scholarly journals Presence of orange tubercles does not always indicate accelerated low water corrosion

2019 ◽  
Author(s):  
Hoang C. Phan ◽  
Scott A. Wade ◽  
Linda L. Blackall
Keyword(s):  
Microbial Communities ◽  
Steel Sheet ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Accelerated Corrosion ◽  
Sulfate Reducing ◽  
Metallurgical Analysis ◽  
Different Types ◽  
Steel Surfaces ◽  
Reducing Bacteria

ABSTRACTThe rapid degradation of marine infrastructure at the low tide level due to accelerated low water corrosion (ALWC) is a problem encountered worldwide. Despite this, there is limited understanding of the microbial communities involved in this process. We obtained samples of the orange-coloured tubercles commonly associated with ALWC from two different types of steel sheet piling, located adjacent to each other but with different levels of localised corrosion, at a seaside harbour. The microbial communities from the outer and inner layers of the orange tubercles, and from adjacent seawater, were studied by pure culture isolation and metabarcoding of the 16S rRNA genes. A collection of 119 bacterial isolates was obtained from one orange tubercle sample, using a range of media with anaerobic and aerobic conditions. The metabarcoding results showed that sulfur and iron oxidisers were more abundant on the outer section of the orange tubercles compared to the inner layers, where Deltaproteobacteria (which includes many sulfate reducers) were more abundant. The microbial communities varied significantly between the inner and outer layers of the orange tubercles and also with the seawater, but overall did not differ significantly between the two steel sheet types. Metallurgical analysis found differences in composition, grain size, ferrite-pearlite ratio and the extent of inclusions present between the two steel types investigated.IMPORTANCEThe presence of orange tubercles on marine steel pilings is often used as an indication that accelerated low water corrosion is taking place. We studied the microbial communities in attached orange tubercles on two closely located sheet pilings that were of different steel types. The attached orange tubercles were visually similar, but the extent of underlying corrosion on the different steel surfaces were substantially different. No clear difference was found between the microbial communities present on the two different types of sheet piling. However, there were clear differences in the microbial communities in the corrosion layers of tubercles, which were also different to the microbes present in adjacent seawater. The overall results suggest that the presence of orange tubercles, a single measurement of water quality, or the detection of certain general types of microbes (e.g. sulfate reducing bacteria) should not be taken alone as definitive indications of accelerated corrosion.

scholarly journals Microbial Communities of Orange Tubercles in Accelerated Low-Water Corrosion

2020 ◽  
Vol 86 (13) ◽  
Author(s):  
Hoang C. Phan ◽  
Scott A. Wade ◽  
Linda L. Blackall
Keyword(s):  
Microbial Communities ◽  
Steel Sheet ◽  
Localized Corrosion ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Accelerated Corrosion ◽  
Content Type ◽  
Sulfate Reducing ◽  
Different Types ◽  
Different Levels

ABSTRACT The rapid degradation of marine infrastructure at the low tide level due to accelerated low-water corrosion (ALWC) is a problem encountered worldwide. Despite this, there is limited understanding of the microbial communities involved in this process. We obtained samples of the orange-colored tubercles commonly associated with ALWC from two different types of steel sheet piling, located adjacent to each other but with different levels of localized corrosion, at a seaside harbor. The microbial communities from the outer and inner layers of the orange tubercles and from adjacent seawater were studied by pure culture isolation and metabarcoding of the 16S rRNA genes. A collection of 119 bacterial isolates was obtained from one orange tubercle sample, using a range of media in anaerobic and aerobic conditions. The metabarcoding results showed that sulfur and iron oxidizers were more abundant on the outer sections of the orange tubercles compared to the inner layers, where Deltaproteobacteria (which include many sulfate reducers) were more abundant. The microbial communities varied significantly between the inner and outer layers of the orange tubercles and also with the seawater but overall did not differ significantly between the two steel sheet types. Hence, we saw similar microbial communities in orange tubercles present, but different levels of localized corrosion, for two different types of colocated steel sheet piling. Metallurgical analysis found differences in composition, grain size, ferrite-pearlite ratio, and the extent of inclusions present between the two steel types investigated. IMPORTANCE The presence of orange tubercles on marine steel pilings is often used as an indication that accelerated low-water corrosion is taking place. We studied the microbial communities in attached orange tubercles on two closely located sheet pilings that were of different steel types. The attached orange tubercles were visually similar, but the extents of underlying corrosion on the different steel surfaces were substantially different. No clear difference was found between the microbial communities present on the two different types of sheet piling. However, there were clear differences in the microbial communities in the corrosion layers of tubercles, which were also different from the microbes present in adjacent seawater. The overall results suggest that the presence of orange tubercles, a single measurement of water quality, or the detection of certain general types of microbes (e.g., sulfate-reducing bacteria) should not be taken alone as definitive indications of accelerated corrosion.

scholarly journals ANME-1 archaea drive methane accumulation and removal in estuarine sediments

2020 ◽  
Author(s):  
Richard Kevorkian ◽  
Sean Callahan ◽  
Rachel Winstead ◽  
Karen G. Lloyd
Keyword(s):  
16S Rrna ◽  
Sulfate Reducing Bacteria ◽  
Low Energy ◽  
Estuarine Sediments ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Sulfate Reducing ◽  
Hydrogenotrophic Methanogenesis ◽  
Natural Settings ◽  
Reducing Bacteria

AbstractUncultured members of the Methanomicrobia called ANME-1 perform the anaerobic oxidation of methane (AOM) through a process that uses much of the methanogenic pathway. It is unknown whether ANME-1 obligately perform AOM, or whether some of them can perform methanogenesis when methanogenesis is exergonic. Most marine sediments lack advective transport of methane, so AOM occurs in the sulfate methane transition zone (SMTZ) where sulfate-reducing bacteria consume hydrogen produced by fermenters, making hydrogenotrophic methanogenesis exergonic in the reverse direction. When sulfate is depleted deeper in the sediments, hydrogen accumulates making hydrogenotrophic methanogenesis exergonic, and methane accumulates in the methane zone (MZ). In White Oak River estuarine sediments, we found that ANME-1 comprised 99.5% of 16S rRNA genes from amplicons and 100% of 16S rRNA genes from metagenomes of the Methanomicrobia in the SMTZ and 99.9% and 98.3%, respectively, in the MZ. Each of the 16 ANME-1 OTUs (97% similarity) had peaks in the SMTZ that coincided with peaks of putative sulfate-reducing bacteria Desulfatiglans sp. and SEEP-SRB1. In the MZ, ANME-1, but no putative sulfate-reducing bacteria or cultured methanogens, increased with depth. Using publicly available data, we found that ANME-1 was the only group expressing methanogenic genes during both net AOM and net methanogenesis in an enrichment. The commonly-held belief that ANME-1 perform AOM is based on the fact that they dominate natural settings and enrichments where net AOM is measured. We found that ANME-1 also dominate natural settings and enrichment where net methanogenesis is measured, so we conclude that ANME-1 perform methane production. Alternating between AOM and methanogenesis, either in a single ANME-1 cell or between different subclades with similar 16S rRNA sequences of ANME-1, may confer a competitive advantage, explaining the predominance of low-energy adapted ANME-1 in methanogenic sediments worldwide.Abstract ImportanceLife may operate differently at very low energy levels. Natural populations of microbes that make methane survive on some of the lowest energy yields of all life. From all available data, we infer that these microbes alternate between methane production and oxidation, depending on which process is energy-yielding in the environment. This means that much of the methane produced naturally in marine sediments occurs through an organism that is also capable of destroying it under different circumstances.

scholarly journals Molecular Characterization of Sulfate-Reducing Bacteria in the Guaymas Basin

2003 ◽  
Vol 69 (5) ◽  
pp. 2765-2772 ◽  
Author(s):  
Ashita Dhillon ◽  
Andreas Teske ◽  
Jesse Dillon ◽  
David A. Stahl ◽  
Mitchell L. Sogin
Keyword(s):  
16S Rrna ◽  
Gulf Of California ◽  
Sulfate Reducing Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Terrestrial Organic Matter ◽  
Guaymas Basin ◽  
Sulfate Reducers ◽  
Sulfate Reducing ◽  
Reducing Bacteria

ABSTRACT The Guaymas Basin (Gulf of California) is a hydrothermal vent site where thermal alteration of deposited planktonic and terrestrial organic matter forms petroliferous material which supports diverse sulfate-reducing bacteria. We explored the phylogenetic and functional diversity of the sulfate-reducing bacteria by characterizing PCR-amplified dissimilatory sulfite reductase (dsrAB) and 16S rRNA genes from the upper 4 cm of the Guaymas sediment. The dsrAB sequences revealed that there was a major clade closely related to the acetate-oxidizing delta-proteobacterial genus Desulfobacter and a clade of novel, deeply branching dsr sequences related to environmental dsr sequences from marine sediments in Aarhus Bay and Kysing Fjord (Denmark). Other dsr clones were affiliated with gram-positive thermophilic sulfate reducers (genus Desulfotomaculum) and the delta-proteobacterial species Desulforhabdus amnigena and Thermodesulforhabdus norvegica. Phylogenetic analysis of 16S rRNAs from the same environmental samples resulted in identification of four clones affiliated with Desulfobacterium niacini, a member of the acetate-oxidizing, nutritionally versatile genus Desulfobacterium, and one clone related to Desulfobacula toluolica and Desulfotignum balticum. Other bacterial 16S rRNA bacterial phylotypes were represented by non-sulfate reducers and uncultured lineages with unknown physiology, like OP9, OP8, as well as a group with no clear affiliation. In summary, analyses of both 16S rRNA and dsrAB clone libraries resulted in identification of members of the Desulfobacteriales in the Guaymas sediments. In addition, the dsrAB sequencing approach revealed a novel group of sulfate-reducing prokaryotes that could not be identified by 16S rRNA sequencing.

scholarly journals Marine deep biosphere microbial communities assemble in near-surface sediments in Aarhus Bay

2019 ◽  
Author(s):  
Caitlin Petro ◽  
Birthe Zäncker ◽  
Piotr Starnawski ◽  
Lara M. Jochum ◽  
Timothy G. Ferdelman ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Direct Evidence ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Microbial Populations ◽  
Sediment Surface ◽  
Deep Biosphere ◽  
Near Surface ◽  
Sulfate Reducing ◽  
Core Set

AbstractAnalyses of microbial diversity in marine sediments have identified a core set of taxa unique to the marine deep biosphere. Previous studies have suggested that these specialized communities are shaped by processes in the surface seabed, in particular that their assembly is associated with the transition from the bioturbated upper zone to the nonbioturbated zone below. To test this hypothesis, we performed a fine-scale analysis of the distribution and activity of microbial populations within the upper 50 cm of sediment from Aarhus Bay (Denmark). Sequencing and qPCR were combined to determine the depth distributions of bacterial and archaeal taxa (16S rRNA genes) and sulfate-reducing microorganisms (dsrBgene). Mapping of radionuclides throughout the sediment revealed a region of intense bioturbation at 0-6 cm depth. The transition from bioturbated sediment to the subsurface below (7 cm depth) was marked by a shift from dominant surface populations to common deep biosphere taxa (e.g. Chloroflexi & Atribacteria). Changes in community composition occurred in parallel to drops in microbial activity and abundance caused by reduced energy availability below the mixed sediment surface. These results offer direct evidence for the hypothesis that deep subsurface microbial communities present in Aarhus Bay mainly assemble already centimeters below the sediment surface, below the bioturbation zone.

scholarly journals Diversity and Activity of Sulfate-Reducing Prokaryotes in Kamchatka Hot Springs

2021 ◽  
Vol 9 (10) ◽  
pp. 2072
Author(s):  
Evgenii N. Frolov ◽  
Alexandra V. Gololobova ◽  
Alexandra A. Klyukina ◽  
Elizaveta A. Bonch-Osmolovskaya ◽  
Nikolay V. Pimenov ◽  
...  
Keyword(s):  
16S Rrna ◽  
Microbial Communities ◽  
Hot Springs ◽  
Minor Component ◽  
Sulfur Cycle ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Significant Group ◽  
Sulfate Reducing ◽  
Terrestrial Hot Springs

Microbial communities of the Kamchatka Peninsula terrestrial hot springs were studied using radioisotopic and cultural approaches, as well as by the amplification and sequencing of dsrB and 16S rRNA genes fragments. Radioisotopic experiments with 35S-labeled sulfate showed that microbial communities of the Kamchatka hot springs are actively reducing sulfate. Both the cultivation experiments and the results of dsrB and 16S rRNA genes fragments analyses indicated the presence of microorganisms participating in the reductive part of the sulfur cycle. It was found that sulfate-reducing prokaryotes (SRP) belonging to Desulfobacterota, Nitrospirota and Firmicutes phyla inhabited neutral and slightly acidic hot springs, while bacteria of phylum Thermodesulofobiota preferred moderately acidic hot springs. In high-temperature acidic springs sulfate reduction was mediated by archaea of the phylum Crenarchaeota, chemoorganoheterotrophic representatives of genus Vulcanisaeta being the most probable candidates. The 16S rRNA taxonomic profiling showed that in most of the studied communities SRP was present only as a minor component. Only in one microbial community, the representatives of genus Vulcanisaeta comprised a significant group. Thus, in spite of comparatively low sulfate concentrations in terrestrial hot springs of the Kamchatka, phylogenetically and metabolically diverse groups of sulfate-reducing prokaryotes are operating there coupling carbon and sulfur cycles in these habitats.

scholarly journals Anaerobic Oxidation of o -Xylene, m -Xylene, and Homologous Alkylbenzenes by New Types of Sulfate-Reducing Bacteria

1999 ◽  
Vol 65 (3) ◽  
pp. 999-1004 ◽  
Author(s):  
Gerda Harms ◽  
Karsten Zengler ◽  
Ralf Rabus ◽  
Frank Aeckersberg ◽  
Dror Minz ◽  
...  
Keyword(s):  
Crude Oil ◽  
Enrichment Culture ◽  
Sulfate Reducing Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Organic Substrates ◽  
Sulfate Reducing ◽  
Concomitant Reduction ◽  
Reducing Bacteria ◽  
Growth Experiments

ABSTRACT Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed that the isolates affiliated with known completely oxidizing sulfate-reducing bacteria of the δ subclass of the classProteobacteria. Strain oXyS1 showed the highest similarities to Desulfobacterium cetonicum andDesulfosarcina variabilis (similarity values, 98.4 and 98.7%, respectively). Strain mXyS1 was less closely related to known species, the closest relative being Desulfococcus multivorans (similarity value, 86.9%). Complete mineralization of o-xylene and m-xylene was demonstrated in quantitative growth experiments. Strain oXyS1 was able to utilize toluene, o-ethyltoluene, benzoate, ando-methylbenzoate in addition to o-xylene. Strain mXyS1 oxidized toluene, m-ethyltoluene,m-isoproyltoluene, benzoate, andm-methylbenzoate in addition to m-xylene. Strain oXyS1 did not utilize m-alkyltoluenes, whereas strain mXyS1 did not utilize o-alkyltoluenes. Like the enrichment culture, both isolates grew anaerobically on crude oil with concomitant reduction of sulfate to sulfide.

scholarly journals Desulfoglaeba alkanexedens gen. nov., sp. nov., an n-alkane-degrading, sulfate-reducing bacterium

2006 ◽  
Vol 56 (12) ◽  
pp. 2737-2742 ◽  
Author(s):  
Irene A. Davidova ◽  
Kathleen E. Duncan ◽  
Ok Kyoung Choi ◽  
Joseph M. Suflita
Keyword(s):  
Type Strain ◽  
Novel Species ◽  
Sulfate Reducing Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Oily Wastewater ◽  
Sulfate Reducing ◽  
Production Water ◽  
Large Clusters ◽  
Reducing Bacteria

Two novel sulfate-reducing bacteria, strains ALDCT and Lake, which were able to oxidize n-alkanes, were isolated from a naval oily wastewater-storage facility (VA, USA) and from oilfield production water (OK, USA), respectively. The type strain (ALDCT) had a narrow substrate specificity and could grow only with n-alkanes (from C6 to C12), pyruvate, butyrate, hexanoic acid and 4-methyloctanoic acid. Cells of strain ALDCT stained Gram-negative and were slightly curved, short rods with oval ends (2.5–3.0×1.0–1.4 μm), often occurring in pairs. Cells tended to form aggregates or large clusters and were non-motile and did not form endospores. Optimum growth occurred between 31 and 37 °C and at pH 6.5–7.2. NaCl was not required for growth, but salt concentrations up to 55 g l−1 could be tolerated. The DNA G+C content was 53.6 mol%. Phylogenetic analysis of the 16S rRNA genes revealed that strains ALDCT and Lake were closely related, but not identical (99.9 % similarity). The two strains were not closely related to other known alkane-degrading, sulfate-reducing bacteria or to other genera of the Deltaproteobacteria. Therefore, it is proposed that strain ALDCT (=JCM 13588T=ATCC BAA-1302T) represents the type strain of a novel species and genus, with the name Desulfoglaeba alkanexedens gen. nov., sp. nov.

scholarly journals Detection and Quantification of Functional Genes of Cellulose- Degrading, Fermentative, and Sulfate-Reducing Bacteria and Methanogenic Archaea

2010 ◽  
Vol 76 (7) ◽  
pp. 2192-2202 ◽  
Author(s):  
L. P. Pereyra ◽  
S. R. Hiibel ◽  
M. V. Prieto Riquelme ◽  
K. F. Reardon ◽  
A. Pruden
Keyword(s):  
Cellulose Degradation ◽  
Methanogenic Archaea ◽  
Sulfate Reducing Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Significant Advance ◽  
Sulfate Reducing ◽  
Degrading Bacteria ◽  
Fermentative Bacteria ◽  
Reducing Bacteria

ABSTRACT Cellulose degradation, fermentation, sulfate reduction, and methanogenesis are microbial processes that coexist in a variety of natural and engineered anaerobic environments. Compared to the study of 16S rRNA genes, the study of the genes encoding the enzymes responsible for these phylogenetically diverse functions is advantageous because it provides direct functional information. However, no methods are available for the broad quantification of these genes from uncultured microbes characteristic of complex environments. In this study, consensus degenerate hybrid oligonucleotide primers were designed and validated to amplify both sequenced and unsequenced glycoside hydrolase genes of cellulose-degrading bacteria, hydA genes of fermentative bacteria, dsrA genes of sulfate-reducing bacteria, and mcrA genes of methanogenic archaea. Specificity was verified in silico and by cloning and sequencing of PCR products obtained from an environmental sample characterized by the target functions. The primer pairs were further adapted to quantitative PCR (Q-PCR), and the method was demonstrated on samples obtained from two sulfate-reducing bioreactors treating mine drainage, one lignocellulose based and the other ethanol fed. As expected, the Q-PCR analysis revealed that the lignocellulose-based bioreactor contained higher numbers of cellulose degraders, fermenters, and methanogens, while the ethanol-fed bioreactor was enriched in sulfate reducers. The suite of primers developed represents a significant advance over prior work, which, for the most part, has targeted only pure cultures or has suffered from low specificity. Furthermore, ensuring the suitability of the primers for Q-PCR provided broad quantitative access to genes that drive critical anaerobic catalytic processes.

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