High-throughput sequencing approach in analysis of microbial communities colonizing natural gas pipelines

Microbial Communities in Underground Gas Reservoirs Offer Promising Biotechnological Potential

Securing new sources of renewable energy and achieving national self-sufficiency in natural gas have become increasingly important in recent times. The study described in this paper focuses on three geologically diverse underground gas reservoirs (UGS) that are the natural habitat of methane-producing archaea, as well as other microorganisms with which methanogens have various ecological relationships. The objective of this research was to describe the microbial metabolism of methane in these specific anoxic environments during the year. DNA sequencing analyses revealed the presence of different methanogenic communities and their metabolic potential in all sites studied. Hydrogenotrophic Methanobacterium sp. prevailed in Lobodice UGS, members of the hydrogenotrophic order Methanomicrobiales predominated in Dolní Dunajovice UGS and thermophilic hydrogenotrophic members of the Methanothermobacter sp. were prevalent in Tvrdonice UGS. Gas composition and isotope analyses were performed simultaneously. The results suggest that the biotechnological potential of UGS for biomethane production cannot be neglected.

Microbially induced corrosion impacts on the oil industry

The numerous structural impacts on oil installations caused by corrosion make this issue a concern in the oil industry. Although chemical corrosion is relevant in this sector, it is indisputable that the microbial corrosion or bio-corrosion plays a preponderant role, with considerable economic losses. Microbial corrosion invariably depends on the formation of a biofilm on the attacked surface. Biofilm structures provide the conditions that favor the development of microbial groups related to corrosion. Despite the several microbial species are described as corrosive, certain groups, such as sulfate- and nitrate-reducing bacteria, acetogenic bacteria, and methanogenic archaea are the most commonly related. In spite of environmental factors influence the prevalence of certain species, it is increasingly accepted that the relationships between different species are determinant in corrosion. Such relationships can be evidenced by several surveys of microbial communities involved in bio-corrosion. Here, the main microbes related to corrosion in metallic structures used in oil installations are presented, as well as their metabolisms involved in the deterioration of metallic surfaces.

Microbial community profiles grown on 1020 carbon steel surfaces in seawater-isolated microcosm

Corrosion of metallic alloys is a concern worldwide, with impacts affecting different production sectors and consequent economic losses in the order of billions of dollars annually. Biocorrosion is a form of corrosion where the participation of microorganisms can induce, accelerate, or inhibit corrosive processes. In this study, it was evaluated that the changes in profile communities, by the sequencing of the 16S ribosomal gene, grown over steel coupons in a microcosm with no additional oxygen supplementation for 120 days. Analysis of abundance and diversity indices indicates marked changes in microbial structures throughout the 120-day period. Homology results of OTUs generated by Illumina sequencing indicated Proteobacteria phylum as the dominant group, comprising about 85.3% of the total OTUs, followed by Firmicutes and Bacteriodetes, both with 7.35%. Analyses at lower taxonomic levels suggested the presence of representatives described as corroders, such as Citreicella thiooxidans, Thalassospira sp., and Limnobacter thiooxidans. In conclusion, the results suggest that no additional oxygen supplementation profoundly altered the core of microbial communities, with a predominance of facultative anaerobic species.

High-throughput sequencing approach in analysis of microbial communities colonizing natural gas pipelines

This study provides a deep modern insight into the phylogenetic diversity among bacterial consortia found in working and nonworking high‐methane natural gas pipelines located in Poland. The working pipeline was characterized by lower biodiversity (140–154 bacterial genera from 22 to 23 classes, depending on the source of the debris) in comparison to the off‐gas pipeline (169 bacterial genera from 23 classes). The sediment recovered from the working pipeline contained mostly DNA identified as belonging to the phylum Firmicutes (66.4%–45.9% operational taxonomic units [OTUs]), predominantly Bacillus (41.4%–31.1% OTUs) followed by Lysinibacillus (2.6%–1.5% OTUs) and Clostridium (2.4%–1.8% OTUs). In the nonworking pipeline, Proteobacteria (46.8% OTUs) and Cyanobacteria (27.8% OTUs) were dominant. Over 30% of the Proteobacteria sequences showed homologies to Gammaproteobacteria, with Pseudomonas (7.1%), Enhydrobacter (2.1%), Stenotrophomonas (0.5%), and Haempohilus (0.4%) among the others. Differences were noted in terms of the chemical compositions of deposits originating from the working and nonworking gas pipelines. The deposits from the nonworking gas pipeline contained iron, as well as carbon (42.58%), sulphur (15.27%), and oxygen (15.32%). This composition can be linked to both the quantity and type of the resident microorganisms. The presence of a considerable amount of silicon (17.42%), and of aluminum, potassium, calcium, and magnesium at detectable levels, may likewise affect the metabolic activity of the resident consortia in the working gas pipeline. All the analyzed sediments included both bacteria known for causing and intensifying corrosion (e.g., Pseudomonas, Desulfovibrio, Shewanella, Serratia) and bacteria that can protect the surface of pipelines against deterioration (e.g., Bacillus). Biocorrosion is not related to a single mechanism or one species of microorganism, but results from the multidirectional activity of multiple microbial communities. The analysis presented here of the state of the microbiome in a gas pipeline during the real gas transport is a particularly valuable element of this work.