Burne R A, Chen Y Y, Penders J E
Department of Dental Research, University of Rochester, School of Medicine and Dentistry, New York 14642, USA.
Adv Dent Res. 1997 Apr;11(1):100-9. doi: 10.1177/08959374970110010101.
The purpose of this study was to develop methods for the consistent production of biofilms of S. mutans containing reporter gene fusions, and to examine the expression of genes involved in sucrose metabolism in adherent populations of this organism. Three strains of S. mutans harboring reporter gene fusions to the gene promoter regions of the gtfBC genes, ftf, and scrA were grown in a Rototorque biofilm fermenter in a tryptone-yeast extract-sucrose medium. Quasi-steady-state levels of reporter gene activity were measured after the biofilms were grown for either 48 hrs of 7 days. Also, induction of gene expression by the addition of sucrose to biofilm cells was monitored. Reporter gene activity was measurable from all gene fusion strains. This study (i) establishes the feasibility of doing detailed molecular and physiologic studies on immobilized populations of S. mutans, (ii) demonstrates that the polysaccharide synthesis machinery of S. mutans is differentially expressed in biofilms, and (iii) opens the way for a more detailed analysis of the environmental signals and signal transduction pathways governing the regulation of gene expression by S. mutans cells that are immobilized on a solid surface.
本研究的目的是开发用于持续生产含有报告基因融合体的变形链球菌生物膜的方法，并检测该生物体附着群体中参与蔗糖代谢的基因的表达。三株携带与gtfBC基因、ftf和scrA基因启动子区域融合的报告基因的变形链球菌菌株，在胰蛋白胨 - 酵母提取物 - 蔗糖培养基中于Rototorque生物膜发酵罐中培养。在生物膜生长48小时或7天后，测量报告基因活性的准稳态水平。此外，监测向生物膜细胞中添加蔗糖对基因表达的诱导作用。所有基因融合菌株均可检测到报告基因活性。本研究（i）确立了对固定化的变形链球菌群体进行详细分子和生理学研究的可行性，（ii）证明变形链球菌的多糖合成机制在生物膜中差异表达，（iii）为更详细地分析控制固定在固体表面的变形链球菌细胞基因表达调控的环境信号和信号转导途径开辟了道路。
