부산대학교 도서관

Biodiversity of soil is routinely assessed with environmental DNA—most often by massive parallel sequencing of marker genes (eDNA metabarcoding). Soil biodiversity may be investigated in relation to biodiversity research or as a tool in forensic investigations. After sampling, the taxonomic composition of soil biotic communities may change. In order to minimize community changes, it is desirable to reduce biological activity, e.g., by freezing immediately after sampling. However, this may be impossible due to remoteness of study sites or, in forensic cases, where soil has been attached to an item of interest for protracted periods of time. Here, we investigated the effect of storage duration and conditions on the assessment of the soil biota with eDNA metabarcoding. We extracted eDNA from freshly collected soil samples and again from the same samples after storage under contrasting temperature conditions and contrasting exposure (open/closed tubes). We used four different primer sets targeting bacteria, fungi, protists (cercozoans), and general eukaryotes. We quantified differences in richness, evenness, and community composition. Subsequently, we tested whether we could correctly infer habitat type and original sample identity after storage using a large reference dataset. We found stronger community composition differences with extended storage time and with higher storage temperature, and differences between open and closed tubes. However, for samples stored
INTRODUCTION A teaspoon of soil may contain more than a billion bacterial cells, meters of fungal hyphae and profuse numbers of protists, nematodes, and small arthropods (Bardgett & van der [...]