Nanoparticles Biosynthesized by Yeast: A Review of their application

The green biosynthesis of nanoparticles is one of the most discussed topic of current nanotechnology. It has been estimated the plants, bacteria, yeasts or some lower organism could synthesize nanoparticles such as quantum dots, organic and inorganic based nanoparticles. Yeasts are eukaryotic microorganisms and generally, several strains play an important role in food industry due their ability to sugar fermentation. A novel approach of their use could be a production of metal nanoparticles and nanostructures via their reducing enzymes intracellularly or extracellularly. The focus of this review is the application of yeast in the green synthesis of inorganic nanoparticles and the innovation use in the fermentation industry

Polyphenolic composition of grape stems

This study is focused on the study of polyphenolic compounds in grape stems as by-product of winemaking industry. Two white varieties of Grüner Veltliner and Sauvignon and two red varieties of Blauer Portugieser and Cabernet Moravia were selected for the study. Antioxidant activity, concentration of total polyphenols and concentration of individual phenolic compounds were determined. The results show a higher concentration of polyphenols and higher values of antioxidant activity in red varieties. The Blauer Portugieser variety contained the highest concentrations of syringic acid 1.346 mg.L-1, caffeic acid 20 mg.L-1, ferulic acid 1.192 mg.L-1, coumaric acid 3.231 mg.L-1, trans-resveratrol 14.195 mg.L-1, catechin 79.314 mg.L-1 and epicatechin 33.205 mg.L-1. Cabernet Moravia contained the highest concentration of protocatechuic acid 1.201 mg.L-1, the Sauvignon variety reached the highest concentration of gallic acid 4.015 mg.L-1 and hydroxybenzoic acid 0.076 mg.L-1. The highest values of alpha-amino acids were determined in the Blauer Portugieser variety 165.3 mg L-1 and the lowest in the Grüner Veltliner variety 33.3 mg L-1. The highest concentration of ammonia nitrogen was 214 mg L-1 for the Blauer Portugieser variety and the lowest concentration of ammonia nitrogen was measured in Cabernet Moravia 35.7 mg L-1

Study of antioxidant and antimicrobial properties of grapevine seeds, grape and rosehip pressing

In our experiment, we studied the antimicrobial and antioxidative effect of phytogenic additives. Three additives (grapevine seeds, grape and rosehip pressings) were selected to be monitored. The extracts about concentrations of 1:3 and 1:5 were prepared from them. The monitoring of antimicrobial properties was focused on the pathogenic bacteria Clostridium perfringens and Escherichia coli causing a serious disease in avian species. The bacteria were prepared in the dilutions of 102, 104 and 106. The antimicrobial effect was observed in the inhibition zones. The antioxidant activity was determined using DPPH method within the antioxidant analysis. Furthermore, the content of flavanols, hydroxycinnamic acids and the total content of polyphenolic compounds was also determined. In the monitoring of the antimicrobial effect of grapevine seeds, grape and rosehip pressings at E. coli, a reduced growth of KTJ (colony forming units) was observed in the disk area during the dilution of 106 and 104. Reduced growth of C. perfringens at a dilution of 106 was noticed using the extracts of grapevine seeds and grape pressings. Low reduced growth of C. perfringens at a dilution of 106 was found out using rosehip pressings. In a dilution of 102 and 104 in C. perfringens and 102 in E. Coli, a very low increase of KTJ was observed therefore the zones of inhibition were not possible to measure. In all monitored additives, the antimicrobial effect was proved. The additives reduced the growth of pathogenic E. coli and C. perfringens. Within the antioxidant analysis, the highest antioxidant activity was found out in grapevine seeds (7.021 g.L-1 GAE), which also contained the highest content of flavanols (3000 times higher than the rosehip pressings and 300 times higher than grapevine seeds pressings), hydroxycinnamic acids (1000 times higher than in grape pressings and 7600 times higher than in rosehip pressings) and the total content of polyphenolic compounds (580 times higher than grape pressings and 2000 times higher than the rosehip pressings) of the monitored additives

Study of physico-chemical changes of CdTe QDs after their exposure to environmental conditions.

The irradiance of ultraviolet (UV) radiation is a physical parameter that significantly influences biological molecules by affecting their molecular structure. The influence of UV radiation on nanoparticles has not been investigated much. In this work, the ability of cadmium telluride quantum dots (CdTe QDs) to respond to natural UV radiation was examined. The average size of the yellow QDs was 4 nm, and the sizes of green, red and orange QDs were 2 nm. Quantum yield of green CdTe QDs-MSA (mercaptosuccinic acid)-A, yellow CdTe QDs-MSA-B, orange CdTe QDs-MSA-C and red CdTe QDs-MSA-D were 23.0%, 16.0%, 18.0% and 7.0%, respectively. Green, yellow, orange and red CdTe QDs were replaced every day and exposed to daily UV radiation for 12 h for seven consecutive days in summer with UV index signal integration ranging from 1894 to 2970. The rising dose of UV radiation led to the release of cadmium ions and the change in the size of individual QDs. The shifts were evident in absorption signals (shifts of the absorbance maxima of individual CdTe QDs-MSA were in the range of 6–79 nm), sulfhydryl (SH)-group signals (after UV exposure, the largest changes in the differential signal of the SH groups were observed in the orange, green, and yellow QDs, while in red QDs, there were almost no changes), fluorescence, and electrochemical signals. Yellow, orange and green QDs showed a stronger response to UV radiation than red ones

Effect of biosynthesized silver nanoparticles on bacterial biofilm changes in S. aureus and E. coli.

One approach for solving the problem of antibiotic resistance and bacterial persistence in biofilms is treatment with metals, including silver in the form of silver nanoparticles (AgNPs). Green synthesis is an environmentally friendly method to synthesize nanoparticles with a broad spectrum of unique properties that depend on the plant extracts used. AgNPs with antibacterial and antibiofilm effects were obtained using green synthesis from plant extracts of Lagerstroemia indica (AgNPs_LI), Alstonia scholaris (AgNPs_AS), and Aglaonema multifolium (AgNPs_AM). Nanoparticles were characterized by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) analysis. The ability to quench free radicals and total phenolic content in solution were also evaluated. The antibacterial activity of AgNPs was studied by growth curves as well as using a diffusion test on agar medium plates to determine minimal inhibitory concentrations (MICs). The effect of AgNPs on bacterial biofilms was evaluated by crystal violet (CV) staining. Average minimum inhibitory concentrations of AgNPs_LI, AgNPs_AS, AgNPs_AM were 15 ± 5, 20 + 5, 20 + 5 μg/mL and 20 ± 5, 15 + 5, 15 + 5 μg/mL against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, respectively. The E. coli strain formed biofilms in the presence of AgNPs, a less dense biofilm than the S. aureus strain. The highest inhibitory and destructive effect on biofilms was exhibited by AgNPs prepared using an extract from L. indica

Nano-selenium and its nanomedicine applications: a critical review.

Traditional supplements of selenium generally have a low degree of absorption and increased toxicity. Therefore, it is imperative to develop innovative systems as transporters of selenium compounds, which would raise the bioavailability of this element and allow its controlled release in the organism. Nanoscale selenium has attracted a great interest as a food additive especially in individuals with selenium deficiency, but also as a therapeutic agent without significant side effects in medicine. This review is focused on the incorporation of nanotechnological applications, in particular exploring the possibilities of a more effective way of administration, especially in selenium-deficient organisms. In addition, this review summarizes the survey of knowledge on selenium nanoparticles, their biological effects in the organism, advantages, absorption mechanisms, and nanotechnological applications for peroral administration

A summary of new findings on the biological effects of selenium in selected animal species: a critical review.

Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease), in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it causes VESD (vitamin E/selenium deficiency) syndrome. The prevention of these health disorders can be achieved by an adequate selenium supplementation to the diet. The review summarizes the survey of knowledge on selenium, its biological significance in the organism, the impact of its deficiency in mammalian livestock (comparison of ruminants vs. non-ruminants, herbivore vs. omnivore) and possibilities of its peroral administration. The databases employed were as follows: Web of Science, PubMed, MEDLINE and Google Scholar

The Effect of Different Fining Treatments on Phenolic and Aroma Composition of Grape Musts and Wines

The study evaluated the effect of different fining treatments such as oenological additives and the influence of oxygen and hyperoxygenation on the phenolic and aroma composition of grape musts and wines. The oxidative method, hyperoxygenation and fining agents polyvinyl polypyrrolidone (PVPP), pea protein and chitosan were used for the removal of phenolic compounds compared to the control experiment. The content of phenolic substances was determined by high performance liquid chromatography. A total of 24 volatiles—higher alcohols, ethyl esters and acetate esters were determined using gas chromatography-mass spectrometry. A lower concentration of caftaric acid was observed in hyperoxygenated (0.21 mg·L−1), oxidated (0.37 mg·L−1), PVPP-treated (35.50 mg·L−1), pea protein-treated (42.56 mg·L−1) and chitosan-treated variants (44.40 mg·L−1), in contrast to the control must (caftaric acid 50.38 mg·L−1). In the final wine, the results were similar with a lower concentration of caftaric acid in hyperoxygenated (7.10 mg·L−1), oxidated (14.88 mg·L−1), PVPP-treated (23.49 mg·L−1), pea protein-treated (29.49 mg·L−1) and chitosan-treated variant (30.02 mg·L−1), in contrast to the control wine (caftaric acid 32.19 mg·L−1)

Sustainable Viticulture on Traditional ‘Baran’ Training System in Eastern Turkey

Erzincan plain is one of the most fascinating regions in Turkey for plant biodiversity. The area is very rich in terms of gene, species and ecosystem diversity. Having a number of natural habitats, mountains, etc., the region is one of the richest regions in Turkey for plant endemism as well. In northern parts of the region, in particular in Üzümlü, Bayırbağ and Pişkidağ districts, grape production dominates agriculture production and the famous ‘Karaerik’ grape cultivar has been cultivated for a long time on the very special traditional ‘Baran’ training system to avoid cold damage that occurs in winter months. The cultivar is harvested between 1 September and 1 October according to altitude in the region. The cultivar is well known in Turkey and there is a great demand for this cultivar in Turkey due to its perfect berry characteristics. In this study, yield, marketable product, cluster weight, cluster form, organic acids, specific sugars and sensory characteristics of the ‘Karaerik’ grape cultivar grown in three altitudes (1200 m a.s.l., 1400 m a.s.l. and 1600 m a.s.l., respectively) in Üzümlü district were investigated. For each altitude, grape clusters were sampled from ten vineyards and an average sample was formed. Marketable product, cluster weight, cluster form, organic acids and specific sugars were determined on those samples. Yield was determined as per decare. Sensory characteristics of samples were determined by five expert panelists. Results showed that the cluster weight was the highest in lower altitude and increasing altitude formed a more conical cluster form compared to winged cylindrical clusters at lower altitudes. The highest yield (740 kg per decare) was obtained in 1200 m a.s.l. and was followed by 1400 m a.s.l. (682 kg per decare) and 1600 m a.s.l. (724 kg per decare), respectively. Altitude strongly affected sugar and organic acid composition and ratio in berries of the ‘Karaerik’ grape. Fructose and tartaric acid were the main sugar and organic acid at all altitudes and were found between 10.04–14.02 g/100 g and 2.17–3.66 g/100 g, respectively. Sensory scores were also the highest at lower altitudes and decreased parallel to altitude increase

Formation, Losses, Preservation and Recovery of Aroma Compounds in the Winemaking Process

A wine’s aroma profile is an important part of the criteria affecting wine acceptability by consumers. Its characterisation is complex because volatile molecules usually belong to different classes such as alcohols, esters, aldehydes, acids, terpenes, phenols and lactones with a wide range of polarity, concentrations and undesirable off-aromas. This review focused on mechanisms and conditions of the formation of individual aroma compounds in wine such as esters and higher alcohols by yeast during fermentation. Additionally, aroma losses during fermentation are currently the subject of many studies because they can lead to a reduction in wine quality. Principles of aroma losses, their prevention and recovery techniques are described in this review