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1.
Mar Pollut Bull ; 200: 116157, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38364643

RESUMO

The Blue Growth strategy promises a sustainable use of marine resources for the benefit of the society. However, oil pollution in the marine environment is still a serious issue for human, animal, and environmental health; in addition, it deprives citizens of the potential economic and recreational advantages in the affected areas. Bioremediation, that is the use of bio-resources for the degradation of pollutants, is one of the focal themes on which the Blue Growth aims to. A repertoire of marine-derived bio-products, biomaterials, processes, and services useful for efficient, economic, low impact, treatments for the recovery of oil-polluted areas has been demonstrated in many years of research around the world. Nonetheless, although bioremediation technology is routinely applied in soil, this is not still standardized in the marine environment and the potential market is almost underexploited. This review provides a summary of opportunities for the exploiting and addition of value to research products already validated. Moreover, the review discusses challenges that limit bioremediation in marine environment and actions that can facilitate the conveying of valuable products/processes towards the market.


Assuntos
Poluentes Ambientais , Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Animais , Humanos , Biodegradação Ambiental , Petróleo/metabolismo , Poluentes Químicos da Água/análise
2.
Mar Drugs ; 21(4)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37103395

RESUMO

Two linear proline-rich peptides (1-2), bearing an N-terminal pyroglutamate, were isolated from the marine bacterium Microbacterium sp. V1, associated with the marine sponge Petrosia ficiformis, collected in the volcanic CO2 vents in Ischia Island (South Italy). Peptide production was triggered at low temperature following the one strain many compounds (OSMAC) method. Both peptides were detected together with other peptides (3-8) via an integrated, untargeted MS/MS-based molecular networking and cheminformatic approach. The planar structure of the peptides was determined by extensive 1D and 2D NMR and HR-MS analysis, and the stereochemistry of the aminoacyl residues was inferred by Marfey's analysis. Peptides 1-8 are likely to arise from Microbacterium V1 tailor-made proteolysis of tryptone. Peptides 1 and 2 were shown to display antioxidant properties in the ferric-reducing antioxidant power (FRAP) assay.


Assuntos
Antioxidantes , Peptídeos Cíclicos , Animais , Peptídeos Cíclicos/química , Microbacterium , Prolina , Espectrometria de Massas em Tandem , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Peptídeos , Bactérias
3.
Mar Drugs ; 20(7)2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35877717

RESUMO

A local strain of Nannochloropsis granulata (Ng) has been reported as the most productive microalgal strain in terms of both biomass yield and lipid content when cultivated in photobioreactors that simulate the light and temperature conditions during the summer on the west coast of Sweden. To further increase the biomass and the biotechnological potential of this strain in these conditions, mixotrophic growth (i.e., the simultaneous use of photosynthesis and respiration) with glycerol as an external carbon source was investigated in this study and compared with phototrophic growth that made use of air enriched with 1-2% CO2. The addition of either glycerol or CO2-enriched air stimulated the growth of Ng and theproduction of high-value long-chain polyunsaturated fatty acids (EPA) as well as the carotenoid canthaxanthin. Bioassays in human prostate cell lines indicated the highest antitumoral activity for Ng extracts and fractions from mixotrophic conditions. Metabolomics detected betaine lipids specifically in the bioactive fractions, suggesting their involvement in the observed antitumoral effect. Genes related to autophagy were found to be upregulated by the most bioactive fraction, suggesting a possible therapeutic target against prostate cancer progression. Taken together, our results suggest that the local Ng strain can be cultivated mixotrophically in summer conditions on the west coast of Sweden for the production of high-value biomass containing antiproliferative compounds, carotenoids, and EPA.


Assuntos
Microalgas , Estramenópilas , Biomassa , Dióxido de Carbono/metabolismo , Carotenoides/metabolismo , Glicerol , Humanos , Microalgas/metabolismo , Estramenópilas/metabolismo , Suécia
4.
Mar Drugs ; 20(7)2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35877715

RESUMO

Marine organisms have been shown to be a valuable source for biologically active compounds for the prevention and treatment of cancer, inflammation, immune system diseases, and other pathologies. The advantage of studying organisms collected in the marine environment lies in their great biodiversity and in the variety of chemical structures of marine natural products. Various studies have focused on marine organism compounds with potential pharmaceutical applications, for instance, as immunomodulators, to treat cancer and immune-mediated diseases. Modulation of the immune system is defined as any change in the immune response that can result in the induction, expression, amplification, or inhibition of any phase of the immune response. Studies very often focus on the effects of marine-derived compounds on macrophages, as well as lymphocytes, by analyzing the release of mediators (cytokines) by using the immunological assay enzyme-linked immunosorbent assay (ELISA), Western blot, immunofluorescence, and real-time PCR. The main sources are fungi, bacteria, microalgae, macroalgae, sponges, mollusks, corals, and fishes. This review is focused on the marine-derived molecules discovered in the last three years as potential immunomodulatory drugs.


Assuntos
Produtos Biológicos , Neoplasias , Animais , Organismos Aquáticos/química , Bactérias , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Fungos/química , Imunidade , Neoplasias/tratamento farmacológico
5.
Pharmaceutics ; 14(3)2022 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-35335990

RESUMO

Cancer cell migration is a hallmark of the aggressiveness and progression of malignancies such as high-risk neuroblastoma. Given the lack of effective therapeutic solutions to counteract cancer progression, basic research aims to identify novel bioactive molecules with inhibitory potential on cancer cell migration. In this context, this work investigated the role of members of the salicylaldehyde secondary metabolite set from the sponge endophyte fungus Eurotium chevalieri MUT 2316 as potential inhibitors of human neuroblastoma SH-SY5Y cell migration. Since tetrahydroauroglaucin (TAG) and dihydroauroglaucin (DAG) were isolated in large amounts, both were evaluated for their anticancer properties towards SH-SY5Y cells. Both molecules were found to be non-cytotoxic by MTT assay and cytofluorimetric analysis. Moreover, DAG showed efficacy in inhibiting the highly migratory phenotype of SH-SY5Y cells by wound healing assay; whereas TAG, although structurally similar to DAG, showed no anti-migratory effect. Therefore, this work provides good reasons to conduct further in vitro and in vivo studies focusing on DAG as a potentially useful migrastatic natural marine molecule.

6.
Pharmaceuticals (Basel) ; 14(12)2021 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-34959729

RESUMO

Marine pharmacology is an exciting and growing discipline that blends blue biotechnology and natural compound pharmacology together. Several sea-derived compounds that are approved on the pharmaceutical market were discovered in sponges, marine organisms that are particularly rich in bioactive metabolites. This paper was specifically aimed at reviewing the pharmacological activities of extracts or purified compounds from marine sponges that were collected in the Mediterranean Sea, one of the most biodiverse marine habitats, filling the gap in the literature about the research of natural products from this geographical area. Findings regarding different Mediterranean sponge species were individuated, reporting consistent evidence of efficacy mainly against cancer, infections, inflammatory, and neurological disorders. The sustainable exploitation of Mediterranean sponges as pharmaceutical sources is strongly encouraged to discover new compounds.

7.
Mar Biotechnol (NY) ; 23(6): 892-903, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34714443

RESUMO

The phylum Mollusca represents one of the largest groups of marine invertebrates. Nowadays, molluscan shellfish belonging to the classes Bivalvia and Gastropoda are of commercial interest for fisheries and aquaculture. Although bioactive properties of bivalve molluscs have been widely investigated and several dietary supplements have been brought to the market, the bioactive potentialities of marine gastropods are poorly documented. The present study investigated the bioactive properties of tissue extracts derived from Haliotis tuberculata coccinea, or "European abalone," an edible abalone species distributed in the Mediterranean Sea and the northeast Atlantic Ocean. A bioactive organic compound-rich extract was obtained using ethyl acetate as extracting solvent. It showed antimicrobial activity towards the methicillin-resistant Staphylococcus epidermidis strain RP62A, the emerging multi-drug-resistant Stenotrophomonas maltophilia D71 and Staphylococcus aureus ATCC 6538P, being the most sensitive strain. It also showed anthelmintic activity, evaluated through the toxicity against the target model helminth Caenorhabditis elegans. In addition, the ethyl acetate extract demonstrated a selective cytotoxic activity on the cancer cell lines A375, MBA-MD 231, HeLa, and MCF7, at the concentration of 250 µg/mL. The fatty acid composition of the bioactive extract was also investigated through FAME analysis. The fatty acid profile showed 45% of saturated fatty acids (SAFA), 22% of monounsaturated fatty acids (MUFA), and 33% of polyunsaturated fatty acids (PUFA). The presence of some biologically important secondary metabolites in the extract was also analysed, revealing the presence of alkaloids, terpenes, and flavonoids.


Assuntos
Bivalves , Gastrópodes , Staphylococcus aureus Resistente à Meticilina , Acetatos , Animais
8.
Int J Mol Sci ; 22(16)2021 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-34445761

RESUMO

Natural products of microbial origin have inspired most of the commercial pharmaceuticals, especially those from Actinobacteria. However, the redundancy of molecules in the discovery process represents a serious issue. The untargeted approach, One Strain Many Compounds (OSMAC), is one of the most promising strategies to induce the expression of silent genes, especially when combined with genome mining and advanced metabolomics analysis. In this work, the whole genome of the marine isolate Rhodococcus sp. I2R was sequenced and analyzed by antiSMASH for the identification of biosynthetic gene clusters. The strain was cultivated in 22 different growth media and the generated extracts were subjected to metabolomic analysis and functional screening. Notably, only a single growth condition induced the production of unique compounds, which were partially purified and structurally characterized by liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). This strategy led to identifying a bioactive fraction containing >30 new glycolipids holding unusual functional groups. The active fraction showed a potent antiviral effect against enveloped viruses, such as herpes simplex virus and human coronaviruses, and high antiproliferative activity in PC3 prostate cancer cell line. The identified compounds belong to the biosurfactants class, amphiphilic molecules, which play a crucial role in the biotech and biomedical industry.


Assuntos
Antivirais/metabolismo , Glicolipídeos/metabolismo , Rhodococcus/metabolismo , Animais , Antivirais/análise , Chlorocebus aethiops , Técnicas de Cultura , Ensaios de Seleção de Medicamentos Antitumorais , Ésteres/metabolismo , Genoma Bacteriano , Glicolipídeos/química , Humanos , Metaboloma , Testes de Sensibilidade Microbiana , Estrutura Molecular , Células PC-3 , Rhodococcus/química , Rhodococcus/genética , Succinatos/metabolismo , Tensoativos/química , Tensoativos/metabolismo , Células Vero
9.
Viruses ; 13(7)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209556

RESUMO

Vitis vinifera represents an important and renowned source of compounds with significant biological activity. Wines and winery bioproducts, such as grape pomace, skins, and seeds, are rich in bioactive compounds against a wide range of human pathogens, including bacteria, fungi, and viruses. However, little is known about the biological properties of vine leaves. The aim of this study was the evaluation of phenolic composition and antiviral activity of Vitis vinifera leaf extract against two human viruses: the Herpes simplex virus type 1 (HSV-1) and the pandemic and currently widespread severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). About 40 phenolic compounds were identified in the extract by HPLC-MS/MS analysis: most of them were quercetin derivatives, others included derivatives of luteolin, kaempferol, apigenin, isorhamnetin, myricetin, chrysoeriol, biochanin, isookanin, and scutellarein. Leaf extract was able to inhibit both HSV-1 and SARS-CoV-2 replication in the early stages of infection by directly blocking the proteins enriched on the viral surface, at a very low concentration of 10 µg/mL. These results are very promising and highlight how natural extracts could be used in the design of antiviral drugs and the development of future vaccines.


Assuntos
Antivirais/farmacologia , Herpesvirus Humano 1/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta/química , SARS-CoV-2/efeitos dos fármacos , Vitis/química , Células A549 , Animais , Produtos Biológicos/análise , Produtos Biológicos/farmacologia , Linhagem Celular , Chlorocebus aethiops , Cromatografia Líquida de Alta Pressão , Humanos , Células MCF-7 , Fenóis/farmacologia , Extratos Vegetais/análise , Espectrometria de Massas em Tandem , Células Vero
10.
Antioxidants (Basel) ; 9(12)2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33256101

RESUMO

The marine environment represents a prosperous existing resource for bioprospecting, covering 70% of the planet earth, and hosting a huge biodiversity. Advances in the research are progressively uncovering the presence of unknown microorganisms, which have evolved unique metabolic and genetic pathways for the production of uncommon secondary metabolites. Fungi have a leading role in marine bioprospecting since they represent a prolific source of structurally diverse bioactive metabolites. Several bioactive compounds from marine fungi have already been characterized including antibiotics, anticancer, antioxidants and antivirals. Nowadays, the search for natural antioxidant molecules capable of replacing those synthetic currently used, is an aspect that is receiving significant attention. Antioxidants can inactivate reactive oxygen and nitrogen species, preventing the insurgence of several degenerative diseases including cancer, autoimmune disorders, cardiovascular and neurodegenerative diseases. Moreover, they also find applications in different fields, including food preservation, healthcare and cosmetics. This review focuses on the production of antioxidants from marine fungi. We begin by proposing a survey of the available tools suitable for the evaluation of antioxidants, followed by the description of various classes of marine fungi antioxidants together with their extraction strategies. In addition, a view of the future perspectives and trends of these natural products within the "blue economy" is also presented.

11.
Sci Rep ; 8(1): 1190, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29352134

RESUMO

In order to exploit the rich reservoir of marine cold-adapted bacteria as a source of bioactive metabolites, ethyl acetate crude extracts of thirteen polar marine bacteria were tested for their antiproliferative activity on A549 lung epithelial cancer cells. The crude extract from Pseudoalteromonas haloplanktis TAC125 was the most active in inhibiting cell proliferation. Extensive bioassay-guided purification and mass spectrometric characterization allowed the identification of 4-hydroxybenzoic acid (4-HBA) as the molecule responsible for this bioactivity. We further demonstrate that 4-HBA inhibits A549 cancer cell proliferation with an IC50 value ≤ 1 µg ml-1, and that the effect is specific, since the other two HBA isomers (i.e. 2-HBA and 3-HBA) were unable to inhibit cell proliferation. The effect of 4-HBA is also selective since treatment of normal lung epithelial cells (WI-38) with 4-HBA did not affect cell viability. Finally, we show that 4-HBA is able to activate, at the gene and protein levels, a specific cell death signaling pathway named pyroptosis. Accordingly, the treatment of A549 cells with 4-HBA induces the transcription of (amongst others) caspase-1, IL1ß, and IL18 encoding genes. Studies needed for the elucidation of mode of action of 4-HBA will be instrumental in depicting novel details of pyroptosis.


Assuntos
Adenocarcinoma/metabolismo , Antineoplásicos/farmacologia , Neoplasias Pulmonares/metabolismo , Parabenos/farmacologia , Pseudoalteromonas/química , Piroptose/efeitos dos fármacos , Adenocarcinoma de Pulmão , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Biomarcadores , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Parabenos/química , Parabenos/isolamento & purificação , Pseudoalteromonas/metabolismo , Transdução de Sinais/efeitos dos fármacos
12.
Sci Rep ; 7(1): 839, 2017 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-28404986

RESUMO

Cold environments dominate Earth's biosphere, hosting complex microbial communities with the ability to thrive at low temperatures. However, the underlying molecular mechanisms and the metabolic pathways involved in bacterial cold-adaptation mechanisms are still not fully understood. Herein, we assessed the metabolic features of the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 (PhTAC125), a model organism for cold-adaptation, at both 4 °C and 15 °C, by integrating genomic and phenomic (high-throughput phenotyping) data and comparing the obtained results to the taxonomically related Antarctic bacterium Pseudoalteromonas sp. TB41 (PspTB41). Although the genome size of PspTB41 is considerably larger than PhTAC125, the higher number of genes did not reflect any higher metabolic versatility at 4 °C as compared to PhTAC125. Remarkably, protein S-thiolation regulated by glutathione and glutathionylspermidine appeared to be a new possible mechanism for cold adaptation in PhTAC125. More in general, this study represents an example of how 'multi-omic' information might potentially contribute in filling the gap between genotypic and phenotypic features related to cold-adaptation mechanisms in bacteria.


Assuntos
Aclimatação , Temperatura Baixa , Genoma Bacteriano , Pseudoalteromonas/metabolismo , Glutationa/análogos & derivados , Glutationa/metabolismo , Fenótipo , Pseudoalteromonas/genética , Espermidina/análogos & derivados , Espermidina/metabolismo
13.
BMC Genomics ; 18(1): 93, 2017 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-28095778

RESUMO

BACKGROUND: Pseudoalteromonas is a genus of ubiquitous marine bacteria used as model organisms to study the biological mechanisms involved in the adaptation to cold conditions. A remarkable feature shared by these bacteria is their ability to produce secondary metabolites with a strong antimicrobial and antitumor activity. Despite their biotechnological relevance, representatives of this genus are still lacking (with few exceptions) an extensive genomic characterization, including features involved in the evolution of secondary metabolites production. Indeed, biotechnological applications would greatly benefit from such analysis. RESULTS: Here, we analyzed the genomes of 38 strains belonging to different Pseudoalteromonas species and isolated from diverse ecological niches, including extreme ones (i.e. Antarctica). These sequences were used to reconstruct the largest Pseudoalteromonas pangenome computed so far, including also the two main groups of Pseudoalteromonas strains (pigmented and not pigmented strains). The downstream analyses were conducted to describe the genomic diversity, both at genus and group levels. This allowed highlighting a remarkable genomic heterogeneity, even for closely related strains. We drafted all the main evolutionary steps that led to the current structure and gene content of Pseudoalteromonas representatives. These, most likely, included an extensive genome reduction and a strong contribution of Horizontal Gene Transfer (HGT), which affected biotechnologically relevant gene sets and occurred in a strain-specific fashion. Furthermore, this study also identified the genomic determinants related to some of the most interesting features of the Pseudoalteromonas representatives, such as the production of secondary metabolites, the adaptation to cold temperatures and the resistance to abiotic compounds. CONCLUSIONS: This study poses the bases for a comprehensive understanding of the evolutionary trajectories followed in time by this peculiar bacterial genus and for a focused exploitation of their biotechnological potential.


Assuntos
Evolução Molecular , Genoma Bacteriano , Pseudoalteromonas/genética , Regiões Antárticas , Antibacterianos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Temperatura Baixa , Bases de Dados Genéticas , Transferência Genética Horizontal , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Filogenia , Pseudoalteromonas/classificação , Metabolismo Secundário/genética
14.
Genome Announc ; 4(3)2016 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-27198032

RESUMO

We report here the draft genome sequence of the Flavobacterium sp. TAB 87 strain, isolated from Antarctic seawater during a summer campaign near the French Antarctic station Dumont d'Urville (60°40'S, 40°01'E). It will allow for comparative genomics and the fulfillment of both fundamental and application-oriented investigations. It allowed the recognition of genes associated with the production of bioactive compounds and antibiotic resistance.

15.
PLoS One ; 10(11): e0142883, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26587842

RESUMO

This study investigated the relationship between host efflux system of the non-vertebrate nematode Caenorhabditis elegans and Burkholderia cepacia complex (Bcc) strain virulence. This is the first comprehensive effort to profile host-transporters within the context of Bcc infection. With this aim, two different toxicity tests were performed: a slow killing assay that monitors mortality of the host by intestinal colonization and a fast killing assay that assesses production of toxins. A Virulence Ranking scheme was defined, that expressed the toxicity of the Bcc panel members, based on the percentage of surviving worms. According to this ranking the 18 Bcc strains were divided in 4 distinct groups. Only the Cystic Fibrosis isolated strains possessed profound nematode killing ability to accumulate in worms' intestines. For the transporter analysis a complete set of isogenic nematode single Multidrug Resistance associated Protein (MRP) efflux mutants and a number of efflux inhibitors were interrogated in the host toxicity assays. The Bcc pathogenicity profile of the 7 isogenic C. elegans MRP knock-out strains functionality was classified in two distinct groups. Disabling host transporters enhanced nematode mortality more than 50% in 5 out of 7 mutants when compared to wild type. In particular mrp-2 was the most susceptible phenotype with increased mortality for 13 out 18 Bcc strains, whereas mrp-3 and mrp-4 knock-outs had lower mortality rates, suggesting a different role in toxin-substrate recognition. The use of MRP efflux inhibitors in the assays resulted in substantially increased (>40% on average) mortality of wild-type worms.


Assuntos
Infecções por Burkholderia/genética , Burkholderia cepacia/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Animais , Infecções por Burkholderia/tratamento farmacológico , Infecções por Burkholderia/microbiologia , Burkholderia cepacia/patogenicidade , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Modelos Animais de Doenças , Técnicas de Inativação de Genes , Humanos , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo
16.
Biotechnol Prog ; 31(4): 890-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25920073

RESUMO

A salt-tolerant esterase, designated H9Est, was identified from a metagenomic library of the Karuola glacier. H9Est gene comprised 1071 bp and encoded a polypeptide of 357 amino acids with a molecular mass of 40 kDa. Sequence analysis revealed that H9Est belonged to the family IV of bacterial lypolitic enzyme. H9Est was overexpressed in Escherichia coli and the purified enzyme showed hydrolytic activity towards p-nitrophenyl esters with carbon chain from 2 to 8. The optimal esterase activity was at 40°C and pH 8.0 and the enzyme retained its activity towards some miscible organic solvents such as polyethylene glycol. A three-dimensional model of H9Est revealed that S200, D294, and H324 formed the H9Est catalytic triad. Circular Dichroism spectra and molecular dynamic simulation indicated that the esterase had a wide denaturation temperature range and flexible loops that would be beneficial for H9Est performance at low temperatures while retaining heat-resistant features.


Assuntos
Esterases/química , Esterases/genética , Camada de Gelo/microbiologia , Metagenoma/genética , Tolerância ao Sal/genética , Sequência de Aminoácidos , Biotecnologia , Temperatura Baixa , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Esterases/classificação , Esterases/metabolismo , Biblioteca Gênica , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência
17.
Mol Immunol ; 62(1): 10-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24929449

RESUMO

In fish, the first line of defense is represented by the innate immune system and the lysozyme is one of the molecules involved in this mechanism of protection. Three types of lysozymes have been identified in metazoan, the c-type (chicken or conventional), the g-type (goose-type) and the i-type (invertebrate type). They are all involved in the hydrolysation of the bacterial cell wall. Our work has been focused on the molecular characterization, expression analysis by real-time PCR, both at basal condition and after in vivo challenges, and 3D structural studies on the g-type lysozyme from sea bass (Dicentrarchus labrax L.). Moreover, a recombinant sea bass lysozyme has been produced in Escherichia coli and used to investigate the activity of the enzyme at different pH and temperatures and to perform antibacterial assays against typical fish pathogens. The cloned sea bass cDNA for g-type lysozyme (accession number FN667957) consists of 742 bp and translates for a putative protein of 188 amino acids. The molecular weight is 20.251, 41Da with a theoretical pI of 8.53, two cysteine residues along the sequence and no putative signal peptide. These features of the enzyme are in agreement with the expected characteristics of a proper g-type lysozyme, except for the cysteine residues that in fish are quite variable in number. An alignment between known g-type lysozyme sequences evidences that the amino acid residues thought to be involved in the enzyme catalysis (Glu(71), Asp(84) and Asp(95) in sea bass) are quite well conserved between mammalian, avian and fish sequences. The sea bass g-type lysozyme gene is composed of four exons and three introns and this gene structure is more compact compared to other known fish lysozyme homologues. Modeling of 3D structure has been performed on the template structure of g-type lysozyme from Atlantic cod. The catalytic site appears well conserved when compared with known structures of fish g-type lysozymes (cod and salmon). The basal expression of lysozyme transcripts is highest in gills, followed by head kidney and peripheral blood leukocytes. The lysozyme expression is up regulated in head kidney leukocytes both after challenge with the fish bacterial pathogen Photobacterium damselae subsp. piscicida. The lytic activity, determined using as substrate Micrococcus lysodeikticus, was optimal at pH 5.5 and at a temperature of 30°C. In conclusion, these results suggest that the identified g-type lysozyme should be involved in the innate immune responses of sea bass.


Assuntos
Bass/imunologia , Bass/microbiologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Muramidase/genética , Muramidase/imunologia , Sequência de Aminoácidos , Animais , Antibacterianos/farmacologia , Bass/genética , Clonagem Molecular , Proteínas de Peixes/química , Proteínas de Peixes/classificação , Regulação Enzimológica da Expressão Gênica , Modelos Moleculares , Dados de Sequência Molecular , Muramidase/química , Muramidase/classificação , Filogenia , Conformação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
18.
Mar Genomics ; 13: 37-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24401162

RESUMO

Herein we present the draft genomes of three Psychrobacter strains isolated from Antarctic sponges and able to inhibit the growth of bacteria belonging to the Burkholderia cepacia complex, responsible for infections of the respiratory system in patients affected by Cystic Fibrosis. The comparative analysis of the annotated genomes of these Psychrobacter strains highlighted their differences in terms of overall genomic content (e.g. shared gene sets) and allowed the identification of gene clusters hypothetically involved in the biosynthesis of antimicrobial compounds.


Assuntos
Antibacterianos/análise , Complexo Burkholderia cepacia/efeitos dos fármacos , Genoma Bacteriano/genética , Poríferos/microbiologia , Psychrobacter/química , Psychrobacter/genética , Animais , Regiões Antárticas , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Sequência de Bases , Mapeamento de Sequências Contíguas , Genômica , Anotação de Sequência Molecular , Dados de Sequência Molecular , Filogenia , Psychrobacter/classificação , Análise de Sequência de DNA , Especificidade da Espécie
19.
Microbiol Res ; 169(7-8): 593-601, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24231161

RESUMO

In this work we analyzed the ability of three Arthrobacter strains (namely TB23, TB26 and CAL618), which were isolated from the Antarctic sponges Haliclonissa verrucosa and Lyssodendrix nobilis, to specifically inhibit the growth of a panel of 40 Burkholderia cepacia complex strains, representing a major cause of infections in patients that are affected by Cystic Fibrosis. The inhibitory activity was due to the synthesis of antimicrobial compounds, very likely volatile organic compounds (VOCs), and was partially dependent on the growth media that were used for Antarctic strains growth. The phylogenetic analysis revealed that two of them (i.e. CAL 618 and TB23) were very close and very likely belonged to the same Arthrobacter species, whereas the strain TB26 was placed in a distant branch. The genome of the strains TB26 and CAL618 was also sequenced and compared with that of the strain TB23. The analysis revealed that TB23 and CAL618 shared more genomic properties (GC content, genome size, number of genes) than with TB26. Since the three strains exhibited very similar inhibition pattern vs Bcc strains, it is quite possible that genes involved in the biosynthesis of antimicrobial compounds very likely belong to the core genome.


Assuntos
Arthrobacter/genética , Arthrobacter/metabolismo , Complexo Burkholderia cepacia/efeitos dos fármacos , Complexo Burkholderia cepacia/crescimento & desenvolvimento , Poríferos/microbiologia , Compostos Orgânicos Voláteis/farmacologia , Animais , Arthrobacter/isolamento & purificação , Genoma Bacteriano , Genômica , Filogenia , Compostos Orgânicos Voláteis/metabolismo
20.
Biochimie ; 95(9): 1795-806, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23796575

RESUMO

The ciliated protozoon Euplotes focardii, originally isolated from the coastal seawaters of Terra Nova Bay in Antarctica, shows a strictly psychrophilic phenotype, including optimal survival and multiplication rates at 4-5 °C. This characteristic makes E. focardii an ideal model species for identifying the molecular bases of cold adaptation in psychrophilic organisms, as well as a suitable source of novel cold-active enzymes for industrial applications. In the current study, we characterized the patatin-like phospholipase from E. focardii (EfPLP), and its enzymatic activity was compared to that of the homologous protein from the mesophilic congeneric species Euplotes crassus (EcPLP). Both EfPLP and EcPLP have consensus motifs conserved in other patatin-like phospholipases. By analyzing both esterase and phospholipase A2 activity, we determined the thermostability and the optimal pH, temperature dependence and substrates of these enzymes. We demonstrated that EfPLP shows the characteristics of a psychrophilic phospholipase. Furthermore, we analyzed the enzymatic activity of three engineered versions of the EfPLP, in which unique residues of EfPLP, Gly80, Ala201 and Val204, were substituted through site-directed mutagenesis with residues found in the E. crassus homolog (Glu, Pro and Ile, respectively). Additionally, three corresponding mutants of EcPLP were also generated and characterized. These analyses showed that the substitution of amino acids with rigid and bulky charged/hydrophobic side chain in the psychrophilic EfPLP confers enzymatic properties similar to those of the mesophilic patatin-like phospholipase, and vice versa. This is the first report on the isolation and characterization of a cold-adapted patatin-like phospholipase from eukaryotes. The results reported in this paper support the idea that enzyme thermal-adaptation is based mainly on some amino acid residues that influence the structural flexibility of polypeptides and that EfPLP is an attractive biocatalyst for industrial processes at low temperatures.


Assuntos
Adaptação Fisiológica , Temperatura Baixa , Euplotes/fisiologia , Fosfolipases/metabolismo , Homologia de Sequência de Aminoácidos , Sequência de Aminoácidos , Clonagem Molecular , Estabilidade Enzimática , Euplotes/enzimologia , Euplotes/genética , Concentração de Íons de Hidrogênio , Cinética , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Fosfolipases/química , Fosfolipases/genética , Fosfolipases/isolamento & purificação , Conformação Proteica , Análise de Sequência
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