北京大学定量生物学中心

学术报告

题 目： Mechanical Principles of Biofilm Formation

报告人： Dr. Jing Yan

普林斯顿大学分子生物系与机械工程系

时 间： 2017-05-15 (周一), 13:00-14:00

地 点： 北京大学老化学楼东配楼一层101报告厅

主持人： 汤超 教授

摘要：

Biofilms are surface-associated bacterial communities embedded in an extracellular matrix. Biofilm cells are a major problem in the context of chronic infections, because biofilm dwelling cells have increased antibiotic resistance compared to their planktonic counterparts. Investigations so far have mainly focused on the genetic and regulatory features driving biofilm formation. However, still lacking is a fundamental biophysical and biomechanical understanding of how bacteria, in time and space, build these dense three-dimensional structures. During this talk, I will discuss about our recently progress in using Vibrio cholerae as a model biofilm former to reveal the mechanical principles behind biofilm formation. I will first present a new methodology to image living, growing bacterial biofilms at single-cell resolution, and demonstrate how cell-cell adhesion and cell-surface adhesion balance each other to cause V. cholerae biofilms to transition from a two-dimensional branched morphology to an ordered three-dimensional cluster. Next, I will demonstrate how matrix production enables biofilm cells to establish an osmotic pressure differential between the biofilm and the external environment, and use this osmotic pressure to facilitate the biofilm expansion. Finally, I will present various mechanical instabilities that takes place when biofilms grow on soft tissue-like substrates. We also complemented these mechanical studies by genetic analyses and ecological competition experiments to decipher the biological consequences of the biomechanical phenomena observed in bacterial biofilms.

报告人简介：

严兢博士本科毕业于北京大学化学与分子工程学院。博士期间，他就读于伊利诺伊大学香槟分校的材料科学与工程系，专攻软物质物理。在博士期间，他发展了一系列由外场驱动的非平衡态胶体材料。博士毕业后，他转向生物方向并就职于普利斯顿大学的分子生物系与机械工程系，主要研究方向为细菌菌膜的形成与治理。在博士及博士后期间，其曾在自然，自然材料等杂志上发表文章，并获得2016年度美国Burroughs Wellcome基金会的交叉学科成就奖。