Antimicrobial Coating Efficacy for Prevention of Pseudomonas aeruginosa Biofilm Growth on ISS Water System Materials

Abstract

Biofilms can lead to biofouling, microbially induced corrosion, physical impediment and eventual loss in function of water systems, and other engineered systems. The remoteness and closed environment of the International Space Station (ISS) make it vulnerable to unchecked biofilm growth; thus, biofilm mitigation strategies are crucial for current ISS operation and future long duration and deep-space crewed missions. In this study, a space flown bacterial strain of Pseudomonas aeruginosa (PA14) was used as a model organism for its ability to form biofilms. Additionally, a novel antimicrobial coating’s ability to reduce biofilm accumulation on stainless steel, Teflon, titanium, and Inconel (all used in the ISS water treatment and handling systems) was analyzed. Coated materials demonstrated reductions of P. aeruginosa biofilm across all materials when tested in a continuous flow system with tryptic soy broth medium. However, the coating lost efficacy in potato dextrose broth medium. These findings were corroborated via scanning electron microscopy. This study illustrates the fundamental importance of using multiple approaches to test antibiofilm strategies, as well as the specificity in which conditions such strategies can be implemented.

Phylogenomics, phenotypic, and functional traits of five novel (Earth-derived) bacterial species isolated from the International Space Station and their prevalence in metagenomes

“…Such missions will be measured in multiple years rather than in months and will have no or little resupply from Earth. In such cases, the microbiome of www.nature.com/scientificreports/ the space vessel or habitat will need to be monitored for multiple reasons: the spread of pathogens through the air or on surfaces which could infect humans 63 or plants 64 as well as the spread of antimicrobial resistance genes 65 , the health of human commensal microbiomes (and potential overgrowth of secondary pathogens), and the potential for biofouling of fluid lines or water supplies via microbial overgrowth 66 . Also, with no resupply from Earth there is no ability to gain access to Earth's massive microbial biodiversity.…”

Vitreous Magnesium Sulfate Hydrate as a Potential Mechanism for Preservation of Microbial Viability on Europa

“…No evidence of cytoplasmic leakage was detected within the room temperature treatment samples (Figure 6(A)). Additionally, thin filaments are seen that resemble those associated with biofilms or cells that are coated in extracellular polymeric substrates (EPS) and dried out (Mhatre et al 2020;Mettler et al 2022). As P. haloplanktis is not known to form biofilms and was collected in the late log phase of growth, it is more likely that the filaments seen here are small amounts of EPS on the surface of the cells (Figures 6(A) and (B)) and EPS-like fluids that are leaking out of the cells when they undergo traumatic lysing (Figures 6(B) and (C)).…”

Phylogenetic affiliations and genomic characterization of novel bacterial species and their abundance in the International Space Station

“…Like the proverbial mustard seed, perhaps we inadvertently carry a planet’s worth of microbial diversity wherever we travel. The novel microbes described herein are not necessarily any more noteworthy than those which might be isolated from an office building on Earth [though they are likely far more resilient given the harsh conditions [ 67 ] of the space environment], and yet each hosts significant potential for affecting human health [ 5 ] or for use in assisting plant growth [ 68 ], bioremediation or manufacturing, and offers a glimpse into the genetic and metabolic potential of the microbial diversity of the ISS [ 69 ].…”