Phys.org August 4, 2021
Researchers at the University of Delaware hypothesized that the microbial communities of concrete reflect those of the concrete components and that these communities change as the concrete ages. To show how microbial communities change over 2 years of outdoor weathering they used two sets of concrete cylinders, one prone to the concrete-degrading alkali-silica reaction (ASR) and the other having the risk of the ASR mitigated. After identifying and removing taxa that were likely laboratory or reagent contaminants, they found that precursor materials, particularly the large aggregate (gravel), were the probable source of ∼50 to 60% of the bacteria observed in the first cylinders from each series. Overall, community diversity decreased over 2 years. Most of the concrete microbiome was composed of Proteobacteria, Firmicutes, and Actinobacteria, although community composition changed seasonally and over multiyear time scales and was likely influenced by environmental deposition. According to the researchers understanding which microbes survive in concrete, under what conditions, and for how long has potential implications for biorepair of concrete…read more. Open Access TECHNICAL ARTICLEÂ
Concrete bacterial community relative abundance. Credit: mSystems, May/June 2021 Volume 6 Issue 3 e01153-20