Valorization of Spirodela polyrrhiza biomass for the production of biofuels for distributed energy.

Considering the main objectives of a circular economy, Lemnaceae plants have great potential for different types of techniques to valorize their biomass for use in biofuel production. For this reason, scientific interest in this group of plants has increased in recent years. The aim of this study was to evaluate the effects of salt stress on the growth and development of S. polyrrhiza and the valorization of biomass for biofuel and energy production in a circular economy. Plants were grown in a variety of culture media, including standard 'Z' medium, tap water, 1% digestate from a biogas plant in Piaszczyna (54° 01' 21″ N, 17° 10' 19″ E), Poland) and supplemented with different concentrations of NaCl (from 25 to 100 mM). Plants were cultured under phytotron conditions at 24 °C. After 10 days of culture, plant growth, fresh and dry biomass, as well as physio-chemical parameters such as chlorophyll content index, gas exchange parameters (net photosynthesis, transpiration, stomatal conductance and intercellular CO2 concentration), chlorophyll fluorescence measurements were analyzed. After 10 days of the experiment, the percentage starch content of Spirodela shoot segments was determined. S. polyrrhiza was shown to have a high starch storage capacity under certain unfavorable growth conditions, such as salt stress and nutrient deficiency. In the W2 (50 mM NaCl) series, compared to the control (Control2), starch levels were 76% higher in shoots and 30% lower in roots. The analysis of the individual growth and development parameters of S. polyrrhiza plants in the experiment carried out indicates new possibilities for the use of this group of plants in biofuel and bioethanol production.

Effects of N,N-bis(3-aminopropyl)dodecylamine on antioxidant enzyme activities, mitochondrial morphology and metabolism in Aspergillus niger.

The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSP) as well as of succinate dehydrogenase (SDG), NADH dehydrogenase (NDG) and fumarate hydratase (FHT) were examined in relation to mitochondrial ultrastructure changes in Aspergillus niger exposed to N,N-bis(3-aminopropyl)dodecylamine (Apd) that was shown to exhibit fungicidal activity. There was a progressive increase in SOD, CAT and GSP activities 1 and 4 h after 0.05 and 0.1 % Apd application. However, this was followed by a pronounced activity decrease when 0.05 % Apd treatment was prolonged by 1 d. The destructive effect on fungal morphology was observed when this fungicidal agent was applied at the concentration of 0.1 % for 1 d. In the treated hyphae mitochondria degenerated after all organelles. The morphological malformations of mitochondria had an impact on their metabolic state; however, the activities of SDG, NDG and FHT were affected to a different extent. In A. niger the fungicidal effect of Apd could be mediated by oxidative stress impairing the vital mitochondria-related cellular functions.

Glutathione and glutathione metabolizing enzymes in tissues and blood of breast cancer patients.

Many reports indicate that glutathione and enzymes cooperating with it are important in neoplastic processes. Glutathione (GSH) concentrations and glutathione S-transferase (GSH STr) and glutathione peroxidase (GSH-Px) activities were determined in breast cancer tissue and adjacent healthy tissues, as well as in blood of 28 patients. There were considerable differences in the investigated parameters among individual patients. Therefore we analyzed the paired samples of normal and cancerous tissues from the same individual. In 68% of the patients the activities of GSH-Px and in 85% patients those of GSH STr were found to be higher in the tumor than in the normal tissue. GSH concentration in 48% tumor samples were higher and in 44% lower than in corresponding normal tissues. Statistically significant correlation was found between GSH-Px and GSH STr in normal (r = 0.51, p < 0.005) and in cancer tissues (r = 0.64, p = 0.001). Correlation coefficient between GSH Px activity in normal and corresponding cancer tissues was r = 0.71 (p < 0.001), however this correlation in the case of GSH STr was much lower but still significant (r = 0.38, p < 0.05). No significant correlation in the determined parameters was found between erythrocytes or plasma and normal or cancer tissues.

The influence of atmospheric chromium on selenium content and glutathione peroxidase activity in blood of tannery workers.

The concentration of selenium and thiobarbituric acid reactive substances (TBARS) and activity of glutathione peroxidase (GSH-Px) were determined in blood of 34 workers of a tannery in Gniezno, Poland, who worked in an area containing chromium compounds. Fourteen workers were exposed to chromium compounds at concentrations of 0.11 +/- 0.07 mg Cr/m3 (mean +/- SD) and 20 at concentrations 5-10 times lower i.e., 0.022 +/- 0.009 mg Cr/m3. Excretion of Se in urine was measured in all of the investigated workers. Decreased Se concentration in whole blood and blood plasma and elevated TBARS concentration in blood plasma were found in the whole group of investigated tanners as compared to controls. Tanners working in areas with high chromium concentrations had a statistically significant decrease in Se concentration in blood and plasma and decreased urinary excretion of the microelement as compared with other tanners. TBARS concentration was 2.5 times lower in workers exposed to higher chromium concentrations (p < 0.005) than in other workers. Positive linear correlations were found between the concentration of Se in blood and the amount of the element excreted in urine (r = 0.48; p < 0.005), the concentration of Se in blood plasma and in urine (r = 0.46; p < 0.01), and the concentration of Se in blood and erythrocyte GSH-Px activity (r = 0.42; p < 0.02). The observed differences between Se concentration in blood and urine of tannery workers and people who are not employed in the industry may indicate a kind of specific adaptation of the body to the working environment containing chromium compounds.

Vitamin E, thiobarbituric acid reactive substance concentrations and superoxide dismutase activity in the blood of children with juvenile rheumatoid arthritis.

OBJECTIVE: To study the role of active oxygen species in tissue injury in rheumatoid arthritis. METHODS: We examined the levels of thiobarbituric acid reactive substances (TBARS) and antioxidants of the first line antioxidative defence of the organism, i.e. vitamin E (VE) and superoxide dismutase (SOD) in the blood of 74 young patients with juvenile rheumatoid arthritis (JRA) and in 138 healthy children, all aged 3-15. RESULTS: A statistically significant increase of TBARS was found in the blood plasma of the children with JRA compared with the control group. In the whole group of patients and in the patients over 6 years of age, the VE concentration was in the red blood cells (RBC) was significantly lower in children who had suffered from JRA for more than one year and in those with the systemic form of the disease. The type of treatment also affected the values for the plasma VE and SOD in the RBC. CONCLUSION: Our results seem to confirm the supposition of increased oxidative stress in children with JRA and low antioxidant levels in terms of SOD activity and vitamin E concentrations.

[Selenium, glutathione peroxidase and TBARS in plasma of children with malignant diseases of the hematopoietic system]. / Selen, peroksydaza glutationowa i zwiazki TBA-reaktywne w osoczu dzieci z chorobami rozrostowymi ukladu krwiotwórczego.

The selenium and TBARS concentrations and glutathione peroxidase activity were measured in the plasma of children with leukemia, lymphoma and histiocytosis X. A group of fifty-four children aged 1 to 16 years was divided into the following age groups: 1-3, 3-7, 7-16 years. In the patients aged 3-7 and 7-16 years, plasma selenium concentration and glutathione peroxidase activity were significantly lower than in age-matched healthy children.

The effect of coronary angioplasty on superoxide anion generation and lipid peroxidation. Propriety of pharmacological intervention.

In patients with unstable angina pectoris, subjected (n = 20) or not subjected (n = 12) to percutaneous transluminal coronary angioplasty (PTCA), baseline superoxide anion (O.2-) generation by neutrophils in the coronary sinus blood was significantly higher than that found in the basilic vein blood of control healthy subjects (n = 12). During reperfusion following effective PTCA, neutrophil counts in the coronary sinus blood tended to decrease, an effect accompanied by a significant decrease in the neutrophil O.2- generation and enhancement of blood plasma lipid peroxidation as reflected by increased malonyldialdehyde concentrations.

[Biochemical aspects of cardiomyocyte damage during ischemia and reperfusion]. / Biochemiczne aspekty uszkodzenia komórek miesnia sercowego w czasie niedotlenienia i reoksygenacji.

Universally accepted free radical damage cardiomyocytes hypothesis during ischemia and reperfusion, establish the pathway of reaction which destroys these cells. Free radicals may also break through antioxidative barrier of the cells. This process comprise also series of "paradoxal phenomena".

Selenium concentration and glutathione peroxidase activity in blood of children with cancer.

In this work we studied 205 children with cancer, aged 6 months to 7 years, who had been diagnosed as suffering from various types of neoplasm. In blood of these children we determined the selenium concentration and glutathione peroxidase activity by fluorometric and spectrophometric methods, respectively. The control group consisted of 128 healthy children. In all groups of children with cancer we observed a significantly lower selenium concentration and lowered glutathione peroxidase activity. We found statistical differences in selenium concentration between first or second and third, and between first and fourth or fifth stages of the disease, only in 3-7 year-old patients. Glutathione peroxidase activity was statistically depressed in the same age group between the first or second and third stages of the disease. Generally, there were no differences in the concentration of the microelement or in the glutathione peroxidase activity between children before and during treatment with cytostatics.

Plasma trace element (Se, Zn, Cu) concentrations in maternal and umbilical cord blood in Poland. Relation with birth weight, gestational age, and parity.

Selenium (Se), copper (Cu), and zinc (Zn) concentrations were determined in plasma of 64 mothers at delivery, 58 nonpregnant women, 64 neonates, and 12 infants, aged 2-12 mo. Se and Zn concentrations in mothers at delivery were significantly lower, and Cu higher than in nonpregnant women. Mean Se and Cu concentrations in newborns were statistically lower than those in mothers at delivery, and Zn and Cu concentrations in preterm infants (n = 13) were significantly higher than in fullterm infants (n = 51). Maternal parity had no significant influence on the distribution of plasma trace element levels. No significant differences were observed in Se and Zn levels in maternal and cord blood plasma according to birth weight, contrary to maternal Cu concentration. Significant correlations were found between maternal and cord blood Se content, and between maternal plasma Cu concentration and birth weight of neonates.

Glutathione peroxidase activity, lipid peroxides and selenium status in blood in patients with Down's syndrome.

The concentrations of selenium and lipid peroxides and the catalytic activity of glutathione peroxidase were measured in the blood of 6 children (6-16 years of age) and 8 adults (17-27 years old) with Down's syndrome (trisomy 21). The values were compared with those for a control group of age-matched normal people. The selenium concentration in whole blood, erythrocytes and plasma was significantly lower in trisomy 21 patients than in normal subjects (p less than 0.001) in both age groups. No statistically significant differences were observed in selenium concentration in whole blood, erythrocytes and plasma between children and adults in the Down's syndrome group. Glutathione peroxidase catalytic activity in erythrocytes was significantly higher in Down's syndrome children than in healthy children (p less than 0.001). Plasma glutathione peroxidase catalytic activity in both investigated age groups was statistically considerably lower in the Down's syndrome patient group. The concentration of lipid peroxides, expressed as the malondialdehyde concentration, is lower in Down's syndrome patients. No correlation between selenium concentration, glutathione peroxidase catalytic activity and amount of lipid peroxides was found in the trisomy 21 patient group.

Glutathione peroxidase activity, lipid peroxides and selenium concentration in various rat organs.

Total and selenium-dependent glutathione peroxidase activity, lipid peroxides and selenium concentration were determined in tissues of rats kept upon standard diet. The selenium concentration as calculated per mg of protein is as follows: liver greater than kidney greater than lung greater than heart greater than muscles greater than brain greater than erythrocytes. The lipid peroxide concentration as expressed by the malondialdehyde amount is a follows: brain greater than heart greater than muscles greater than lung greater than kidney greater than liver. In all the analyzed tissues, Se-GSH-Px activity was found as measured with t-butyl hydroperoxide as substrate, and total GSH-Px activity, as assayed with cumene hydroperoxide. A highly significant correlation was found between Se-GSH-Px activity and selenium concentration in selected tissues (r = 0.91, p less than 0.01), and an inverse linear correlation between lipid peroxides concentration and Se-GSH-Px activity (r = -0.75, p less than 0.1). Se-independent GSH-Px activity was estimated as the difference between total GSH-Px and Se-GSH-Px activity. In all the investigated rat tissues higher activity of Se-dependent GSH-Px than that of Se-independent GSH-Px was observed. In erythrocytes and muscles only the selenium dependent enzyme was detected. Also glutathione S-transferase activity was estimated in the above tissues. No GSH S-transferase activity was found in rat erythrocytes.

Glutathione peroxidase activity, selenium and lipid peroxides levels in blood of cancer children.

The concentrations of whole blood and plasma selenium, plasma lipid peroxides and the glutathione peroxidase activity in plasma and erythrocytes were measured in untreated and treated children with neuro- (n = 23) and nephroblastoma (n = 32) aged 6 months to 15 years. The patients were divided into the following groups: 0.5-1, 1-3, 3.5-6 and 8-15 years old. In all the groups of cancer patients investigated selenium concentration in whole blood and plasma and glutathione peroxidase activity in erythrocytes and plasma were significantly lower than in the age-matched healthy children. The concentrations of lipid peroxides in plasma of children with cancer was higher than in the age-matched control group. No differences were observed between the levels of the determined parameters in children with neuro- and nephroblastoma. Nor were there any differences in the determined parameters between children before and during treatment with cytostatics and between children at different stages of the disease. A significant linear correlation was found between plasma selenium concentration and glutathione peroxidase activity in the erythrocytes and plasma of children with cancer.

Selenium status, lipid peroxides concentration, and glutathione peroxidase activity in the blood of power station and rubber factory workers.

Concentration of selenium in whole blood and plasma, lipid peroxides in plasma, and glutathione peroxidase activities in red blood cell hemolysates and plasma were determined in 49 coal power plant workers and in 50 rubber factory workers. The results were compared with those obtained for 58 nonindustrial controls. Whole blood selenium was significantly lower and plasma lipid peroxides were significantly higher in power plant workers when compared to the nonindustrial group. In the rubber factory workers, whole blood selenium and red blood cells and plasma glutathione peroxidase activities were significantly lower than in the control group. Urinary output of selenium was also significantly decreased in rubber factory workers. Slightly elevated lipid peroxides were also observed in that group. It seems reasonable to conclude that the lower blood selenium and decreased urinary output of this element may result from increased loss of selenium with perspiration. No correlation has been observed between selenium concentration and glutathione peroxidase activity and between enzyme activity and lipid peroxides concentration in the industrial group.

The effect of granulocyte factor (GF) on the production of interleukins and Tac antigen expression.

In the course of adherence granulocytes secrete the granulocyte factor (GF) which modifies lymphocyte functions in vitro. GF augments the interleukins production and diminishes mitogen induced Tac antigen expression in vitro, which may result in diminished IL-2 utilization. Consequently, such cells probably do not absorb IL-2 and do not exert their "inhibitory" potency measured in two step culture. The presented data show a relative deficit in interleukin generation in RA patients and have suggested the role of granulocytes in immunoregulation presumably in the course of diseases accompanied by inflammatory processes.

Red blood cell glutathione peroxidase activity as a function of selenium supplementation in dietary treated children with phenylketonuria.

Red blood cell glutathione peroxidase (GSH-Px) activity of six patients with phenylketonuria treated with aminoacid mixture and protein hydrolysate diets was significantly lower (11.2 IU/g Hb) than that of 21 age-matched healthy children (14.9 IU/g Hb). When the diets were supplemented with yeast rich in selenium the red blood cell GSH-Px activity increased already after one month of treatment to 16.1 IU/g Hb (P less than 0.001) and remained at that level during subsequent two months of selenium supplementation. A high significantly positive correlation has been found between calculated red blood cell selenium level and GSH-Px activity within three months of selenium supplementation.