High-Level Abundances ofMethanobacterialesandSyntrophobacteralesMay Help To Prevent Corrosion of Metal Sheet Piles

Abstract

Iron sheet piles are widely used in flood protection, dike construction, and river bank reinforcement. Their corrosion leads to gradual deterioration and often makes replacement necessary. Natural deposit layers on these sheet piles can prevent degradation and significantly increase their life span. However, little is known about the mechanisms of natural protective layer formation. Here, we studied the microbially diverse populations of corrosion-protective deposit layers on iron sheet piles at the Gouderak pumping station in Zuid-Holland, the Netherlands. Deposit layers, surrounding sediment and top sediment samples were analyzed for soil physicochemical parameters, microbially diverse populations, and metabolic potential. Methanogens appeared to be enriched 18-fold in the deposit layers. After sequencing, metagenome assembly and binning, we obtained four nearly complete draft genomes of microorganisms (Methanobacteriales, two Coriobacteriales, and Syntrophobacterales) that were highly enriched in the deposit layers, strongly indicating a potential role in corrosion protection. Coriobacteriales and Syntrophobacterales could be part of a microbial food web degrading organic matter to supply methanogenic substrates. Methane-producing Methanobacteriales could metabolize iron, which may initially lead to mild corrosion but potentially stimulates the formation of a carbonate-rich protective deposit layer in the long term. In addition, Methanobacteriales and Coriobacteriales have the potential to interact with metal surfaces via direct interspecies or extracellular electron transfer. In conclusion, our study provides valuable insights into microbial populations involved in iron corrosion protection and potentially enables the development of novel strategies for in situ screening of iron sheet piles in order to reduce risks and develop more sustainable replacement practices. IMPORTANCE Iron sheet piles are widely used to reinforce dikes and river banks. Damage due to iron corrosion poses a significant safety risk and has significant economic impact. Different groups of microorganisms are known to either stimulate or inhibit the corrosion process. Recently, natural corrosion-protective deposit layers were found on sheet piles. Analyses of the microbial composition indicated a potential role for methane-producing archaea. However, the full metabolic potential of the microbial communities within these protective layers has not been determined. The significance of this work lies in the reconstruction of the microbial food web of natural corrosion-protective layers isolated from noncorroding metal sheet piles. With this work, we provide insights into the microbiological mechanisms that potentially promote corrosion protection in freshwater ecosystems. Our findings could support the development of screening protocols to assess the integrity of iron sheet piles to decide whether replacement is required.

Iron to Gas: Versatile Multiport Flow-Column Revealed Extremely High Corrosion Potential by Methanogen-Induced Microbiologically Influenced Corrosion (Mi-MIC)

“…Members of the M. maripaludis such as KA1 and OS7 are capable of secreting extracellular hydrogenases that transfers electrons from the metal surface to form hydrogen for methanogenesis. However, it is known that Methanobacterium IM1 have higher affinity for elemental iron than for H 2 (Beese-Vasbender et al, 2015;Kip et al, 2017;in 't Zandt et al, 2019). Though the specific mechanisms are still under investigation, it was speculated that Methanobacterium IM1 can tightly adhere to the metal surface, allowing cell-surface redox mediators to effectively transfer electrons (Beese-Vasbender et al, 2015).…”

“…Periodic sulfide measurements were conducted by collecting samples from individual sections of the column (Figure 1). At the end of the experiment, columns were taken apart by section and cleaned using NACE protocol SP0775-2013 (Haroon et al, 2013;Pinnock et al, 2018). Beads were weighed before and after the experiment by section using a Sartorius analytical scale (Sartorius AG, Germany) to calculate the individual corrosion rate (CR).…”

“…Under abiotic CO 2 -rich environments, i.e., oil and gas pipelines, semi-conductive magnetite (Fe 3 O 4 ) and chukanovite (Fe 2 (OH) 2 CO 3 ) could also be formed (Joshi, 2015;Barker et al, 2018), due to the inability of siderite reaching the supersaturation level. In the presence of brine solutions, additional minerals such as MgCO 3 and CaCO 3 are possible corrosion products (Barker et al, 2018;in 't Zandt et al, 2019) and changing the state of the siderite crystal structure. Furthermore, many of the isolated corrosive MA are marine microorganisms that require a salinity of 0.6 M eq of NaCl for growth, at this salinity the K sp would decrease resulting in an increased siderite solubility (Barker et al, 2018).…”

Opportunistic interactions on Fe0 between methanogens and acetogens from a climate lake

“…With these results we expand the diversity of microbial interactions on Fe 0 between acetogens and methanogens (from competition (Palacios et al, 2019b) to opportunism (this study)). Some studied suggested that methanogens like Methanothermobacter may have a protective role during corrosion (in 't Zandt et al, 2019), however here we show how such methanogens are positively affected by acetogenic partners. In consequence we recommend that the corrosive effects of methanogens should be investigated not only in pure culture but also in consortia with bacterial partners before suggesting they have a protective anticorrosive role.…”

“…But it is unknown whether any of these species can act as autotrophic acetogens, which is the only possibility in this enrichment. Of these, some Bacillus induced corrosion under nitrate reducing conditions (Wan et al, 2018;Xu et al, 2013), but in other instances Bacillus species inhibited corrosion by forming a passivating film of extracellular polymeric substances and/or calcite (Guo et al, 2019;. Corrosion was also inhibited by a Desulfitobacterium that oxidized Fe(III)-minerals to vivanite, forming a protective passivating layer on the metal surface (Comensoli et al, 2017).…”