Chemistry & Biochemistry Department, Cal Poly Pomona, Pomona, CA, 91768, USA.
Department of Biological Sciences, CSU Northridge, Northridge, CA, USA.
Anal Biochem. 2021 Jan 1;612:113957. doi: 10.1016/j.ab.2020.113957. Epub 2020 Sep 19.
We describe herein a simple procedure for quantifying endospore abundances in ancient and organic-rich permafrost. We repeatedly (10x) extracted and fractionated permafrost using a tandem filter assembly composed of 3 and 0.2 μm filters. Then, the 0.2 μm filter was washed (7x), autoclaved, and the contents eluted, including dipicolinic acid (DPA). Time-resolved luminescence using Tb(EDTA) yielded a LOD of 1.46 nM DPA (6.55 × 10 endospores/mL). In review, DPA/endospore abundances were ~2.2-fold greater in older 33 ky permafrost (258 ± 36 pmol DPA gdw; 1.15 × 10 ± 0.16 × 10 spores gdw) versus younger 19 ky permafrost (p = 0.007297). This suggests that dormancy increases with permafrost age.
我们在此描述了一种简单的方法，用于定量古代富含有机质永冻层中的孢子丰度。我们使用由 3μm 和 0.2μm 过滤器组成的串联过滤器组件，反复（10 次）提取和分级永冻层。然后，用 0.2μm 过滤器（7 次）冲洗、高压灭菌并洗脱内容物，包括二吡啶羧酸（DPA）。使用 Tb（EDTA）进行时间分辨发光，得到 DPA 的检测限为 1.46nM（6.55×10 个孢子/mL）。总的来说，在较老的 33 千年前的永冻层中，DPA/孢子丰度（258±36 pmol DPA gdw；1.15×10±0.16×10 个孢子 gdw）比年轻的 19 千年前的永冻层（p = 0.007297）高出约 2.2 倍。这表明休眠期随永冻层年龄的增加而增加。
