| 1. |
- Chen, Xin, 1980, et al.
(författare)
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Graphene Oxide Attenuates Toxicity of Amyloid-β Aggregates in Yeast by Promoting Disassembly and Boosting Cellular Stress Response
- 2023
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Ingår i: Advanced Functional Materials. - 1616-3028 .- 1616-301X. ; 33:45
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, with the aggregation of misfolded amyloid-β (Aβ) peptides in the brain being one of its histopathological hallmarks. Recently, graphene oxide (GO) nanoflakes have attracted significant attention in biomedical areas due to their capacity of suppressing Aβ aggregation in vitro. The mechanism of this beneficial effect has not been fully understood in vivo. Herein, the impact of GO on intracellular Aβ42 aggregates and cytotoxicity is investigated using yeast Saccharomyces cerevisiae as the model organism. This study finds that GO nanoflakes can effectively penetrate yeast cells and reduce Aβ42 toxicity. Combination of proteomics data and follow-up experiments show that GO treatment alters cellular metabolism to increases cellular resistance to misfolded protein stress and oxidative stress, and reduces amounts of intracellular Aβ42 oligomers. Additionally, GO treatment also reduces HTT103QP toxicity in the Huntington's disease (HD) yeast model. The findings offer insights for rationally designing GO nanoflakes-based therapies for attenuating cytotoxicity of Aβ42, and potentially of other misfolded proteins involved in neurodegenerative pathology.
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| 2. |
- Derouiche, Abderahmane, 1980, et al.
(författare)
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Bacillus subtilis single-stranded DNA-binding protein SsbA is phosphorylated at threonine 38 by the serine/threonine kinase YabT
- 2016
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Ingår i: Periodicum Biologorum. - : Hrvatski Prirodoslovno Drustvo (Croatian Society for Natural Sciences). - 0031-5362 .- 1849-0964. ; 118:4, s. 399-404
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Tidskriftsartikel (refereegranskat)abstract
- © 2016, Croatian Society of Natural Sciences. All rights reserved.Background and purpose: Single-stranded DNA-binding proteins participate in all stages of DNA metabolism that involve single-stranded DNA, from replication, recombination, repair of DNA damage, to natural competence in species such as Bacillus subtilis. B. subtilis single-stranded DNA-binding proteins have previously been found to be phosphorylated on tyrosine and arginine residues. While tyrosine phosphorylation was shown to enhance the DNA-binding properties of SsbA, arginine phosphorylation was not functionally characterized. Materials and methods: We used mass spectrometry analysis to detect phosphorylation of SsbA purified from B. subtilis cells. The detected phosphorylation site was assessed for its influence on DNA-binding in vitro, using electrophoretic mobility shift assays. The ability of B. subtilis serine/ threonine kinases to phosphorylate SsbA was assessed using in vitro phosphorylation assays. Results: In addition to the known tyrosine phosphorylation of SsbA on tyrosine 82, we identified a new phosphorylation site: threonine 38. The in vitro assays demonstrated that SsbA is preferentially phosphorylated by the B. subtilis Hanks-type kinase YabT, and phosphorylation of threonine 38 leads to enhanced cooperative binding to DNA. Conclusions: Our findings contribute to the emerging picture that bacterial proteins, exemplified here by SsbA, undergo phosphorylation at multiple residues. This results in a complex regulation of cellular functions, and suggests that the complexity of the bacterial cellular regulation may be underestimated.
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| 3. |
- Kalantari, Aida, 1986, et al.
(författare)
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Conversion of Glycerol to 3-Hydroxypropanoic Acid by Genetically Engineered Bacillus subtilis
- 2017
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 8:APR
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Tidskriftsartikel (refereegranskat)abstract
- 3-Hydroxypropanoic acid (3-HP) is an important biomass-derivable platform chemical that can be converted into a number of industrially relevant compounds. There have been several attempts to produce 3-HP from renewable sources in cell factories, focusing mainly on Escherichia coli, Klebsiella pneumoniae, and Saccharomyces cerevisiae. Despite the significant progress made in this field, commercially exploitable large-scale production of 3-HP in microbial strains has still not been achieved. In this study, we investigated the potential of Bacillus subtilis as a microbial platform for bioconversion of glycerol into 3-HP. Our recombinant B. subtilis strains overexpress the two-step heterologous pathway containing glycerol dehydratase and aldehyde dehydrogenase from K. pneumoniae. Genetic engineering, driven by in silico optimization, and optimization of cultivation conditions resulted in a 3-HP titer of 10 g/L, in a standard batch cultivation. Our findings provide the first report of successful introduction of the biosynthetic pathway for conversion of glycerol into 3-HP in B. subtilis. With this relatively high titer in batch, and the robustness of B. subtilis in high density fermentation conditions, we expect that our production strains may constitute a solid basis for commercial production of 3-HP.
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| 4. |
- Mokkapati, Venkata Raghavendra Subrahmanya Sar, 1981, et al.
(författare)
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Bacterial response to graphene oxide and reduced graphene oxide integrated in agar plates
- 2018
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 5:11
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Tidskriftsartikel (refereegranskat)abstract
- There are contradictory reports in the literature regarding the anti-bacterial activity of graphene, graphene oxide (GO) and reduced graphene oxide (rGO). This controversy is mostly due to variations in key parameters of the reported experiments, like: type of substrate, form of graphene, number of layers, type of solvent and most importantly, type of bacteria. Here, we present experimental data related to bacterial response to GO and rGO integrated in solid agar-based nutrient plates-a standard set-up for bacterial growth that is widely used by microbiologists. Bacillus subtilis and Pseudomonas aeruginosa strains were used for testing bacterial growth. We observed that plate-integrated rGO showed strong anti-bacterial activity against both bacterial species. By contrast, plate-integrated GO was harmless to both bacteria. These results reinforce the notion that the response of bacteria depends critically on the type of graphene material used and can vary dramatically from one bacterial strain to another, depending on bacterial physiology.
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| 5. |
- Pandit, Santosh, 1987, et al.
(författare)
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Vertically Aligned Graphene Coating is Bactericidal and Prevents the Formation of Bacterial Biofilms
- 2018
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Ingår i: Advanced Materials Interfaces. - : Wiley. - 2196-7350. ; 5:7
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Tidskriftsartikel (refereegranskat)abstract
- The key first step in developing bacterial infections related to implants and medical devices is the attachment of planktonic bacterial cells, and subsequent formation of biofilms. Herein, it is reported that graphene, a 2D carbon-based material, can be effectively used to prevent bacterial attachment. The key parameter for this effect is the orientation of graphene with respect to the coated surface. Chemical vapor deposition (CVD) graphene, deposited horizontally on the surface, exhibits no antibacterial effect. By contrast, an array of graphene flakes grown perpendicularly to the surface by a plasma-enhanced CVD (PECVD) process prevent biofilm formation. Electron microscopy reveals that the exposed edges of vertically aligned graphene flakes penetrate the bacterial membrane and drain the cytosolic content. Bacteria are not able to develop resistance to this killing mechanism during multiple exposures. By keeping the height of the vertical graphene coating between 60 and 100 nm, the coating is able to effectively kill bacteria, while being completely harmless to mammalian cells.
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| 6. |
- Rahimi, Shadi, 1982, et al.
(författare)
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Automated Prediction of Bacterial Exclusion Areas on SEM Images of Graphene–Polymer Composites
- 2023
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Ingår i: Nanomaterials. - 2079-4991. ; 13:10
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Tidskriftsartikel (refereegranskat)abstract
- To counter the rising threat of bacterial infections in the post-antibiotic age, intensive efforts are invested in engineering new materials with antibacterial properties. The key bottleneck in this initiative is the speed of evaluation of the antibacterial potential of new materials. To overcome this, we developed an automated pipeline for the prediction of antibacterial potential based on scanning electron microscopy images of engineered surfaces. We developed polymer composites containing graphite-oriented nanoplatelets (GNPs). The key property that the algorithm needs to consider is the density of sharp exposed edges of GNPs that kill bacteria on contact. The surface area of these sharp exposed edges of GNPs, accessible to bacteria, needs to be inferior to the diameter of a typical bacterial cell. To test this assumption, we prepared several composites with variable distribution of exposed edges of GNP. For each of them, the percentage of bacterial exclusion area was predicted by our algorithm and validated experimentally by measuring the loss of viability of the opportunistic pathogen Staphylococcus epidermidis. We observed a remarkable linear correlation between predicted bacterial exclusion area and measured loss of viability (R2 = 0.95). The algorithm parameters we used are not generally applicable to any antibacterial surface. For each surface, key mechanistic parameters must be defined for successful prediction.
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| 7. |
- Ruan, Hengzhi, 1995, et al.
(författare)
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Biomimetic Antibacterial Gelatin Hydrogels with Multifunctional Properties for Biomedical Applications
- 2023
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Ingår i: ACS Applied Materials & Interfaces. - 1944-8252 .- 1944-8244. ; 15:47, s. 54249-54249–54265
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Tidskriftsartikel (refereegranskat)abstract
- A facile novel approach of introducing dopamine and [2-(methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide via dopamine-triggered in situ synthesis into gelatin hydrogels in the presence of ZnSO4 is presented in this study. Remarkably, the resulting hydrogels showed 99.99 and 100% antibacterial efficiency against Gram-positive and Gram-negative bacteria, respectively, making them the highest performing surfaces in their class. Furthermore, the hydrogels showed adhesive properties, self-healing ability, antifreeze properties, electrical conductivity, fatigue resistance, and mechanical stability from −100 to 80 °C. The added multifunctional performance overcomes several disadvantages of gelatin-based hydrogels such as poor mechanical properties and limited thermostability. Overall, the newly developed hydrogels show significant potential for numerous biomedical applications, such as wearable monitoring sensors and antibacterial coatings.
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| 8. |
- Ruan, Hengzhi, 1995, et al.
(författare)
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Polysaccharide-based antibacterial coating technologies
- 2023
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Ingår i: Acta Biomaterialia. - 1878-7568 .- 1742-7061. ; 168, s. 42-77
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Forskningsöversikt (refereegranskat)abstract
- To tackle antimicrobial resistance, a global threat identified by the United Nations, is a common cause of healthcare-associated infections (HAI) and is responsible for significant costs on healthcare systems, a substantial amount of research has been devoted to developing polysaccharide-based strategies that prevent bacterial attachment and biofilm formation on surfaces. Polysaccharides are essential building blocks for life and an abundant renewable resource that have attracted much attention due to their intrinsic remarkable biological potential antibacterial activities. If converted into efficient antibacterial coatings that could be applied to a broad range of surfaces and applications, polysaccharide-based coatings could have a significant potential global impact. However, the ultimate success of polysaccharide-based antibacterial materials will be determined by their potential for use in manufacturing processes that are scalable, versatile, and affordable. Therefore, in this review we focus on recent advances in polysaccharide-based antibacterial coatings from the perspective of fabrication methods. We first provide an overview of strategies for designing polysaccharide-based antimicrobial formulations and methods to assess the antibacterial properties of coatings. Recent advances on manufacturing polysaccharide-based coatings using some of the most common polysaccharides and fabrication methods are then detailed, followed by a critical comparative overview of associated challenges and opportunities for future developments. Statement of significance: Our review presents a timely perspective by being the first review in the field to focus on advances on polysaccharide-based antibacterial coatings from the perspective of fabrication methods along with an overview of strategies for designing polysaccharide-based antimicrobial formulations, methods to assess the antibacterial properties of coatings as well as a critical comparative overview of associated challenges and opportunities for future developments. Meanwhile this work is specifically targeted at an audience focused on featuring critical information and guidelines for developing polysaccharide-based coatings. Including such a complementary work in the journal could lead to further developments on polysaccharide antibacterial applications.
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| 9. |
- Stancik, Ivan Andreas, et al.
(författare)
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Serine/Threonine Protein Kinases from Bacteria, Archaea and Eukarya Share a Common Evolutionary Origin Deeply Rooted in the Tree of Life
- 2018
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Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836 .- 1089-8638. ; 430:1, s. 27-32
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Tidskriftsartikel (refereegranskat)abstract
- The main family of serine/threonine/tyrosine protein kinases present in eukarya was defined and described by Hanks et al. in 1988 (Science, 241, 42–52). It was initially believed that these kinases do not exist in bacteria, but extensive genome sequencing revealed their existence in many bacteria. For historical reasons, the term “eukaryotic-type kinases” propagated in the literature to describe bacterial members of this protein family. Here, we argue that this term should be abandoned as a misnomer, and we provide several lines of evidence to support this claim. Our comprehensive phylostratigraphic analysis suggests that Hanks-type kinases present in eukarya, bacteria and archaea all share a common evolutionary origin in the lineage leading to the last universal common ancestor (LUCA). We found no evidence to suggest substantial horizontal transfer of genes encoding Hanks-type kinases from eukarya to bacteria. Moreover, our systematic structural comparison suggests that bacterial Hanks-type kinases resemble their eukaryal counterparts very closely, while their structures appear to be dissimilar from other kinase families of bacterial origin. This indicates that a convergent evolution scenario, by which bacterial kinases could have evolved a kinase domain similar to that of eukaryal Hanks-type kinases, is not very likely. Overall, our results strongly support a monophyletic origin of all Hanks-type kinases, and we therefore propose that this term should be adopted as a universal name for this protein family.
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| 10. |
- Abdel-Haleem, Alyaa M., et al.
(författare)
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Integrated Metabolic Modeling, Culturing, and Transcriptomics Explain Enhanced Virulence of Vibrio cholerae during Coinfection with Enterotoxigenic Escherichia coli
- 2020
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Ingår i: mSystems. - 2379-5077. ; 5:5
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Tidskriftsartikel (refereegranskat)abstract
- Gene essentiality is altered during polymicrobial infections. Nevertheless, most studies rely on single-species infections to assess pathogen gene essentiality. Here, we use genome-scale metabolic models (GEMs) to explore the effect of coinfection of the diarrheagenic pathogen Vibrio cholerae with another enteric pathogen, enterotoxigenic Escherichia coli (ETEC). Model predictions showed that V. cholerae metabolic capabilities were increased due to ample cross-feeding opportunities enabled by ETEC. This is in line with increased severity of cholera symptoms known to occur in patients with dual infections by the two pathogens. In vitro co-culture systems confirmed that V. cholerae growth is enhanced in cocultures relative to single cultures. Further, expression levels of several V. cholerae metabolic genes were significantly perturbed as shown by dual RNA sequencing (RNAseq) analysis of its cocultures with different ETEC strains. A decrease in ETEC growth was also observed, probably mediated by nonmetabolic factors. Single gene essentiality analysis predicted conditionally independent genes that are essential for the pathogen's growth in both single-infection and coinfection scenarios. Our results reveal growth differences that are of relevance to drug targeting and efficiency in polymicrobial infections. IMPORTANCE Most studies proposing new strategies to manage and treat infections have been largely focused on identifying druggable targets that can inhibit a pathogen's growth when it is the single cause of infection. In vivo, however, infections can be caused by multiple species. This is important to take into account when attempting to develop or use current antibacterials since their efficacy can change significantly between single infections and coinfections. In this study, we used genome-scale metabolic models (GEMs) to interrogate the growth capabilities of Vibrio cholerae in single infections and coinfections with enterotoxigenic E. coli (ETEC), which cooccur in a large fraction of diarrheagenic patients. Coinfection model predictions showed that V. cholerae growth capabilities are enhanced in the presence of ETEC relative to V. cholerae single infection, through cross-fed metabolites made available to V. cholerae by ETEC. In vitro, cocultures of the two enteric pathogens further confirmed model predictions showing an increased growth of V. cholerae in coculture relative to V. cholerae single cultures while ETEC growth was suppressed. Dual RNAseq analysis of the cocultures also confirmed that the transcriptome of V. cholerae was distinct during coinfection compared to single-infection scenarios where processes related to metabolism were significantly perturbed. Further, in silico gene-knockout simulations uncovered discrepancies in gene essentiality for V. cholerae growth between single infections and coinfections. Integrative model-guided analysis thus identified druggable targets that would be critical for V. cholerae growth in both single infections and coinfections; thus, designing inhibitors against those targets would provide a broader spectrum of coverage against cholera infections.
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| 11. |
- Abujubara, Helal, et al.
(författare)
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Substrate-derived Sortase A inhibitors: targeting an essential virulence factor of Gram-positive pathogenic bacteria
- 2023
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Ingår i: Chemical Science. - 2041-6520 .- 2041-6539. ; 14:25, s. 6975-6985
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Tidskriftsartikel (refereegranskat)abstract
- The bacterial transpeptidase Sortase A (SrtA) is a surface enzyme of Gram-positive pathogenic bacteria. It has been shown to be an essential virulence factor for the establishment of various bacterial infections, including septic arthritis. However, the development of potent Sortase A inhibitors remains an unmet challenge. Sortase A relies on a five amino acid sorting signal (LPXTG), by which it recognizes its natural target. We report the synthesis of a series of peptidomimetic inhibitors of Sortase A based on the sorting signal, supported by computational binding analysis. By employing a FRET-compatible substrate, our inhibitors were assayed in vitro. Among our panel, we identified several promising inhibitors with IC50 values below 200 mu M, with our strongest inhibitor - LPRDSar - having an IC50 of 18.9 mu M. Furthermore, it was discovered that three of our compounds show an effect on growth and biofilm inhibition of pathogenic Staphylococcus aureus, with the inclusion of a phenyl ring seemingly key to this effect. The most promising compound in our panel, BzLPRDSar, could inhibit biofilm formation at concentrations as low as 32 mu g mL(-1), manifesting it as a potential future drug lead. This could lead to treatments for MRSA infections in clinics and diseases such as septic arthritis, which has been directly linked with SrtA.
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| 12. |
- Acet, Ömür, et al.
(författare)
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Inhibition of bacterial adhesion by epigallocatechin gallate attached polymeric membranes
- 2023
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Ingår i: Colloids and Surfaces B: Biointerfaces. - : Elsevier BV. - 0927-7765 .- 1873-4367. ; 221
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Tidskriftsartikel (refereegranskat)abstract
- Microbial adhesion and formation of biofilms cause a serious problem in several areas including but not limited to food spoilage, industrial corrosion and nosocomial infections. These microbial biofilms pose a serious threat to human health since microbial communities in the biofilm matrix are protected with exopolymeric substances and difficult to eradicate with antibiotics. Hence, the prevention of microbial adhesion followed by biofilm formation is one of the promising strategies to prevent these consequences. The attachment of antimicrobial agents, coatings of nanomaterials and synthesis of hybrid materials are widely used approach to develop surfaces having potential to hinder bacterial adhesion and biofilm formation. In this study, epigallocatechin gallate (EGCG) is attached on p(HEMA-co-GMA) membranes to prevent the bacterial colonization. The attachment of EGCG to membranes was proved by Fourier-transform infrared spectroscopy (FT-IR). The synthesized membrane showed porous structure (SEM), and desirable swelling degree, which are ideal when it comes to the application in biotechnology and biomedicine. Furthermore, EGCG attached membrane showed significant potential to prevent the microbial colonization on the surface. The obtained results suggest that EGCG attached polymer could be used as an alternative approach to prevent the microbial colonization on the biomedical surfaces, food processing equipment as well as development of microbial resistant food packaging systems.
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| 13. |
- Aminian-Dehkordi, Javad, et al.
(författare)
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A Systems-Based Approach for Cyanide Overproduction by Bacillus megaterium for Gold Bioleaching Enhancement
- 2020
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Ingår i: Frontiers in Bioengineering and Biotechnology. - : Frontiers Media SA. - 2296-4185. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- With the constant accumulation of electronic waste, extracting precious metals contained therein is becoming a major challenge for sustainable development. Bacillus megaterium is currently one of the microbes used for the production of cyanide, which is the main leaching agent for gold recovery. The present study aimed to propose a strategy for metabolic engineering of B. megaterium to overproduce cyanide, and thus ameliorate the bioleaching process. For this, we employed constraint-based modeling, running in silico simulations on iJA1121, the genome-scale metabolic model of B. megaterium DSM319. Flux balance analysis (FBA) was initially used to identify amino acids to be added to the culture medium. Considering cyanide as the desired product, we used growth-coupled methods, constrained minimal cut sets (cMCSs) and OptKnock to identify gene inactivation targets. To identify gene overexpression targets, flux scanning based on enforced objective flux (FSEOF) was performed. Further analysis was carried out on the identified targets to determine compounds with beneficial regulatory effects. We have proposed a chemical-defined medium for accelerating cyanide production on the basis of microplate assays to evaluate the components with the greatest improving effects. Accordingly, the cultivation of B. megaterium DSM319 in a chemically-defined medium with 5.56 mM glucose as the carbon source, and supplemented with 413 μM cysteine, led to the production of considerably increased amounts of cyanide. Bioleaching experiments were successfully performed in this medium to recover gold and copper from telecommunication printed circuit boards. The results of inductively coupled plasma (ICP) analysis confirmed that gold recovery peaked out at around 55% after 4 days, whereas copper recovery continued to increase for several more days, peaking out at around 85%. To further validate the bioleaching results, FESEM, XRD, FTIR, and EDAX mapping analyses were performed. We concluded that the proposed strategy represents a viable route for improving the performance of the bioleaching processes.
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| 14. |
- Aminian-Dehkordi, Javad, et al.
(författare)
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Manually curated genome-scale reconstruction of the metabolic network of Bacillus megaterium DSM319
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Bacillus megaterium is a microorganism widely used in industrial biotechnology for production of enzymes and recombinant proteins, as well as in bioleaching processes. Precise understanding of its metabolism is essential for designing engineering strategies to further optimize B. megaterium for biotechnology applications. Here, we present a genome-scale metabolic model for B. megaterium DSM319, iJA1121, which is a result of a metabolic network reconciliation process. The model includes 1709 reactions, 1349 metabolites, and 1121 genes. Based on multiple-genome alignments and available genome-scale metabolic models for other Bacillus species, we constructed a draft network using an automated approach followed by manual curation. The refinements were performed using a gap-filling process. Constraint-based modeling was used to scrutinize network features. Phenotyping assays were performed in order to validate the growth behavior of the model using different substrates. To verify the model accuracy, experimental data reported in the literature (growth behavior patterns, metabolite production capabilities, metabolic flux analysis using C-13 glucose and formaldehyde inhibitory effect) were confronted with model predictions. This indicated a very good agreement between in silico results and experimental data. For example, our in silico study of fatty acid biosynthesis and lipid accumulation in B. megaterium highlighted the importance of adopting appropriate carbon sources for fermentation purposes. We conclude that the genome-scale metabolic model iJA1121 represents a useful tool for systems analysis and furthers our understanding of the metabolism of B. megaterium.
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| 15. |
- Aminian-Dehkordi, Javad, et al.
(författare)
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Synthetic biology tools for environmental protection
- 2023
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Ingår i: Biotechnology Advances. - 0734-9750. ; 68
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Forskningsöversikt (refereegranskat)abstract
- Synthetic biology transforms the way we perceive biological systems. Emerging technologies in this field affect many disciplines of science and engineering. Traditionally, synthetic biology approaches were commonly aimed at developing cost-effective microbial cell factories to produce chemicals from renewable sources. Based on this, the immediate beneficial impact of synthetic biology on the environment came from reducing our oil dependency. However, synthetic biology is starting to play a more direct role in environmental protection. Toxic chemicals released by industries and agriculture endanger the environment, disrupting ecosystem balance and biodiversity loss. This review highlights synthetic biology approaches that can help environmental protection by providing remediation systems capable of sensing and responding to specific pollutants. Remediation strategies based on genetically engineered microbes and plants are discussed. Further, an overview of computational approaches that facilitate the design and application of synthetic biology tools in environmental protection is presented.
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| 16. |
- Avaz, S., et al.
(författare)
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Graphene based nanosensor for aqueous phase detection of nitroaromatics
- 2017
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 7:41, s. 25519-25527
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Tidskriftsartikel (refereegranskat)abstract
- A graphene-based nanosensor was fabricated to selectively detect nitrotriazolone (NTO) molecules with a molecularly imprinted film via simple electrical measurements. Molecularly imprinted polymer comprising chitosan was used as sensitive layer. Gold electrodes for electrical measurements were lithographically fabricated on Si/SiO2 substrate, followed by monolayer graphene transfer and polymeric film coating. Monolayer graphene and molecularly imprinted polymer were characterized by ATR-FTIR, UV-Vis, SEM and Raman spectroscopy. Transfer-length measurements (TLM) indicate that the sensor selectively and linearly responds against aqueous NTO solutions within a wide range of concentration of 0.01-0.1 mg mL(-1) that covers the lowest toxic level of NTO determined by USEPA. This nanosensor with embedded electrodes is re-usable and suitable for field applications, offering real-time electrical measurements unlike current techniques where complex analytics are required.
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| 17. |
- Balasubramanian, Suvasini, et al.
(författare)
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Exploring the secretome of Corynebacterium glutamicum ATCC 13032
- 2024
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Ingår i: Frontiers in Bioengineering and Biotechnology. - 2296-4185. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- The demand for alternative sources of food proteins is increasing due to the limitations and challenges associated with conventional food production. Advances in biotechnology have enabled the production of proteins using microorganisms, thus prompting the exploration of attractive microbial hosts capable of producing functional proteins in high titers. Corynebacterium glutamicum is widely used in industry for the production of amino acids and has many advantages as a host organism for recombinant protein production. However, its performance in this area is limited by low yields of target proteins and high levels of native protein secretion. Despite representing a challenge for heterologous protein production, the C. glutamicum secretome has not been fully characterized. In this study, state-of-the-art mass spectrometry-based proteomics was used to identify and analyze the proteins secreted by C. glutamicum. Both the wild-type strain and a strain that produced and secreted a recombinant β-lactoglobulin protein were analyzed. A total of 427 proteins were identified in the culture supernatants, with 148 predicted to possess a secretion signal peptide. MS-based proteomics on the secretome enabled a comprehensive characterization and quantification (based on abundance) of the secreted proteins through label-free quantification (LFQ). The top 12 most abundant proteins accounted for almost 80% of the secretome. These are uncharacterized proteins of unknown function, resuscitation promoting factors, protein PS1, Porin B, ABC-type transporter protein and hypothetical membrane protein. The data can be leveraged for protein production by, e.g., utilizing the signal peptides of the most abundant proteins to improve secretion of heterologous proteins. In addition, secretory stress can potentially be alleviated by inactivating non-essential secreted proteins. Here we provide targets by identifying the most abundant, secreted proteins of which majority are of unknown function. The data from this study can thus provide valuable insight for researchers looking to improve protein secretion and optimize C. glutamicum as a host for secretory protein production.
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| 18. |
- Balusamy, Sri Renukadevi, et al.
(författare)
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A comprehensive and systemic review of ginseng-based nanomaterials: Synthesis, targeted delivery, and biomedical applications
- 2023
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Ingår i: Medicinal Research Reviews. - : Wiley. - 0198-6325 .- 1098-1128. ; 43:5, s. 1374-1410
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Forskningsöversikt (refereegranskat)abstract
- Among 17 Panax species identified across the world, Panax ginseng (Korean ginseng), Panax quinquefolius (American ginseng), and Panax notoginseng (Chinese ginseng) are highly recognized for the presence of bioactive compound, ginsenosides and their pharmacological effects. P. ginseng is widely used for synthesis of different types of nanoparticles compared to P. quinquefolius and P. notoginseng. The use of nano-ginseng could increase the oral bioavailability, membrane permeability, and thus provide effective delivery of ginsenosides to the target sites through transport system. In this review, we explore the synthesis of ginseng nanoparticles using plant extracts from various organs, microbes, and polymers, as well as their biomedical applications. Furthermore, we highlight transporters involved in transport of ginsenoside nanoparticles to the target sites. Size, zeta potential, temperature, and pH are also discussed as the critical parameters affecting the quality of ginseng nanoparticles synthesis.
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| 19. |
- Balusamy, Sri Renukadevi, et al.
(författare)
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Advancing sustainable agriculture: a critical review of smart and eco-friendly nanomaterial applications
- 2023
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Ingår i: Journal of Nanobiotechnology. - 1477-3155. ; 21:1
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Forskningsöversikt (refereegranskat)abstract
- Undoubtedly, nanoparticles are one of the ideal choices for achieving challenges related to bio sensing, drug delivery, and biotechnological tools. After gaining success in biomedical research, scientists are exploring various types of nanoparticles for achieving sustainable agriculture. The active nanoparticles can be used as a direct source of micronutrients or as a delivery platform for delivering the bioactive agrochemicals to improve crop growth, crop yield, and crop quality. Till date, several reports have been published showing applications of nanotechnology in agriculture. For instance, several methods have been employed for application of nanoparticles; especially metal nanoparticles to improve agriculture. The physicochemical properties of nanoparticles such as core metal used to synthesize the nanoparticles, their size, shape, surface chemistry, and surface coatings affect crops, soil health, and crop-associated ecosystem. Therefore, selecting nanoparticles with appropriate physicochemical properties and applying them to agriculture via suitable method stands as smart option to achieve sustainable agriculture and improved plant performance. In presented review, we have compared various methods of nanoparticle application in plants and critically interpreted the significant differences to find out relatively safe and specific method for sustainable agricultural practice. Further, we have critically analyzed and discussed the different physicochemical properties of nanoparticles that have direct influence on plants in terms of nano safety and nanotoxicity. From literature review, we would like to point out that the implementation of smaller sized metal nanoparticles in low concentration via seed priming and foliar spray methods could be safer method for minimizing nanotoxicity, and for exhibiting better plant performance during stress and non-stressed conditions. Moreover, using nanomaterials for delivery of bioactive agrochemicals could pose as a smart alternative for conventional chemical fertilizers for achieving the safer and cleaner technology in sustainable agriculture. While reviewing all the available literature, we came across some serious drawbacks such as the lack of proper regulatory bodies to control the usage of nanomaterials and poor knowledge of the long-term impact on the ecosystem which need to be addressed in near future for comprehensive knowledge of applicability of green nanotechnology in agriculture.
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| 20. |
- Balusamy, Sri Renukadevi, et al.
(författare)
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Chitosan, chitosan nanoparticles and modified chitosan biomaterials, a potential tool to combat salinity stress in plants
- 2022
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 284
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Forskningsöversikt (refereegranskat)abstract
- Chitosan being non-toxic, biocompatible, and biodegradable gained considerable interest among agriculturists. Our research review discusses about the role of Cs, chitosan nanoparticles (CsNPs), and modified chitosan biomaterials (CsBMs) under salt stress to improve growth parameters such as plant height, weight, stem width, fruit yield, pigments such as chlorophyll a, b, total chlorophyll, and carotenoid contents, as well as antioxidant and non-antioxidative enzymes. Upon Cs treatment and salt stress, total aminoacids (TAA), glutamic acids, and gamma-aminobutyric acid (GABA) were increased. Furthermore, Cs activated SOS1 pathway and increased various gene transcripts involved in sodium compartmentalization, proton motive force, energy production, and phenol metabolism. On the other hand, CsNPs and modified CsBMs treated plants under salinity stress increased indole terpene alkaloid metabolism, defense related genes, decreased ROS production by enhancing JA signaling, increased essential oil, anthocyanins, membrane stability, alkaloids, and diterpene glycosides. This is the first review that specifically brings insights about the physiological and biochemical parameters of the plants by comparing Cs/CsNPs/modified CsBMs treatment options under salt stress and encourages the use of CsNPs and modified CsBMs compared to Cs for better plant function under salinity stress.
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| 21. |
- Bonne Kohler, Julie, et al.
(författare)
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Importance of protein Ser/Thr/Tyr phosphorylation for bacterial pathogenesis
- 2020
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Ingår i: FEBS Letters. - : Wiley. - 1873-3468 .- 0014-5793. ; 594:15, s. 2339-2369
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Forskningsöversikt (refereegranskat)abstract
- Protein phosphorylation regulates a large variety of biological processes in all living cells. In pathogenic bacteria, the study of serine, threonine, and tyrosine (Ser/Thr/Tyr) phosphorylation has shed light on the course of infectious diseases, from adherence to host cells to pathogen virulence, replication, and persistence. Mass spectrometry (MS)-based phosphoproteomics has provided global maps of Ser/Thr/Tyr phosphosites in bacterial pathogens. Despite recent developments, a quantitative and dynamic view of phosphorylation events that occur during bacterial pathogenesis is currently lacking. Temporal, spatial, and subpopulation resolution of phosphorylation data is required to identify key regulatory nodes underlying bacterial pathogenesis. Herein, we discuss how technological improvements in sample handling, MS instrumentation, data processing, and machine learning should improve bacterial phosphoproteomic datasets and the information extracted from them. Such information is expected to significantly extend the current knowledge of Ser/Thr/Tyr phosphorylation in pathogenic bacteria and should ultimately contribute to the design of novel strategies to combat bacterial infections.
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| 22. |
- Cantatore, Valentina, 1986, et al.
(författare)
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Design strategy of a graphene based bio-sensor for glucose
- 2018
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Ingår i: Carbon. - : Elsevier BV. - 0008-6223. ; 137, s. 343-348
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Tidskriftsartikel (refereegranskat)abstract
- A novel graphene-based glucose sensor-design is formulated and explored in silico. An ad hoc host molecule is tailored to bind to glucose by multiple hydrogen bonds. A pyridinic core is chosen for this receptor in order to allow for “socket-plug” dative bonding to boron sites of boron doped graphene. The modeling employs DFT (Density Functional Theory) together with an effective aqueous environment to take into account the solvation effect. High selectivity is demonstrated for the suggested host molecule towards glucose as compared to other possible competitors in blood such as fructose, biotin and ascorbic acid. A route to achieve improved sensitivity, exploiting the hydrophilic/hydrophobic properties of the host + glucose system for enhanced selective binding to the hydrophobic boron doped graphene support is discussed.
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| 23. |
- Cao, Zhejian, 1991, et al.
(författare)
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Synthesis of Metal-Organic Frameworks through Enzymatically Recycled Polyethylene Terephthalate
- 2023
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Ingår i: ACS Sustainable Chemistry & Engineering. - 2168-0485. ; 11:43, s. 15506-15512
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Tidskriftsartikel (refereegranskat)abstract
- Polyethylene terephthalate (PET) as one of the most produced plastics contributes to global waste pollution. Upcycling PET into value-added products therefore is of environmental and economic interest. Terephthalic acid (TPA), the monomer of PET, is a common linker for metal-organic framework (MOF) synthesis; thus, PET-to-MOF upcycling raises much research attention. However, conventional PET-to-MOF upcycling often requires PET depolymerization with strong acids or bases and high temperatures, which can lead to environmental and energy penalties. As an alternative, PETase offers a sustainable approach to depolymerizing PET under mesophilic and mild pH conditions. Here we report UiO-66, MOF-5, and MIL-101 syntheses using enzymatically recycled TPA as linkers. The enzymatically recycled TPA demonstrated low impurity, and the obtained MOFs possessed comparable crystallinity, thermal stability, and surface area. These results reveal the feasibility of MOF synthesis by using enzymatically recycled PET.
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| 24. |
- Chen, Yanyan, 1990, et al.
(författare)
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Graphene nanospikes exert bactericidal effect through mechanical damage and oxidative stress
- 2024
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Ingår i: Carbon. - 0008-6223. ; 218
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Tidskriftsartikel (refereegranskat)abstract
- Microbial contamination of biomedical surfaces is an important clinical challenge, driving the development of new antibacterial materials. Nanoprotrusions on the wing surface of some insects have intrinsic antibacterial and antifouling properties, which inspires fabrication of biomimetic nanopatterns on medical devices. Herein, we report a broad-spectrum bactericidal surface consisting of graphene nanospikes synthesized by plasma-enhanced chemical vapor deposition. Similar coatings have been reported before, but the killing mechanism and main parameters for efficiency of such coatings have not been clarified. We investigated the correlation of anti-biofilm efficiency of graphene nanospikes to their major physicochemical parameters. While height and thickness of nanospikes did not directly correlate with bactericidal effects, edge/defect density showed linear correlation with lethality for both Gram-negative and Gram-positive bacteria. We further demonstrated that the killing mechanism is synergistic, depending on physical rupture of bacterial membranes as well as considerable oxidative damage to the cells. Of note, for the first time, we quantify the level of oxidative stress induced by graphene nanospikes in two bacterial species using genetically encoded biosensors. Our work provides a fundamental understanding of the impact of various parameters of graphene nanostructures on the bactericidal efficiency, enabling rational design of graphene-based bactericidal surfaces.
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| 25. |
- Chen, Yanyan, 1990, et al.
(författare)
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Interactions Between Graphene-Based Materials and Biological Surfaces: A Review of Underlying Molecular Mechanisms
- 2021
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Ingår i: Advanced Materials Interfaces. - : Wiley. - 2196-7350. ; 8:24
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Forskningsöversikt (refereegranskat)abstract
- Understanding the underlying molecular mechanism of how graphene materials (GMs) interact with biological surfaces is the key to develop safe and effective biomedical applications of GMs. Here, a systematic and comprehensive mechanistic perspective of interactions between pristine GMs and biological membranes is provided. To this end, first the known mechanisms of interaction between GMs and membrane components are summarized and classified, with a focus on phospholipids, cholesterol, and membrane proteins. Both experimental observations and computational simulations are included. Detailed experimental conditions and physiochemical properties of GMs are listed for each cited application. At the end of this review, current challenges and conflicts that limit biomedical applications of GMs are discussed. Based on reported mechanisms, guidelines for future studies to address the remaining challenges are proposed, specifically with respect to modulating the intrinsic properties of GMs for more efficient and safer therapeutic applications.
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