Chair of Chemistry of Biogenic Resources, Technical University of Munich, Campus for Biotechnology and Sustainability, Schulgasse 16, 94315, Straubing, Germany.
Chair of Chemistry of Biogenic Resources, Technical University of Munich, Campus for Biotechnology and Sustainability, Schulgasse 16, 94315, Straubing, Germany; Chair of Bioprocess Engineering, Technical University of Munich, Campus for Biotechnology and Sustainability, Schulgasse 16, 94315, Straubing, Germany.
Carbohydr Polym. 2019 Jun 1;213:236-246. doi: 10.1016/j.carbpol.2019.02.055. Epub 2019 Mar 1.
Xanthan is an extensively studied viscosifying agent discovered in 1961. Acetylation and pyruvylation have a major influence on its rheological properties and the effect of these groups on the conformation and rheological properties of xanthan have been studied for decades. However, these studies rely mainly on chemical modifications and therefore the degree of pyruvylation and acetylation as well as regioselectivity of deacetylation cannot be controlled. Here, we present an in-depth rheological characterization of natural xanthan and seven xanthan-variants, with defined acetylation and pyruvylation patterns created via genetic modification of Xanthomonas campestris LMG 8031. By that approach xanthan-variants with defined acetylation and pyruvylation patterns in their most natural state due to the mild production conditions were obtained. It was possible to link the defined substituent patterns to their corresponding rheological properties to give novel structure-function relationship insights of xanthan-variants in salt-free environments and in the presence of mono- and divalent cations.
黄原胶是一种在 1961 年被发现的、研究广泛的增稠剂。乙酰化和丙酮酸化对其流变性能有重大影响，几十年来，人们一直在研究这些基团对黄原胶构象和流变性能的影响。然而，这些研究主要依赖于化学修饰，因此无法控制丙酮酸化和乙酰化的程度以及脱乙酰化的区域选择性。在这里，我们对天然黄原胶和七种黄原胶变体进行了深入的流变特性分析，这些变体通过黄单胞菌 LMG 8031 的遗传修饰，具有确定的乙酰化和丙酮酸化模式。通过这种方法，可以在最自然的状态下获得具有确定乙酰化和丙酮酸化模式的黄原胶变体，这是由于温和的生产条件。可以将确定的取代基模式与相应的流变性能联系起来，从而在无盐环境中和存在单离子和二价阳离子的情况下，为黄原胶变体提供新的结构-功能关系见解。
