The mechanical properties of Saccharomyces cerevisiae
The mechanical properties of Saccharomyces cerevisiae
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DOI：
10.1073/pnas.97.18.9871
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发表时间：
2000-08-29
影响因子：
11.1
通讯作者：
Middelberg, APJ
中科院分区：
文献类型：
--
作者：
Smith, AE;Zhang, ZB;Middelberg, APJ
细胞壁力学特性在酿酒酵母的生长和形态中起着不可或缺的作用，与对酿酒酵母遗传学的大量了解相比，对其力学特性几乎一无所知。我们已经开发了一种微操作技术来测量单个细胞破裂所需的力，并且最近建立了一个数学模型来从这些数据中提取细胞壁的力学特性。在这里，我们确定了S， cerevisiae细胞壁的平均表面模量分别为11.1 +/- 0.6 N/m和12.9 +/- 0.7 N/m，分别给出了相应的杨氏模量112 +/- 6 MPa和107 +/- 6 MPa。这一结果表明，酵母细胞群在进入固定阶段时通过增加细胞壁厚度和表面模量而增强，而不改变细胞壁材料的平均弹性特性。我们还确定了细胞壁的平均破裂应变在指数期为82% +/- 3%，在固定期为80% +/- 3%，这一发现提供了一个失效准则，可用于预测何时施加应力（例如，由于流体流动）将导致细胞壁破裂。本工作通过工程方法分析了酵母在不同生长阶段的压缩实验。
Cell-wall mechanical properties play an integral part in the growth and form of Saccharomyces cerevisiae, In contrast to the tremendous knowledge on the genetics of S. cerevisiae, almost nothing is known about its mechanical properties. We have developed a micromanipulation technique to measure the force required to burst single cells and have recently established a mathematical model to extract the mechanical properties of the cell wall from such data, Here we determine the average surface modulus of the S, cerevisiae cell wall to be 11.1 +/- 0.6 N/m and 12.9 +/- 0.7 N/m in exponential and stationary phases, respectively, giving corresponding Young's moduli of 112 +/- 6 MPa and 107 +/- 6 MPa, This result demonstrates that yeast cell populations strengthen as they enter stationary phase by increasing wall thickness and hence the surface modulus, without altering the average elastic properties of the cell-wall material. We also determined the average breaking strain of the cell wall to be 82% +/- 3% in exponential phase and 80% +/- 3% in stationary phase, This finding provides a failure criterion that can be used to predict when applied stresses (e,g,, because of fluid flow) will lead to wall rupture, This work analyzes yeast compression experiments in different growth phases by using engineering methodology.