A Passaged 3-species Synthetic Microbial Community

We constructed <em>de novo</em> a community of three model bacterial species, <em>Vibrio cholerae, Staphylococcus aureus, </em>and <em>Escherichia coli</em>, which all constitutively produce a distinct fluorescent protein. This fluorescence permitted hourly fluorescence tracking over three daily passages. Cells were quantified using a 10μm hemocytometer, imaged in a Nikon ELCIPSE Ti microscope, using a combination of brightfield and fluorescence microscopy. The filters used were GFP for green, YFP for yellow, and dsRed for red fluorescent proteins. Counts from four hemocytometer squares were averaged to quantify each replicate.我们从头（de novo）构建了由三种模式细菌物种组成的人工群落，分别为霍乱弧菌（Vibrio cholerae）、金黄色葡萄球菌（Staphylococcus aureus）与大肠杆菌（Escherichia coli），这三类菌株均组成型表达一种独特的荧光蛋白。该荧光标记特性支持在每日三次传代的实验周期内，开展每小时一次的荧光追踪。细胞定量采用10μm规格的血细胞计数板完成，成像环节使用尼康ECLIPSE Ti显微镜，并结合明场成像与荧光成像技术。所用滤光片分别为绿色荧光蛋白（GFP）滤片、黄色荧光蛋白（YFP）滤片与红色荧光蛋白（dsRed）滤片。对四个血细胞计数板方格的计数结果取平均值，以量化每个重复实验样本。