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The anthropogenic activities toward meeting the energy requirements have resulted in an alarming rise in environmental pollution levels. Among pollutants, polycyclic aromatic hydrocarbons (PAHs) are the most predominant due to their persistent and toxic nature. Amidst the several pollutants depuration methods, bioremediation utilizing biodegradation is the most viable alternative. This study investigated the biodegradation efficacy using developed microbial consortium PBR-21 for 2-4 ringed PAHs named naphthalene (NAP), anthracene (ANT), fluorene (FLU), and pyrene (PYR). The removal efficiency was observed up to 100 ± 0.0%, 70.26 ± 4.2%, 64.23 ± 2.3%, and 61.50 ± 2.6%, respectively, for initial concentrations of 400 mg L-1 for NAP, ANT, FLU, and PYR respectively. Degradation followed first-order kinetics with rate constants of 0.39 d-1, 0.10 d-1, 0.08 d-1, and 0.07 d-1 and half-life t 1 / 2 of 1.8 h, 7.2 h, 8.5 h, and 10 h, respectively. The microbial consortia were found to be efficient towards the co-contaminants with 1 mM concentration. Toxicity examination indicated that microbial-treated PAHs resulted in lesser toxicity in aquatic crustaceans (Artemia salina) than untreated PAHs. Also, the study suggests that indigenous microbial consortia PBR-21 has the potential to be used in the bioremediation of PAH-contaminated environment.
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Antracenos , Poluentes Ambientais , Naftalenos , Hidrocarbonetos Policíclicos Aromáticos , Pirenos , Poluentes do Solo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Consórcios Microbianos , Fluorenos/toxicidade , Biodegradação Ambiental , Poluentes do Solo/metabolismoRESUMO
Cadherins are a family of cell surface glycoproteins that mediate Ca2+-dependent cell to cell adhesion. They organize to form large macromolecular assemblies at the junctions of cells in order to form and maintain the integrity of tissue structures, thereby playing an indispensable role in the multicellular organization. Notably, a large body of research on E- and N-cadherin, the two most widely studied members of the cadherin superfamily, suggest for homophilic associations among them to drive cell adhesion. Interestingly, latest studies also highlight for direct crosstalk among these two classical cadherins to form heterotypic connections in physiological as well as in disease environment. However, the molecular details for the heterophilic association of E-cadherin and N-cadherin has not been investigated yet, which we aimed to address in this work. Using surface plasmon resonance and flow cytometry based biophysical studies we observed heterophilic interaction between E- and N-cadherin mediated through the membrane distal ectodomains. Further, the heterodimeric interface of E-cadherin and N-cadherin was mapped using structure-guided mutational studies followed by complementary biophysical analyses to identify the important interface residues involved in the interaction. The results obtained imply significant resemblance in the interface residues of E-cadherin that are crucial for homophilic recognition of E-cadherin and heterophilic recognition of N-cadherin as well.
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Caderinas , Caderinas/metabolismo , Adesão Celular/fisiologia , Dimerização , Mutação , Ligação ProteicaRESUMO
Preparation of curd at home is quite challenging as it requires skills like addition of proper amount of starter culture, maintenance and storage of inoculum for the preparation of good and consistent quality curd. The present work utilized bacterial attachment property of PVDF (Polyvinylidene fluoride) membrane to prepare a strip which can be dipped into milk for the preparation of consistent quality curd. Shelf-life of the strip is around 100 days. The strip prepared curd was well comparable with the curd prepared by the commercial inoculum based on their pH, % lactic acid, % syneresis and bacterial load. Strip of size 5 × 5 cm2 was enough for preparation of 500 mL curd. It was proved by different analytical techniques like AFM, SEM and FTIR that PVDF was not having any leaching property during curd preparation. It can also be used in repeated contact with food products, as it is FDA (Food and Drug Administration) compliant and non-toxic. The curd strip has significant industrial relevance as it is a cost-effective alternative of any commercial inoculum (very expensive) and also meets the demand of consumers with the rising health awareness and busy lifestyles. Further, it is spillage proof, portable, ready-to-use. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05339-3.
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Dual functional activity by the same organic-inorganic hybrid material toward selective metal ion detection and its adsorption has drawn more attraction in the field of sensing. However, most of the hybrid materials in the literature are either for sensing studies or adsorption studies. In this manuscript, a fluorescent active hybrid material SiO2 @PBATPA is synthesized by covalent coupling of anthracene-based chelating ligand N,N'-(propane-1,3-diyl) bis(N-(anthracen-9-ylmethyl)-2-((3-(triethoxysilyl)propyl) amino) acetamide) (PBATPA) within the mesopores of newly synthesized cubic mesoporous silica. The synthetic strategy is designed to form an exclusively intramolecular excimer on a solid surface, which is then used as a sensory tool for selective detection of metal ions through fluorescence quenching by the destruction of excimer upon metal ion binding. The dual functions of sensing and adsorption studies show selectivity toward Hg2+ and Cu2+ among various metal ions with detection limits of 37 and 6 ppb, respectively, and adsorption capacities of 482 and 246 mg g-1 , respectively. This material can be used as a sensory cum adsorbent material in real food samples and living organisms such as the brine shrimp Artemia salina without any toxic effects from the material.
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Antracenos/química , Cobre/isolamento & purificação , Corantes Fluorescentes/química , Mercúrio/isolamento & purificação , Dióxido de Silício/química , Adsorção , Animais , Artemia/química , Artemia/efeitos dos fármacos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Cobre/toxicidade , Concentração de Íons de Hidrogênio , Íons , Cinética , Mercúrio/toxicidade , Porosidade , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Termogravimetria , Testes de ToxicidadeRESUMO
Phycocyanin is a natural brilliant blue colored, fluorescent protein, which is commonly present in cyanobacteria. In this study, C-phycocyanin was extracted and purified from Spirulina platensis, which are multicellular and filamentous cyanobacteria of greater importance because of its various biological and pharmacological potential. It was analyzed for its binding affinity towards blood cells, algal cells, genomic DNA of microalgae, and bacteria at different temperature and incubation time. It showed good binding affinity with these components even at low concentration of 2.5 µM. The purpose of this study was to evaluate the applicability of C-phycocyanin as a green fluorescent dye substituting carcinogenic chemical dyes.
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Estruturas Celulares/metabolismo , Ficocianina/química , Ficocianina/metabolismo , Spirulina/metabolismo , Animais , Plaquetas/metabolismo , Bovinos , DNA Bacteriano/metabolismo , Eritrócitos/metabolismo , Escherichia coli/metabolismo , Fluorescência , Genoma Bacteriano , Linfócitos/metabolismo , Microalgas/metabolismoRESUMO
Extracellular vesicles (EVs) are small membrane-enclosed structures that have gained much attention from researchers across varying scientific fields in the past few decades. Cells secrete diverse types of EVs into the extracellular milieu which include exosomes, microvesicles, and apoptotic bodies. These EVs play a crucial role in facilitating intracellular communication via the transport of proteins, lipids, DNA, rRNA, and miRNAs. It is well known that a number of viruses hijack several cellular pathways involved in EV biogenesis to aid in their replication, assembly, and egress. On the other hand, EVs can also trigger host antiviral immune responses by carrying immunomodulatory molecules and viral antigens on their surface. Owing to this intricate relationship between EVs and viruses, intriguing studies have identified various EV-mediated viral infections and interrogated how EVs can alter overall viral spread and longevity. This review provides a comprehensive overview on the EV-virus relationship, and details various modes of EV-mediated viral spread in the context of clinically relevant enveloped and non-enveloped viruses.
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Phytoplankton acts as carbon sinks due to photosynthetic efficacy and their diversity is expressed by SWDI (Shannon-Weaver Diversity Index), which depends on water quality parameters. The coastal water of Diu was studied for three seasons, and the relationship between different parameters and SWDI was established. Subsequently, an attempt was made to build up a prediction model of SWDI based on multilayer perceptron Artificial neural network (ANN) using the R programme. Analysis shows interrelationship between the water quality parameters and phytoplankton diversity is same in linear principal component analysis (PCA) and neural network model. Variations of different parameters depend on seasonal changes. The ANN model shows that ammonia and phosphate are key parameters that influence the SWDI of phytoplankton. Seasonal variation in SWDI is related to variation in water quality parameters, as explained by both ANN and PCA. Hence, the ANN model can be an important tool for coastal environmental interaction study.
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Monitoramento Ambiental , Fitoplâncton , Qualidade da Água , Índia , Estações do AnoRESUMO
To search for novel proteases from environmental isolates which can induce apoptosis in cancer cells, we have purified subtilisin from Bacillus amyloliquefaciens and studied its anti-cancer properties. Subtilisin induced apoptosis in colon (HT29) and breast (MCF7) cancer cells but showed no effect on mouse peritoneal macrophages and normal breast cells (MCF10A). Western blot analysis showed that Bax, Bcl-2 level remained unchanged but tubulin level decreased significantly. Subtilisin does not induce the intrinsic pathway of apoptosis, rather it induced tubulin degradation in MCF-7 cells, whereas in normal cells (MCF-10A) tubulin degradation was not observed. Subtilisin activates ubiquitination and proteasomal-mediated tubulin degradation which was completely restored in presence of proteasome inhibitor MG-132. We further observed PARKIN, one of the known E3-ligase, is overexpressed and interacts with tubulin in subtilisin treated cells. Knockdown of PARKIN effectively downregulates ubiquitination and inhibits degradation of tubulin. PARKIN activation and tubulin degradation lead to ER-stress which in turn activates caspase-7 and PARP cleavage, thus guiding the subtilisin treated cells towards apoptosis. To our knowledge this is the first report of subtilisin induced apoptosis in cancer cells by proteasomal degradation of tubulin.
Assuntos
Bacillus amyloliquefaciens , Neoplasias , Animais , Apoptose , Bacillus amyloliquefaciens/metabolismo , Caspase 7 , Camundongos , Neoplasias/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Subtilisina , Tubulina (Proteína)/metabolismo , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteína X Associada a bcl-2RESUMO
Environmental impact of COVID-19 imposed lockdown (2020) and the new normal condition (2021) on two different beaches of India (Ghoghla beach, Diu and Somnath beach, Veraval) were compared with the pre-lockdown era, 2013. The lockdown phase favored the natural restoration of the beaches and showed infinitesimal values of the parameters tested when compared with the pre-lockdown regime. However, the new normal situation in 2021 opened up the accessibility of these beaches to the tourists and pilgrims resulting in significant changes of water quality. The release of diluted sewage mixed with freshwater from the Somnath town to the sea has led to the drastic change in beach water quality. The mean cadmium concentration increased drastically in beach waters (Ghoghla: 1.35, 0.28 and 7.09 µg/L; Somnath: 0.45, 0.28 and 0.58 µg/L) during pre-to-post lockdown, respectively. However, post-lockdown resulted in the rise of toxic heavy metals in the sediments of Somnath beach but Ghoghla beach remained to be pristine which may be due to the Blue Flagship status. The total number of marine bacteria was higher during 2013 and 2021 when compared during lockdown describing greater human interventions. For instance, Vibrio spp. count in Ghoghla beach water during pre-lockdown phase was 7733 CFU/mL and this value reduced to 70 and 5 CFU/mL in the lockdown and post-lockdown phases. Interestingly, the diversity of planktonic and benthic components showed a different trend from pre-to-post lockdown due to significant change in the inorganic nutrients and metal bioaccumulation. To our knowledge, this will be the first comprehensive assessment to report the environmental and ecological health of Ghoghla beach and Somnath beach during the pre-to-post lockdown.
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Praias , COVID-19 , Humanos , Esgotos , Cádmio , Controle de Doenças Transmissíveis , Cidades , Índia , Monitoramento AmbientalRESUMO
A detailed coastal water monitoring near Diu coast, western part of India was performed from October, 2020 to May, 2021 covering the 2nd lockdown time. Average monthly fluctuation from 7 different sampling stations of total 9 physico-chemical parameters such as pH, salinity, turbidity, nitrite (NO2), nitrate (NO3), ammonia (NH3), phosphate (PO4), total alkalinity and silicate were recorded. Initially, Mann-Kendall trend test for all the 9 parameters showed non-zero trend, which may be either linear or non-linear. During 2nd lockdown period, there was a fluctuation of value for parameters like pH, salinity, nitrate, nitrite and phosphate. Average total bacterial count and differential bacterial count also gradually decreased from March, 2021 sampling. Principal component analysis (PCA) plot covering all the physico-chemical parameters as well as the differential bacterial count showed a distinct cluster of all bacterial count with total alkalinity value. Subsequently, mathematical equation was formulated between total alkalinity value and all differential bacterial count. Upto our knowledge, this is the first report where mathematical equation was formulated to obtain value of different bacterial load based on the derived total alkalinity value of the coastal water samples near Diu, India.
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COVID-19 , Qualidade da Água , Carga Bacteriana , Controle de Doenças Transmissíveis , Monitoramento Ambiental , Humanos , Índia , Nitratos/análise , Nitritos/análise , Fosfatos/análiseRESUMO
Tuberculosis, caused by Mycobacterium tuberculosis, is predominantly a disease of the lungs acquired by inhaling mycobacteria from infected individuals via airborne droplets. In order to facilitate their entry into the alveolar macrophages, mycobacteria have a collection of pathogen-associated molecular patterns (PAMPs) on their surface that are known to detect certain pattern recognition receptors present on the surface of host cells. A major group of these PAMPs includes mycobacterial lipoproteins, of which, the 19 kDa surface antigen LpqH, has been reported to play a critical role in both host-pathogen interactions as well as pleiotropic immune regulation. Despite its crucial involvement in tuberculosis, the detailed structure-function relationship of this protein remains to be explored. Here, we report the high-resolution crystal structure of the non-acylated LpqH (LpqH48-159) at a resolution of 1.26 Å, which adopts a unique fold. Flow cytometry-based experiments show that the protein can bind and induce apoptosis in PMA-activated human monocytic cell line THP-1, indicative of the preservation of functionality of the protein. Furthermore, analysis of conservation of LpqH sequences from Mycobacterium species reveals a patch of conserved residues on the surface which may play a role in its binding partner recognition and hence in host-pathogen interaction.
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Mycobacterium tuberculosis , Tuberculose , Lipoproteínas/metabolismo , Monócitos/metabolismo , Moléculas com Motivos Associados a Patógenos/metabolismo , Tuberculose/microbiologiaRESUMO
Shrimp diseases are frequently reported to be caused by closely related vibrios, and in many cases they are tentatively but inaccurately identified as Vibrio harveyi and related vibrios. In the present study, 28 biochemically identified V. harveyi-related strains isolated from diseased shrimps were randomly selected for further characterization by molecular tools. Twenty-six strains were identified as Vibrio campbellii and two as V. harveyi by sequence analysis of 16S rRNA and uridylate kinase genes. Haemolysin-gene-based species-specific multiplex PCR also confirmed these results. Experimental challenge studies using Artemia as a model showed that eight isolates were highly pathogenic, three were moderately pathogenic and the remaining 17 were non-pathogenic. Ribotyping with BglI clearly distinguished V. campbellii from V. harveyi, but it failed to separate pathogenic and non-pathogenic clusters. Artemia nauplii challenged with a fluorescently labelled highly pathogenic strain (IPEY54) showed patches in the digestive tract. However, no patches were observed for a non-pathogenic strain (IPEY41). Direct bacterial counts also supported colonization potential for the highly pathogenic strain. To our knowledge, this is the first report on the isolation and accurate identification of large numbers of V. campbellii associated with shrimp disease in aquacultural farms. V. campbellii has long been considered to be non-pathogenic and classified with V. harveyi-related bacteria. However, we show that this species may be an emerging aquaculture pathogen. This study will help to formulate suitable strategies to combat this newly identified pathogen.
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Artemia/microbiologia , Penaeidae/microbiologia , Vibrio/classificação , Vibrio/isolamento & purificação , Animais , Aquicultura , Técnicas de Tipagem Bacteriana , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Modelos Animais de Doenças , Proteínas Hemolisinas/genética , Índia , Dados de Sequência Molecular , Núcleosídeo-Fosfato Quinase/genética , Filogenia , RNA Ribossômico 16S/genética , Ribotipagem , Análise de Sequência de DNA , Vibrio/genética , Vibrio/patogenicidadeRESUMO
Environmental remediation with a single platform for selective sensing and removal of toxic analytes with recyclability of the material has always been a desirable system for sustainability. However, materials comprising all the abovementioned advantages are rarely known for oxoanions. We herein developed a fluorogenic napthalimide-based functionalized mesoporous silica material (SiO2@NBDBIA) as a signaling and remediation system for oxoanions (CrO42-, Cr2O72-, and MnO4-) from a pool of several anions. The fluorescence quenching of the SiO2@NBDBIA material in the presence of CrO42-, Cr2O72-, and MnO4- ions gives the limit of detection (LOD) values of 6.23, 25.2, and 20.32 ppb, respectively, which are well below the maximum contaminant level demarcated by the United States Environmental Protection Agency. The maximum adsorption capacities of the material for the abovementioned oxoanions are found to be 352, 363, and 330 mg/g, respectively, which are well above those mentioned in the literature reports. Contrary to the literature-dominated irreversible ion-exchange mechanism, the reversible hydrogen-bonded binding of the material with the oxoanions leads to the recyclability of the material easily, which is very rare in the literature. The DFT calculations were performed to examine the interactions between the material and oxoanions. For real applications, this material was also used as a fluorescence probe to detect these oxoanions in the actual water samples, and more interestingly, used as a biosensing probe for these oxoanions in the living organism Artemia salina through fluorescence imaging. Thus, the SiO2@NBDBIA material is a unique example of recyclable material for detecting and remediating oxoanions.
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Cromo , Dióxido de Silício , Íons , Compostos de Manganês , Óxidos , Dióxido de Silício/química , Estados UnidosRESUMO
Vibrio parahaemolyticus is a renowned enteropathogen known for infecting humans. The infection usually involves various genes which help bacterium bypass the immune system of the host. Type III secretion system (T3SS) is an essential factor for the infection. The present study introduces the probable structure of VopJ, a T3SS effector of V. parahaemolyticus. The vopJ gene was amplified and sequenced from V. parahaemolyticus. The model generated through homology modelling showed a Z score of around 2.5, which fits quite near in the standard model available in the databases. The model has only a couple of outlier amino acids, which indicate a good fit of the model. Docking studies with small molecules like Acetyl-CoA, Inositol hexakisphosphate, GTP, and AMP have shown negative ΔG - 10.49, -52.80, -8.36 and -9.02, respectively, which indicates spontaneous binding. The molecular simulation studies have also supported the binding with a low RMSD value of less than 0.5 nm. The RMSF values obtained using the modelling were also quite low (>0.35 nm), which indicates the consistency achieved using the docking studies. These small molecules are very crucial in the MAPK pathways, which is essential for the immune response from the host cell. This effector can thus have an ability to highjack the immune system and help the bacterium in the potent infection. Up to our understanding, this is the first report which describes the in-silico model to understand the mode of infection of T3SS in enteropathogen V. parahaemolyticus. Communicated by Ramaswamy H. Sarma.
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Proteínas de Bactérias , Vibrio parahaemolyticus , Proteínas de Bactérias/genética , Simulação de Dinâmica Molecular , Sistemas de Secreção Tipo IIIRESUMO
Immunoglobulin (Ig) domains are one of the most widespread protein domains encoded by the human genome and are present in a large array of proteins with diverse biological functions. These Ig domains possess a central structure, the immunoglobulin-fold, which is a sandwich of two ß sheets, each made up of anti-parallel ß strands, surrounding a central hydrophobic core. Apart from humans, proteins containing Ig-like domains are also distributed in a vast selection of organisms including vertebrates, invertebrates, plants, viruses and bacteria where they execute a wide array of discrete cellular functions. In this review, we have described the key structural deviations of bacterial Ig-folds when compared to the classical eukaryotic Ig-fold. Further, we have comprehensively grouped all the Ig-domain containing adhesins present in both Gram-negative and Gram-positive bacteria. Additionally, we describe the role of these particular adhesins in host tissue attachment, colonization and subsequent infection by both pathogenic and non-pathogenic Escherichia coli as well as other bacterial species. The structural properties of these Ig-domain containing adhesins, along with their interactions with specific Ig-like and non Ig-like binding partners present on the host cell surface have been discussed in detail.
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Adesinas Bacterianas/química , Infecções Bacterianas/imunologia , Infecções Bacterianas/microbiologia , Imunoglobulinas/química , Adesinas Bacterianas/genética , Animais , Interações Hospedeiro-Patógeno/imunologia , HumanosRESUMO
In the present study, we have demonstrated synthesis of agar aldehyde (Aald) from seaweed polysaccharide and its further successful application for preparation of Aald mediated solid silver nanocomposite (Aald-AgNPs). Aald-AgNPs were characterized for biophysical properties by FTIR, XRD, SEM, TEM, XPS, and UV-vis spectroscopy. Aald-AgNPs were further tested in vitro and in vivo for anticancer activity. The results of the in vitro study revealed that Aald-AgNPs exhibited activity against 3 cancer cell lines. Aald-AgNPs were found to act through causing dose dependent increase in cell size, inducing anueploidy, mitochondrial disintegration and increasing septa formation in cell cytoplasm. Results of in vivo anticancer activity against ME-180, Colon-26, and HL-60 xenograft mice tumor models showed 64 %, 27.3 % and 51 % reduction in tumor volume, respectively with 83-100 % survival rate. Aald-AgNPs exhibited excellent antibacterial activity. It was interesting to note that Aald-AgNPs did not exhibit any significant detrimental effect on viability and metabolic activity of normal bone marrow derived mesenchymal stem cells. This study opens new areas of research for chemists and biologists to use seaweed-derived polymers to develop nanocomposites for cancer therapeutics.
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Ágar/administração & dosagem , Aldeídos/administração & dosagem , Antineoplásicos/administração & dosagem , Biopolímeros/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Nanocompostos/administração & dosagem , Alga Marinha , Prata/administração & dosagem , Animais , Antibacterianos/administração & dosagem , Linhagem Celular Tumoral , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Camundongos Endogâmicos BALB C , Neoplasias/tratamento farmacológicoRESUMO
INTRODUCTION: Fibrinolytic enzymes must currently originate a significant product in the arena of medical research. Very limited studies are stated on fibrinolyticenzyme production from actinomycetes. METHODS: Streptomyces sp. isolated from marine soil was chosen to optimize its fibrinolytic protease production.16s rRNA sequencing confirmed the isolated potent strain to be Streptomyces rubiginosus VITPSS1. A fibrinolytic protease was then purified from Streptomyces rubiginosus VITPSS1, with the target of producing a cost effective feasible enzyme from a potential actinomycete. RESULTS: SDS-PAGE results exhibited a protein band of about 45 kDa and the fibrinolytic band was detected by zymography. Optimization of physical and nutritional parameters for fibrinolytic protease production from a marine soil isolate Streptomyces strain was done by response surface methodology. The optimal cultural condition for fibrinolytic protease production was obtained with response surface methodology was based on OFAT results, it was inferred that glycerol, Soyabean meal, pH 7.2 and temperature 37°C. The optimization of the production of fibrinolytic protease with response surface methodology bring about two-folds increase in production by Streptomyces rubiginosus VITPSS1. CONCLUSION: Thus, this study presents its novelty by highlighting the potential of marine Streptomyces as a significant source for fibrinolytic enzyme production.
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Fibrinolíticos/química , Peptídeo Hidrolases , Streptomyces/enzimologia , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Biologia Marinha , Peptídeo Hidrolases/química , Streptomyces/químicaRESUMO
A newly emerged Vibrio cholerae O1 El Tor variant strain with multidrug resistance is considered a threat to public health. Recent strategies to suppress virulence factors production instead of bacterial growth may lead to less selective pressure for the emergence of resistant strains. The use of spices and their active constituents as the inhibitory agents against cholera toxin (CT) production in V. cholerae may be an alternative approach to treat cholera. In this study, we examined the potential of sweet fennel seed (Foeniculum vulgare Miller var. dulce) methanol extract to inhibit CT production in V. cholerae without affecting viability. The methanol extract of sweet fennel seeds significantly inhibited CT production in various V. cholerae strains, regardless of serogroup or biotype. Interestingly, trans-anethole and 4-allylanisole, essential oil components of sweet fennel seeds, also demonstrated similar effects. Here, we report that sub-bactericidal concentrations of sweet fennel seed methanol extract and its major components can drastically inhibit CT production in various V. cholerae strains.
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Antibacterianos/metabolismo , Toxina da Cólera/antagonistas & inibidores , Toxina da Cólera/biossíntese , Foeniculum/química , Expressão Gênica/efeitos dos fármacos , Extratos Vegetais/metabolismo , Vibrio cholerae/efeitos dos fármacos , Antibacterianos/isolamento & purificação , Metanol , Viabilidade Microbiana/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Sementes/química , Solventes , Vibrio cholerae/genéticaRESUMO
2.5% w/w DNA (Salmon testes) was solubilized in a bio-deep eutectic solvent [(bio-DES), obtained by the complexation of choline chloride and ethylene glycol at 1:2 molar ratio] containing 1% w/w of silver chloride (AgCl) to yield a AgCl decorated DNA based hybrid material. Concentration dependent formation of AgCl crystals in the DES was observed and upon interaction with DNA it gave formation of a cephalopod shaped hybrid material. DNA was found to maintain its chemical and structural stability in the material. Further, AgCl microstructures were found to have orderly self assembled on the DNA helices indicating the electrostatic interaction between Ag(+) and phosphate side chain of DNA as a driving force for the formation of the material with ordered microstructural distribution of AgCl. Furthermore, the functionalized material exhibited excellent antibacterial and bactericidal activity against both Gram negative and Gram positive pathogenic bacteria.
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Antibacterianos/química , Antibacterianos/farmacologia , DNA/química , Compostos de Prata/química , Prata/química , Solventes/química , Animais , Bactérias/efeitos dos fármacos , Fosfatos/química , Eletricidade EstáticaRESUMO
Use of natural compounds as antivirulence drugs could be an alternative therapeutic approach to modify the outcome of bacterial infections, particularly in view of growing resistance to available antimicrobials. Here, we show that sub-bactericidal concentration of anethole, a component of sweet fennel seed, could suppress virulence potential in O1 El Tor biotype strains of toxigenic Vibrio cholerae, the causative agent of the ongoing 7th cholera pandemic. The expression of cholera toxin (CT) and toxin coregulated pilus (TCP), the major virulence factors of V. cholerae, is controlled through a regulatory cascade involving activation of ToxT with synergistic coupling interaction of ToxR/ToxS with TcpP/TcpH. We present evidence that anethole inhibits in vitro expression of CT and TCP in a toxT-dependent but toxR/toxS-independent manner and through repression of tcpP/tcpH, by using bead-ELISA, western blotting and quantitative real-time RT-PCR assays. The cyclic AMP (cAMP)-cAMP receptor protein (CRP) is a well-studied global signaling system in bacterial pathogens, and this complex is known to suppress expression of tcpP/tcpH in V. cholerae. We find that anethole influences the virulence regulatory cascade by over-expressing cyaA and crp genes. Moreover, suppression of toxigenic V. cholerae-mediated fluid accumulation in ligated ileum of rabbit by anethole demonstrates its potentiality as an antivirulence drug candidate against the diseases caused by toxigenic V. cholerae. Taken altogether, these results revealing a mechanism of virulence inhibition in V. cholerae by the natural compound anethole, may have relevance in designing antivirulence compounds, particularly against multiple antibiotic resistant bacterial pathogens.