One of the major challenges nanotechnology during last decade has been development new procedures to synthesize nanoparticles. In this context, biosynthetic methods have taken hold since they are simple, safe and eco-friendly.

Antarctica is an attractive target for human exploration and scientific investigation, however the negative effects of activity on this continent are long lasting can have serious consequences native ecosystem. Various areas been contaminated with diesel fuel, which contains harmful compounds such as heavy metals polycyclic aromatic hydrocarbons (PAH). Bioremediation PAHs by microorganisms ecological, economical safe decontamination approach. Since introduction foreign organisms into...

The vast application of fluorescent semiconductor nanoparticles (NPs) or quantum dots (QDs) has prompted the development new, cheap and safer methods that allow generating QDs with improved biocompatibility. In this context, green biological production represents a still unexplored area. This work reports intracellular CdTe biosynthesis in bacteria. Escherichia coli overexpressing gshA gene, involved glutathione (GSH) biosynthesis, was used to produce QDs. Cells exhibited higher reduced...

Fluorescent nanoparticles or quantum dots (QDs) have been intensely studied for basic and applied research due to their unique size-dependent properties. There is an increasing interest in developing ecofriendly methods synthesize these since they improve biocompatibility avoid the generation of toxic byproducts. The use biological systems, particularly prokaryotes, has emerged as a promising alternative. Recent studies indicate that QDs biosynthesis related factors such cellular redox...

Here we report the biological synthesis of CdS fluorescent nanoparticles (Quantum Dots, QDs) by polyextremophile halophilic bacteria isolated from Atacama Salt Flat (Chile), Uyuni (Bolivia) and Dead Sea (Israel). In particular, a Halobacillus sp. DS2, strain presenting high resistance to NaCl (3-22%), acidic pH (1-4) cadmium (CdCl2 MIC: 1,375 mM) was used for QDs biosynthesis studies. synthesize in presence concentrations process related with their capacity generate S2- these conditions....

Periodontitis, characterized by persistent inflammation in the periodontium, is intricately connected to systemic diseases, including oral cancer. Bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, play a pivotal role periodontitis development because they contribute dysbiosis tissue destruction. Thus, comprehending interplay between these bacteria their impacts on holds significant relevance clinical understanding treatment advancement. In present work, we explored, for...

Multiple applications of nanotechnology, especially those involving highly fluorescent nanoparticles (NPs) or quantum dots (QDs) have stimulated the research to develop simple, rapid and environmentally friendly protocols for synthesizing NPs exhibiting novel properties increased biocompatibility. In this study, a simple protocol chemical synthesis glutathione (GSH)-capped CdTe QDs (CdTe-GSH) resembling conditions found in biological systems is described. Using only CdCl2, K2TeO3 GSH, were...

Previously we reported the biosynthesis of intracellular cadmium sulfide quantum dots (CdS QDs) at low temperatures by Antarctic strain Pseudomonas fragi GC01. Here studied role volatile sulfur compounds (VSCs) in CdS QDs P. The nanoparticles was evaluated presence sulfate, sulfite, thiosulfate, sulfide, cysteine and methionine as sole sources. Intracellular occurred with all sources tested. However, extracellular observed only cultures amended (Cys) (Met). Extracellular were characterized...

Diesel oil is the main source of energy used in Antarctica. Since diesel composed toxic compounds such as polycyclic aromatic hydrocarbons (PAHs) and heavy metals, it represents a constant threat to organisms inhabiting this continent. In present study, we characterized chemical biological parameters diesel-exposed soils obtained from King George Island Contaminated PAH concentrations 1000 times higher than non-exposed soils. Some contaminated soil samples also exhibited high cadmium lead. A...

The pandemic that started in Wuhan (China) 2019 has caused a large number of deaths, and infected people around the world due to absence effective therapy against coronavirus 2 severe acute respiratory syndrome (SARS-CoV-2). Viral maturation requires activity main viral protease (M

Abstract Background Bacterial biosynthesis of fluorescent nanoparticles or quantum dots (QDs) has emerged as a unique mechanism for heavy metal tolerance. However, the physiological pathways governing removal QDs from bacterial cells remains elusive. This study investigates role minicells, previously identified means eliminating damaged proteins and enhancing resistance to stress. Building on our prior work, which unveiled formation minicells during cadmium in Escherichia coli , we...

Abstract Background Quantum Dots (QDs) are fluorescent nanoparticles with exceptional optical and optoelectronic properties, finding widespread utility in diverse industrial applications. Presently, chemically synthesized QDs employed solar cells, bioimaging, various technological domains. However, many applications demand prolonged lifespans under conditions of high-energy radiation. Over the past decade, microbial biosynthesis nanomaterials has emerged as a sustainable cost-effective...

The bacterial synthesis of fluorescent semiconductor nanoparticles or quantum dots (QDs), presents a sustainable method for producing nanomaterials with customized optical properties and significant technological potential. However, the underlying cellular mechanisms this process remain elusive. Specifically, role structures in QD generation has not been thoroughly investigated. In study, we examined morphological changes Escherichia coli during biosynthesis cadmium sulfide (CdS) QDs, using...

WaaL is a membrane enzyme that catalyzes key step in lipopolysaccharide (LPS) synthesis: the glycosidic bonding of sugar at proximal end undecaprenyl-diphosphate (Und-PP) O-antigen with terminal lipid A-core oligosaccharide (OS). Utilizing an vitro assay, we demonstrate here ligation purified Escherichia coli occurs without adenosine-5′-triphosphate (ATP) and magnesium ions. Furthermore, E. Pseudomonas aeruginosa proteins cannot catalyze ATP hydrolysis vitro. We also show lysine substitution...

In the present work, we report use of bacterial cells for production CdS/CdSe Core/Shell quantum dots (QDs), a complex nanostructure specially designed to improve their performance as photosensitizer in photovoltaic devices. The method requires incorporation L-cysteine, CdCl2 and Na2SeO3 Escherichia coli cultures allows tight control QDs properties. obtained were photophysically structurally characterized. When compared CdS QDs, classical shift UV-visible spectra nanostructures was observed...

In this study, we introduce a biological method for the production of ternary Quantum Dots (QDs): complex nanostructures with tunable optical and structural properties that utilizes post-synthesis modifications through cation exchange. This versatile in-situ exchange being reported first time shows great potential extending scope microbial synthesis. By using bacterial-based method, easily synthesize purify CdS, CdSAg, Ag2S nanocrystals size below 15 nm variable morphologies exhibit...

Abstract Background Microbes are present in almost every environment on Earth, even those with extreme environmental conditions such as Antarctica, where rocks may represent the main refuge for life. Lithobiontic communities composed of microorganisms capable colonizing and, it is a not so well studied bacterial community, they very interesting source diversity and functional traits potential biotechnological applications. In this work we analyzed ability Antarctic lithobiontic bacterium to...

Recently, we reported the production of Cadmium sulfide (CdS) fluorescent semiconductor nanoparticles (quantum dots, QDs) by acidophilic bacteria Acidithiobacillus genus. Here, report that addition inorganic phosphate to thiooxidans ATCC 19703 cultures favors biosynthesis CdS QDs at acidic conditions (pH 3.5). The effect pH, and cadmium concentrations on was studied using Response Surface Methodology (RSM), a multivariate technique for analytical optimization scarcely used in microbiological...

P. gingivalis has been extensively associated with both the onset and progression of periodontitis. We previously isolated characterized two strains, one from a patient exhibiting severe chronic periodontitis (CP3) another periodontally healthy individual (H3). CP3 strain possessed higher ability forming biofilms invade gingival epithelial cells, compared to H3. Here, we aimed determine whether differences in virulence between these strains could be explained by presence or absence specific...