Primary Succession Changes the Composition and Functioning of the Protist Community on Mine Tailings, Especially Phototrophic Protists

Abstract

Primary succession in mine tailings is a prerequisite for tailing vegetation. Microorganisms, including bacteria, fungi, and protists, play an important role in this process in the driving force for improving the nutritional status. Compared to bacteria and fungi, protist populations have rarely been investigated regarding their role in mine tailings, especially for those inhabiting tailings associated with primary succession. Protists are the primary consumers of fungi and bacteria, and their predatory actions promote the release of nutrients immobilized in the microbial biomass, as well as the uptake and turnover of nutrients, affecting the functions of the wider ecosystems. In this study, three different types of mine tailings associated with three successional stages (original tailings, biological crusts, and Miscanthus sinensis grasslands) were selected to characterize the protistan community diversity, structure, and function during primary succession. Some members classified as consumers dominated the network of microbial communities in the tailings, especially in the original bare land tailings. The keystone phototrophs of Chlorophyceae and Trebouxiophyceae showed the highest relative abundance in the biological crusts and grassland rhizosphere, respectively. In addition, the co-occurrences between protist and bacterial taxa demonstrated that the proportion of protistan phototrophs gradually increased during primary succession. Further, the metagenomic analysis of protistan metabolic potential showed that abundances of many functional genes associated with photosynthesis increased during the primary succession of tailings. Overall, these results suggest that the primary succession of mine tailings drives the changes observed in the protistan community, and in turn, the protistan phototrophs facilitate the primary succession of tailings. This research offers an initial insight into the changes in biodiversity, structure, and function of the protistan community during ecological succession on tailings.

Phagotrophic Protists Modulate Copper Resistance of the Bacterial Community in Soil

“…The phagotrophic protistan community exhibited strong tolerance to Cu pollution, as indicated by unchanged α-diversity and relative low community turnover along A Cu gradients. This result is supported by a recent study, showing that protists in mine tailings contain high relative abundances of metal resistance genes . However, long-term field Cu pollution led to an increase in the relative abundance of phagotrophic lineages in Cercozoa and Amoebozoa but a decrease in the relative abundance of Ciliophora.…”

“…This result is supported by a recent study, showing that protists in mine tailings contain high relative abundances of metal resistance genes. 52 However, long-term field Cu pollution led to an increase in the relative abundance of phagotrophic lineages in Cercozoa and Amoebozoa but a decrease in the relative abundance of Ciliophora. Cercozoa, composed of mostly ameboid and flagellate protists, are dominant phagotrophic protists in various soil habitats (e.g., agricultural soil, forest, grassland, and urban greenspaces).…”

Chemolithotrophic Biological Nitrogen Fixation Fueled by Antimonite Oxidation May Be Widespread in Sb-Contaminated Habitats

“…Total DNA was extracted by DNeasy Powersoil Kit (Qiagen, Dresden, Germany) and used to quantify the nifH and aioA gene abundances, molecular markers for N fixation and Sb oxidation, respectively. The qPCR primer sequences are provided in Supporting Table 2.…”

“…DNA Extraction and qPCR. Total DNA was extracted by DNeasy Powersoil Kit (Qiagen, Dresden, Germany) 37 and used to quantify the nif H 38 and aioA 39 respectively. The qPCR primer sequences are provided in Supporting Table 2.…”

Microbiota of the rhizosphere zone of Calamagrostis epigeios from a coal mine waste dump

“…Microorganisms of mine tailings provide many important biogeochemical processes, in particular, carbon (Sun et al, 2018) and nitrogen fixation (Sun et al, , 2020aLi et al, 2022b), cycles of metals and metalloids (Sun et al, 2020b;Li et al, 2021). As a result of their metabolism, microorganisms affect the ecosystem and create conditions for the overgrowth of mine tailings (Li et al, 2022a). The insufficient content of nutrients is one of the factors that limit the phytoremediation of mine tailings.…”