scholarly journals Biogenic synthesis of silver nanoparticles from waste banana plant stems and their antibacterial activity against Escherichia coli and Staphylococcus Epidermis

2017 ◽  
Vol 5 (9) ◽  
pp. 3769 ◽  
Author(s):  
Huu Dang ◽  
Derek Fawcett ◽  
Gerrard Eddy Jai Poinern
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Ag Nanoparticles ◽  
Inhibition Zone ◽  
Gram Negative Bacteria ◽  
Banana Plant ◽  
Biogenic Synthesis ◽  
Maximum Inhibition ◽  
Staphylococcus Epidermis ◽  
First Time

Background: This study for the first time presents an eco-friendly and room temperature procedure for biologically synthesizing silver (Ag) nanoparticles from waste banana plant stems.Methods: A simple and straightforward green chemistry based technique used waste banana plant stems to act as both reducing agent and capping agent to produce Ag nanoparticles, which were subsequently characterized. In addition, antibacterial studies were conducted using the Kirby-Bauer sensitivity method.Results: Advanced characterisation revealed the Ag nanoparticles had a variety of shapes including cubes, truncated triangular and hexagonal plates, and ranged in size from 70 nm up to 600 nm. The gram-negative bacteria Escherichia coli showed the maximum inhibition zone of 12 mm.Conclusions: The study has shown that waste banana plant stems can generate Ag nanoparticles with antibacterial activity against Escherichia coli and Staphylococcus epidermis.

scholarly journals Green synthesis of gold nanoparticles from waste macadamia nut shells and their antimicrobial activity against Escherichia coli and Staphylococcus epidermis

2019 ◽  
Vol 7 (4) ◽  
pp. 1171 ◽  
Author(s):  
Huu Dang ◽  
Derek Fawcett ◽  
Gerrard Eddy Jai Poinern
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Green Chemistry ◽  
Staphylococcus Epidermidis ◽  
Au Nanoparticles ◽  
Inhibition Zone ◽  
Au Nanoparticle ◽  
Maximum Inhibition ◽  
Macadamia Nut ◽  
Export Revenue

Background: The study for the first time demonstrates an eco-friendly and room temperature procedure for biosynthesizing gold (Au) nanoparticles from waste Macadamia nut shells. Currently Australia contributes around 40% to the global market and generates around AUS $150 million of export revenue. However, a consequence of large nut production is the generation of large quantities of waste nut shells. The green chemistry-based method is clean, nontoxic and eco-friendly. The method presented in this study produced a variety of Au nanoparticle sizes and shapes.Methods: The straightforward green chemistry-based technique used waste Macadamia nut shells to generate Au nanoparticles, which were subsequently studied using several advanced characterization techniques. Furthermore, the Kirby-Bauer sensitivity method was used to evaluate the antibacterial properties of the extracts and synthesized gold nanoparticles.Results: Advanced characterisation revealed the Au nanoparticles were crystalline, ranged in size from 50nm up to 2µm, and had spherical, triangular and hexagonal morphology. The gram-negative bacteria Escherichia coli produced a maximum inhibition zone of 11mm, while Staphylococcus epidermidis produced a maximum inhibition zone of 9mm.Conclusions: The study has shown that waste Macadamia nut shell extracts have no antibacterial activity, but the synthesised Au nanoparticles did display antibacterial activity to both Escherichia coli and Staphylococcus epidermidis. Thus, the present work has demonstrated a waste valorisation strategy that can be used to produce high-value Au nanoparticles with antimicrobial properties for use in future pharmaceuticals.

scholarly journals Biogenic synthesis of gold nanoparticles from waste watermelon and their antibacterial activity against Escherichia coli and Staphylococcus epidermidis

2019 ◽  
Vol 7 (7) ◽  
pp. 2499 ◽  
Author(s):  
Wisut Chums-ard ◽  
Derek Fawcett ◽  
Chun Che Fung ◽  
Gerrard Eddy Jai Poinern
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Staphylococcus Epidermidis ◽  
Au Nanoparticles ◽  
Antibacterial Properties ◽  
Advanced Characterization ◽  
Inhibition Zone ◽  
Au Nanoparticle ◽  
Characterization Techniques ◽  
Maximum Inhibition

Background: Globally, large quantities (tonnes) of diverse sources of food wastes derived from horticulture are produced and offer a valuable renewable source of biochemical compounds. Developing new recycling and food waste utilisation strategies creates unique opportunities for producing gold (Au) nanoparticles with desirable antibacterial properties. The present study used an eco-friendly procedure for biologically synthesizing gold (Au) nanoparticle shapes from waste Citrullis lanatus var (watermelon).Methods: The green chemistry-based procedure used in this study was straightforward and used both red and green parts of waste watermelon. The generated Au nanoparticles were subsequently evaluated using several advanced characterization techniques. The antibacterial properties of the various extracts and synthesised nanoparticles were evaluated using the Kirby-Bauer sensitivity method.Results: The advanced characterization techniques revealed the Au particles ranged in size from nano (100 nm) up micron (2.5 µm) and had a variety of shapes. The red watermelon extract tended to produce spheres and hexagonal plates, while the green watermelon extract tended to generate triangular shaped nanoparticles. Both red and green watermelon extracts produced nanoparticles with similar antibacterial properties. The most favourable response was achieved using a 5:1 green watermelon-based mixture for Staphylococcus epidermidis, which produced a maximum inhibition zone of 12 mm. While gram-negative bacteria Escherichia coli produced a maximum inhibition zone of 10 mm for the same mixture.Conclusions: The study has shown both red and green parts of waste watermelon can be used to produce Au nanoparticles with antibacterial activity towards both Escherichia coli and Staphylococcus epidermidis. The study has also demonstrated an alternative method for producing high-value Au nanoparticles with potential pharmaceutical applications.

Iso-octenidine: Promising Octenidine Analogue with Improved Solubility

2020 ◽  
Vol 17 ◽  
Author(s):  
Igor K. Yakuschenko ◽  
Nataliya N. Pozdeeva ◽  
Viktoriya A. Mumyatova ◽  
Alexey A. Terentiev ◽  
Svyatoslav Ya. Gadomsky
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Micrococcus Luteus ◽  
Octenidine Dihydrochloride ◽  
First Time

: Iso-octenidine, an isomer of octenidine dihydrochloride, was synthesized and studied for the first time. Isooctenidine was demonstrated to be 3-fold more soluble in water in comparison to original octenidine, and both substances had remarkably similar antibacterial activity (tested on Escherichia Coli and Micrococcus luteus).

scholarly journals Structure of the master regulator Rns reveals an inhibitor of enterotoxigenic Escherichia coli virulence regulons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charles R. Midgett ◽  
Kacey Marie Talbot ◽  
Jessica L. Day ◽  
George P. Munson ◽  
F. Jon Kull
Keyword(s):  
Escherichia Coli ◽  
Small Molecules ◽  
Family Member ◽  
Shigella Flexneri ◽  
Decanoic Acid ◽  
Enterotoxigenic Escherichia Coli ◽  
Gram Negative Bacteria ◽  
Enteric Infections ◽  
First Time ◽  
Arac Family

AbstractEnteric infections caused by the gram-negative bacteria enterotoxigenic Escherichia coli (ETEC), Vibrio cholerae, Shigella flexneri, and Salmonella enterica are among the most common and affect billions of people each year. These bacteria control expression of virulence factors using a network of transcriptional regulators, some of which are modulated by small molecules as has been shown for ToxT, an AraC family member from V. cholerae. In ETEC the expression of many types of adhesive pili is dependent upon the AraC family member Rns. We present here the 3 Å crystal structure of Rns and show it closely resembles ToxT. Rns crystallized as a dimer via an interface similar to that observed in other dimeric AraC’s. Furthermore, the structure of Rns revealed the presence of a ligand, decanoic acid, that inhibits its activity in a manner similar to the fatty acid mediated inhibition observed for ToxT and the S. enterica homologue HilD. Together, these results support our hypothesis that fatty acids regulate virulence controlling AraC family members in a common manner across a number of enteric pathogens. Furthermore, for the first time this work identifies a small molecule capable of inhibiting the ETEC Rns regulon, providing a basis for development of therapeutics against this deadly human pathogen.

scholarly journals Proteomic response of Escherichia coli to a membrane lytic and iron chelating truncated Amaranthus tricolor defensin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tessa B. Moyer ◽  
Ashleigh L. Purvis ◽  
Andrew J. Wommack ◽  
Leslie M. Hicks
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antimicrobial Peptides ◽  
Mechanism Of Action ◽  
Gram Negative Bacteria ◽  
Amaranthus Tricolor ◽  
Core Motif ◽  
Gram Negative ◽  
E Coli ◽  
Membrane Lysis

Abstract Background Plant defensins are a broadly distributed family of antimicrobial peptides which have been primarily studied for agriculturally relevant antifungal activity. Recent studies have probed defensins against Gram-negative bacteria revealing evidence for multiple mechanisms of action including membrane lysis and ribosomal inhibition. Herein, a truncated synthetic analog containing the γ-core motif of Amaranthus tricolor DEF2 (Atr-DEF2) reveals Gram-negative antibacterial activity and its mechanism of action is probed via proteomics, outer membrane permeability studies, and iron reduction/chelation assays. Results Atr-DEF2(G39-C54) demonstrated activity against two Gram-negative human bacterial pathogens, Escherichia coli and Klebsiella pneumoniae. Quantitative proteomics revealed changes in the E. coli proteome in response to treatment of sub-lethal concentrations of the truncated defensin, including bacterial outer membrane (OM) and iron acquisition/processing related proteins. Modification of OM charge is a common response of Gram-negative bacteria to membrane lytic antimicrobial peptides (AMPs) to reduce electrostatic interactions, and this mechanism of action was confirmed for Atr-DEF2(G39-C54) via an N-phenylnaphthalen-1-amine uptake assay. Additionally, in vitro assays confirmed the capacity of Atr-DEF2(G39-C54) to reduce Fe3+ and chelate Fe2+ at cell culture relevant concentrations, thus limiting the availability of essential enzymatic cofactors. Conclusions This study highlights the utility of plant defensin γ-core motif synthetic analogs for characterization of novel defensin activity. Proteomic changes in E. coli after treatment with Atr-DEF2(G39-C54) supported the hypothesis that membrane lysis is an important component of γ-core motif mediated antibacterial activity but also emphasized that other properties, such as metal sequestration, may contribute to a multifaceted mechanism of action.

scholarly journals Identifikasi Senyawa Metabolit Sekunder, Uji Antimikroba dan Antioksidan Ekstrak Akar Gantung Hornstedtia Scyphifera Var. Fusiformis Holttum (Sijangkang)

2019 ◽  
Vol 10 (2) ◽  
pp. 94-98
Author(s):  
Adlis Santoni ◽  
Mai Efdi ◽  
Akmel Suhada
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Ethyl Acetate ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Inhibition Zone ◽  
Endemic Plant ◽  
Dpph Method ◽  
Hexane Extracts

Hornstedtia scyphifera var. fusiformis Holttum is endemic plant of Zingiberaceae family that distributed in Sumatera. Hornstedtia scyphifera var. fusiformis Holttum contained some secondary metabolite such as phenolic, saponin, triterpenoid and alkaloid. The biological activity of methanol, ethyl acetate, and n-hexane extracts from Hornstedtia scyphifera var. fusiformis Holttum suspended roots was tested for antibacterial and antioxydant activity. Antioxidant activity was analized by DPPH method. The antibacterial activity  was tested by used disk difussion method againts Staphylococcus aureus bacteria (gram-positive bacteria) and Escherichia coli (gram-negative bacteria). Almost all of Hornstedtia scyphifera var. fusiformis Holttum suspended roots extract were given antibacterial activity, nonetheless the biggest inhibition zone of Escherichia coli that was inhibited by n-hexane and ethyl acetate extracts which have inhibition zone 10 mm at  concentration 500 mg/L and also againts Staphylococcus aureus, the biggest inhibition by ethyl acetate and n-hexane extracts which have inhibition zone 10.30 mm at concentration 500 mg/L. Among all extracts tested, methanol extract of the possessed moderate free radical scavenging activity with IC50 = 51.89 mg/L.

scholarly journals Antibacterial activity of Escherichia coli from squid ink (Loligo sp.) n-Hexane extracts

2021 ◽  
Vol 869 (1) ◽  
pp. 012033
Author(s):  
D R Utami ◽  
I Irwan ◽  
S Agustina ◽  
S Karina ◽  
S Afriani
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Secondary Metabolite ◽  
Bioactive Compound ◽  
Inhibition Zone ◽  
Hexane Extract ◽  
Inhibition Zone Diameter ◽  
E Coli ◽  
Hexane Extracts ◽  
Intermediate Concentration

Abstract Squid is one of the export commodities in Indonesia. In general, the use of squid meat, while the ink is only as waste. In fact, Squid ink contain bioactive compound that potential as anti-inflammatory, antihypertensive, anti-diabetic,anti-microbial and anti-malaria agents. The purpose of the study is to determine the types of secondary metabolite compounds contained in n-hexane extract of Loligo sp. ink using maceration method to determine its antibacterial activity against Escherichia coli. The results of secondary metabolite compounds obtained from the n-hexane extract of Loligo sp. ink are alkaloid, saponins, glycosides and phenol. The results of antibacterial test against E. coli using the disc method obtained the average of inhibition zone diameter at the concentration of 4% is 6.3 mm (intermediate), concentration of 8% is 7.83 mm (intermediate), concentration of 16% is 14.5 mm (susceptible) and concentration of 32% is 10.83 mm (intermediate). The antibacterial activity in n-hexane extract of Loligo sp. ink is optimal at the concentration of 16% against E. coli bacteria.

scholarly journals UJI AKTIVITAS ANTIBAKTERI DAN ANTI-UV Phyllidiella nigra DAN BAKTERI SIMBIOTIKNYA DARI PERAIRAN TANJUNG MANDOLANG

2020 ◽  
Vol 8 (2) ◽  
pp. 61
Author(s):  
Tessalonica Dajoh ◽  
Robert A Bara ◽  
Esther Angkouw ◽  
Medy Ompi ◽  
Rosita A Lintang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Secondary Metabolites ◽  
Bacillus Megaterium ◽  
Absorption Maximum ◽  
Chemical Compounds ◽  
Inhibition Zone ◽  
Defense System ◽  
E Coli ◽  
Self Defense

Phyllidiella nigra is an organism that is suspected to have secondary metabolites because their ability to develop its self defense system by camouflage and using chemical compounds derived from their nature diet as deterrent against their predators. The purpose of this study was to isolate symbiotic bacterial derived from P. nigra, extracted and followed by, the antibacterial assays against Escherichia coli and Bacillus megaterium as well as the anti-UV assay. The results showed that the five isolates tested had an antibacterial activity with the highest average inhibition zone against E. coli DSM 498 bacteria, isolate 1 (14.67 mm), isolate 5 (14 mm), and against B. Megaterium DSM 32T bacteria, isolate 3 (13.33 mm). The three isolates which had the highest inhibition zone and P. nigra extract were tested for anti-UV assay using a UV-Vis Spectrophotometer. The results obtained isolate 3 has absorption of UV-A with the UV absorbtion maximum at λ 340 nm and P. nigra extract has absorption on UV-B radiation with UV absorption maximum at λ 290 nm. Key words: Nudibranchia, Bacteria, Anti-bacteial, Anti-UV Phyllidiella nigra merupakan organisme yang diduga memiliki metabolit sekunder karena mampu mengembangkan sistem pertahanan dirinya dengan cara kamuflase dan menggunakan senyawa kimia sebagai racun yang didapat dari makanannya. Tujuan dari penelitian ini yaitu mendapatkan isolat bakteri yang bersimbiosis dengan P. nigra, mendapatkan ekstrak dari baktri simbion, dan menguji antibakteri dan anti-UV ekstrak etil aseta bakteri simbion dengan metode difusi agar terhadap bakteri Escherichia coli dan Bacillus megaterium. Hasil penelitian didapatkan kelima isolat yang diuji memiliki aktivitas antibakteri dengan rerata zona hambat tertinggi terhadap bakteri E. coli DSM 498 yaitu isolat 1 (14,67 mm), isolat 5 (14 mm), dan terhadap baktri B. megaterium DSM 32T yaitu isolat 3 (13,33 mm). Ketiga isolat yang memiliki zona hambat tertinggi dan ekstrak P. nigra diujikan anti-UV menggunakan alat UV-Vis Spektrofotometer. Hasil yang didapat isolat 3 memiliki serapan terhadap radiasi sinar UV-A dengan puncak tertinggi pada λ 340 nm dan ekstrak P. nigra memiliki serapan terhadap radiasi sinar UV-B dengan puncak tertinggi berada pada λ 290 nm. Kata kunci: Nudibranchia, Bacteria, Anti-bacteial, Anti-UV

scholarly journals ANTIBACTERIAL ACTIVITY OF CHITOSAN AND HYDROLYZED COCONUT OIL AND THEIR COMBINATION AGAINST BACILLUS CEREUS AND ESCHERICHIA COLI

2016 ◽  
Vol 9 (5) ◽  
pp. 69 ◽  
Author(s):  
Jansen Silalahi ◽  
Petrika Situmorang ◽  
Popi Patilaya ◽  
Yosy Ce Silalahi
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Bacillus Cereus ◽  
Coconut Oil ◽  
Inhibition Zone ◽  
Research Centre ◽  
Virgin Coconut Oil ◽  
Inhibition Zone Diameter ◽  
E Coli ◽  
Zone Diameter

ABSTRACTObjective: The purpose of this study was to evaluate the antibacterial activity of chitosan, hydrolyzed coconut oil and their combination againstBacillus cereus and Escherichia coli.Methods: The materials used in this study were powder of chitosan (obtained from prawn shell produced by Laboratory of Research Centre FMIPAUniversity of Sumatera Utara) and virgin coconut oil (VCO) product of Siti Nurbaya-Indonesia. VCO was partially hydrolyzed by Lipozyme TL IM(active at sn-1,3 position) and the result called hydrolyzed virgin coconut oil (HVCO). The bacteria used in this study were B. cereus and E. coli. Theantibacterial activity of chitosan in 1% acetic acid and HVCO in dimethylsulfoxide was tested by Kirby–Bauer agar diffusion method using paper discwith diameter of 6 mm.Results: The results showed that the minimum inhibitory concentration of chitosan against B. cereus and E. coli is at concentration of 0.05% withinhibition zone diameter of 6.86 mm and 7.56 mm, respectively. MIC of HVCO against B. cereus is at concentration of 0.25% with inhibition zonediameter of 6.40 mm, and against E. coli is at a concentration of 0.50% with inhibition zone diameter of 6.20 mm. The inhibition zone diameter ofchitosan 0.05% and HVCO 0.25% in combination against B. cereus is 8.33 mm which is higher than half the sum of chitosan 0.05% and HVCO 0.25%(6.63 mm). The inhibition zone diameter of chitosan 0.05% and 0.5% HVCO in combination against E. coli is 8.53 mm which is higher than half thesum of chitosan 0.05% and HVCO 0.5% (6.53 mm).Conclusion: The findings of this study indicate that chitosan is more antibacterial than HVCO, and the interaction between chitosan and HVCO incombination demonstrated to be synergistic against B. cereus and E. coli.Keywords: Antibacterial, Chitosan, Coconut oil, Combination, Bacillus cereus, Escherichia coli.®

Sign in / Sign up

Export Citation Format

Share Document