Changes in fatty acid composition of Stenotrophomonas maltophilia KB2 during co-metabolic degradation of monochlorophenols

The changes in the cellular fatty acid composition of Stenotrophomonas maltophilia KB2 during cometabolic degradation of monochlorophenols in the presence of phenol as well as its adaptive mechanisms to these compounds were studied. It was found that bacteria were capable of degrading 4-chlorophenol (4-CP) completely in the presence of phenol, while 2-chlorophenol (2-CP) and 3-chlorophenol (3-CP) they degraded partially. The analysis of the fatty acid profiles indicated that adaptive mechanisms of bacteria depended on earlier exposure to phenol, which isomer they degraded, and on incubation time. In bacteria unexposed to phenol the permeability and structure of their membranes could be modified through the increase of hydroxylated and cyclopropane fatty acids, and straight-chain and hydroxylated fatty acids under 2-CP, 3-CP and 4-CP exposure, respectively. In the exposed cells, regardless of the isomer they degraded, the most important changes were connected with the increase of the contribution of branched fatty acid on day 4 and the content of hydroxylated fatty acids on day 7. The changes, particularly in the proportion of branched fatty acids, could be a good indicator for assessing the progress of the degradation of monochlorophenols by S. maltophilia KB2. In comparison, in phenol-degrading cells the increase of cyclopropane and straight-chain fatty acid content was established. These findings indicated the degradative potential of the tested strain towards the co-metabolic degradation of persistent chlorophenols, and extended the current knowledge about the adaptive mechanisms of these bacteria to such chemicals

Kinetics of styrene biodegradation by Pseudomonas sp. E-93486

The research into kinetics of styrene biodegradation by bacterial strain Pseudomonas sp. E-93486 coming from VTT Culture Collection (Finland) was presented in this work. Microbial growth tests in the presence of styrene as the sole carbon and energy source were performed both in batch and continuous cultures. Batch experiments were conducted for initial concentration of styrene in the liquid phase changed in the range of 5–90 gm−3. The Haldane model was found to be the best to fit the kinetic data, and the estimated constants of the equation were: μm= 0.1188 h−1, KS=5.984 mg l−1, and Ki=156.6 mg l−1. The yield coefficient mean value Yapp xs for the batch culture was 0.72 gdry cells weight(gsubstrate)−1. The experiments conducted in a chemostat at various dilution rates (D=0.035–0.1 h−1) made it possible to determine the value of the coefficient for maintenance metabolism md=0.0165 h−1 and the maximum yield coefficient value YM xs ¼ 0:913. Chemostatexperiments confirmed the high value of yield coefficient Yapp xs observed in the batch culture. The conducted experiments showed high activity of the examined strain in the styrene biodegradation process and a relatively low sensitivity to inhibition of its growth at higher concentrations of styrene in the solution. Such exceptional features of Pseudomonas sp. E-93486 make this bacterial strain the perfect candidate for technical applications

Kinetics of vinyl acetate biodegradation by Pseudomonas fluorescens PCM 2123

The microbial degradation of vinyl acetate (VA) by Pseudomonas fluorescens PCM 2123 strain was studied in both batch and continuous modes. The purpose of the experiments was to determine the kinetic model of the cell growth and biodegradation rate of vinyl acetate (VA), which was the sole carbon and energy source for tested microorganisms. The experiments, carried out in a batch reactor for several initial concentrations of growth substrate in the liquid phase ranging from 18.6 to 373 gsubstrate·m–3 (gs·m–3) made it possible to choose the kinetic model and to estimate its constants. The Haldane inhibitory model with the values of constants: μm = 0.1202 h–1, KS = 17.195 gs·m–3, Ki = 166.88 gs·m–3 predicted the experimental data with the best accuracy. To set the parameters of maintenance metabolism it was necessary to carry out a series of continuous cultures at different dilution rates (0.05 to 0.072 h–1) and concentrations of VA in the liquid supplied to the chemostat ranging from 30.9 to 123.6 gs·m–3. The obtained data-base enabled to determine the coefficient for maintenance metabolism (me = 0.0251 gsubstrate·gcell dry weight –1·h–1 (gs·gcdw –1·h–1)) as well as the maximal and observed values of yield coefficients, Yxs M = 0.463 gcdw·gs –1 and (Yxs)obs = 0.411 gcdw·gs –1, respectively. The developed kinetics was verified by comparison of the computed and obtained in batch experiments profiles of changes in biomass and growth substrate concentrations

Antioxidative effects of α-lipoic acid in the brain, liver and kidneys in selected mouse organs exposed to zymosan

This study investigated the role of exogenous α-lipoic acid (ALA) in the inflammation caused by zymosan application. Seventy-two adult male white mice were divided into twelve groups: three control groups, three Zymosan groups, three ALA groups and three groups being the combination of Zymosan and ALA. In the experimental groups, the animals were decapitated after 3, 6 and 24 hours after the injection. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were determined in the brain, liver and kidneys of the mice. After the injection of Zymosan, it was found that the activity of SOD, CAT and GSH-Px in the brain, liver and kidneys of mice was significantly lower in all time periods. The administration of ALA resulted in an opposite effect, namely, it increased the activity of the enzymes studied in the selected organs of mice. The Zymosan and ALA combination significantly inhibited the decrease in the activity of the enzymes compared with the values obtained in the groups of animals which received Zymosan only. The results of our study, using the Zymosan-induced inflammation, clearly indicate that ALA is an anti-inflammatory agent

Effect of Nickel as Stress Factor on Phenol Biodegradation by Stenotrophomonas maltophilia KB2

This study focuses on the phenol biodegradation kinetics by Stenotrophomonas maltophilia KB2 in a nickel-contaminated medium. Initial tests proved that a nickel concentration of 33.3 mg L1 caused a cessation of bacterial growth. The experiments were conducted in a batch bioreactor in several series: without nickel, at constant nickel concentration and at varying metal concentrations (1.67–13.33 g m3). For a constant Ni2+ concentration (1.67 or 3.33 g m3), a comparable bacterial growth rate was obtained regardless of the initial phenol concentration (50–300 g m3). The dependence m = f (S0) at constant Ni2+ concentration was very well described by the Monod equations. The created varying nickel concentrations experimental database was used to estimate the parameters of selected mathematical models, and the analysis included different methods of determining metal inhibition constant KIM. Each model showed a very good fit with the experimental data (R2 values were higher than 0.9). The best agreement (R2 = 0.995) was achieved using a modified Andrews equation, which considers the metal influence and substrate inhibition. Therefore, kinetic equation parameters were estimated: mmax = 1.584 h1, KS = 185.367 g m3, KIS = 106.137 g m3, KIM = 1.249 g m3 and n = 1.0706

Impact of the Biological Cotreatment of the Kalina Pond Leachate on Laboratory Sequencing Batch Reactor Operation and Activated Sludge Quality

Hauling landfill leachate to o site urban wastewater treatment plants is a way to achieve pollutant removal. However, the implementation of biological methods for the treatment of landfill leachate can be extremely challenging. This study aims to investigate the e ect of blending wastewater with 3.5% and 5.5% of the industrial leachate from the Kalina pond (KPL) on the performance of sequencing batch reactor (SBR) and capacity of activated sludge microorganisms. The results showed that the removal e ciency of the chemical oxygen demand declined in the contaminated SBR from 100% to 69% and, subsequently, to 41% after the cotreatment with 3.5% and 5.5% of the pollutant. In parallel, the activities of the dehydrogenases and nonspecific esterases declined by 58% and 39%, and 79% and 81% after 32 days of the exposure of the SBR to 3.5% and 5.5% of the leachate, respectively. Furthermore, the presence of the KPL in the sewage a ected the sludge microorganisms through a reduction in their functional capacity as well as a decrease in the percentages of the marker fatty acids for di erent microbial groups. A multifactorial analysis of the parameters relevant for the wastewater treatment process confirmed unambiguously the negative impact of the leachate on the operation, activity, and structure of the activated sludge

Analiza zaburzeń neuropsychiatrycznych wywołanych infekcją Tropheryma whipplei

Whipple’s disease is a rare, chronic systemic infection caused by gram-positive Tropheryma whipplei actinobacterium.So far, the reasons for the Tropheryma whipplei infection have not been explained. Clinical symptoms are non-specificand may suggest other diseases, mainly gastrointestinal disease. Nervous system symptoms such as personality disorders,behavioral disorders, depressive symptoms and disturbances of consciousness are also observed.The aim of the study is to collect information on neuropsychological disorders found in Whipple’s disease.Central nervous system (CNS) involvement can take place in three cases: classic form, in the relapse of previously treatedclassic form (with changes in the digestive system) and in isolated CNS infection (without evidence of gastrointestinalinvolvement by T. whipplei). Neurological disorders resulting from CNS involvement are variable and may be similar toother diseases of the nervous system. Treatment is difficult due to the long-term course of the disease and non-specificityof its symptoms, which is why the problem is the selection of effective pharmacotherapy. Untreated disease resultsin worsening neuropsychological disorders. Pharmacotherapy involves the use of antibiotics. The use of antibacterialtherapy reduces the risk of recurrence of clinical symptoms.Choroba Whipple’a jest rzadkim, przewlekłym zakażeniem układowym wywołanym przez gram-dodatnie aktynobakterie Tropheryma whipplei. Dotychczas nie wyjaśniono przyczyn zakażenia tym patogenem. Objawy kliniczne są niespecyficzne i mogą sugerować inne choroby, w tym głównie choroby układu pokarmowego. Obserwuje się również objawy ze strony układu nerwowego, takie jak zaburzenia osobowości, zaburzenia zachowania, objawy depresyjne oraz zaburzenia świadomości. Celem pracy jest zebranie informacji na temat zaburzeń neuropsychologicznych występujących w Chorobie Whipple’a. Zajęcie ośrodkowego układu nerwowego (OUN) może mieć miejsce w trzech przypadkach: klasycznej postaci, w nawrocie wcześniej leczonej klasycznej postaci (ze zmianami w układzie pokarmowym) oraz w izolowanej infekcji OUN (bez dowodów zajęcia układu pokarmowego przez T. whipplei). Zaburzenia neurologiczne wynikające z zajęcia OUN są różnorodne i mogą być podobne do innych chorób układu nerwowego. Leczenie jest utrudnione ze względu na długotrwały przebieg choroby i niespecyficzność jej objawów, dlatego też problemem jest dobór skutecznej farmakoterapii. Nieleczona choroba skutkuje pogłębieniem zaburzeń neuropsychologicznych. Farmakoterapia polega na zastosowaniu antybiotyków. Wdrożenie terapii przeciwbakteryjnej zmniejsza ryzyko nawrotów objawów klinicznych

The effects of caffeine on the motility and viability of stallion spermatozoa at different temperature conditions

The purpose of this study was to evaluate the dose-and time-dependent effect of caffeine treatment on the motility and viability of stallion spermatozoa at different temperatures. Six dose groups (A to F) were established with changing caffeine concentrations (from 0.625 to 10 mg/mL). The control samples were prepared by diluting the ejaculate only with physiological salt solution. The samples were examined after 0, 1, 2 and 3 h of incubation at 5 degrees C and 37 degrees C. The motility parameters were evaluated by Computer Assisted Semen Analyzer (CASA) system, and the viability was assessed by the mito-chondrial toxicity test at the end of the incubation. A positive effect of the lowest tested caffeine concentration on the motility parameters was observed throughout the incubation period at 5 degrees C. At the end of the 3h incubation, the viability in every sample in these groups, treated with any caffeine concentration, showed lower values compared to the control. At the higher incubation temperature (37 degrees C), caffeine positively affected the motility in samples B (P < 0.05) and D, E, F (P < 0.001) after 3 h of incubation; however, the viability showed a slightly decreasing tendency. Our results suggest that caffeine, in an optimal concentration, may be used as a component of stallion semen extenders

A comparative study of biodegradation of vinyl acetate by environmental strains

Four Gram-negative strains, E3_2001, EC1_2004, EC3_3502 and EC2_3502, previously isolated from soil samples, were subjected to comparative studies in order to select the best vinyl acetate degrader for waste gas treatment. Comparison of biochemical and physiological tests as well as the results of fatty acids analyses were comparable with the results of 16S rRNA gene sequence analyses. The isolated strains were identified as Pseudomonas putida EC3_2001, Pseudomonas putida EC1_2004, Achromobacter xylosoxidans EC3_3502 and Agrobacterium sp. EC2_3502 strains. Two additional strains, Pseudomonas fluorescens PCM 2123 and Stenotrophomonas malthophilia KB2, were used as controls. All described strains were able to use vinyl acetate as the only source of carbon and energy under aerobic as well as oxygen deficiency conditions. Esterase, alcohol dehydrogenase and aldehyde dehydrogenase were involved in vinyl acetate decomposition under aerobic conditions. Shorter degradation times of vinyl acetate were associated with accumulation of acetic acid, acetaldehyde and ethanol as intermediates in the culture fluids of EC3_2001 and KB2 strains. Complete aerobic degradation of vinyl acetate combined with a low increase in biomass was observed for EC3_2001 and EC1_2004 strains. In conclusion, P. putida EC1_2004 is proposed as the best vinyl acetate degrader for future waste gas treatment in trickle-bed bioreactors