scholarly journals Identification of Antimicrobial Peptides from the Microalgae Tetraselmis suecica (Kylin) Butcher and Bactericidal Activity Improvement

Marine Drugs ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. 453 ◽  
Author(s):  
Guzmán ◽  
Wong ◽  
Román ◽  
Cárdenas ◽  
Alvárez ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Bioactive Peptides ◽  
De Novo ◽  
Helical Structure ◽  
Antimicrobial Activities ◽  
Peptide Sequence ◽  
Tetraselmis Suecica ◽  
Defense Strategies ◽  
Key Residues

The outburst of microbial resistance to antibiotics creates the need for new sources of active compounds for the treatment of pathogenic microorganisms. Marine microalgae are of particular interest in this context because they have developed tolerance and defense strategies to resist the exposure to pathogenic bacteria, viruses, and fungi in the aquatic environment. Although antimicrobial activities have been reported for some microalgae, natural algal bioactive peptides have not been described yet. In this work, acid extracts from the microalga Tetraselmis suecica with antibacterial activity were analyzed, and de novo sequences of peptides were determined. Synthetic peptides and their alanine and lysine analogs allowed identifying key residues and increasing their antibacterial activity. Additionally, it was determined that the localization of positive charges within the peptide sequence influences the secondary structure with tendency to form an alpha helical structure.

scholarly journals Sponge-Associated Actinobacteria: Morphological Character and Antibacterial Activity against Pathogenic Bacteria

2017 ◽  
Vol 3 (1) ◽  
pp. 21-26
Author(s):  
SASMIATI FARACH DITA ◽  
SRI BUDIARTI ◽  
YULIN LESTARI
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Marine Ecosystem ◽  
Morphological Characteristics ◽  
Antibacterial Activities ◽  
Morphological Characters ◽  
Antimicrobial Activities ◽  
Shigella Dysenteriae ◽  
Rrna Gene

Sponge-associated actinobacteria may diverse and have potency to produce bioactive compounds. Diversity and antimicrobial activity of indigenous sponge-associated actinobacteria isolated from the marine ecosystem in Indonesia have not much been explored. This work aimed to assess morphological and antibacterial activity of sponge-associated actinobacteria. The morphological characteristics were examined based on their color of aerial and substrate mycelia, and pigmentation, while antibacterial activities were assayed using the antagonist technique. The selected actinobacterial isolate was identified using 16S rRNA gene. Various sponge-associated actinobacteria were successfully isolated from Hyrtios sp., Callyspongia sp., and Neofibularia sp. sponges. A total of 62 actinobacterial isolates were obtained, and each isolate showed a variety of morphological characters, which could be seen in aerial mass color, substrate mass color, and pigmentation. Actinobacterial isolates were tested against human pathogenic bacteria, i.e. Staphylococcus aureus and Methicillin-Resistant S. aureus, representing Gram-positive, and Escherichia coli EPEC K1-1 and Shigella dysenteriae, representing Gram-negative. Most of actinobacterial isolates had antimicrobial activities at least against one of pathogenic bacteria. High activity was shown by NOHa.2, isolated from Neofibularia, and HRHa.5 isolated from Hyrtios. The NOHa.2 showed the highest antimicrobial activity against S. dysenteriae, meanwhile, HRHa.5 showed antimicrobial activity against 3 of 4 tested bacterial pathogens. These data showed diversity of sponge-asccociated actinobacteria from marine ecosystem in Indonesia, and several of them have potency as source of antibacterial compounds

scholarly journals Antimicrobial Activities of Different Fractions from Mucus of the Garden Snail Cornu aspersum

Biomedicines ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 315 ◽  
Author(s):  
Aleksandar Dolashki ◽  
Lyudmila Velkova ◽  
Elmira Daskalova ◽  
N. Zheleva ◽  
Yana Topalova ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Antibacterial Activity ◽  
Tandem Mass Spectrometry ◽  
De Novo ◽  
Antimicrobial Activities ◽  
Biologically Active ◽  
New Drugs ◽  
Tandem Mass ◽  
Bacterial Strains ◽  
Cornu Aspersum

Natural products have long played a major role in medicine and science. The garden snail Cornu aspersum is a rich source of biologically active natural substances that might be an important source for new drugs to treat human disease. Based on our previous studies, nine fractions containing compounds with Mw <3 kDa; <10 kDa; <20 kDa; >20 kDa; >30 kDa>50 kDa and between 3 and 5 kDa; 5 and 10 kDa; and 10 and 30 kDa were purified from the mucus of C. aspersum and analyzed by tandem mass spectrometry (MALDI-TOF/TOF). Seventeen novel peptides with potential antibacterial activity were identified by de novo MS/MS sequencing using tandem mass spectrometry. The different fractions were tested for antibacterial activity against Gram─ (Pseudomonas aureofaciens and Escherichia coli) and Gram+ (Brevibacillus laterosporus) bacterial strains as well the anaerobic bacterium Clostridium perfringens. These results revealed that the peptide fractions exhibit a predominant antibacterial activity against B. laterosporus; the fraction with Mw 10–30 kDa against E. coli; another peptide fraction <20 kDa against P. aureofaciens; and the protein fraction >20 kDa against the bacterial strain C. perfringens. The discovery of new antimicrobial peptides (AMPs) from natural sources is of great importance for public health due to the AMPs’ effective antimicrobial activities and low resistance rates.

Biogenic Synthesis of Gold Nanoparticles and Their Antimicrobial Activities

2020 ◽  
pp. 216-233
Author(s):  
Snežana Radisavljević ◽  
Biljana Petrović
Keyword(s):  
Drug Delivery ◽  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
Biomedical Applications ◽  
Food Packaging ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bactericidal Effect ◽  
Antimicrobial Activities ◽  
Physiochemical Properties

Gold nanoparticles (AuNPs) are widely used in biomedical applications, especially diagnostic and drug delivery. The antibacterial activity of nanoparticles depends on the dimensions of the particles. AuNPs may associate with the surface of the cell membrane and cause disorder such as respiration and permeability. The method of binding of particles for bacteria depends on their surface available for interaction. Smaller particles which have the larger surface area available for interaction will show better bactericidal effect than the larger particles. Useful antibacterial agents should also be toxic to various pathogenic bacteria with the ability to coat different surfaces like biomaterials, devices, textiles, food packaging, and so on. The biological and physiochemical properties of synthesized AuNPs have impact on the use of gold nanoparticles like antimicrobial agents, especially for water purification, as well as other biomedical applications.

scholarly journals Antimicrobial Activity of Snake β-Defensins and Derived Peptides

Toxins ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Nancy Oguiura ◽  
Poliana Garcia Corrêa ◽  
Isabella Lemos Rosmino ◽  
Ana Olívia de Souza ◽  
Kerly Fernanda Mesquita Pasqualoto
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Micrococcus Luteus ◽  
Peptide Sequence ◽  
Tryptophan Residue ◽  
High Antimicrobial Activity ◽  
Bacteria And Fungi ◽  
Microbroth Dilution ◽  
And Staphylococcus Aureus

β-defensins are antimicrobial peptides presenting in vertebrate animals. They participate in innate immunity, but little is known about them in reptiles, including snakes. Although several β-defensin genes were described in Brazilian snakes, their function is still unknown. The peptide sequence from these genes was deduced, and synthetic peptides (with approximately 40 amino acids and derived peptides) were tested against pathogenic bacteria and fungi using microbroth dilution assays. The linear peptides, derived from β-defensins, were designed applying the bioisosterism strategy. The linear β-defensins were more active against Escherichia coli, Micrococcus luteus, Citrobacter freundii, and Staphylococcus aureus. The derived peptides (7–14 mer) showed antibacterial activity against those bacteria and on Klebsiella pneumoniae. Nonetheless, they did not present activity against Candida albicans, Cryptococcus neoformans, Trychophyton rubrum, and Aspergillus fumigatus showing that the cysteine substitution to serine is deleterious to antifungal properties. Tryptophan residue showed to be necessary to improve antibacterial activity. Even though the studied snake β-defensins do not have high antimicrobial activity, they proved to be attractive as template molecules for the development of antibiotics.

scholarly journals Nano zinc oxide – An alternate zinc supplement for livestock

2020 ◽  
Vol 13 (1) ◽  
pp. 121-126
Author(s):  
K. Geetha ◽  
M. Chellapandian ◽  
N. Arulnathan ◽  
A. Ramanathan
Keyword(s):  
Antibacterial Activity ◽  
Zno Nanoparticles ◽  
Pathogenic Bacteria ◽  
Antimicrobial Activities ◽  
Precipitation Method ◽  
Dependent Manner ◽  
Bacterial Strains ◽  
Nano Zno ◽  
Zinc Supplement

Aim: This study was aimed to investigate antimicrobial and cytotoxicity effect of nano ZnO in in vitro for the application of livestock feed supplement. Materials and Methods: Nano ZnO was synthesized by wet chemical precipitation method using zinc acetate as a precursor and sodium hydroxide was used for reducing the precursor salt. The properties of synthesized powder were characterized using ultraviolet (UV)–visible spectroscopy, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD), respectively. In vitro antimicrobial activities were analyzed against the pathogenic bacteria in poultry Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Streptococcus aeruginosa. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was conducted to analyze the cytotoxicity effect of nano ZnO. Results: SEM showed a spherical ZnO particle in the range of 70-100 nm. The size of the particle and purity of the sample were confirmed by XRD. The nano-sized ZnO particles exhibited the UV absorption peak at 335 nm. In FTIR spectroscopy, pure ZnO nanoparticles showed stretching vibrations at 4000-5000 cm-1. ZnO nanoparticles exhibited remarkable antibacterial activity against E. coli, S. aureus, K. pneumoniae, and S. aeruginosa bacterial strains. Cell viability was significantly reduced in a dose-dependent manner in the cytotoxicity study. Conclusion: From the broad-spectrum antibacterial activity and the lower cytotoxicity observed at the prescribed dose, it is concluded that nano ZnO powder is a potential alternate zinc supplement for livestock.

scholarly journals Antimicrobial activities and phytochemical screening of leaf extract of Mikania micrantha H.B.K

2018 ◽  
Vol 30 ◽  
pp. 274-286
Author(s):  
Anjana Devkota ◽  
Anita Sahu
Keyword(s):  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Pathogenic Bacteria ◽  
Leaf Extract ◽  
Methanol Extract ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Phytochemical Screening ◽  
Mikania Micrantha ◽  
Crude Leaf Extract

Antimicrobial activities and phytochemical screening of leaves of Mikania micrantha was tested in laboratory against phytopathogenic fungi and human pathogenic bacteria. The leaves samples were extracted in distilled water and methanol. The crude extracts of leaves were assessed in-vitro for antimicrobial activity using different concentrations (50, 100, 150,200, and 250 mg/ml) against five fungal strains (viz. Sclerotium rolfsii, Phytopthora capsici, Alternaria brassicae, Fusarium oxysporum and Botrytis cinerea) and six bacterial strains (Klebsiella pneumoniae, Proteus mirabilis, Escherichia coli, Bacillus subtilis, Enterococcusfaecalis and Staphylococcus aureus). Antifungal activity was tested by Poison Food Technique and Linear Mycelium growth Reduction (LMGR) percentage was determined. In crude extractof M. micrantha, the highest LMGR percentage was found in F. oxysporum in both distilledwater and methanol extract. Antibacterial activity was carried out by Disc Diffusion method. In the crude leaf extract of M. micrantha Gram negative bacteria was found more resistant than Gram positive bacteria. Methanol extract was found more effective in determining the Zone of Inhibition for all the strains of bacteria in all the concentrations. The plant extracts were found more effective in showing antibacterial activity than antifungal activity. The phytochemicalscreening revealed that the selected species contained tannin, saponins, alkaloid, flavonoid, cardiac glycosides and terpenoids. This result supports the potential of this plant species used as a new chemotherapeutic drug.

scholarly journals Antimicrobial Compounds from the Mucus of Garden Snail Cornu aspersa

2020 ◽  
Author(s):  
Aleksandar Dolashki ◽  
Lyudmila Velkova ◽  
Elmira Daskalova ◽  
N. Zheleva ◽  
Yana Topalova ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Antibacterial Activity ◽  
Tandem Mass Spectrometry ◽  
De Novo ◽  
Antimicrobial Activities ◽  
Biologically Active ◽  
New Drugs ◽  
Tandem Mass ◽  
Bacterial Strains ◽  
Natural Substances

Natural products have long played a major role in medicine and science. The garden snail Cornu aspersa is a rich source of biologically active natural substances which might be an important source for new drugs to treat human disease. Based on our previous studies seven fractions containing compounds with Mw &amp;lt;3 kDa, &amp;lt;10 kDa, &amp;lt;20 kDa, &amp;gt;20 kDa, and between 3-5 kDa, 5-10 kDa, and 10-30 kDa were purified from the mucus of C. aspersa and analyzed by tandem mass spectrometry (MALDI-TOF/TOF). Seventeen novel peptides with potential antibacterial activity have been identified by de novo MS/MS sequencing using tandem mass spectrometry. The different fractions were tested for antibacterial activity against Gram─ (Pseudomonas aureofaciens and Escherichia coli) and Gram+ (Brevibacillus laterosporus) bacterial strains as well anaerobic bacterium Clostridium perfringens. These results revealed that the peptide fractions exhibit a predominant antibacterial activity against B. laterosporus, the fraction with Mw 10 &ndash; 30 kDa against E. coli, another peptide fraction &amp;lt;20 kDa against P. aureofaciens, and the protein fraction &amp;gt;20 kDa against the bacterial strain C. perfringens. The discovery of new antimicrobial peptides (AMPs) from natural sources is of great importance for public health due to their effective antimicrobial activities and low resistance rates.

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>

Sign in / Sign up

Export Citation Format

Share Document