scholarly journals Preparation and characterization of epigallocatechin-3-gallate loaded melanin nanocomposite (EGCG @MNPs) for improved thermal stability, antioxidant and antibacterial activity

LWT ◽  
2021 ◽  
pp. 112599
Author(s):  
Wangchen Zhao ◽  
Ziyu Liu ◽  
Xiaoyun Liang ◽  
Siqi Wang ◽  
Jie Ding ◽  
...  
2013 ◽  
Vol 750-752 ◽  
pp. 1609-1612 ◽  
Author(s):  
Yang Ti ◽  
Jian Ru Wu ◽  
Da Jun Chen

In this paper, Fe-OCAP/PU blends were prepared. The mechanical properties and thermal stability of the samples were studied by tensile tests and thermogravimetric analysis, respectively. Results showed that the mechanical properties and thermal stability of the samples were improved with the increase of Fe-OCAP content. The antibacterial property of Fe-OCAP and Fe-OCAP/PU films was investigated by agar diifusion method and shake flask method, respectively. Fe-OCAP and Fe-OCAP/PU films showed efficient antibacterial activity againstS.aureus.


2020 ◽  
Author(s):  
Xiaohong Yu ◽  
Zhicai Yang ◽  
Keyue Li ◽  
Rui Liu ◽  
Huijie Pei ◽  
...  

Abstract Background: Lactic acid bacteria (LAB) can produce bacteriostatic substances, among which bacteriocins attracted wide attention in food preservation for decades. Up to date, nisin (class I bacteriocins) has been considered to be the only bacteriocin produced by Lactococcus lactis strains for commercial use. Moreover, there are many other reports concerning the isolated bacteriocins for potential application in food industry while some exhibited a narrow bactericidal spectrum, thermal stability and low acid-base stability. Jinhua ham is a representative of traditional dry-cured meat product in China. The microbial community structure and diversity was speculated to be responsible for flavor and quality formation of Jinhua ham, protecting from the spoilage microorganisms contamination. However, no studies was performed to investigate the bacteriocin from LAB in Jinhua ham. Thus, the objective of this study was to screen out high-efficiency, safe and non-toxic bacteriocin-producing lactic acid bacteria (LAB) from Jinhua Ham and subsequently perform the purification, identification and characterization of its bacteriocin. Results: The bacteriocin-producing LAB was screened from Jinhua ham and then designated as Pediococcus pentosaceus Z-1 by colony morphology and 16S rDNA sequencing. The bacteriocin was then crudely extracted from the bacterial cell-free supernatant by pH adsorption, and further purified by cellulose DEAE-52 ion exchange and Sephadex G-50 chromatography columns. The tricine-SDS-PAGE electrophoresis showed a highly purified protein band with 8227.35 Da with 60 amino acids identified by MALDI-TOF-MS analysis. The bacteriocin was named as pediocin Z-1 and its antibacterial activity exhibited an acid-base stability between pH 2-10 and a thermal stability at a range of 50-110°C. The pediocin Z-1 was sensitive to proteases and showed an inhibitory effect against Gram-positive bacteria and Gram-negative bacteria, including Listeria monocytogenes, Staphylococcus aureus, Salmonella typhimurium, Salmonella potsdam and Escherichia coli. Conclusions: Our data suggest that pediocin Z-1 has a comparable effect of antibacterial activity with nisin and it is promising that pediocin Z-1 has great potential for application prospect in the food industry.


2020 ◽  
Vol 10 (4) ◽  
pp. 93-97
Author(s):  
Anil Kumar A ◽  
Raja Sheker K ◽  
Naveen B ◽  
Abhilash G ◽  
Akila CR

Seas assets that give us a variety of characteristic items to control bacterial, contagious and viral ailment and mostly utilized for malignancy chemotherapy practically from spineless creatures, for example, bryozoans, wipes, delicate corals, coelenterates, ocean fans, ocean bunnies, molluscs and echinoderms. In the previous 30 - 40 years, marine plants and creatures have been the focal point of overall endeavours to characterize the regular results of the marine condition. Numerous marine characteristic items have been effectively exceptional to the last phases of clinical preliminaries, including dolastatin-10, a group of peptides disengaged from Indian ocean rabbit, Dollabella auricularia. Ecteinascidin-743 from mangrove tunicate Ecteinascidia turbinata, Didemnins was isolated from Caribbean tunicate Trididemnum solidum and Conopeptides from cone snails (Conus sp.), and a developing number of up-and-comers have been chosen as promising leads for expanded pre-clinical appraisals. Sea anemones possess numerous tentacles containing stinging cells or cnidocytes. The stinging cells are equipped with small organelles known as nematocysts. The two species of sea anemones namely, Heteractis magnificaandStichodactyla haddoni, were collected from Mandapam coastal waters of Ramanathapuram district, Tamilnadu, India. The Nematocyst was collected and centrifuged, and the supernatant was lyophilized and stored for further analysis. The amount of protein from Heteractis Magnifica and Stichodactyla haddoni was estimated. The crude extract has shown haemolytic activity on chicken blood and goat blood. In the antibacterial activity of the sea anemone against six bacterial strains Staphylococcus aureus, Salmonella typhii, Salmonella paratyphii, Klebsiella pneumonia, Vibrio cholerae, Pseudomonas aeruginosa. Antibacterial activity of H. Magnifica and S.haddoni was measured as the radius of the zone of inhibition.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2449
Author(s):  
Beata Kaczmarek-Szczepańska ◽  
Olha Mazur ◽  
Marta Michalska-Sionkowska ◽  
Krzysztof Łukowicz ◽  
Anna Maria Osyczka

In this study, hydrogels based on chitosan cross-linked by glyoxal have been investigated for potential medical applications. Hydrogels were loaded with tannic acid at different concentrations. The thermal stability and the polyphenol-releasing rate were determined. For a preliminary assessment of the clinical usefulness of the hydrogels, they were examined for blood compatibility and in the culture of human dental pulp cells (hDPC). The results showed that after immersion in a polyphenol solution, chitosan/glyoxal hydrogels remain nonhemolytic for erythrocytes, and we also did not observe the cytotoxic effect of hydrogels immersed in tannic acid (TA) solutions with different concentration. Tannic acid was successfully released from hydrogels, and its addition improved material thermal stability. Thus, the current findings open the possibility to consider such hydrogels in clinics.


e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 673-681
Author(s):  
Yanchao Qiao ◽  
Lijie Duan

AbstractAntibacterial materials have found widespread interest in different fields nowadays. In this study, curcumin (Cur) was incorporated into the polyvinyl butyral (PVB) matrix by dissolving in ethanol for improving the functional properties of a pure PVB film. We found that Cur was uniformly dispersed in the PVB matrix, which showed good compatibility. Moreover, the incorporation of Cur could also improve thermal stability, hydrophilicity, and mechanical property. The UV-vis spectra of the PVB–Cur film demonstrated that the film could block ultraviolet radiation. Subsequently, the antibacterial activity of the PVB–Cur film was measured by the colony-counting method against S. aureus and E. coli. The results showed that the PVB–Cur film exhibited good antibacterial activity. Therefore, the PVB–Cur film was considered as a promising material for food and medical packaging applications.


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