Improving the quantification of microbial cell abundances in subseafloor sediments through a combination of newly developed cell extraction and automated cell enumeration techniques

深海海底生物圈的勘探是IODP内发展最快的研究领域之一。其中最基本的参数是微生物总量及其随深度的分布。由于目前的方法缺乏灵敏度和人工分析极其耗时，该参数仍不能令人满意地量化。申请人最近开发了一种新的细胞提取技术，该技术通过从沉积物中半定量地去除细胞来降低检测限，从而允许使用更多的沉积物。由于在每个样品上计数更多的细胞，计数统计数据得到了显著改善，但代价是增加了处理时间。在自动化样品处理领域的共同倡议者的最新进展允许处理更多数量的样品。这两种技术的结合有可能通过更好的计数统计和更高的样本数，极大地提高我们对微生物种群密度的精细尺度动态的理解，特别是在细胞极度匮乏的环境中。然而，结合这两种技术绝非易事，需要对细胞提取和自动计数进行仔细的修改。建议的访问将用于制定两种方法结合的细节。

Exploration of the deep subseafloor biosphere is one of the most rapidly advancing fields of research within IODP. One the most fundamental parameters is the total amount of microbial biomass and its distribution with depth. This parameter can still not be quantified satisfactorily because of a lack of sensitivity of the current methods and the extremely time consuming manual analysis. The applicant recently developed a new cell extraction technique, which allows for a much lower detection limit by removing the cells semiquantitatively from the sediment, allowing more sediment to be used. Counting statistics improve significantly due to more cells being counted on each sample, however at the cost of increased processing time. Recent advances by the co-proponent in the field of automated sample processing allow for a much greater number of samples being processed. A combination of both techniques has the potential to greatly improve our understanding of the fine-scale dynamics of microbial population densities through better counting statistics and higher sample numbers, especially in extremely cell-poor environments. However, combining the two techniques is far from easy and requires careful modifications on both the cell extraction and the automated counting. The proposed visit will be used to work out the details for the combination of the two methods.