scholarly journals Antimicrobial cellulose acetate films by incorporation of geranyl acetate for active food packaging application

2022 ◽  
Vol 11 (1) ◽  
pp. e40111125141
Author(s):  
Laura Cassol Mohr Celuppi ◽  
Ana Paula Capelezzo ◽  
Leticia Bavaresco Cima ◽  
Rubieli Carla Frezza Zeferino ◽  
Micheli Zanetti ◽  
...  

The development of new antimicrobial polymeric materials is in prominence due to its versatility of applications, especially for the manufacture of active packaging food. Cellulose acetate is an example of polymeric material used to this purpose, due to its characteristics of biodegradability and easy processing, in addition its natural origin and no toxicity. Geranyl acetate is an ester derived from geraniol, which has good antimicrobial properties and good thermal stability, which makes it interesting to be applied as an antimicrobial agent, avoiding the trivial and often problematic metallic nanoparticles and also volatile essential oils. In this work, antibacterial and antifungal cellulose acetate films were obtained through the incorporation of geranyl acetate ester (in concentrations of 0.5 and 1.0% v/v), by using the casting technique. This new material was tested against gram-positive and gram-negative bacteria and fungi. Results showed that it is possible to obtain antibacterial and antifungal cellulose acetate films with the incorporation of geranyl acetate ester, with excellent antibacterial activity against gram-positive and gram-negative bacteria and good antifungal activity.

2020 ◽  
Vol 16 (9) ◽  
pp. 1416-1425
Author(s):  
Katarzyna Arkusz ◽  
Ewa Paradowska ◽  
Marta Nycz ◽  
Justyna Mazurek-Popczyk ◽  
Katarzyna Baldy-Chudzik

Current research on the antibacterial properties of implant surfaces has focused on using titanium nanotubes (TNTs) with diameters of 100 and 200 nm, which simultaneously show the best antibacterial properties, poor osseointegration, and ability to immobilize proteins. Therefore, the research aimed to develop an implantable material based on titanium dioxide nanotubes with a diameter of 50 nm doped with silver (AgNPs) and gold nanoparticles (AuNPs), indicating good absorption and antibacterial properties. Moreover, metallic nanoparticles deposited by varying methods should maintain sphericity and lack of agglomeration. For this purpose, the surface charge, wettability, stability of nanoparticles, and antibacterial properties against Gram-positive and Gram-negative bacteria, i. e., Staphylococcus epidermidis, Streptococcus mutans, and Pseudomonas aeruginosa , were performed. Obtained results indicate a greater resistance to leaching of silver nanoparticles compared to gold nanoparticles. These results are reflected in microbiological studies, both into the time and the effectiveness of the implantable material's antibacterial activity. A greater antibacterial effect of AgNPs than AuNPs has been confirmed. Also, AgNPs inhibit the multiplication of Gram-negative bacteria to a greater extent than Gram-positive bacteria. It has been proven that the TNT platforms deposited with metal nanoparticles via the voltammetric method are more effective in deactivating microorganisms. Besides, the results have proven that smaller TNTs effectively reduce live bacteria as nanotubes with a diameter of 100 and 200 nm.


2011 ◽  
Vol 8 (1) ◽  
pp. 478-483
Author(s):  
Baghdad Science Journal

In this study Oscillatoria limnetica and Chroococus minor were isolated ?purified and identification from water canal around Baghdad University Campus. The water of this canals originally from Tigris River. BG-11 culture media was used for their cultivation in suitable laboratory conditions (25c°, 200µE/m2/sec) for 16:8 hrs. Light: dark. Each culture was harvested at the end of exponential phase .Organic solvents used for extraction were Ethanol? Hexane and Methanol 95% to extract the crude active Intracellular and Extracellular substances, and evaporated down to dryness .Antibacterial and antifungal activity of these different extracts were evaluated against 6 strains of gram positive bacteria and gram negative bacteria in addition to fungi, Agar diffusion method was used in this evaluation. Results showed that the extracellular products which extracted by hexane and the extracellular products which extracted by ethanol from Oscillatoria limnetica were have higher antagonistic activity against bacteria and Fungi comparing with methanol extracts .However higher antibacterial and antifungal were obtained against the studied strains of comparing with methanol and ethanol extracts of the same algae products. The gram positive bacteria studied revealed higher susceptibility to attack by the intracellular and extracellular extracts comparing with the gram negative bacteria. These extracts revealed higher antibacterial activity against Bacillus subtilise and the average of inhibition zone were 26, 22 mm. for intracellular and extracellular products of O.limnetica respectively. However, C. minor intracellular products extract has the antagonistic activity against Staphylococcus aureus with 28 mm inhibition zone


Author(s):  
Pratik K. Talpara ◽  
Guarang G. Dubal ◽  
Viresh H. Shah

The synthesis of novel Pyrano[2,3-d]pyrimidine derivatives, had been synthesized by three component domino Knoevenagel hetero Diels-Alder reaction. The products were assayed for their in vitro biological assay antibacterial activity against with two Gram-positive bacteria Staphylococcus aureus MTCC-96, Streptococcus pyogenes MTCC 443, two Gram-negative bacteria Escherichia coli MTCC 442, Pseudomonas aeruginosa MTCC 441 and three fungal strains Candida albicans MTCC 227, Aspergillus Niger MTCC 282, Aspergillus clavatus MTCC 1323 taking ampicillin, chloramphenicol, ciprofloxacin, norfloxacin, nystatin, and griseofulvin as standard drugs. Among the various synthesized heterocyclic compounds, 1b, 1c and 1g are display broad spectrum antibacterial and antifungal activities against both gram-positive and gram-negative bacteria as compared with standard drugs.


Biologia ◽  
2006 ◽  
Vol 61 (3) ◽  
Author(s):  
Ömer Ertürk

AbstractEleven ethanolic extracts from spices of Melissa officinalis, Mentha piperita, Laurus nobilis, Rhus coriaria, Dianthus coryophyllum, Piper nigrum, Capsicum annum, Juniperus oxycedrus, Erica arborea, Colutea arborescens, and Cuminum cyminum collected from various regions of Turkey and local markets were assayed for the in vitro antibacterial activity against 3 Gram-positive (Bacillus subtilis, Staphylococcus aureus and S. epidermidis) and 2 Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), using agar dilution methods. In addition, their possible toxicity to Candida albicans and Aspergillus niger was determined, using both agar dilution and disc-diffusion methods. The minimum inhibition concentration (MIC) of the M. piperita, L. nobilis and J. oxycedrus ethanolic extracts was 5 mg/mL for all the microorganisms tested. P. aeruginosa was the most sensitive bacterial strain to P. nigrum and E. arborea extracts among both Gram-positive and Gram-negative bacteria tested with MIC of 5 mg/mL. The extracts of L. nobilis, D. coryophyllum, J. oxycedrus and C. arborescens showed higher inhibitory activity against the yeast C. albicans and the fungus A. niger than the standard antifungal nystatin.


Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.


Author(s):  
Sushma Vashisht ◽  
Manish Pal Singh ◽  
Viney Chawla

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.


Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.


2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.


2020 ◽  
Vol 8 (1) ◽  
pp. 122
Author(s):  
Eghbert Eghbert Elvan Eghbert Elvan Ampou ◽  
Iis Iis Triyulianti ◽  
Nuryani Widagti ◽  
Suciadi Catur Nugroho ◽  
Yuli Pancawati

Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of gram-positive and gram-negative bacteria. The method used for field sampling is time swim, which is by diving at a depth of 5-10 meters for ± 30 minutes and randomly taking samples of coral mucus using siring or by taking directly on corals (reef branching). Mucus samples were analyzed by bacterial isolation in the laboratory. The result shows that there were differences between gram-positive and gram-negative bacteria in the three research sites and that gram-positive bacteria were higher or dominant. Further research that can identify the bacteria species and explain its relationship to the ecosystem is highly recommended.Keywords: Bacteria, Scleractinian coral, gram-positive and -negative, Bunaken, Morotai, Raja Ampat  AbstrakPenelitian tentang karang keras (Scleractinian coral) yang terkontaminasi bakteri masih belum banyak dilakukan, terutama di perairan Indonesia. Penelitian ini mengambil sampel mucus karang pada tahun 2010 di 3 (tiga) lokasi berbeda, yakni Bunaken (Mei); Morotai (September) dan Raja Ampat (November), yang difokuskan pada analisis bakteri gram postif dan gram negatif. Metode yang digunakan untuk pengambilan sampel di lapangan adalah time swim, yaitu dengan penyelaman pada kedalaman 5-10 meter selama ±30 menit dan mengambil sampel mucus karang secara acak menggunakan siring atau dengan mengambil langsung pada karang (fraksi cabang). Sampel mucus dianalisis dengan cara isolasi bakteri di laboratorium. Hasil analisis menunjukkan bahwa ada perbedaan antara bakteri gram positif dan gram negative di tiga lokasi survei dan bakteri gram positif lebih tinggi atau dominan. Penelitian lebih lanjut yang dapat menentukan jenis bakteri serta menjelaskan hubungannya dengan ekosistem sangat disarankan untuk dilakukan.Kata Kunci : Bakteri, Scleractinian coral, gram positif dan negatif, Bunaken, Morotai, Raja Ampat


2014 ◽  
Vol 35 (8) ◽  
pp. 907
Author(s):  
Hu LI ◽  
Ming-kun CHEN ◽  
Hui WANG ◽  
Yan CHEN ◽  
Xian-hao SU ◽  
...  

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