School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China.
School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA.
J Basic Microbiol. 2021 May;61(5):396-405. doi: 10.1002/jobm.202000635. Epub 2021 Mar 8.
The growth discrepancy of Bacillus subtilis biofilms along different directions under the competitive growth drive the formation of anisotropic biofilm morphology directly. Two biofilms growing from two inoculating positions with different distances exhibit promoting or inhibiting growth behavior. Here we develop an optical imaging technology to observe the cell differentiation and the growth dynamics when the biofilm grows. It shows that the spatiotemporal distribution of different phenotypes affects the biofilm morphological evolution. We develop a program to calculate the velocity of cell motion within the biofilm, which is based on the feature point matching approach. We find the cell differentiation ununiformity in the neighboring region and its opposite region leads to the cell velocity difference in the competitive environment, the different cell motion further influences the biofilm morphology evolution. When biofilms grow with a long inoculating distance, there is always a gap between the them; when biofilms grow with a short inoculating distance, two biofilms gradually merge into a whole. Our work establishes a relationship between microscopic cells and macroscopic biofilm morphological which enables us to study the competitive growth process of biofilms from multiple perspectives.
枯草芽孢杆菌生物膜在竞争生长驱动力的作用下沿着不同方向的生长差异直接导致各向异性生物膜形态的形成。从两个不同距离的接种位置生长的两个生物膜表现出促进或抑制生长的行为。在这里，我们开发了一种光学成像技术来观察生物膜生长时的细胞分化和生长动态。结果表明，不同表型的时空分布会影响生物膜形态的演化。我们开发了一个程序来计算生物膜内细胞运动的速度，该程序基于特征点匹配方法。我们发现，在竞争环境中，相邻区域和相反区域的细胞分化不均匀会导致细胞速度的差异，不同的细胞运动进一步影响生物膜形态的演化。当生物膜以长接种距离生长时，它们之间总会有一个间隙；当生物膜以短接种距离生长时，两个生物膜逐渐融合为一个整体。我们的工作建立了微观细胞和宏观生物膜形态之间的关系，使我们能够从多个角度研究生物膜的竞争生长过程。
