RESUMO
Biofilms represent resilient microbial communities responsible for inducing chronic infections in human subjects. Given the escalating challenges associated with antibiotic therapy failures in clinical infections linked to biofilm formation, a peptide-based approach emerges as a promising alternative to effectively combat these notoriously resistant biofilms. Contrary to conventional antimicrobial peptides, which predominantly target cellular membranes, antibiofilm peptides necessitate a multifaceted approach, addressing various "biofilm-specific factors." These factors encompass Extracellular Polymeric Substance (EPS) degradation, membrane targeting, cell signaling, and regulatory mechanisms. Recent research endeavors have been directed toward assessing the potential of peptides as potent antibiofilm agents. However, to translate these peptides into viable clinical applications, several critical considerations must be meticulously evaluated during the peptide design process. This review serves to furnish an all-encompassing summary of the pivotal factors and parameters that necessitate contemplation for the successful development of an efficacious antibiofilm peptide.
RESUMO
Increasing number of reports on uranium contamination in groundwater bodies is a growing concern. Deinococcus radiodurans biofilm-based U(VI) bioremediation has great potential to provide solution. This study focuses on the kinetic modelling of uranium biosorption by D. radiodurans biofilm biomass and identification of the functional groups involved in the sequestration process. The effect of temperature, pH and amount of biofilm dry mass were studied using two uranyl ion concentrations (100 and 1000 mg/L). D. radiodurans dry biomass showed good affinity for uranyl ion adsorption. The kinetic experiments revealed that the biosorption process was spontaneous and exothermic in nature. The modelling of kinetic adsorption data revealed that U(VI) sorption by D. radiodurans biofilm biomass follows a pseudo-second-order reaction. Mechanism of U(VI) sorption was suggested to follow an intra-particle diffusion model, which includes covalent bonding between U(VI) and functional groups present on the surface of biofilm biomass, and diffusional barrier acts as a rate limiting step. External mass transfer was the rate-limiting step as evident from Boyd and Elovich plot. Chemical modifications in surface functional groups of biofilm biomass, confirmed the involvement of carboxyl, phosphate, and hydroxyl groups in uranium binding as a significant loss in U(VI) sorption capacity was recorded in these chemically modified biomasses. XRD data indicated the formation of metal deposits, predominantly as uranyl phosphates.
Assuntos
Deinococcus , Urânio , Adsorção , Biofilmes , Concentração de Íons de Hidrogênio , Cinética , Urânio/análiseRESUMO
Deinococcus radiodurans is the most radiation-tolerant organism ever known. It has gained importance in recent years as a potential candidate for bioremediation of heavy metals, especially the radioactive type. This study investigates the efficiency of a recombinant D. radiodurans (DR1-bf+) strain with an ability to form biofilm for uranium remediation. The modified Arsenazo III dye method was used to estimate the uranium concentration. Uranyl nitrate aqueous solution was generated during the operation of nuclear fuel reprocessing. The D. radiodurans biofilm (DR1-bf+) grown in the presence of 20 mM Ca2+ showed remarkable ability of uranyl ion removal. DR1-bf+ (Ca2+) biofilm removed ~75+/-2% of 1000 mg/L uranium within 30 min post-treatment from uranyl nitrate aqueous solution. Uranium removal rate was also found to be directly proportional to biofilm age. This study discusses the ability of D. radiodurans biofilm in uranium removal.