Petrisor Alexandru I, Decho Alan W
Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA.
J Microbiol Methods. 2004 Feb;56(2):173-80. doi: 10.1016/j.mimet.2003.10.008.
Marine stromatolites are generated through the interactions of environmental parameters and specific microbial processes. The activities of endolithic bacteria, that bore canals through calcium carbonate (CaCO(3)) sand grains (ooids) and reprecipitate the CaCO(3) as a single layer (i.e. micritic laminae) are especially important in the longer term stability of the stromatolite macrostructure. Image analysis and classification approaches have been used previously, but only seldom as a quantitative microscopic tool. Here, we develop a new approach that enables the quantification of microscale (i.e. micrometers to millimeters) spatial structure within marine stromatolites. To demonstrate our approach, images were acquired from two different layers of a stromatolite: "orange layers", where microboring of canals within ooids was relatively abundant, and "white layers" where microboring was greatly reduced or lacking. Images were then transformed into spatial maps. Computation of canal and ooid grain areas within each image was conducted and statistically compared between replicate samples from the two stromatolite layers. This allowed quantification of the areas of ooid grains that were microbored. Based on our results, we suggest that our method could be widely applicable to sedimentary environments, and other areas of fundamental research.
海洋叠层石是通过环境参数与特定微生物过程的相互作用而形成的。内生细菌在碳酸钙（CaCO₃）砂粒（鲕粒）中钻出管道，并将CaCO₃重新沉淀为单层（即微晶层），其活动对于叠层石宏观结构的长期稳定性尤为重要。图像分析和分类方法此前已被使用，但很少作为一种定量显微镜工具。在此，我们开发了一种新方法，能够对海洋叠层石内的微观尺度（即微米到毫米）空间结构进行量化。为了展示我们的方法，从一个叠层石的两个不同层获取了图像：“橙色层”，其中鲕粒内管道的微钻孔相对丰富；以及“白色层”，其中微钻孔大大减少或不存在。然后将图像转换为空间图。对每个图像内的管道和鲕粒面积进行计算，并对来自两个叠层石层的重复样本进行统计比较。这使得能够对被微钻孔的鲕粒面积进行量化。基于我们的结果，我们认为我们的方法可广泛应用于沉积环境以及其他基础研究领域。
