Lignite coal burning seam in the remote Altai Mountains harbors a hydrogen-driven thermophilic microbial community

Thermal ecosystems associated with underground coal combustion sites are rare and less studied than geothermal features. Here we analysed microbial communities of near-surface ground layer and bituminous substance in an open quarry heated by subsurface coal fire by metagenomic DNA sequencing. Taxonomic classification revealed dominance of only a few groups of Firmicutes. Near-complete genomes of three most abundant species, ‘Candidatus Carbobacillus altaicus’ AL32, Brockia lithotrophica AL31, and Hydrogenibacillus schlegelii AL33, were assembled. According to the genomic data, Ca. Carbobacillus altaicus AL32 is an aerobic heterotroph, while B. lithotrophica AL31 is a chemolithotrophic anaerobe assimilating CO2 via the Calvin cycle. H. schlegelii AL33 is an aerobe capable of both growth on organic compounds and carrying out CO2 fixation via the Calvin cycle. Phylogenetic analysis of the large subunit of RuBisCO of B. lithotrophica AL31 and H. schlegelii AL33 showed that it belongs to the type 1-E. All three Firmicutes species can gain energy from aerobic or anaerobic oxidation of molecular hydrogen, produced as a result of underground coal combustion along with other coal gases. We propose that thermophilic Firmicutes, whose spores can spread from their original geothermal habitats over long distances, are the first colonizers of this recently formed thermal ecosystem

Enrichment and isolation of acidophilic microorganisms from sediments of gold mine waste leachate

Microorganisms living in acidic environments associated with various types of mining wastes can be used for bioremediation of acid mine drainage (AMD) and related waste streams. We studied microbial diversity of the acidic sediments of a leachate puddle at the basement of a waste rock pile from gold mining in abandoned gold deposit in Martiga (Kemerovo region, West Siberia, Russia). The enrichments were established from four sediment samples with a pH ranging from 2.29 to 6.16. The enrichments cultures were set up at aerobic and anaerobic conditions. Pure cultures of bacteria involved in iron and sulfur oxidation were isolated. The isolated iron- and sulfur-oxidizing cultures were affiliated with Acidithiobacillus and Acidocella genera as was revealed by 16S rRNA gene sequencing. Strains of Desulfosporosinus-like spore-forming bacteria were isolated under anaerobic conditions. The pure culture isolates physiological and biochemical characterization is underway, which will provide new knowledge of AMD formation and natural processes of metal attenuation. The strains can also be prospective agents for use in bioleaching and bioremediation processes

Enrichment and isolation of acidophilic microorganisms from sediments of gold mine waste leachate

Microorganisms living in acidic environments associated with various types of mining wastes can be used for bioremediation of acid mine drainage (AMD) and related waste streams. We studied microbial diversity of the acidic sediments of a leachate puddle at the basement of a waste rock pile from gold mining in abandoned gold deposit in Martiga (Kemerovo region, West Siberia, Russia). The enrichments were established from four sediment samples with a pH ranging from 2.29 to 6.16. The enrichments cultures were set up at aerobic and anaerobic conditions. Pure cultures of bacteria involved in iron and sulfur oxidation were isolated. The isolated iron- and sulfur-oxidizing cultures were affiliated with Acidithiobacillus and Acidocella genera as was revealed by 16S rRNA gene sequencing. Strains of Desulfosporosinus-like spore-forming bacteria were isolated under anaerobic conditions. The pure culture isolates physiological and biochemical characterization is underway, which will provide new knowledge of AMD formation and natural processes of metal attenuation. The strains can also be prospective agents for use in bioleaching and bioremediation processes

Search for new cultured lipophilic bacteria in industrial fat-containing wastes

Fat-containing wastes that are generated as a result of industrial production of food products and are being accumulated in large quantities in wastewater and sewage treatment plants and present a serious environmental problem. Microorganisms that decompose various types of lipids may be potential candidates for creation of commercial bioformulations for fat destruction. The aim of the study was to obtain pure cultures of lipophilic bacteria from fat-containing wastes, to study their diversity and activity for the development of a biological product. As a result, 30 strains of different phylogenetic groups with lipolytic activity was obtained. The most isolated strains were represented by enterobacteria and pseudomonas members within the Gammaproteobacteria. Almost half of the isolated strains were closely related to conditionally pathogenic microorganisms such as Serratia, Klebsiella etc. Non-pathogenic strains and promising for biotechnology ones belonged to Pseudomonas citronellolis, P. nitroreducens, P. synxantha, P. extremaustralis, Bacillus subtilis, B. amyloliquefaciens, Brevibacillus brevis and Microvirgula sp

Metagenome sequence of a microbial community from the gold mine tailings in the Kuzbass area, Russia

The metagenome of a microbial community of the sediments from a highly acidic iron-rich puddle at the tailings dump of the Komsomolskaya gold mine in the Kuzbass area, Siberia, Russia, was sequenced. Binning of contigs yielded a near-complete genome of the dominant bacterium, representing a novel deep lineage of Deltaproteobacteria

Metagenome sequence of a microbial community from the gold mine tailings in the Kuzbass area, Russia

The metagenome of a microbial community of the sediments from a highly acidic iron-rich puddle at the tailings dump of the Komsomolskaya gold mine in the Kuzbass area, Siberia, Russia, was sequenced. Binning of contigs yielded a near-complete genome of the dominant bacterium, representing a novel deep lineage of Deltaproteobacteria

Isolation of new thermophilic sulfidogens from microbial mat associated with groundwater discharge in the Tunkin valley

Spore-forming sulfate-reducing bacteria, previously assigned to the genus Desulfotomaculum, are typical inhabitants of thermal groundwater biotopes (Aüllo et al., 2013; Frank et al., 2016). Due to their ability to form spores, to grow autotrophically, and to survive high temperatures, this group is a successful colonizer of groundwaters. Revision of the genus Desulfotomaculum resulted in description of four new genera, Desulfallas, Desulfofundulus, Desulfofarcimen, and Desulfohalotomaculum (Watanabe et al., 2018

Lignite coal burning seam in the remote Altai Mountains harbors a hydrogen-driven thermophilic microbial community

Thermal ecosystems associated with underground coal combustion sites are rare and less studied than geothermal features. Here we analysed microbial communities of near-surface ground layer and bituminous substance in an open quarry heated by subsurface coal fire by metagenomic DNA sequencing. Taxonomic classification revealed dominance of only a few groups of Firmicutes. Near-complete genomes of three most abundant species, ‘Candidatus Carbobacillus altaicus’ AL32, Brockia lithotrophica AL31, and Hydrogenibacillus schlegelii AL33, were assembled. According to the genomic data, Ca. Carbobacillus altaicus AL32 is an aerobic heterotroph, while B. lithotrophica AL31 is a chemolithotrophic anaerobe assimilating CO2 via the Calvin cycle. H. schlegelii AL33 is an aerobe capable of both growth on organic compounds and carrying out CO2 fixation via the Calvin cycle. Phylogenetic analysis of the large subunit of RuBisCO of B. lithotrophica AL31 and H. schlegelii AL33 showed that it belongs to the type 1-E. All three Firmicutes species can gain energy from aerobic or anaerobic oxidation of molecular hydrogen, produced as a result of underground coal combustion along with other coal gases. We propose that thermophilic Firmicutes, whose spores can spread from their original geothermal habitats over long distances, are the first colonizers of this recently formed thermal ecosystem