scholarly journals Electrospun Active Biopapers of Food Waste Derived Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with Short-Term and Long-Term Antimicrobial Performance

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 506 ◽  
Author(s):  
Kelly J. Figueroa-Lopez ◽  
Sergio Torres-Giner ◽  
Daniela Enescu ◽  
Luis Cabedo ◽  
Miguel A. Cerqueira ◽  
...  

This research reports about the development by electrospinning of fiber-based films made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from fermented fruit waste, so-called bio-papers, with enhanced antimicrobial performance. To this end, different combinations of oregano essential oil (OEO) and zinc oxide nanoparticles (ZnONPs) were added to PHBV solutions and electrospun into mats that were, thereafter, converted into homogeneous and continuous films of ~130 μm. The morphology, optical, thermal, mechanical properties, crystallinity, and migration into food simulants of the resultant PHBV-based bio-papers were evaluated and their antimicrobial properties were assessed against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in both open and closed systems. It was observed that the antimicrobial activity decreased after 15 days due to the release of the volatile compounds, whereas the bio-papers filled with ZnONPs showed high antimicrobial activity for up to 48 days. The electrospun PHBV biopapers containing 2.5 wt% OEO + 2.25 wt% ZnONPs successfully provided the most optimal activity for short and long periods against both bacteria.

2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.


2013 ◽  
Vol 469 ◽  
pp. 140-147 ◽  
Author(s):  
Hui Juan Bao ◽  
Yan Jiang ◽  
Jia Qi Liu ◽  
Hai Yue Zhang

Chitosan-PE bi-layer films exhibit antimicrobial activity but poor antioxidant activity. Oregano essential oil (100μL/100mL) was incorporated into chitosan solution to improve films antioxidant and antimicrobial behaviors. The present work investigated the scavenging of O2·, ·OH, DPPH radical and reducing power of film, antimicrobial activity was also evaluated. The results showed that the scavenging effect of film solution on O2·, ·OH, and DPPH was 80.87%, 85.56%, and 87.24%, respectively. Reducing power of film increased with the improvement of oregano essential oil. The antibacterial activity againstE. ColiandB. Subtilisincreased from 80.77% to 96.15% and from 93.02% to 98.10%, respectively. The preservation experiments showed that chitosan-PE film incorporated with oregano essential oil could extend the shelf life of pork to 810 days at 4°C.


PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e107445 ◽  
Author(s):  
Ulfat I. Baig ◽  
Bharati J. Bhadbhade ◽  
Dincy Mariyam ◽  
Milind G. Watve

2021 ◽  
Vol 10 (1) ◽  
pp. 167-172
Author(s):  
Natalya Vladimirovna Tsybulya ◽  
Tatyana Dmitrievna Fershalova

The paper continues multi-year integrated studies of the numerous taxons of tropical Begonia genus, which allowed us to evaluate the adaptive capacity of the representatives of this genus relying on the revealed morphological, rhythmological and biochemical features. The investigation of antimicrobial activity of intact plants and different fractions of plant extracts allowed us to distinguish several promising representatives of this genus exhibiting activity against a broad range of test microorganisms. The involvement of these plants within phytomodules in child care centers caused a substantial decrease in total microbial contamination of the air. The paper contains results of the experimental investigation of seasonal antimicrobial activity of 13 species, 8 hybrids. The phytoncide activity was measured by exposing the streak cultures of microbial test species bacteria Staphylococcus epidermidis, Esсherichia coli and yeast-like fungi Candida albicans to the volatile emissions of plants. It has been established that 95% of begonias are distinguished by the pronounced activity against S. epidermidis bacteria, 48% against E. coli bacteria and 43% against fungi Candida albicans. The seasonal specificity of the antimicrobial action of begonias was detected: the growth of the colonies of S. epidermidis bacteria is inhibited to the highest extent during spring and summer, at the phase of intense growth, while the activity against E. coli is the highest during autumn and winter at the phase of moderate growth. The taxons with clearly pronounced, long-term and universal antimicrobial action to the studied test objects were revealed and recommended for practical planting in various types of indoor environments. The data obtained in the study may serve as the basis for further investigation of the chemical composition of volatile exometabolites by the example of the representatives of Gireoudia and Coelocentrum sections that have exhibited high antimicrobial activity against S. epidermidis and E. coli.


2019 ◽  
Vol 41 part 3 (2) ◽  
pp. 45-50
Author(s):  
O. A. Viltsaniuk ◽  
P. V. Belyaev ◽  
T. P. Osolodchenko ◽  
O. O. Viltsaniuk

Introduction. The problem of purulent-inflammatory processes treatment and the prevention of sepsis remains one of the most pressing problems of surgery.Purpose of the study. Is to estimate the effectiveness of sorption composition with antimicrobial properties on the basis of nanodisperse silica on the adhesive properties of microorganisms and to substantiate the expediency of its use for the purulent and inflammatory processes treatment and prevention of sepsis.Materials and methods.To determine the antimicrobial activity and the influence of the antiseptics of decasan, myramistin, ethonium, chlorhexidine and the sorption on the microorganisms adhesion properties composition was used the method of diffusion in agar of the museum strains of microorganisms S. Aureus ATCC 25923, E. Coli ATCC 25922, R. Vulgaris 4636, R. Aureginosa ATCC 27853, S. AIbicans 855/653, SI. Perfringens 28, Peptostreptococcus anaerobicus 22, Bacteroides fragilis 13/83, and clinical strains of S. Aureus, R. Aeuroginosa, E. Coli. Adhesive properties of microorganisms were studied according to the Brillis method et al. (1986) with the subsequent statistical processing of the data.Results. Studies have shown that antiseptics have high antimicrobial activity and reduce the adhesion ability of microorganisms. But the use of only antiseptics or only antibiotics for the purification of purulent foci can lead to toxins absorption and tissue decay products from purulent foci. That processes could be the trigger mechanism for sepsis development. The sorption composition is able to reduce the adhesive activity of bacteria, allows to absorb toxic substances from pathological foci, what preventing their resorption and thereby prevent the development of sepsis.Conclusions. The composition made from sorbents and antiseptics is not inferior to antimicrobial activity to antiseptics, which can reduce the virulence of bacteria, by reducing their adhesive activity, and absorb toxins of microorganisms and tissue decomposition products on their surface, thus prevent their absorption, which will prevent the purulent-inflammatory process progression and sepsis development.Keywords: sorption composition, nanodisperse silica, antiseptics, adhesive properties of microorganisms, prevention of sepsis.


2019 ◽  
Vol 947 ◽  
pp. 13-20
Author(s):  
Jem Valerie D. Perez ◽  
Joy Vanessa D. Perez ◽  
Raniv D. Rojo ◽  
Maria Lourdes P. Dalida ◽  
Debora F. Rodrigues

Bacterial proliferation and biofilm formation has emerged as a significant concern in the long-term use of industrial apparatus. This study describes the antimicrobial properties of a novel chitosan-polyethyleneimine-graphene oxide (CS-PEI-GO) nanocomposite against E. coli. The nanocomposite is a stable material with minimal dispersibility in storage water after more than 7 days. The antimicrobial activity is contact-time-dependent, with direct contact (92% bacterial inactivation after 3h exposure) having superior results compared with dynamic contact (~50% inactivation after 3h exposure). In addition, the incorporation of GO also translated to enhanced production of ROS—oxidation of GSH was higher in CS-PEI-GO (31.78%) as compared to CS-PEI alone (5.69%). This may be attributed to previously proposed mechanisms of mechanical membrane damage and reactive oxygen species production that may be more pronounced with prolonged contact. This may be due to the positively charged chitosan and the negatively charged cell membrane facilitating the coating of cells that could allow the oxygen-containing functional groups of GO to induce oxidative stress and lead to cell death.


2020 ◽  
Vol 307 ◽  
pp. 217-222 ◽  
Author(s):  
Maishara Syazrinni Rooshde ◽  
Wan Rafizah Wan Abdullah ◽  
Amie Zaidah Amran ◽  
Noradhiha Farahin Ibrahim ◽  
Fazilah Ariffin ◽  
...  

Biofouling and biofilms exist as ubiquitous, undesirable accumulation of flora and fauna upon a given substrate when being immersed into an aquatic medium. Therefore, a novel antifouling based materials with the incorporation of nanotechnology has been developed for the prevention of biofouling in its initial stage through photocatalytic treatment. This study investigated the antimicrobial properties of photoactive Cerium (Ce) doped ZnO powder and explores its potential properties for future antifouling application. ZnO nanoparticles was doped with 0.4 mol% Ce was synthesized through the combination of modified citrate gelation technique and solid state sintering. The successful preparation of Ce doped ZnO was confirmed by XRD and SEM. The antimicrobial activity of Ce doped ZnO against E. coli and S. aureus was determined through antibacterial susceptibility test by agar well diffusion method whilst its photocatalytic inactivation efficiency against selected bacteria was analysed through photodegradation testing under UV light irradiation. The findings demonstrated that the synthesized Ce doped ZnO powder exhibited antibacterial effect against Gram-positive bacteria (S. aureus) and excellent photocatalytic efficiency to inactivate both Gram-negative (E. coli) and Gram-positive (S. aureus). 2 g/L of Ce doped ZnO catalyzed the 100% disinfection of both bacteria in 180 min of UV light exposure. Thus, this proved that Ce doped ZnO powder has the potential as efficient antifouling agent.


2012 ◽  
Vol 78 (6) ◽  
pp. 1752-1764 ◽  
Author(s):  
Ryan C. Fink ◽  
Elaine P. Black ◽  
Zhe Hou ◽  
Masayuki Sugawara ◽  
Michael J. Sadowsky ◽  
...  

ABSTRACTAn increasing number of outbreaks of gastroenteritis recently caused byEscherichia coliO157:H7 have been linked to the consumption of leafy green vegetables. Although it is known thatE. colisurvives and grows in the phyllosphere of lettuce plants, the molecular mechanisms by which this bacterium associates with plants are largely unknown. The goal of this study was to identifyE. coligenes relevant to its interaction, survival, or attachment to lettuce leaf surfaces, comparingE. coliK-12, a model system, andE. coliO157:H7, a pathogen associated with a large number of outbreaks. Using microarrays, we found that upon interaction with intact leaves, 10.1% and 8.7% of the 3,798 shared genes were differentially expressed in K-12 and O157:H7, respectively, whereas 3.1% changed transcript levels in both. The largest group of genes downregulated consisted of those involved in energy metabolism, includingtnaA(33-fold change), encoding a tryptophanase that converts tryptophan into indole. Genes involved in biofilm modulation (bhsAandybiM) and curli production (csgAandcsgB) were significantly upregulated inE. coliK-12 and O157:H7. BothcsgAandbhsA(ycfR) mutants were impaired in the long-term colonization of the leaf surface, but onlycsgAmutants had diminished ability in short-term attachment experiments. Our data suggested that the interaction ofE. coliK-12 and O157:H7 with undamaged lettuce leaves likely is initiated via attachment to the leaf surface using curli fibers, a downward shift in their metabolism, and the suppression of biofilm formation.


2002 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Mamadou Baro

This paper examines rural livelihood systems in Haiti from both a political andecological perspective. While political developments in Haiti have taken center stage inmost analyses, the environmental impacts of population growth, highly varied livelihoodstrategies, and migration opportunities appear to have played a major role in the current tragic situation. Illegal migration not only seems to alleviate short term poverty but also appears to benefit households long term as revenues from migration improve households' land holding situation. Nevertheless, the steadily declining ecological situation may already be exceeding the creative livelihood strategies of Haitian producers.Key words: Haiti, political economy, political ecology, livelihood strategies,households, livestock, agriculture, migration.


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