Bacterial biofilm colonization and succession in tropical marine waters are similar across different types of stone materials used in seawall construction

Abstract

Seawalls are important in protecting coastlines from currents, erosion, sea-level rise, and flooding. They are, however, associated with reduced biodiversity, due to their steep orientation, lack of microhabitats, and the materials used in their construction. Hence, there is considerable interest in modifying seawalls to enhance the settlement and diversity of marine organisms, as microbial biofilms play a critical role facilitating algal and invertebrate colonization. We assessed how different stone materials, ranging from aluminosilicates to limestone and concrete, affect biofilm formation. Metagenomic assessment of marine microbial communities indicated no significant impact of material on microbial diversity, irrespective of the diverse surface chemistry and topography. Based on KEGG pathway analysis, surface properties appeared to influence the community composition and function during the initial stages of biofilm development, but this effect disappeared by Day 31. We conclude that marine biofilms converged over time to a generic marine biofilm, rather than the underlying stone substrata type playing a significant role in driving community composition.

Biodeterioration and Chemical Corrosion of Concrete in the Marine Environment: Too Complex for Prediction

“…Different concrete compositions showed different colonization patterns during the first weeks, but these differences tended to even out, suggesting a replacement of initially adhering microorganisms with more generic concrete colonizers, as also suggested by Ref. [39]. No special acid-producing genera were detected in the sessile populations, although calcium was removed from the concrete surfaces, indicating corrosion.…”

“…Ref. [39], after a series of experiments to assess the effects of different stone substrata (including concrete) on marine biofilm formation, similarly concluded that the biofilms converged over time to a generic marine type and that the underlying substrata did not play a significant role in community composition. Where the substrata are similar, as in this case where they were all types of natural or artificial stone, this may be true, but there are certainly differences between the biofilm-formers on very different substrates in seawater, such as concrete and wood, for example [60].…”

“…is unknown, although there is no evidence of this from studies on the better-studied sewer pipe corrosion. Recently, however, there have been publications indicating that the initial microbial population attaching to concrete in the marine environment changes with time to produce a common "generic" concrete biofilm [39][40][41]. Earlier results had indicated this possibility.…”

Coastal greening of grey infrastructure: an update on the state-of-the-art

“…Natanzi et al (2021) reported differences in the relative abundances of cyanobacteria, diatoms associated with different concrete mixtures after one month. Conversely, after a similar deployment time (31 days), Summers et al (2022) found no differences in microbial diversity among the same stone types tested in Hartanto et al (2022). Whilst it appears that surface properties may influence microbial communities early on, it appears that communities converge later in the ecological succession process.…”

“…-Consideration of greater number of materials (Becker et al, 2020;Hsiung et al, 2020;Schaefer et al, 2020Schaefer et al, , 2023Vivier et al, 2021a;Natanzi et al, 2021;Dauvin et al, 2022;Dodds et al, 2022;Hartanto et al, 2022;Lapinski et al, 2022;Summers et al, 2022).…”