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A killer phenotype, associated with the production and secretion of killer toxins, is widespread among yeasts and in competitive conditions gives an advantage to killer yeast strains in relation to other, sensitive microorganisms colonizing the same ecological niche. Killer toxins are proteins, usually glycoproteins, that are able to kill strains of susceptible yeasts. Each killer toxin has unique properties that vary depending on the strain of yeast that produces it. These differences concern the location of genes that encode toxins, molecular weight, as well as mechanisms of action. Some strains of killer yeast are characterized by a wide range of antagonistic activity, inhibit the development of a number of yeast strains, as well as molds, and have been studied for many years in terms of their biotechnological potential. Killer yeast and its toxins can find potential application in many fields: in the production of food and beverages, especially during wine fermentation and maturation, in biological control of plant pathogens, in yeast biotyping and as new antifungal agents.

The aim of this study was to investigate whether the type and form of oil (raw/non-oxidised (N) or post-frying/oxidised (O)) consumed in high-fat diets affect the oxidative status of an organism, as observed by malondialdehyde (MDA) concentration as an oxidative factor and antioxidant enzyme activity.

The purpose of the study was to evaluate the impact of the Saccharomyces cerevisiae and S. kudriavzevii mixed culture on the fermentation, chemical and aromatic composition of semi-sweet white wines. The variables tested in the experiment were the initial ratio of yeast in mixed cultures and the time of inoculation of the S. kudriavzevii co-culture. The addition of S. kudriavzevii to the inoculum did not significantly change the chemical composition of the wines obtained. No reduction in ethanol yield was found in mixed culture fermented wines; however, in some variants of the experiment, the ethanol content was higher. The mixed cultures of S. cerevisiae and S. kudriavzevii increased the level of volatile compounds in white grape wines. Wines fermented with the co-culture of S. kudriavzevii were characterized by a more diversified ester profile. The mixed cultures of S. cerevisiae and S. kudriavzevii raised the levels of terpenes in white wines. The most promising results were obtained for mixed culture variants, in which S. kudriavzevii was sequentially inoculated on the sixth day of fermentation.

This study attempts to determine whether the increased blood lead concentration affects the posturographic test and to determine the relationship between the parameters of posture stability and selected parameters of oxidative stress. The study population consisted of 268 male employees and was divided into two equal subgroups, depending on the lead content in the blood. A posturographic examination was performed. Concentrations of lead, cadmium, zinc protoporphyrin, selected essential elements, and selected markers of oxidative stress in the blood were tested. Higher blood lead concentrations positively affected the values of the sway results: the field and the mean velocity of the center of the feet pressure in posturography. The absolute value of the proprioception ratio was similar in both subgroups. The content of malondialdehyde shows a statistically significantly higher value in a subgroup with high blood lead concentration and exhibits significant correlations only with some of the posturography parameters. The lipofuscin content in erythrocytes correlates with the results of the posturography test. Zinc protoporphyrin, total oxidant status, total antioxidant capacity, selected minerals, and metals did not correlate with the results of the posturography test. In conclusion, posturographic results correlate only with selected markers of oxidative stress, so it can be assumed that the effect on the body balance is only partial.

A new method was proposed to produce alginate bio-films containing Pichia membranifaciens and Wickerhamomyces anomalus killer yeast to control the post-harvest fungal decay in organic apples caused by Botrytis cinerea and Penicillium italicum . Coatings with W. anomalus killer yeast effectively controlled the growth of P. italicum during storage at 22 °C. W. anomalus killer yeast incorporated in alginate reduced the P. italicum incidence from 90% (control) to 35% after 14 days of storage at 22 °C. Alginate biofilms with W. anomalus or P. membranifaciens also limited the incidence of the fungal decay of apples inoculated with B. cinerea compared with the control fruits, although the antagonistic capability against B. cinerea was lower than against P. italicum . The survival of W. anomalus cells in alginate coating was higher than P. membranifaciens . The incorporation of killer yeasts into alginate had no significant effect on the mechanical properties (tensile strength, percent elongation at break) of alginate coating, however, they increased the thickness of the biofilm. The bioactive coating reduced the fruit weight loss and had no significant effects on the fruit firmness during storage at 2 °C. As organic apples, produced without any synthetic fungicides, are especially prone to fungal decay during storage, the proposed alginate biofilms containing killer yeast seem to be a very promising solution by offering non-chemical, biological control of post-harvest pathogens.

The current study is focused on the influence of hyperglycemia on weight loss in obese premenopausal women. Specifically, the study evaluated the impact of a six-month individualized low-calorie diet combined with moderate exercise on weight reduction and glucose metabolism in obese women with normoglycemia compared to obese women with moderate hyperglycemia. The results indicated that patients with normoglycemia achieved a successful weight loss, which was connected to a decrease in adipose tissue and reflected by diminished content of visceral fat area (VFA) and percent body fat. In contrast, weight reduction in patients with hyperglycemia was connected not only to the loss of VFA but also to undesired decrease in skeletal muscle mass as well as intracellular and total body water. These unfavorable outcomes were observed despite normalization of glucose metabolism reflected by statistically significant lowering glucose, fructosamine, advanced glycation end-products, and HOMA-IR levels. Overall, the obtained results indicate the importance of the measurement of the carbohydrate profile in obese women and the need for an early introduction of weight reduction strategies before the development of hyperglycemia.

Although weight loss is recommended for obese patients, it remains questionable how much weight loss is optimal. A novel index that accurately determines the risk of cardiovascular diseases (CVDs) in terms of weight loss is needed. The modified Atherogenic Index of Plasma (AIP), presented here is unique in the literature. It is calculated based on data for anti-atherogenic, high-density lipoprotein cholesterol (HDL-C) fractions, instead of the total HDL-C. This study investigates whether weight loss correlates with CVD risk, and whether the modified AIP allows more accurate diagnostics in obese/overweight people. According to the increase or decrease of AIP during weight loss, 52 Polish patients were subdivided into two groups: group I (increased AIP; n = 16) and group II (decreased AIP; n = 36). The patients' body mass composition and fasting serum lipid parameters (total cholesterol, triglycerides, HDL-C, and LDL-C (low-density lipoprotein cholesterol)), and cholesterol in 21 lipoprotein sub-fractions were determined. Over six months, all patients reduced their body mass by about 10%. There were no significant differences in anthropometric measures between groups. Increases in large and intermediate HDL-C fractions 1 to 6 and decreases in smaller fractions 7 to 10 were observed in group II. In group I, HDL-C fractions 1 and 10 decreased, while cholesterol in other fractions increased. Increases were observed in the antiatherogenic HDL-C of 52% of group II and 4% of group I. As for atherogenic HDL-C, a decrease of 24% was observed in group II and an increase of 9% in group I. In group I, increases of very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and large LDL fractions were noticed, and the reverse in group II. The results show that the modified AIP is a more accurate indicator of CVD risk than existing indices, and that uncontrolled weight reduction does not necessarily have a beneficial influence, and may adversely affect the cardiovascular system., Competing Interests: The authors declare no conflict of interest.

Background: Fluorine influences many processes occurring in the organism. Controversies over the evaluation of the biological effects of this substance are due to a small difference between tolerable and toxic fluorine doses. One of the main mechanisms of the fluorine toxic action is its ability to induce oxidative stress via reactive oxygen species generation and antioxidant defense system impairment. It is important to evaluate possible interactions between fluorine and other substances that may increase or decrease its toxicity., Material and Methods: The study lasted for 35 days. Twenty-four rats were divided into 4 groups: the control, with sodium fluoride (NaF) in the diet, with sodium fluoride, methionine and vitamin E (NaF+M+E) in the diet, with sodium fluoride and vitamin E (NaF+E) in the diet. The biochemical analysis conducted in animal liver homogenates included determination of activities of: total superoxide dismutase (t-SOD), superoxide dismutase with copper and zinc (CuZnSOD), superoxide dismutase with manganese (MnSOD), glutathione peroxidase (GPX), catalase (CAT), glutathione reductase (GR), glutathione S-transferase (GST) and the malondialdehyde (MDA) concentration., Results: The activities of CuZn- SOD, GPX, CAT and MDA concentration were changed significantly. There were no differences in the activities of t-SOD, MnSOD, GR and GST among the experiment., Conclusions: In the conducted experiment, the run-out of enzymatic protection of liver by decreasing of the activities of antioxidant enzymes (CAT and GPX) and increasing the MDA concentration in NaF group was observed. The addition of vitamin E and methionine does not significantly stimulate the enzymatic antioxidant system, however, it causes of MDA concentration decreases. Med Pr 2018;69(4):403–412, (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Background: Oils are often fried which reduces their beneficial biological and nutritional properties, contributing to disturbances in homeostasis. Some antioxidant substances can improve stability of oils. The aim of the study was to examine the effect of α-lipoic acid (ALA) on the concentration of sulfhydryl groups, lipid peroxides, malondialdehyde, creatinine and urea in serum of rats fed high fat diet for 3 months., Material and Methods: Thirty six Wistar rats were equally divided into 6 groups: the control group on standard breeding diet (SB), oxidized oil (OU) group on SB with 10% oxidized oil, ALA10 group on SB with ALA 10 mg/kg of body weight (b.w.), OU+ALA10 group on SB with oxidized oil and ALA (10 mg/kg b.w.), ALA50 group on SB with ALA in a dose of 50 mg/kg b.w., OU+ALA50 group on SB with oxidized oil and ALA (50 mg/kg b.w.). Oil was oxidized in 180°C for 6 h., Results: We observed decrease in concentration of protein sulfhydryl (PSH) groups in all study groups except for ALA10 vs. control group (C) and increase in OU+ALA10 and OU+ALA50 vs. OU; increase in the lipid hydroperoxide (LHP) concentration in OU, OU+ALA10 and OU+ALA50 vs. C and decrease in all study groups vs. OU; increase of malondialdehyde (MDA) in OU vs. all other groups. And also increase in creatinine and urea concentration in OU group., Conclusions: High fat diet rich in oxidized oil intensifies the lipid peroxidation process and oxidation of sulfhydryl groups. It can also impair kidney function. Administration of lipoic acid in a dose of 10 mg/kg b.w. inhibits the lipid peroxidation and protects sulfhydryl groups. Med Pr 2017;68(3):391-399., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

We hypothesized that addition of substances with antioxidant activity could decrease the concentrations of biomarkers of oxidative stress and inflammatory process, thus inhibiting nonalcoholic steatohepatitis development. We investigated the influence of α-lipoic acid (ALA) and garlic administration on the development of adverse changes in rabbit liver and serum under oxidative stress conditions induced with HFD from oxidized oils. We determined 8-hydroxy-2'-deoxyguanosine (8 OHdG) and malondialdehyde (MDA) in liver homogenates, total oxidant status (TOS), lipid peroxides (LOO) and tumor necrosis factor alpha (TNFα) in blood serum, and TNFα and IL-1α genes expression in liver. The results indicate that the intake of dietary ALA and garlic was significantly associated with decreases of 8 OHdG and MDA levels in rabbits' liver tissue as well as TOS and LOO levels in rabbits' serum. Similarly, TNFα and IL-1α gene expressions were suppressed due to ALA and garlic supplementation. The histopathological analysis confirmed that HFD results in liver disorder leading to steatosis. This adverse effect of HFD was ameliorated by the supplementation of ALA and garlic. The obtained results indicate a beneficial effect of ALA and garlic administration by reducing the oxidative stress intensity and the levels of some proinflammatory cytokines in rabbits fed HFD.

cAMP receptor protein (CRP), allosterically activated by cAMP, regulates the expression of several genes in Escherichia coli. As binding of cAMP leads to undefined conformational changes in CRP, we performed a steady-state and time-resolved fluorescence study to show how the binding of the ligand influences the structure and dynamics of the protein. We used CRP mutants containing a single tryptophan residue at position 85 or 13, and fluorescently labeled with 1,5-I-AEDANS attached to Cys178. Binding of cAMP in the CRP-(cAMP)2 complex leads to changes in the Trp13 microenvironment, whereas its binding in the CRP-(cAMP)4 complex alters the surroundings of Trp85. Time-resolved anisotropy measurements indicated that cAMP binding in the CRP-(cAMP)2 complex led to a substantial increase in the rotational mobility of the Trp13 residue. Measurement of fluorescence energy transfer (FRET) between labeled Cys178 and Trp85 showed that the binding of cAMP in the CRP-(cAMP)2 complex caused a substantial increase in FRET efficiency. This indicates a decrease in the distance between the two domains of the protein from 26.6 A in apo-CRP to 18.7 A in the CRP-(cAMP)2 complex. The binding of cAMP in the CRP-(cAMP)4 complex resulted in only a very small increase in FRET efficiency. The average distance between the two domains in CRP-DNA complexes, possessing lac, gal or ICAP sequences, shows an increase, as evidenced by the increase in the average distance between Cys178 and Trp85 to approximately 20 A. The spectral changes observed provide new structural information about the cAMP-induced allosteric activation of the protein.