer initial concentration, pH, temperature, agitation, etc. In this context, the objective of this work was to evaluate xylitol enzymatic production under different Tris buffer initial concentrations in order to determine the best condition for this parameter to begin the reaction. The best results were obtained when Tris buffer initial concentration was 0.22 M, reaching 0.31 g L(-1) h(-1) xylitol volumetric productivity with 99% xylose-xylitol conversion efficiency. Although the increase in buffer concentration allowed better pH maintenance, it hindered the catalysis. The results demonstrate that this bioreaction is greatly influenced by involved ions concentrations.
木糖的酶法生产可以替代化学法和微生物法，因为具有更高的转化率等优势。然而，为了达到充分的转化，需要研究许多参数的影响，如缓冲液初始浓度、pH 值、温度、搅拌等。在这种情况下，本工作的目的是评估不同 Tris 缓冲液初始浓度下的木糖醇酶法生产情况，以确定该参数开始反应的最佳条件。当 Tris 缓冲液初始浓度为 0.22 M 时，获得了最佳结果，木糖醇的比产率达到 0.31 g L(-1) h(-1)，木糖-木糖醇的转化率达到 99%。尽管缓冲液浓度的增加可以更好地维持 pH 值，但它阻碍了催化作用。结果表明，这种生物反应受到涉及的离子浓度的极大影响。
