The effects of calcium–silicate–hydrate (C–S–H) seeds on reference microorganisms

Abstract

Building materials are constantly improved with various additives and admixtures in order to achieve goals ranging from obtaining increased durability or antimicrobial activity up to reducing the carbon footprint left by the cement production. Since nanomaterials were proposed for cement products, many studies explored the possibilities for their incorporation. One of the novel trends in studying these materials is evaluating their impact on living organisms, with the focus not only on toxicology but also on the application potential. Therefore, in this study, we investigated the effects of three types of calciumsilicate-hydrate (C-S-H) seeds on reference microorganisms in the scope of their basic physiology and primary metabolism. Shape, size and elemental composition of C-S-H seeds were also evaluated. The tests on the reference microorganisms have shown that the reaction to these nanomaterials can be specific and depends on the strain as well as the type of used nanomaterial. Furthermore, the presence of C-S-H seeds in the growth environment led to metabolic stimulation that resulted in faster growth, higher biochemical activity, and increased biofilm formation. Based on our findings, we conclude that even though C-S-H seeds have antimicrobial potential, they can be potentially used to promote the growth of selected microbial strains. This phenomenon could be further investigated towards the formation of beneficial biofilms on building materials.

Basic physiology of Pseudomonas aeruginosa contacted with carbon nanocomposites

“…After 6 and 12 h, other reads have strengthened the results, providing more insight into population growth and inhibition dynamics. The nanomaterials did not lead to complete inhibition of bacterial growth, similar to the observation made in the previous studies (Sikora et al 2018;Augustyniak et al 2020b). All nanomaterials containing titanium dioxide or carbon nanotubes caused a decrease in the OD, especially in the highest concentrations.…”

Investigating the release of ZnO nanoparticles from cement mortars on microbiological models

“…In recent years, there is a growing concern about the safety of using NPs in cementitious composites. Thus, the amount of the research works increased substantially (Bräu et al 2012;Spinazzè et al 2016;Bossa et al 2017Bossa et al , 2019Diamond et al 2017;Miller et al 2017;Strokova et al 2018;Funk et al 2019;Torres-Carrasco et al 2019;Augustyniak et al 2020b). In Funk et al (2019) analyzed micro-and nano-components' release from cementitious composites containing TiO 2 and SiO 2 NPs after freeze-thawing.…”

“…In works (Bossa et al 2017(Bossa et al , 2019Diamond et al 2017), extensive evaluations on the release behavior and understanding the phenomena underlying the mechanism on releasing TiO 2 nanoparticles were performed. In our recent research (Augustyniak et al 2020b), the effects of commercially available and laboratory synthesized calcium-silicate-hydrate (C-S-H) nanostructures on the reference microorganisms were tested. These studies have shown that there, in some cases, the addition of C-S-H changes the growth environment for bacteria in a way that promotes their growth (Augustyniak et al 2020b).…”

“…In our recent research (Augustyniak et al 2020b), the effects of commercially available and laboratory synthesized calcium-silicate-hydrate (C-S-H) nanostructures on the reference microorganisms were tested. These studies have shown that there, in some cases, the addition of C-S-H changes the growth environment for bacteria in a way that promotes their growth (Augustyniak et al 2020b). However, this effect depended on the type of admixture and a particular bacterial strain.…”

“…Moreover, in most available literature studies, the number of released NPs from cement-based composites is only quantitatively and qualitatively evaluated. Only a few studies dealt with the influence of nanoparticles on microorganisms with a focus on their physiological characteristics, even though they were found to be an excellent indicator for initial screening of the potentially harmful effects of NPs (Coutand et al 2011;Holden et al 2014;Sikora et al 2018a;Augustyniak et al 2020b).…”