High Degradation Capacity Research Articles

FeMoO4-graphene oxide photo-electro-catalyst for berberine removal and hydrogen evolution

Photo-electro-catalytic degradation of antibiotics such as berberine in water with simultaneous hydrogen evolution is an attractive option. It can control pollution using solar energy and provide clean energy. The photo electrodes play vital role in this kind of photocatalytic electrolytic cell. To obtain better electrode with high degradation capacity and fast hydrogen generation rate, using a facile one-pot hydrothermal process, a series of nano-structured composite FeMoO4-GO (graphene oxide) catalysts with improved absorbance in 250–800 nm were synthesized, and loaded on CFC (carbon fiber cloth). Their photo electrode performance were compared. Using SEM(scanning electron microscope), XRD (X-ray diffraction) and XPS(X-ray photoelectron spectroscopy), the catalysts were characterized, and LSV(linear sweep voltammetry), CV(cyclic voltammetry) and EIS(electrochemical impedance) were used to characterize the electrodes. In 1 M KCl supporting electrolyte, at current density 10 mA cm−2, 90% berberine was removed in 30 min and hydrogen generation rate was 3.1 μmol cm−2 min−1 in photo-electro-catalysis system. The results show rapid hydrogen generation and enhanced pollutant degradation.

Hyperthermophilic pretreatment composting significantly accelerates humic substances formation by regulating precursors production and microbial communities

Hyperthermophilic pretreatment composting (HPC) is superior to traditional composting (TC) with enhanced compost maturity and accelerated humic substances (HS) formation. However, the regulators affecting HS formation, which is of great importance in evaluating the compost maturity, are still unclear. This study aimed to examine and compare the effects of HPC and TC on (i) HS formations under varying precursors, (ii) bacterial and fungal dynamics, and (iii) factors affecting HS formations. Results revealed that HS formation was accelerated in the heating, thermophilic and maturity phases for HPC, whereas the synthesis of HS was observed in the maturity phase for TC. Particularly, concentrations of humic acid, polyphenols, amino acids, polysaccharides and reducing sugar were increased in compost by 50, 60, 52, 44 and 92%, respectively after the hyperthermophilic pretreatment. These increased precursors could stimulate the activity of Planococcaceae that possessed a high degradation capacity on D-mannitol in the heating stage. Additionally, the thermophilic microbes Solibacillus and Aspergillus with high degradation capacity on lignocelluloses and lignin, respectively dominated in the thermophilic stage. These microorganisms may promote the formation of precursors and thus accelerated synthesis of HS in HPC. Finally, structural equation model (SEM) showed polyphenol and reducing sugar were the key precursors to directly or indirectly promote HS formation in HPC and the higher temperature rise as well as the higher N content provided advantages over TC in improving HS formation. This study provides the stability to the accelerated humification process in HPC and reveals its potential applicability in improving HS formation.

Biodegradation of 2,4,6-Trinitrotoluene (TNT) with Bacteria Isolated from TNT-polluted Waste Pink Water

In this study, bacterial strains that can use TNT as a nitrogen source isolated from TNT contaminated pink water. We isolated 5 bacterial strains and the isolated bacteria were cultured in medium containing TNT and TNT degradation capacities of isolates were determined by spectrophotometric analysis. According to the results of the analysis that have done, 3 bacterial isolates that have high TNT degradation capacity were selected and the isolates were identified with firstly Gram-staining then with 16S rRNA sequence analysis method. According to the sequence of 16S rRNA, water isolates were identified as Stenotrophomonas maltophilia (SU K2), Klebsiella pneumoniae (SU K3), Raoultella planticola (SU K4). During the TNT degradation studies, at the end of 24 h incubation time, in the medium containing 100 mg/L TNT, TNT degradation rate for SU K2, SU K3 and SU K4 were determined 70 %, 96 % and 93 % respectively. 4-aminodinitrotoluene and 2-aminodinitrotoluene accumulations were detected in the culture medium of all isolates as intermediate products formed during the degradation of TNT by HPLC analysis. Additionally, nitrite accumulation was detected in the culture medium of all isolates and the influence of temperature and pH on the degradation of TNT was also investigated. It was determined that SU K2 isolates have the highest TNT degradation capacity at 35 °C, the others have at 30 °C and all isolates degraded TNT fastest at pH 7. The results of the study show that the new isolates can be useful for the removal of TNT in a wastewater treatment system.

Effect of Ce3+ on the photocatalytic activity of MAlCe ternary hydrotalcites-like compounds in methylene blue photodegradation

MgAlCe ternary hydrotalcites-like compounds (MgAlCe-HTlc) with different Al3+/Ce3+ molar ratio were synthesized by co-precipitation method. In addition, MAlCe-HTlc (M: Co, Ni, Zn) with Al3+/Ce3+ molar ratio 0.95: 0.05 were also synthesized. The attained LDH were characterized by SEM, EDX, XRD, FT-IR, TG-DTA, XPS and UV-Vis DRS techniques. The results indicated that the synthesized MgAlCe-HTlc appeared to be the typical layered structure when it contains Al3+ and Ce3+ ions simultaneously. Three kinds of attained MAlCe-HTlc also had typical layered structure of LDH. Furthermore, the thermal stability of MgAlCe-HTlc decreased by the substitution of Ce3+ for Al3+ ions. When Mg2+ was replaced by Co2+, Ni2+ or Zn2+, the decomposition temperatures reduced. The Ce 3d spectrum of Mg3Al0.8Ce0.2-HTlc before and after used indicated presence of mixed valence states of Ce3+ and Ce4+. The MgAlCe-HTlc exhibited a relatively high degradation capacity for methylene blue (MB), while degradation ability of Mg3Al0.95Ce0.05-HTlc/H2O2 was highest. The remaining rate of the MB was about 6.46% after irradiation for 80 min. The order of degradation effects about MB was as follow: MgAlCe-HTlc>ZnAlCe-HTlc>CoAlCe-HTlc≈NiAlCe-HTlc. In addition, the effects of different parameters such as pH of the solution, catalyst type and dosage, concentration of MB, as well as the stability of catalyst were investigated. The photocatalytic degradation mechanism of MB showed that the OH, h+ and superoxide anion produced in Mg3Al0.95Ce0.05-HTlc/H2O2 system were all active species, while OH played a major role.

Screening and enzymatic activity of high-efficiency gellan lyase producing bacteria Pseudoalteromonas hodoensis PE1

ABSTRACT Gellan is a widely used microbial polysaccharide and one of the more effective ways to expand its application value would be to investigate the mechanism of gellan lyase and to produce gellan oligosaccharide. In this study, efficient gellan degrading bacteria were screened. One of the strains with high efficient gellan degradation capacity was labeled PE1. Through physiological and biochemical analysis of 16S rDNA, the species was identified as Pseudoalteromonas hodoensis. The optimum conditions for enzymatic activity and how it was affected by metal ions were determined, and the results showed that the lyase activities were much higher than those of previously reported (about 20 times). The gellan degradation products were determined by thin-layer chromatography and the oligosaccharides were determined by high-efficiency liquid chromatography to analyze the action site of lyase. This study laid a solid foundation which elucidates the production and application of gellan oligosaccharides. Research highlights ● High efficiency gellan lyase producing bacteria ● Optimization of reaction conditions for gellan degradation ● Oligosaccharides were detected by TLC and HPLC to speculate the lyase action sites.

Biodegradation characteristics and genomic functional analysis of indole‐degrading bacterial strain Acinetobacter sp. JW

AbstractBACKGROUNDIndole, an important type of N‐heterocyclic aromatic compound, is considered a toxic and odorous pollutant in coking and municipal wastewater. For efficient bioremediation of indole‐containing wastewater, an indole‐degrading bacterial strain JW was isolated from activated sludge in this study. The indole biodegradation characteristics and the whole‐genome sequence of strain JW were also determined.RESULTSStrain JW, capable of utilizing indole as the sole carbon and nitrogen source, was identified as Acinetobacter sp. based on 16S rRNA gene sequence analysis. It was able to completely degrade 100 mg L−1 indole within 20 h, and transform organic nitrogen to ammonia (NH4+‐N) and nitrate (NO3−‐N). Meanwhile, strain JW also presented high capacity for indole degradation at a range of initial indole concentrations (25–200 mg L−1) and pH (6.0–8.0). The key metabolites during indole biodegradation were identified by liquid chromatography coupled to Q‐Exactive high resolution mass spectrometry, and included isatin, anthranilate, salicylate, catechol and indigo. The whole‐genome sequence of strain JW revealed the possible functional genes related to indole biodegradation, such as iif genes, ant genes and downstream metabolic genes. Thus, an indole biodegradation mechanism was proposed based on metabolites identification and genomic analysis.CONCLUSIONThe results suggested that Acinetobacter sp. JW could be a promising biological candidate for bioremediation of indole, and the useful genetic information might enrich our understanding of microbial degradation of indole. © 2018 Society of Chemical Industry

Cellulolytic and ligninolytic potential of new strains of fungi for the conversion of fibrous substrates

This research explored the lignocellulolytic potential of native strains (Hipoxylon sp, Curvularia kusanoi, Trichoderma sp and Aspergillus fumigatus) isolated from natural substrates. Their sequences were deposited in the GenBank, and it‘s lignocellulosic potentialities were determined quantitatively from kinetics of cellulase and ligninase production in wheat straw, and grass hay. All evaluated strains showed high cellulolytic potential and laccase activity where only found in the C. kusanoi L7 strain. The new strains where co-cultivated with a reference strains of Trichoderma viride to determinate the capacity of joint growth, to know if they can be used together for a better degradation of the cell wall. A three-phase purification system was used to isolate the C. kusanoi laccase where a preparation 10 times purer than the initial crude was obtained, with an enzymatic activity of 2800U/L, a specific activity of 544.74U/g and a yield higher than 100%, which showed a more stable behavior at alkaline pH than at acid pH. The purify enzymes showed an optimum range of activity between 30 and 40°C, and a high thermal stability. It is concluded that the isolated strains have a high degradation capacity and the C. kusanoi L7 strain stands out as the one with the greatest potential when expressing in addition to the cellulolytic complex the enzymes involved in the degradation of lignin.

Degradation and mineralization of ciprofloxacin by gas–liquid discharge non-thermal plasma

A typical quinolones antibiotic ciprofloxacin (CIP) in aqueous solution was degraded by a gas–liquid discharge non-thermal plasma system. The discharge plasma power and the emission intensity of the excited reactive species (RS) generated in the gas phase were detected by the oscilloscope and the optical emission spectroscopy. The effects of various parameters on CIP degradation, i.e. input powers, initial concentrations addition of radical scavengers and pH values were investigated. With the increase of discharge power, the degradation efficiency increased but the energy efficiency significantly reduced. The degradation efficiency also reduced under high concentration of initial CIP conditions due to the competitive reactions between the plasma-induced RS with the degradation intermediates of CIP. Different radical scavengers (isopropanol and CCl4) on ·OH and H· were added into the reaction system and the oxidation effects of ·OH radicals have been proved with high degradation capacity on CIP. Moreover, the long-term degradation effect on CIP in the plasma-treated aqueous solution proved that the long-lived RS (H2O2 and O3, etc) might play key roles on the stay effect through multiple aqueous reactions leading to production of ·OH. The degradation intermediates were determined by the method of electrospray ionization (+)-mass spectroscopy, and the possible degradation mechanism were presented.

Effective Degradation of 2,4,6-Trinitrotoluene (TNT) with a Bacterial Consortium Developed from High TNT-degrading Bacteria Isolated from TNT-contaminated Soil

In this study, bacterial strains, capable of using TNT as a nitrogen source, were isolated from TNT-contaminated soil samples collected from military region in Kirikkale, Turkey. We selected three strains that showed the highest TNT degradation capacity and according to 16S rRNA sequence analysis, the strains were identified as Klebsiella pneumoniae (designated SC1 K1, showed 99% homology), Raoultella planticola (designated SC1 K4, showed 99% homology) and Pseudomonas putida (designated SC1 K5, showed 99% homology). These strain were cultured in medium containing 100 mg L-1 TNT, SC1 K1 degraded 90 % of the initial TNT, SC1 K4 degraded 95 % of the initial TNT, and SC1 K5 degraded 84 % of the initial TNT after 24 h of incubation. Then, to remove TNT more efficiently, we constructed a bacterial consortium with these strains. The developed consortium was cultured in medium containing 100 mg L-1 TNT and the consortium removed 97.2 % of the initial TNT after four-hour incubation period. According to HPLC analyses, The consortium transformed TNT to 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene and an unknown metabolite. The isolates showed high TNT degradation capacity compared to many previous studies and the developed bacterial consortium can be used to remediate the TNT-contaminated environments.

Sludge based micro-electrolysis filler for removing tetracycline from solution

In this study, a novel catalytic micro-electrolysis filler (CMEF) was prepared using waste sludge as the main raw materials. The preparation process was optimized in terms of the mass ratio of raw materials and sintering temperature based on the tetracyclines (TCs) removal efficiency. The physicochemical characteristics (e.g., surface area, morphology features, function groups, and valence state of Fe) of the prepared CMEF were determined. Finally, the removing performance and mechanism of CMEF were discussed by removing TCs from solution. The results showed that the optimum conditions for CMEF preparation were a sintering temperature of 1050 °C, and the mass ration for sludge:clay:Fe powder of 3:2:2. The CMEF exhibited a high degradation capacity for TCs with a removal rate up to 99.9% in 2.5 h, and the removal kinetics fit well with a pseudo-second-order model. Introducing Fe into the CMEF significantly promoted TCs removal, comparing to the removal of TCs by sludge based ceramic (without addition of iron). This study provides a novel cost-effective CMEF based on sludge, and is also of significance for co-friend recycling of waste sludge.

High phenol degradation capacity of a newly characterized Acinetobacter sp. SA01: Bacterial cell viability and membrane impairment in respect to the phenol toxicity

An efficient phenol-degrading bacterial strain, belonging to Acinetobacter genus, was isolated and selected to study the impact of different environmentally relevant phenol concentrations on the degradation process. The bacterial isolate, labeled as Acinetobacter sp. SA01 was able to degrade the maximum phenol concentration of 1 g/l during 60 h at optimum condition of pH 7, 30 °C and 180 rpm. Aeration and initial cell density, the two important factors, were carefully examined in the optimal growth conditions. The results showed that these two variables related proportionally with phenol degradation rate. Further investigations showed no effect of inoculum size on the enhancement of degradation of phenol at over 1 g/l. Flow cytometry (FCM) study was performed to find out the relationship between phenol-induced damages and phenol degradation process. Single staining using propidium iodide (PI) showed increased cell membrane permeability with an increase of phenol concentration, while single staining with carboxyfluorescein diacetate (cFDA) demonstrated a considerable reduction in esterase activity of the cells treated with phenol at more than 1 g/l. A detailed investigation of cellular viability using concurrent double staining of cFDA/PI revealed that the cell death increases in cells exposed to phenol at more than 1 g/l. The rate of cell death was low but noticeable in the presence of phenol concentration of 2 g/l, over time. Phenol at concentrations of 3 and 4 g/l caused strong toxicity in living cells of Acinetobacter sp. SA01. The plate count method and microscopy analysis of the cells treated with phenol at 1.5 and 2 g/l confirmed an apparent reduction in cell number over time. It was assumed that the phenol concentrations higher than 1 g/l have destructive effects on membrane integrity of Acinetobacter sp. SA01. Our results also revealed that the toxicity did not reduce by increasing initial cell density. Scanning electron microscopy (SEM) examination of bacterial cells revealed the surface morphological changes following exposure to phenol. The bacterial cells, with wizened appearance and wrinkled surface, were observed by exposing to phenol (1 g/l) at lag phase. A morphological change occurred in the mid-logarithmic phase as the bacterial cells demonstrated coccobacilli form as well as elongated filamentous shape. The wrinkled cell surface were totally disappeared in mid-stationary phase, suggesting that the complete degradation of phenol relieve the stress and direct bacterial cells toward possessing smoother cell membrane.

Statin treatment reduces matrix degradation capacity of proinflammatory polarized macrophages

Background and aimsMacrophages are versatile immune cells involved in tissue degradation and remodeling. Proinflammatory macrophages have the highest capacity of matrix degradation and proteolysis. Within atherosclerotic lesions, proinflammatory macrophages are associated with unstable plaques. Statins have been demonstrated to increase plaque stability. Possible changes of polarized macrophage tissue degradation behavior under statin treatment are currently unknown. MethodsPolarized macrophages were tested in vitro for matrix degradation capacity with or without statin treatment. ResultsProinflammatory macrophages show high matrix degradation capacity, which is lost after statin treatment. Statin concentrations were within a physiological range and did not influence overall macrophage polarization. Proinflammatory macrophages showed however a loss of filopodia where activators of MMPs are located. Loss of matrix degradation in proinflammatory macrophages was associated with changes of MMP14 activation and loss of uPAR localization at filopodia. Supplementation of mevalonate restored localization of uPAR to cellular protrusions and matrix degradation capacity. ConclusionStatins reduce the matrix degradation potential of proinflammatory macrophages by reducing uPAR localization to cellular filopodia and reducing intracellular MMP14 activation.

A Unique Autothermal Thermophilic Aerobic Digestion Process Showing a Dynamic Transition of Physicochemical and Bacterial Characteristics from the Mesophilic to the Thermophilic Phase.

A unique autothermal thermophilic aerobic digestion (ATAD) process has been used to convert human excreta to liquid fertilizer in Japan. This study investigated the changes in physicochemical and bacterial community characteristics during the full-scale ATAD process operated for approximately 3 weeks in 2 different years. After initiating simultaneous aeration and mixing using an air-inducing circulator (aerator), the temperature autothermally increased rapidly in the first 1 to 2 days with exhaustive oxygen consumption, leading to a drastic decrease and gradual increase in oxidation-reduction potential in the first 2 days, reached >50°C in the middle 4 to 6 days, and remained steady in the final phase. Volatile fatty acids were rapidly consumed and diminished in the first 2 days, whereas the ammonia nitrogen concentration was relatively stable during the process, despite a gradual pH increase to 9.3. Principal-coordinate analysis of 16S rRNA gene amplicons using next-generation sequencing divided the bacterial community structures into distinct clusters corresponding to three phases, and they were similar in the final phase in both years despite different transitions in the middle phase. The predominant phyla (closest species, dominancy) in the initial, middle, and final phases were Proteobacteria (Arcobacter trophiarum, 19 to 43%; Acinetobacter towneri, 6.3 to 30%), Bacteroidetes (Moheibacter sediminis, 43 to 54%), and Firmicutes (Thermaerobacter composti, 11 to 28%; Heliorestis baculata, 2.1 to 16%), respectively. Two predominant operational taxonomic units (OTUs) in the final phase showed very low similarities to the closest species, indicating that the process is unique compared with previously published ones. This unique process with three distinctive phases would be caused by the aerator with complete aeration.IMPORTANCE Although the autothermal thermophilic aerobic digestion (ATAD) process has several advantages, such as a high degradation capacity, a short treatment period, and inactivation of pathogens, one of the factors limiting its broad application is the high electric power consumption for aerators with a full-scale bioreactor. We elucidated the dynamics of the bacterial community structures, as well as the physicochemical characteristics, in the ATAD process with a full-scale bioreactor from human excreta for 3 weeks. Our results indicated that this unique process can be divided into three distinguishable phases by an aerator with complete aeration and showed a possibility of shortening the digestion period to approximately 10 days. This research not only helps to identify which bacteria play significant roles and how the process can be improved and controlled but also demonstrates an efficient ATAD process with less electric power consumption for worldwide application.

Activated Hydrotalcites Obtained by Coprecipitation as Photocatalysts for the Degradation of 2,4,6‐Trichlorophenol

A gallery of hydrotalcite‐type mesoporous materials with different Mg/Al molar ratios were synthesized by the coprecipitation method. The materials were activated by heat treatment to test their activity in the photodegradation of 2,4,6‐trichlorophenol under UV light irradiation. The physicochemical properties of the different synthesized and activated materials were determined using XRD, physical adsorption/desorption of N2, FTIR, SEM, DTA, and TGA. Their banned band energy was determined by UV‐Vis to identify their potential to be used as a semiconductor in catalytic photodegradation processes. The results of photodegradation tests of 2,4,6‐trichlorophenol showed that hydrotalcites have a high degradation capacity, up to 100% for the catalyst of Mg/Al ratio = 2, with a high mineralization capacity of 80%. The degradation capacity of most of the catalysts tested is mainly due to the presence of holes and the formation of superoxide free radicals, which are the determining species within the degradation mechanism.

Bacterial Synergism in Lignocellulose Biomass Degradation - Complementary Roles of Degraders As Influenced by Complexity of the Carbon Source.

Lignocellulosic biomass (LCB) is an attractive source of carbon for the production of sugars and other chemicals. Due to its inherent complexity and heterogeneity, efficient biodegradation requires the actions of different types of hydrolytic enzymes. In nature, complex microbial communities that work efficiently and often synergistically accomplish degradation. Studying such synergisms in LCB degradation is fundamental for the establishment of an optimal biological degradation process. Here, we examine the wheat straw degradation potential of synthetic microbial consortia composed of bacteria and fungi. Growth of, and enzyme secretion by, monocultures of degrader strains were studied in aerobic cultures using wheat straw as the sole carbon and energy source. To investigate synergism, co-cultures were constructed from selected strains and their performance was tested in comparison with the respective monocultures. In monoculture, each organism – with a typical enzymatic profile – was found to mainly consume the cellulose part of the substrate. One strain, Flavobacterium ginsengisoli so9, displayed an extremely high degradation capacity, as measured by its secreted enzymes. Among 13 different co-cultures, five presented synergisms. These included four bacterial bicultures and one bacterial–fungal triculture. The highest level of synergism was found in a Citrobacter freundii/Sphingobacterium multivorum biculture, which revealed an 18.2-fold increase of the produced biomass. As compared to both monocultures, this bacterial pair showed significantly increased enzymatic activities, in particular of cellobiohydrolases, mannosidases, and xylosidases. Moreover, the synergism was unique to growth on wheat straw, as it was completely absent in glucose-grown bicultures. Spent supernatants of either of the two partners were found to stimulate the growth on wheat straw of the counterpart organism, in a directional manner. Thus, the basis of the LCB-specific synergism might lie in the specific release of compounds or agents by S. multivorum w15 that promote the activity of C. freundii so4 and vice versa.

Characterization of the biodegradation, bioremediation and detoxification capacity of a bacterial consortium able to degrade the fungicide thiabendazole.

Thiabendazole (TBZ) is a persistent fungicide used in the post-harvest treatment of fruits. Its application results in the production of contaminated effluents which should be treated before their environmental discharge. In the absence of efficient treatment methods in place, biological systems based on microbial inocula with specialized degrading capacities against TBZ could be a feasible treatment approach. Only recently the first bacterial consortium able to rapidly transform TBZ was isolated. This study aimed to characterize its biodegradation, bioremediation and detoxification potential. The capacity of the consortium to mineralize 14C-benzyl-ring labelled TBZ was initially assessed. Subsequent tests evaluated its degradation capacity under various conditions (range of pH, temperatures and TBZ concentration levels) and relevant practical scenarios (simultaneous presence of other postharvest compounds) and its bioaugmentation potential in soils contaminated with increasing TBZ levels. Finally cytotoxicity assays explored its detoxification potential. The consortium effectively mineralized the benzoyl ring of the benzimidazole moiety of TBZ and degraded spillage level concentrations of the fungicide in aqueous cultures (750mg L-1) and in soil (500mgkg-1). It maintained its high degradation capacity in a wide range of pH (4.5-7.5) and temperatures (15-37°C) and in the presence of other pesticides (ortho-phenylphenol and diphenylamine). Toxicity assays using the human liver cancer cell line HepG2 showed a progressive decrease in cytotoxicity, concomitantly with the biodegradation of TBZ, pointing to a detoxification process. Overall, the bacterial consortium showed high potential for future implementation in bioremediation and biodepuration applications.

Abstract 171: Lysosomal Response Tocholesterol Loading is Altered in DBA/2 Mouse Foam Cells Which May Explain Impairedautolysosome Formation and Lipid Droplets Clearance

In a previous study, we identified autolysosome formation as the limiting step for turnover of cholesterol esters in lipid droplets of macrophage foam cells from the athero-sensitive DBA/2 strain compared to the athero-resistant AKR mouse strain. As autophagosome formation was similar in these two strains, we hypothesized that the lysosomal response to acetylated LDL (AcLDL) loading may be defective in DBA/2 vs. AKR foam cells. For all our studies, we cultured AKR and DBA/2 macrophages with or without AcLDL for 24h. AcLDL loaded DBA/2 vs. AKR cells exhibited a 40 to 50% decrease in lysosome number as measured by staining cells with Lysotracker or an anti-Lamp1 antibody, respectively. Lysosomal degradation capacity was assayed by cell incubation with Alexa647-DQ-ovalbumin, and we observed that AcLDL loading led to a 15% decrease in lysosomal capacity in DBA/2 foam cells (p<0.001) while it had no effect in AKR cells. Also, unloaded and loaded AKR cells had higher degradation capacity than DBA/2 cells (31% and 43%, respectively, p<0.001) which couldn’t be explained by a change in lysosomal pH. As the transcription factor TFEB is a key regulator for lysosome biogenesis and function, we analyzed TFEB protein expression by western blot. Upon loading, TFEB was increased in AKR (48%) but not DBA/2 cells leading to a 45% higher TFEB level in AKR vs. DBA/2 foam cells (p<0.05). AKR and DBA/2 macrophages were labeled with a TFEB antibody and the nucleus to cytoplasm fluorescence intensity ratio was assessed. AcLDL loading led to a 37% increase in TFEB nuclear localization in AKR foam cells vs. unloaded cells (p<0.001) with no effect in DBA/2 macrophages. These results were confirmed by western blot after cellular fractionation. In conclusion, we found that DBA/2 vs. AKR foam cells have altered TFEB processing that may explain decreased lysosome number and function and impaired autolysosome formation in DBA/2 cells.

Sonocatalytic rapid degradation of Congo red dye from aqueous solution using magnetic Fe0/polyaniline nanofibers

Nano-sized magnetic Fe0/polyaniline (Fe0/PANI) nanofibers were used as an effective material for sonocatalytic degradation of organic anionic Congo red (CR) dye. Fe0/PANI, was synthesized via reductive deposition of nano-Fe0 onto the PANI nanofibers at room temperature. Prepared catalyst was characterized using HR-TEM, FE-SEM, XRD, FTIR instruments. The efficacy of catalyst in removing CR was assessed colorimetrically using UV–visible spectroscopy under different experimental conditions such as % of Fe0 loading into the composite material, solution pH, initial concentration of dye, catalyst dosage, temperature and ultrasonic power. The optimum conditions for sonocatalytic degradation of CR were obtained at catalyst concentrations=500mg.L−1, concentration of CR=200ppm, solution pH=neutral (7.0), temperature=30°C, % of Fe0 loading=30% and 500W ultrasonic power. The experimental results showed that ultrasonic process could remove 98% of Congo red within 30min with higher Qmax value (Qmax=446.4 at 25°C). The rate of degradation of CR dye was much faster in this ultrasonic technique rather than conventional adsorption process. The degradation efficiency declined with the addition of common inorganic salts (NaCl, Na2CO3, Na2SO4 and Na3PO4). The rate of degradation suppressed more with increasing salt concentration. Kinetic and isotherm studies indicated that the degradation of CR provides pseudo-second order rate kinetic and Langmuir isotherm model compared to all other models tested. The excellent high degradation capacity of Fe0/PANI under ultrasonic irradiation can be explained on the basis of the formation of active hydroxyl radicals (OH) and subsequently a series of free radical reactions.

Dynamics of Microbial Functional Groups in Rhizosphere of Spring Barley

Plant rhizosphere is the portion of soil which is in direct contact with the plant roots. From the microbiological point of view, this area is characterized by strong dynamic of functional groups with high specificity towards the substrate available. Spring barley is a crop with high requirements to the composition of the microflora in the rhizosphere, disturbances produced by agronomic inputs affecting the stability of rhizospheric contact interfaces and ultimately the plant growth. Analysis of changes within the microbial community was carried out with the purpose of defining the disruptive impact of mineral inputs and potential of zeolite to reduce these disruptions. Microbial functional groups were analyzed on the basis of the CO2 export under the specific conditions of soil inoculation on specific substrates over a time period of incubation. Microresp detection plates allow evaluation of a large number of samples under identical conditions of inoculation and the establishment of dynamics of the entire microbial community. The dynamics of the entire microbial communities (basal respiration) is stimulated to increase in case of unilateral application of zeolite and zeolite as a buffer for urea fertilization. General growth trend of microbial communities follows proportional the associated application of zeolite with urea, the most powerful non-symbiotic nitrogen fixation processes being stimulated by this combination of fertilizers. Simultaneously, an increase in the dynamics of denitrifiers was observed, also the decomposition of lignin and cellulose and biological crust formation due to the proliferation of cyanobacteria. Rhizosphere of barley plants is characterized by the presence of actinomycetes as dominant in functional microbial community of all experimental variants analyzed with a high capacity for biological degradation and raised mineralization of organic matter.

Complete biodegradation of chlorpyrifos by engineered Pseudomonas putida cells expressing surface-immobilized laccases

The long-term abuse use of chlorpyrifos-like pesticides in agriculture and horticulture has resulted in significant soil or water contamination and a worldwide ecosystem threat. In this study, the ability of a solvent-tolerant bacterium, Pseudomonas putida MB285, with surface-displayed bacterial laccase, to biodegrade chlorpyrifos was investigated. The results of compositional analyses of the degraded products demonstrate that the engineered MB285 was capable of completely eliminating chlorpyrifos via direct biodegradation, as determined by high-performance liquid chromatography and gas chromatography-mass spectrometry assays. Two intermediate metabolites, namely 3,5,6-trichloro-2-pyridinol (TCP) and diethyl phosphate, were temporarily detectable, verifying the joint and stepwise degradation of chlorpyrifos by surface laccases and certain cellular enzymes, whereas the purified free laccase incompletely degraded chlorpyrifos into TCP. The degradation reaction can be conducted over a wide range of pH values (2–7) and temperatures (5–55 °C) without the need for Cu2+. Bioassays using Caenorhabditis elegans as an indicator organism demonstrated that the medium was completely detoxified of chlorpyrifos by degradation. Moreover, the engineered cells exhibited a high capacity of repeated degradation and good performance in continuous degradation cycles, as well as a high capacity to degrade real effluents containing chlorpyrifos. Therefore, the developed system exhibited a high degradation capacity and performance and constitutes an improved approach to address chlorpyrifos contamination in chlorpyrifos-remediation practice.