From individual response to population ecology: Environmental factors restricting survival of vegetative bacteria at solid-air interfaces

• Published in: The Science of the total environment Vol. 773; p. 144982
• Main Authors: Pashang, Rosha, Gilbride, Kimberley A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.06.2021
• Subjects: Bacteria; Bentonite; Bentonite - analysis; Canada; Deep geological repository; Desiccation; Microbiota; Nuclear waste management; Radioactive Waste - analysis; Solid-air interfaces; Vegetative bacteria; Canada; SRB; MIC; Desiccation; EPS; VBNC; MPN; DGR; NWMO; Nuclear waste management; Deep geological repository; PLFA; AECL; AODC; CFU; Vegetative bacteria; aw; RH; EBS; Bentonite; APM; Solid-air interfaces
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.144982

Combating microbial survival on dry surfaces contributes to improving public health in indoor environments (clinical and industrial settings) and extends to the natural environment. For vegetative bacteria at solid-air interfaces, lack of water impacts cellular response, and acclimation depends on community support in response to ecological processes. Gaining insights about important ecological processes leading to inhibition of microbial survival under extreme conditions, such as vicinity of highly radioactive nuclear waste, is key for improving engineering designs. Canada plans to store used nuclear fuel and radioactive waste in a deep geological repository (DGR) with a multiple-barrier system constructed at an approximate depth of 500 m. Microorganisms in highly compacted bentonite surrounding used fuel containers will be challenged by high pressure, temperature, and radiation, as well as limited water and nutrients. Thus, it is difficult to estimate microbial activities, given that the prime concern for a microbial community is survival, and energy expenditure is regulated. To enable preventive measures and for risk evaluation, a deeper understanding of community-based survival strategies of bacterial cells exposed to air (gaseous phase) during prolonged periods of desiccation is required. An in-depth review of collective studies that assess microbial survival and persistence during desiccation is presented here to augment and direct our prior knowledge about tactics used by bacteria for survival at interfaces in hostile natural environments including and similar to a DGR. [Display omitted] •Inhibition of microbes by limiting hydration cycles•Matric stress impacts microbial activities, mobility, and likelihood of survival•Survival strategies of microbes vary depending on cellular and community-based mechanisms.•Microbial hubs shift between life cycles and metabolic stages.