Department of Fermentation Chemistry and Bioengineering, Institute of Chemical Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic.
Colloids Surf B Biointerfaces. 2011 Jun 1;84(2):491-7. doi: 10.1016/j.colsurfb.2011.02.004. Epub 2011 Mar 1.
One of the industrially important qualities of yeast is their ability to provide the cell-cell and cell-support interactions. This feature of yeast is responsible for technologically significant phenomena such as flocculation (brewing) and yeast biofilm formation (immobilization to supports), whereas these phenomena are time, environment, and strain dependent. Therefore, the goal of this work was to verify the possibility to predict and subsequently select yeast strains capable to colonize solid supports by using physicochemical adhesion models. Three different industrial yeast strains (Saccharomyces cerevisiae) were tested for their adhesion onto spent grain particles in the continuous gas-lift reactor. The cell adhesion energies were calculated, based on physicochemical characteristics of surfaces involved, according to three adhesion models (DLVO theory, thermodynamic approach, and extended DLVO theory). The role of physicochemical surface properties in the cell-cell and cell-support interactions was evaluated by comparing the computed predictions with experimental results. The best agreement between forecast and observation of the yeast adhesion to spent grains was achieved with the extended DLVO (XDLVO) theory, the most complex adhesion model applied in this study. Despite its relative comprehensiveness, the XDLVO theory does not take into account specific biochemical interactions. Consequently, additional understanding of the yeast adhesion mechanism was obtained by means of quantifying the expression of selected FLO genes. The presented approach provides tools to select the appropriately adhesive yeast strains and match them with solid supports of convenient surface properties in order to design immobilized biocatalysts exploitable in biotechnological processes.
酵母的一个重要工业特性是其提供细胞间和细胞与支撑物间相互作用的能力。酵母的这一特性负责技术上重要的现象，如絮凝（酿造）和酵母生物膜形成（固定到支撑物上），而这些现象取决于时间、环境和菌株。因此，这项工作的目标是验证使用物理化学粘附模型来预测和随后选择能够定殖固体支撑物的酵母菌株的可能性。三种不同的工业酵母菌株（酿酒酵母）在连续气升式反应器中用于测试其对废谷物颗粒的粘附。根据涉及的表面的物理化学特性，根据三种粘附模型（DLVO 理论、热力学方法和扩展 DLVO 理论）计算细胞粘附能。通过比较计算预测与实验结果来评估物理化学表面特性在细胞间和细胞与支撑物相互作用中的作用。在这项研究中应用的最复杂的粘附模型扩展 DLVO（XDLVO）理论与酵母对废谷物的粘附的预测与观察结果最为吻合。尽管 XDLVO 理论相对全面，但它没有考虑特定的生化相互作用。因此，通过量化选定 FLO 基因的表达，获得了对酵母粘附机制的更多理解。所提出的方法提供了选择适当粘附性酵母菌株的工具，并将其与具有方便表面特性的固体支撑物匹配，以设计可在生物技术过程中利用的固定化生物催化剂。
