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关键词： beta-glucosidase   Anoxybacillus thermarum   Glucose tolerance   Xylose tolerance  

摘要： The enzymatic lignocellulosic biomass conversion into value-added products requires the use of enzyme-rich cocktails, including beta-glucosidases that hydrolyze cellobiose and cellooligosaccharides to glucose. During hydrolysis occurs accumulation of monomers causing inhibition of some enzymes;thus, glucose/xylose tolerant beta-glucosidases could overcome this drawback. The search of new tolerant enzymes showing additional properties, such as high activity, wide-pH range, and thermal stability is very relevant to improve the bioprocess. We describe a novel beta-glucosidase GH1 from the thermophilic Anoxybacillus thermarum (BgAt), which stood out by the robustness combination of great glucose/xylose tolerance, thermal stability, and high Vmax. The recombinant his-tagged-BgAt was overexpressed in Escherichia coli, was purified in one step, showed a high glucose/xylose tolerance, and activity stimulation (presence of 0.4 M glucose/1.0 M xylose). The optimal activity was at 65 degrees C - pH 7.0. BgAt presented an extraordinary temperature stability (48 h - 50 degrees C), and pH stability (5.5-8.0). The novel enzyme showed outstanding Vmax values compared to other beta-glucosidases. Using p-nitrophenyl-beta-D-glucopyranoside as substrate the values were Vmax (7614 U/mg), and KM (0.360 mM). These values suffer a displacement in Vmax to 14,026 U/mg (glucose), 14,886 U/mg (xylose), and KM 0.877 mM (glucose), and 1.410 mM (xylose).

关键词： Peziza sp   Lipolytic enzymes   Oleaginous strain  

摘要： The present study investigates the biochemical characterization of an extracellular (phospho)lipase from a wood fungus Peziza sp. (medium optimization, inducer concentration and substrate specificity measurements). The strain was identified on the basis of ITS1/ITS4 primers. A 604 bp fragment was amplified by PCR and the obtained nucleotide sequence, showed 99% identity with the ITS region of isolates named as Peziza sp. Interestingly, Peziza sp. has both lipase and phospholipase activities with the same level which require both the presence of Ca2+ and bile salts. Our result shows that the lipase hydrolyzes preferably the olive oil at 45 degrees C, pH 8. Whereas, the phospholipase activity was detected on pure PC at 45 degrees C, pH 9. Lipid extraction from dry biomass using chloroform/methanol (2/1) and quantitative measurement using electron microscope showed that intracellular triglycerides content was significantly high and reaches 20.88%. Gas chromatography analysis shows a majority of C18:1 (76, 98%) and C18:2 (9, 33%). Whereas, saturated fatty acids ranging C16-C20 represent only 11.5% of total lipids composition. [GRAPHICS] .

关键词： Plasmonic sensor   Metal-insulator-metal waveguide   Finite element method   Nanodots   High sensitivity  

摘要： Plasmonic chemical and biological sensors have many advantages such as compact sizes and extremely high sensitivity. Biosensors based on plasmonic waveguides and resonators are one of the most attractive candidates for mobile and portable devices. In this work, we proposed a metal-insulator-metal waveguide semi-ring reso-nator loaded with nanodots periodically decorated in the cavity. The spectral characteristics of the sensor designs are studied via the finite element method. For comparison purpose, a standard semi-ring resonator of equivalent geometric parameters is also studied. It has been shown that the sensitivity of the proposed sensor design can be significantly increased by decorating nanodots in the cavity which allows the sensitivity to reach a value of 1084.21 nm/RIU. With these excellent properties, this chip-scale MIM design is believed to be able to find potential applications in integrated photonic systems, such as optical sensing and optical networking fields.

关键词： Antioxidants   Bacillus sp   strain SDA-4   Bioremediation   Cadmium   Spinach   Nutrient physiology  

摘要： Cadmium (Cd) is highly toxic metal for plant metabolic processes even in low concentration due to its longer half-life and non-biodegradable nature. The current study was designed to assess the bioremediation potential of a Cd-tolerant phytobeneficial bacterial strain Bacillus sp. SDA-4, isolated, characterized and identified from Chakera wastewater reservoir, Faisalabad, Pakistan, together with spinach (as a test plant) under different Cd regimes. Spinach plants were grown with and without Bacillus sp. SDA-4 inoculation in pots filled with 0, 5 or 10 mg kg(-1) CdCl2-spiked soil. Without Bacillus sp. SDA-4 inoculation, spinach plants exhibited reduction in biomass accumulation, antioxidative enzymes and nutrient retention. However, plants inoculated with Bacillus sp. SDA-4 revealed significantly augmented growth, biomass accumulation and efficiency of antioxidative machinery with concomitant reduction in proline and MDA contents under Cd stress. Furthermore, application of Bacillus sp. SDA-4 assisted the Cd-stressed plants to sustain optimal levels of essential nutrients (N, P, K, Ca and Mg). It was inferred that the characterized Cd-tolerant PGPR strain, Bacillus sp. SDA-4 has a potential to reduce Cd uptake and lipid peroxidation which in turn maintained the optimum balance of nutrients and augmented the growth of Cd-stressed spinach. Analysis of bioconcentration factor (BCF) and translocation factor (TF) revealed that Bacillus sp. SDA-4 inoculation with spinach sequestered Cd in rhizospheric zone. Research outcomes are important for understanding morpho-physio-biochemical attributes of spinach-Bacillus sp. SDA-4 synergy which might provide efficient strategies to decrease Cd retention in edible plants and/or bioremediation of Cd polluted soil colloids.

关键词： Inorganic pyrophosphate   Enzymatic method   Biochemical automated analyzer   Nucleic acid sequence-based amplification   Nitroso-PSAP  

摘要： Background and aims: Polymerase chain reaction-based techniques require expensive equipment for fluorescence detection of the products. However, the measurement of inorganic pyrophosphate (PPi) released during DNA synthesis can be used to quantify target genes without such equipment. Here, we devised a high-sensitivity enzymatic assay for detection of PPi. Materials and methods: In our assay method, PPi was converted to hypoxanthine by hypoxanthine phosphoribosyl transferase. Xanthine dehydrogenase converted the hypoxanthine to uric acid and yielded two molecules of NADH, which in turn reduced Fe3+ to Fe2+ (mediated by 1-methoxy-5-ethylphenazinium ethylsulfate). 2Nitroso-5-(N-propyl-N-sulfopropylamino) phenol chelated the Fe2+, which resulted in an intensely colored product that could be measured using a biochemical automated analyzer. Results: The assay was able to detect PPi within 10 min. It was linear between 0 and 10 mu mol/L PPi, and intrarun and inter-run coefficients of variation were 1%-2%. Other validation tests with a biochemical automated analyzer were satisfactory. The assay could potentially be used to directly quantify samples after isothermal nucleic acid sequence-based amplification of a target gene. Conclusion: The method developed here for detection of PPi can be used to measure nucleic acid biomarkers in biological samples in clinical practice using a high-throughput biochemical automated analyzer.

关键词： Lu(2)O(3 )nanoparticles   iPSMA peptide   (Lu2O3)-Lu-177-iPSMA nanoparticles   Radioluminescence   Targeted radiotherapy  

摘要： Among the nanomaterials, rare sesquioxides (lanthanide oxides such as Lu2O3) are of interest due to their adequate thermal conductivity, excellent chemical stability, and high light output. The prostate-specific membrane antigen (PSMA) is an integral multifunctional protein overexpressed in various types of cancer cells. The radiolabeled PSMA inhibitor peptides (iPSMA) have demonstrated their usefulness as specific probes in the treatment and detection of a wide variety of neoplasms, mainly due to their high in vivo recognition by the PSMA protein. The objective of this research was to synthesize Lu2O3-iPSMA nanoparticles (NPs) and characterize their physicochemical properties before and after neutron activation, as well as to assess their biodistribution profile and in vitro potential to target cells overexpressing PSMA. The Lu2O3 NPs were synthesized by the precipitation-calcination method and conjugated to the iPSMA peptide using DOTA (1,4,7,10-tetraazocyclodecaneN,N',N '',N'"-tetraacetic acid) as a linking agent. Results of the physicochemical characterization by FT-IR and UV-Vis spectroscopies, SEM, TEM, DLS, HRTEM, SAED, DSC-TGA, and X-ray diffraction indicated the formation of Lu2O3-iPSMA NPs (diameter of 29.98 +/- 9.07 nm), which were not affected in their physicochemical properties after neutron activation. (Lu2O3)-Lu-177-iPSMA NPs showed high affinity (K-d = 5.7 +/- 1.9 nM) for the PSMA protein, evaluated by the saturation assay on HepG2 hepatocellular carcinoma cells (PSMA-positive). The biodistribution profile of the nanosystem in healthy mice showed the main uptake in the liver. After irradiation, radioactive Lu2O3-iPSMA NPs exhibited radioluminescent properties, making the in vivo acquisition of their biodistribution, via optical imaging, possible. The results obtained from this research validate the execution of additional preclinical studies with the objective of evaluating the potential of the (Lu2O3)-Lu-177-iPSMA NPs for the targeted radiotherapy a

关键词： Eremomastax speciosa   Immature female rats   Infertility   PMSG   Potentialization  

摘要： The present study evaluated the effect of the aqueous extract from leaves of E. speciosa on some physiological and biochemical parameters of reproduction and the onset of puberty in pregnant mare serum gonadotropin (PMSG)-primed immature female rats. High pressure liquid chromatography (HPLC) was used to quantify the phenolic compounds in the methanol/methylene chloride (1:1) extract, the ethanolic and ethyl acetate fractions and the aqueous residue of E. speciosa. E. speciosa (0, 8, 32 or 64 mg/kg) were administered for 15 days to 24 non-PMSG-primed and 24 primed rats with 0.01 IU of PMSG. At the end of the treatment period, animal were sacrificed and their body, ovarian, uterine weight, ovarian protein or cholesterol level, as well as data on puberty onset were recorded. Of the 16 polyphenolic compounds quantitatively revealed in the extracts and fractions of E. speciosa after HPLC analysis, quercetin, rutin, apigenin and eugenol were the most abundant. Non-primed rats showed a significant increase (P < 0.05) in the uterine relative weight at the dose of 8 mg/kg when compared with the other treatments. The uterine proteins and the ovarian cholesterol (P < 0.05), respectively, showed a reduction at doses of 64 mg/kg and 32 mg/kg in non-primed rats. However in PMSG-primed rats, a significant decrease (P < 0.05) was observed in ovarian cholesterol at 64 mg/kg. In conclusion, E. speciosa potentializes the PMSG-inducing effect on folliculogenesis in PMSG-primed rats.

关键词： electromagnetic field   honeybee   biochemical parameters   antioxidants   proteolytic system  

摘要： Two-day-old honeybee workers (+/- 6 h) were placed in cages and supplied with sucrose solution (1 mol/dm(3)) ad libitum. Subsequently, the cages with bees were placed in an electric field (E-field) exposure system with field intensities of 5.0 kV/m, 11.5 kV/m, 23 kV/m, and 34.5 kV/m. The duration of exposure was 1 h, 3 h, and 6 h. The biochemical parameters SOD (superoxide dismutase), CAT (catalase), FRAP (ferric ion reducing antioxidant power), and also acidic, neutral, and alkaline proteases in the worker bee hemolymph were analyzed. The E-field increased activities of antioxidant systems, especially SOD, and also the proteolytic systems. In the groups: 11.5 kV/m-time 6 h, 23.0 kV/m-time 1 h, and 34.5 kV/m-time 1 h, FRAP levels were decreased in comparison with the control samples. These findings are discussed in context with possible consequences for honeybee health in urban and rural environments.