Metagenomic and Metatranscriptomic Study of Microbial Metal Resistance in an Acidic Pit Lake.

摘要: Cueva de la Mora (CM) is an acidic, meromictic pit lake in the Iberian Pyrite Belt characterized by extremely high metal(loid) concentrations and strong gradients oxygen, metal, nutrient concentrations. We hypothesized that geochemical variations with depth would result differences community composition metal resistance strategies among active microbial populations. also gene (MRG) expression correlate toxicity levels for dissolved species lake. Water samples were collected upper oxic layer, chemocline, deep anoxic layer of shotgun metagenomic metatranscriptomic sequencing. Metagenomic analyses revealed dramatic communities depth, consistent changing geochemistry. Based on relative abundance taxa identified each metagenome, Eukaryotes (predominantly Coccomyxa) dominated while Archaea Thermoplasmatales) a combination Bacteria abundant at chemocline. compared across using curated list protein-coding MRGs KEGG Orthology identifiers (KOs) found there broad (e.g., intracellular accumulation) expressed Eukaryotes, Bacteria, Archaea. Although normalized abundances MRG generally higher metal-specific genes was not strongly related to specific concentrations, especially Cu As. potential metagenome assembled genomes (MAGs) from where are highest. Consistent previous work showing mechanisms even strain level, patterns varied MAG populations same depth. Some very few known date, suggesting novel remain be discovered uncultivated acidophiles.