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1.
Int J Mol Sci ; 22(22)2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34830335

RESUMO

The food industry is still searching for novel solutions to effectively ensure the microbiological safety of food, especially fresh and minimally processed food products. Nowadays, the use of bacteriophages as potential biological control agents in microbiological food safety and preservation is a promising strategy. The aim of the study was the isolation and comprehensive characterization of novel bacteriophages with lytic activity against saprophytic bacterial microflora of minimally processed plant-based food products, such as mixed leaf salads. From 43 phages isolated from municipal sewage, four phages, namely Enterobacter phage KKP 3263, Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 have lytic activity against Enterobacter ludwigii KKP 3083, Citrobacter freundii KKP 3655, Enterobacter cloacae KKP 3082, and Serratia fonticola KKP 3084 bacterial strains, respectively. Transmission electron microscopy (TEM) and whole-genome sequencing (WGS) identified Enterobacter phage KKP 3263 as an Autographiviridae, and Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 as members of the Myoviridae family. Genome sequencing revealed that these phages have linear double-stranded DNA (dsDNA) with sizes of 39,418 bp (KKP 3263), 61,608 bp (KKP 3664), 84,075 bp (KKP 3262), and 148,182 bp (KKP 3264). No antibiotic resistance genes, virulence factors, integrase, recombinase, or repressors, which are the main markers of lysogenic viruses, were annotated in phage genomes. Serratia phage KKP 3264 showed the greatest growth inhibition of Serratia fonticola KKP 3084 strain. The use of MOI 1.0 caused an almost 5-fold decrease in the value of the specific growth rate coefficient. The phages retained their lytic activity in a wide range of temperatures (from -20 °C to 50 °C) and active acidity values (pH from 4 to 11). All phages retained at least 70% of lytic activity at 60 °C. At 80 °C, no lytic activity against tested bacterial strains was observed. Serratia phage KKP 3264 was the most resistant to chemical factors, by maintaining high lytic activity across a broader range of pH from 3 to 11. The results indicated that these phages could be a potential biological control agent against saprophytic bacterial microflora of minimally processed plant-based food products.

2.
Acta Sci Pol Technol Aliment ; 20(4): 473-484, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34724371

RESUMO

BACKGROUND: ood producers strive to meet the changing needs of consumers while maintaining the highest nutritional value of the products they supply. Physicochemical methods, which include modified atmosphere packaging, membrane techniques or ultrasounds, are the most frequently used to preserve food. Alternatively, biological methods can be applied, one of which is the use of bacteriophages (phages) to limit bacterial growth in the food environment. The purpose of our research was to verify the possibility of the use of bacteriophages as an antibacterial agent in minimally processed food environments of vegetable origin. The first stage of the research involved the isolation of phages against the dominant bacterial microflora in the analyzed products: broccoli sprouts, spinach leaves and freshly squeezed carrot-celery juice. Bacteriophages were isolated from municipal waste collected from sewage-treatment plants. Specific bacteriophages were isolated for twenty-nine out of thirty identified bacterial strains. The lytic activity of the phages was tested using a Bioscreen C automatic growth analyzer. Three methods for applying the phage cocktail were tested: direct addition of the cocktail, spraying it on, and placing the food product on a pad soaked with the phage mixture. The food products were packaged in a protective atmosphere and stored at 20°C. The total number of bacteria after adding the phage cocktail to the products was determined during the subsequent hours of incubation using classical microbial culturing. A significant decrease in the total number of bacteria was observed in the products containing phage suspensions. The obtained results suggest that application of the phage cocktail offers the possibility to extend the shelf life of the analyzed minimally processed food products by reducing the total number of saprophytic. METHODS: , food producers strive to meet the changing needs of consumers while maintaining the highest nutritional value of the products they supply. Physicochemical methods, which include modified atmosphere packaging, membrane techniques or ultrasounds, are the most frequently used to preserve food. Alternatively, biological methods can be applied, one of which is the use of bacteriophages (phages) to limit bacterial growth in the food environment. The purpose of our research was to verify the possibility of the use of bacteriophages as an antibacterial agent in minimally processed food environments of vegetable origin. The first stage of the research involved the isolation of phages against the dominant bacterial microflora in the analyzed products: broccoli sprouts, spinach leaves and freshly squeezed carrot-celery juice. Bacteriophages were isolated from municipal waste collected from sewage-treatment plants. Specific bacteriophages were isolated for twenty-nine out of thirty identified bacterial strains. The lytic activity of the phages was tested using a Bioscreen C automatic growth analyzer. Three methods for applying the phage cocktail were tested: direct addition of the cocktail, spraying it on, and placing the food product on a pad soaked with the phage mixture. The food products were packaged in a protective atmosphere and stored at 20°C. The total number of bacteria after adding the phage cocktail to the products was determined during the subsequent hours of incubation using classical microbial culturing. A significant decrease in the total number of bacteria was observed in the products containing phage suspensions. The obtained results suggest that application of the phage cocktail offers the possibility to extend the shelf life of the analyzed minimally processed food products by reducing the total number of saprophytic bac. RESULTS: , food producers strive to meet the changing needs of consumers while maintaining the highest nutritional value of the products they supply. Physicochemical methods, which include modified atmosphere packaging, membrane techniques or ultrasounds, are the most frequently used to preserve food. Alternatively, biological methods can be applied, one of which is the use of bacteriophages (phages) to limit bacterial growth in the food environment. The purpose of our research was to verify the possibility of the use of bacteriophages as an antibacterial agent in minimally processed food environments of vegetable origin. The first stage of the research involved the isolation of phages against the dominant bacterial microflora in the analyzed products: broccoli sprouts, spinach leaves and freshly squeezed carrot-celery juice. Bacteriophages were isolated from municipal waste collected from sewage-treatment plants. Specific bacteriophages were isolated for twenty-nine out of thirty identified bacterial strains. The lytic activity of the phages was tested using a Bioscreen C automatic growth analyzer. Three methods for applying the phage cocktail were tested: direct addition of the cocktail, spraying it on, and placing the food product on a pad soaked with the phage mixture. The food products were packaged in a protective atmosphere and stored at 20°C. The total number of bacteria after adding the phage cocktail to the products was determined during the subsequent hours of incubation using classical microbial culturing. A significant decrease in the total number of bacteria was observed in the products containing phage suspensions. The obtained results suggest that application of the phage cocktail offers the possibility to extend the shelf life of the analyzed minimally processed food products by reducing the total number of saprophytic bacteria.

3.
J Microbiol Methods ; 176: 105999, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32659296

RESUMO

The present study examined the effect of six disruption methods of the cell wall (acid hydrolysis, ultrasonication, osmotic shock, pasteurization, homogenization with zirconia balls, and freezing/defrosting) on the efficiency of lipid extraction from yeast cells and the composition of fatty acids. Acid hydrolysis and sonication led to a significant increase in lipid extraction from Cyberlindnera jadinii ATCC 9950 and Rhodotorula glutinis LOCKR13 yeast cells. The amount of lipids extracted in these conditions increased for C. jadinii from 12.46 (biomass not subjected to any pretreatment) to 20.37 and 19.53 g/100 gd.w. after the application of acid hydrolysis and sonication, respectively, and for R. glutinis strain from 13.95 to 21.20 and 17.22 g/100 gd.w., respectively, for the same methods. Initial sonication of biomass led to a significant reduction in the percentage of unsaturated fatty acids. The largest differences in fatty acid composition were found for the sample homogenized with zirconium balls. This process resulted in the degradation of both oleic acid and linolenic acid. The obtained results revealed that the method that significantly increases lipid extraction and does not change the composition of fatty acids is acid hydrolysis with hydrochloric acid. In addition, it is easy, cheap, does not require specialized equipment, and therefore can be implemented in any laboratory.


Assuntos
Candida/química , Ácidos Graxos , Rhodotorula/química , Parede Celular/química , Ácidos Graxos/análise , Ácidos Graxos/isolamento & purificação , Hidrólise , Sonicação/métodos
4.
Int J Mol Sci ; 21(15)2020 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-32722488

RESUMO

Selenium (Se) was found to inhibit the growth of the yeast Candida utilis ATCC 9950. Cells cultured in 30 mg selenite/L supplemented medium could bind 1368 µg Se/g of dry weight in their structures. Increased accumulation of trehalose and glycogen was observed, which indicated cell response to stress conditions. The activity of antioxidative enzymes (glutathione peroxidase, glutathione reductase, thioredoxin reductase, and glutathione S-transferase) was significantly higher than that of the control without Se addition. Most Se was bound to water-insoluble protein fraction; in addition, the yeast produced 20-30 nm Se nanoparticles (SeNPs). Part of Se was metabolized to selenomethionine (10%) and selenocysteine (20%). The HPLC-ESI-Orbitrap MS analysis showed the presence of five Se compounds combined with glutathione in the yeast. The obtained results form the basis for further research on the mechanisms of Se metabolism in yeast cells.


Assuntos
Antioxidantes/metabolismo , Candida/metabolismo , Proteínas Fúngicas/metabolismo , Nanopartículas Metálicas/química , Oxirredutases/metabolismo , Selênio/farmacologia , Selênio/química
5.
World J Microbiol Biotechnol ; 35(10): 157, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31576445

RESUMO

In this study, we aimed to determine the effect of exogenous stress factors (sodium chloride as osmotic stressor, hydrogen peroxide as an inducer of oxidative stress, white light irradiation, and low temperature) on the biosynthesis of carotenoids and lipids by red yeast (Rhodotorula glutinis, R. mucilaginosa, and R. gracilis) during cultivation in media containing potato wastewater and glycerol. According to our results, the yeast were able to grow and biosynthesize lipids and carotenoids in the presence of the applied stress factors. Low temperature caused an increase in the biosynthesis of intracellular lipids and carotenoids. R. gracilis synthesized lipids (21.1 g/100 gd.w.) and carotenoids (360.4 µg/gd.w.) in greater quantities than that of other strains. Under these conditions, there was also an increase in the content of unsaturated fatty acids, especially linoleic and linolenic acids. The highest percentage of polyunsaturated fatty acid (PUFA) (30.4%) was synthesized by the R. gracilis yeast after cultivation at 20°C. Their quantity was 2.5-fold greater than that of the biomass grown in control conditions. The contribution of individual carotenoid fractions depended both on the yeast strain and the culture conditions. Induction of osmotic stress and low temperature intensified the biosynthesis of ß-carotene (up to 73.9% of the total carotenoid content). In oxidative stress conditions, yeast synthesized torulene (up to 82.2%) more efficiently than under other conditions, whereas white light irradiation increased the production of torularhodin (up to 20.0%).


Assuntos
Carotenoides/biossíntese , Meios de Cultura/metabolismo , Lipídeos/biossíntese , Rhodotorula/metabolismo , Meios de Cultura/química , Resíduos Industriais/análise , Rhodotorula/genética , Rhodotorula/crescimento & desenvolvimento
6.
Appl Biochem Biotechnol ; 189(2): 589-607, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31073981

RESUMO

AbstractThe objective of this study was to determine the possibility of simultaneous biosynthesis of lipids and carotenoids by the Rhodotorula yeast strains in media with waste glycerol and deproteinized potato wastewater and to determine the level of pollution reduction by media. On the basis of results obtained during the yeast microcultures in the Bioscreen C system, it was found that potato wastewater and glycerol can be used as components of media for Rhodotorula glutinis, Rhodotorula mucilaginosa, and Rhodotorula gracilis yeast strains. The amount of glycerol added to media higher than 10% significantly decreased the growth rate of yeast. The results of yeast culture in the laboratory shaker flasks showed a possibility of simultaneous production of lipids and carotenoids by R. glutinis, R. mucilaginosa, and R. gracilis yeast strains during cultivation in media containing only waste glycerol and deproteinized potato wastewater. A higher intracellular lipid content (approximately 15 g/100 gd.w.) was obtained for R. mucilaginosa and R. gracilis yeast biomass after cultivation in experimental media with waste glycerol and potato wastewater. In conclusion, the yeast grown in media with potato wastewater supplemented with 3% or 5% glycerol synthesized carotenoids, and their content in biomass did not exceed 230 µg/gd.w.


Assuntos
Carotenoides/biossíntese , Glicerol/química , Lipídeos/biossíntese , Rhodotorula/crescimento & desenvolvimento , Solanum tuberosum/química , Águas Residuárias
7.
Toxins (Basel) ; 11(4)2019 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-30935045

RESUMO

Mycotoxins are harmful contaminants of food and feed worldwide. Feed additives with the abilities to trap mycotoxins are considered substances which regulate toxin transfer from feed to tissue, reducing its absorption in animal digestive tract. Market analysis emphasizes growing interest of feed producers in mycotoxins binders obtained from yeast biomass. The aim of the study was to prescreen cell walls (CW) and ß(1,3)/(1,6)-glucan (ß-G) preparations isolated from Candida utilis ATCC 9950 cultivated on waste potato juice water with glycerol as adsorbents for aflatoxin B1 (AFB1), zearalenone (ZEN), ochratoxin A (OTA), deoxynivalenol (DON), nivalenol (NIV), T-2 toxin (T-2) and fumonisin B1 (FB1). The adsorption was studied in single concentration tests at pH 3.0 and 6.0 in the presence of 1% of the adsorbent and 500 ng/mL of individual toxin. Evaluated CW and ß-G preparations had the potential to bind ZEN, OTA and AFB1 rather than DON, NIV, T-2 toxin and FB1. The highest percentage of adsorption (about 83%), adsorption capacity (approx. 41 µg/ g preparation) and distribution coefficient (458.7mL/g) was found for zearalenone when CW preparation was used under acidic conditions. Higher protein content in CW and smaller particles sizes of the formulation could influence more efficient binding of ZEN, OTA, DON and T-2 toxin at appropriate pH compared to purified ß-G. Obtained results show the possibility to transform the waste potato juice water into valuable Candida utilis ATCC 9950 preparation with mycotoxins adsorption properties. Further research is important to improve the binding capacity of studied preparations by increasing the active surface of adsorption.


Assuntos
Candida , Parede Celular/química , Glucanos/química , Micotoxinas/química , Agricultura , Glicerol/química , Solanum tuberosum/química , Gerenciamento de Resíduos/métodos , Resíduos
8.
Mol Biol Rep ; 46(2): 1797-1808, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30734169

RESUMO

Selenium exhibits health-promoting properties in humans and animals. Therefore, the development of selenium-enriched dietary supplements has been growing worldwide. However, it may also exhibit toxicity at higher concentrations, causing increased oxidative stress. Different species of yeasts may exhibit different tolerances toward selenium. Therefore, in this study, we aimed to determine the effect of selenium on growth and on the antioxidative system in Candida utilis ATCC 9950 and Saccharomyces cerevisiae ATCC MYA-2200 yeast cells. The results of this study have demonstrated that high doses of selenium causes oxidative stress in yeasts, thereby increasing the process of lipid peroxidation. In addition, we obtained an increased level of GSSG from aqueous solutions of yeast biomass grown with selenium supplementation (40-60 mg/L). Increased levels of selenium in aqueous solutions resulted in an increase in the activity of antioxidant enzymes, including glutathione peroxidase and glutathione reductase. These results should encourage future research on the possibility of a thorough understanding of antioxidant system functioning in yeast cells.


Assuntos
Candida/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Selênio/metabolismo , Selênio/farmacologia , Antioxidantes/farmacologia , Candida/enzimologia , Candida/metabolismo , Proliferação de Células/efeitos dos fármacos , Suplementos Nutricionais , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/metabolismo
9.
Acta Sci Pol Technol Aliment ; 18(4): 373-383, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31930789

RESUMO

Phages were discovered relatively recently – at the turn of the 19th and 20th centuries. The idea of using bacteriophages for therapeutic purposes was promoted by d’Herelle, who conducted the first successful experiments with prokaryotic viruses. Works of contemporary scientists on phage therapy were, however, halted due to the discovery of penicillin by Alexander Fleming in 1928. Today, when many bacterial strains have developed resistance to common antibiotics offered by the pharmaceutical industry and when new, so far unknown, bacterial strains have appeared, the concept of using bacteriophages to treat bacterial infections has been revived. Considering the food sector, the search for novel solutions that would ensure the appropriate microbiological quality of minimally processed foods may bring an effective method for eradicating bacte- rial pathogens that induce food-borne infections. The employment of chemical and physical methods of food preservation often lead to the deterioration of its nutritive value and of its physical and organoleptic properties. Minimally processed foods manufactured without any drastic preservation methods can be especially at risk of developing microorganisms, including the pathogenic ones. Low-temperature production processes and cold-storage facilitate the development of psychrophilic microorganisms, while another threat is posed by the high microbiological contamination of raw materials. This work presents a biological method for the eradication of bacteria most commonly found in a food-based environment. The study concept postulated the use of bacteriophages to improve the microbiological quality of food, with special attention paid to minimally processed foods.  .


Assuntos
Bacteriófagos/fisiologia , Manipulação de Alimentos/métodos , Microbiologia de Alimentos/métodos , Conservação de Alimentos/métodos , Carga Bacteriana , Escherichia coli/virologia , Qualidade dos Alimentos , Doenças Transmitidas por Alimentos/prevenção & controle , Humanos , Listeria monocytogenes/virologia , Salmonella/virologia
10.
Biol Trace Elem Res ; 187(1): 316-327, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29675568

RESUMO

This article discusses the effect of selenium in aqueous solutions on aspects of lipid and amino acid metabolism in the cell biomass of Saccharomyces cerevisiae MYA-2200 and Candida utilis ATCC 9950 yeasts. The yeast biomass was obtained by using waste products (potato wastewater and glycerol). Selenium, at a dose of 20 mg/L of aqueous solution, affected the differentiation of cellular morphology. Yeast enriched with selenium was characterized by a large functional diversity in terms of protein and amino acid content. The protein content in the biomass of S. cerevisiae enriched with selenium (42.6%) decreased slightly as compared to that in the control sample without additional selenium supplementation (48.4%). Moreover, yeasts of both strains enriched with selenium contained a large amount of glutamic acid, aspartic acid, lysine, and leucine. Analysis of fatty acid profiles in S. cerevisiae yeast supplemented with selenium showed an increase in the unsaturated fatty acid content (e.g., C18:1). The presence of margaric acid (C17:0) and hexadecanoic acid (C17:1) was found in the C. utilis biomass enriched with selenium, in contrast to that of S. cerevisiae. These results indicate that selenium may induce lipid peroxidation, which consequently affects the loss of integrity of the cytoplasmic membrane. Yeast enriched with selenium with optimal amino acid and lipid composition can be used to prepare a novel formula of dietary supplements, which can be applied directly to various diets for both humans and animals.


Assuntos
Aminoácidos/química , Candida/química , Lipídeos/química , Saccharomyces cerevisiae/química , Selênio/análise , Aminoácidos/metabolismo , Biomassa , Candida/metabolismo , Metabolismo dos Lipídeos , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/metabolismo
11.
Biol Trace Elem Res ; 187(1): 328, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29858965

RESUMO

The authors forgot to include the following information in Materials and Methods.

12.
Appl Microbiol Biotechnol ; 102(21): 9131-9145, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30215128

RESUMO

New ideas on production of yeast origin ß-glucan preparations for industrial application are attracting interest considering market development of that high-value functional polysaccharide. Sellecting an efficient yeast producer and designing culture conditions are a prerequisite for obtaining high yield of ß-glucan. The aim of this study was to describe at the first time the influence of the mode of cultivation (shake-flasks and batch fermentation) and time of culture on characteristic and yield of biomass and ß(1,3)/(1,6)-glucan preparations of Candida utilis ATCC 9950 after cultivation in medium based on waste potato juice water supplemented with 10% of glycerol. After shake-flask culture, the biomass was characterized by higher protein content (app. 26.5%) compared to 19% after batch fermentation while the cultivation on a biofermentor scale promoted polysaccharides biosynthesis. The highest output of purified ß(1,3)/(1,6)-glucan preparation (5.3 gd.w./L), containing app. 85% of that polysaccharide, was found after 48 h cultivation in biofermentor. Batch fermentation promoted biosynthesis of alkali-insoluble ß(1,3)/(1,6)-glucan fraction, decreasing the content of ß(1,6)-glucan. The yield of ß(1,3)/(1,6)-glucan synthesis was 0.063 (g/g glycerol), while the productivity of that polysaccharide reached 0.094 (g/L/h). Longer batch fermentation (72 h) resulted in reduction of production efficiency of ß-glucan preparation under studied conditions. The results of the study provide a new efficient biotechnological solution to produce high-value ß-glucan preparations of C. utilis origin based on valorization of agro-waste potato juice water with glycerol.


Assuntos
Candida/metabolismo , Glicerol/metabolismo , Solanum tuberosum/metabolismo , Águas Residuárias/microbiologia , beta-Glucanas/metabolismo , Técnicas de Cultura Celular por Lotes/métodos , Biomassa , Metabolismo dos Carboidratos/fisiologia , Fermentação/fisiologia , Microbiologia Industrial/métodos
13.
3 Biotech ; 8(9): 388, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30175025

RESUMO

The study investigated the effectiveness of selenium binding from its salt solution by Candida utilis ATCC 9950 yeast biomass cultured on a medium prepared from the agro-food industry wastes, containing an available source of carbon and nitrogen. Selenium binding by C. utilis yeast strain after 48 h of culturing at 28 °C from aqueous solutions with the addition of 30 mg Se/L reached a value of 2.28 mg Se/g of yeast biomass. The kinetics of selenium binding by the yeasts showed a better fit for the pseudo-second-order kinetic model compared to the pseudo-first-order one. Accumulation stability data were analyzed using the Freundlich and Langmuir isotherm models. The presence of competing anions such as SO42- , and HPO42- at a concentration of 0.5 mM resulted in about 35% reduction of selenium binding by the examined C. utilis strain. FTIR analysis showed that sulfur compounds were involved in selenium biosorption by the yeast. Compounds containing ammonium groups appeared to be very important for selenium binding. The results of the study demonstrated that the yeast can be used to effectively bind selenium from aqueous solution. At the same time, it gives the opportunity to obtain a biomass rich in this deficient element, which can also be used in dietary supplement production.

14.
J Biotechnol ; 281: 1-10, 2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-29885339

RESUMO

Changes in cell wall structure of four strains of Sacccharomyces cerevisiae species (brewer's, baker's and probiotic yeast) after culturing on deproteinated potato juice water (DPJW) with diverse addition of glycerol and different pH were investigated. It allowed to select conditions intensifying biosynthesis of ß(1,3)/(1,6)-glucan and mannoproteins of cell walls of tested strains. Yeast cell wall structural polysaccharides show biological activity and technological usability in food industry but also decide about therapeutic properties of yeast biomass. The highest increase in the thickness of walls (by about 100%) and ß-glucan layer (by about 120%) was stated after cultivation of S. cerevisiae R9 brewer's yeast in DPJW supplemented with 5 and 10% (w/v) of glycerol and pH 7.0 while S. cerevisiae var. boulardi PAN yeast synthesized by ab. 70% thicker ß-glucan layer when the pH of growth medium was equal to 5.0. The cells of brewer's yeast (S. cerevisiae R9), probiotic (S. cerevisiae CNCM 1-745) and baker's (S. cerevisiae 102) intensified the ratio of mannoproteins in the structure of cell walls cultivated in mediums supplemented with above 15% of glycerol what point out the protective action of glycoprotein's under osmotic stress conditions. The study confirms at the first time the possibility of using agro-industrial waste in biosynthesis of functional polysaccharides of S. cerevisiae cell wall. It could be an new advantage in production of yeast biomass with therapeutic properties or ß-glucan preparation as a novel food ingredient.


Assuntos
Parede Celular/metabolismo , Glicerol/metabolismo , Resíduos Industriais , Saccharomyces cerevisiae/metabolismo , Solanum tuberosum , beta-Glucanas/metabolismo , Indústria Alimentícia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Gerenciamento de Resíduos/métodos
15.
Microb Cell Fact ; 17(1): 49, 2018 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-29587755

RESUMO

Torulene and torularhodin represent the group of carotenoids and are synthesized by yeasts and fungi. The most important producers of these two compounds include yeasts of Rhodotorula and Sporobolomyces genera. The first reports confirming the presence of torulene and torularhodin in the cells of microorganisms date to the 1930s and 1940s; however, only in the past few years, the number of works describing the properties of these compounds increased. These compounds have strong anti-oxidative and anti-microbial properties, and thus may be successfully used as food, feedstock, and cosmetics additives. In addition, tests performed on rats and mice showed that both torulene and torularhodin have anti-cancerous properties. In order to commercialize the production of these two carotenoids, it is necessary to obtain highly efficient yeast strains, for example, via mutagenization and optimization of cultivation conditions. Further studies on the activity of torulene and torularhodin on the human body are also needed.


Assuntos
Carotenoides/química , Animais , Humanos , Ratos , Ratos Wistar
16.
Biomed Res Int ; 2017: 6061042, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29098157

RESUMO

The search for efficient oleaginous microorganisms, which can be an alternative to fossil fuels and biofuels obtained from oilseed crops, has been going on for many years. The suitability of microorganisms in this regard is determined by their ability to biosynthesize lipids with preferred fatty acid profile along with the concurrent utilization of energy-rich industrial waste. In this study, we isolated, characterized, and identified kefir yeast strains using molecular biology techniques. The yeast isolates identified were Candida inconspicua, Debaryomyces hansenii, Kluyveromyces marxianus, Kazachstania unispora, and Zygotorulaspora florentina. We showed that deproteinated potato wastewater, a starch processing industry waste, supplemented with various carbon sources, including lactose and glycerol, is a suitable medium for the growth of yeast, which allows an accumulation of over 20% of lipid substances in its cells. Fatty acid composition primarily depended on the yeast strain and the carbon source used, and, based on our results, most of the strains met the criteria required for the production of biodiesel. In particular, this concerns a significant share of saturated fatty acids, such as C16:0 and C18:0, and unsaturated fatty acids, such as C18:1 and C18:2. The highest efficiency in lipid biosynthesis exceeded 6.3 g L-1. Kazachstania unispora was able to accumulate the high amount of palmitoleic acid.


Assuntos
Kefir/microbiologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Amido/química , Águas Residuárias/química , Biocombustíveis , Candida/efeitos dos fármacos , Candida/crescimento & desenvolvimento , Carbono/química , Debaryomyces/efeitos dos fármacos , Debaryomyces/crescimento & desenvolvimento , Ácidos Graxos/química , Ácidos Graxos Insaturados/química , Kluyveromyces/efeitos dos fármacos , Kluyveromyces/crescimento & desenvolvimento , Lipídeos/química , Solanum tuberosum/química
17.
Cells ; 6(4)2017 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-29064404

RESUMO

Selenium is an essential trace element that occurs in nature, in both inorganic and organic forms. This element participates in numerous biochemical processes, including antioxidant potential, but the mechanism of its anti-cancer action is still not well known. It should be noted that the anti-cancer properties of selenium depends on its chemical form, therapeutic doses, and the tumor type. Higher nutritional doses of selenium can stimulate human immune system. There are several hypotheses concerning the anticancer activity of selenium, including oxidation of sulfhydryl groups in proteins causing their conformational alterations. Conformational changes in proteins have the ability to weaken the activity of enzymes involved in the metabolism of cancer cells. In case of human fibrinogen sodium selenite, but not selenate, it inhibits protein disulfide exchange reactions, thus preventing formation of a hydrophobic polymer termed parafibrin, circulatory accumulation, of which is associated with numerous degenerative diseases. Parafibrin can specifically form a protein coat around tumor cells that is completely resistant to degradation induced with lymphocyte protease. In this way, cancer cells become protected against destruction by the organism's immune system. Other possible mechanisms of anticancer action of selenium are being still investigated.

18.
Electron. j. biotechnol ; 27: 25-31, May. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1010164

RESUMO

Background: Rhodotorula glutinis is capable of synthesizing numerous valuable metabolites with extensive potential industrial usage. This paper reports the effect of initial culture medium pH on growth and protein, lipid, and carotenoid biosynthesis by R. glutinis. Results: The highest biomass yield was obtained in media with pH 4.0­7.0, and the value after 72 h was 17.2­19.4 gd.w./L. An initial pH of the medium in the range of 4.0­7.0 has no significant effect on the protein (38.5­41.3 g/100 gd.w.), lipid (10.2­12.7 g/100 gd.w.), or carotenoid (191.7­202.9 µg/gd.w.) content in the biomass or on the profile of synthesized fatty acids and carotenoids. The whole pool of fatty acids was dominated by oleic (48.1­53.4%), linoleic (21.4­25.1%), and palmitic acids (13.0­15.8%). In these conditions, the yeast mainly synthesized torulene (43.5­47.7%) and ß-carotene (34.7­38.6%), whereas the contribution of torularhodin was only 12.1­16.8%. Cultivation in medium with initial pH 3.0 resulted in a reduction in growth (13.0 gd.w./L) and total carotenoid (115.8 µg/gd.w.), linoleic acid (11.5%), and torularhodin (4.5%) biosynthesis. Conclusion: The different values of initial pH of the culture medium with glycerol and deproteinized potato wastewater had a significant effect on the growth and protein, lipid, and carotenoid biosynthesis by R. glutinis.


Assuntos
Rhodotorula/metabolismo , Carotenoides/biossíntese , Leveduras , Solanum tuberosum , Proteínas/metabolismo , Biomassa , Águas Residuárias , Glicerol , Concentração de Íons de Hidrogênio , Lipídeos/biossíntese
19.
Electron. j. biotechnol ; 27: 44-48, May. 2017. tab
Artigo em Inglês | LILACS | ID: biblio-1010289

RESUMO

Background: Depletion of petroleum resources has enforced the search for alternative sources of renewable energy. Introduction of biofuels into the market was expected to become a solution to this disadvantageous situation. Attempts to cover fuel demand have, however, caused another severe problem­the waste glycerol generated during biodiesel production at a concentration of approximately 10% w/w. This, in turn, prompted a global search for effective methods of valorization of the waste fraction of glycerol. Results: Utilization of the waste fraction at 48 h with an initial glycerol concentration of 30 g·L-1 and proceeding with 62% efficiency enabled the production of 9 g·L-1 dihydroxyacetone at 50% substrate consumption. The re-use of the immobilized biocatalyst resulted in a similar concentration of dihydroxyacetone (8.7 g·L-1) in two-fold shorter time, with an efficiency of 85% and lower substrate consumption (35%). Conclusions: The method proposed in this work is based on the conversion of waste glycerol to dihydroxyacetone in a reaction catalyzed by immobilized Gluconobacter oxydans cell extract with glycerol dehydrogenase activity, and it could be an effective way to convert waste glycerol into a valuable product.


Assuntos
Células Imobilizadas/metabolismo , Di-Hidroxiacetona/metabolismo , Glicerol/metabolismo , Resíduos , Extratos Celulares , Células Imobilizadas/química , Gluconobacter oxydans , Biocombustíveis , Reciclagem , Energia Renovável , Glicerol/química
20.
Molecules ; 22(3)2017 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-28245620

RESUMO

Selenium is considered an essential component of all living organisms. The use of yeasts as a selenium supplement in human nutrition has gained much interest over the last decade. The accumulation and biochemical transformation of selenium in yeast cells is particularly interesting to many researchers. In this article, we present the results of the determination of selenium and selenomethionine content in the biomass of feed yeast Candida utilis ATCC 9950 obtained from the culture grown in a bioreactor. The results indicated that C. utilis cells performed the biotransformation of inorganic selenium(IV) to organic derivatives (e.g., selenomethionine). Selenium introduced (20-30 mg Se4+∙L-1) to the experimental media in the form of sodium(IV) selenite (Na2SeO3) salt caused a significant increase in selenium content in the biomass of C. utilis,irrespective of the concentration. The highest amount of selenium (1841 µg∙gd.w.-1) was obtained after a 48-h culture in media containing 30 mg Se4+∙L-1. The highest content of selenomethionine (238.8 µg∙gd.w.-1) was found after 48-h culture from the experimental medium that was supplemented with selenium at a concentration of 20 mg Se4+∙L-1. Biomass cell in the cultures supplemented with selenium ranged from 1.5 to 14.1 g∙L-1. The results of this study indicate that yeast cell biomass of C. utilis enriched mainly with the organic forms of selenium can be a valuable source of protein. It creates the possibility of obtaining selenium biocomplexes that can be used in the production of protein-selenium dietary supplements for animals and humans.


Assuntos
Candida/crescimento & desenvolvimento , Meios de Cultura/análise , Selênio/metabolismo , Biomassa , Reatores Biológicos/microbiologia , Biotransformação , Candida/metabolismo , Selenometionina/metabolismo , Selenito de Sódio/metabolismo
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