Sodium Phosphate Buffer Research Articles

PSXII-9 Effects of lauric acid- and hops-based products on select microbial populations of aerobically exposed silage

Abstract Air exposed silages can harbor spoilage and pathogenic microbes which can reduce the palatability, nutritive quality and microbial safety of these feedstuffs. Accordingly, effective, environmentally friendly interventions are sought to rescue the biological and economical value of spoiled silages. The objectives of this study were to test the effects of treating air exposed corn silage with LipoVital GL-45, a Berg + Schmidt GmbH & Co. KG (Hamburg, Germany) product containing 45% monoglyceride of lauric acid (mixed within a 50% di/triglyceride base) alone or mixed with either Chinook or Galena hops or with an experimental extract containing hops β-acids. All treatments were administered as a warm water spray to deliver 1.6% product to the silage on a dry matter basis. Silage samples collected after 24 h ambient incubation were serially diluted in 0.4 M sodium phosphate buffer (pH 6.4) and plated to 3M Petrifilm for enumeration of yeast and molds and total aerobes as well as to Rogosa SL for enumeration of lactic acid bacteria and streptococci. Fluid samples from sampled silage were also inoculated in 10-fold increments to triplicate sets of tubes containing anaerobically prepared Reinforced Clostridial agar supplemented cellobiose and xylose (0.05% wt/vol each) for most probable number enumeration of total anaerobes. Populations of presumptive spore-forming aerobes and anaerobes were measured as described above except inocula were heated to 80 oC for 10 min to kill vegetative cells. An analysis of variance (Statistix Analytical Software, Tallahassee, FL, USA) revealed no treatment effects on yeasts and mold populations (P > 0.05) after 24 h air exposure of the silage, with counts averaging (± SD) 5.0 ± 0.7 log10 CFU/g. Silage treated with combinations of LipoVital GL-45 with Galena hops or the β-acid extract had 0.8 to 0.9 log10 units fewer (P < 0.05) lactic acid bacteria after 24 h air exposure than untreated controls (7.4 ± 0.1 log10 CFU/g). Similarly, silage treated with the LipoVital GL-45/Galena hops combination had 0.6 to 0.7 log10 units fewer (P < 0.05) heat-sensitive and presumptive spore-forming aerobes after 24 h air exposure when compared with controls (5.5 ± 0.2 and 5.2 ± 0.2 log10 CFU/g, respectively). Conversely, most probable numbers of nonheated anaerobe populations were lower (P < 0.05) in silage treated with LipoVital GL-45 combined with the β-acid extract when compared with controls (8.6 ± 0.x and 9.9 ± 0.7 log10 cells/g) with all other treatments being similar to controls. Populations of presumptive spore-forming anaerobes in the air exposed silage were unaffected by treatments, averaging 8.3 ± 0.7 log10 cells/g. Results warrant further research to investigate whether optimized dosages and formulations of LipoVital GL-45, Galena hops and β-acid extracts may ultimately yield treatments to prevent spoilage of air-exposed silages.

Determination of solid-state acidity of lyophilized trehalose containing citrate, phosphate, and histidine buffers using UV/VIS diffuse reflectance and solid-state NMR spectroscopy

Changes in the protonation state of lyophilized proteins can impact structural integrity, chemical stability, and propensity to aggregate upon reconstitution. When a buffer is chosen, the freezing/drying process may result in dramatic changes in the protonation state of the protein due to ionization shift of the buffer. In order to determine whether protonation shifts are occurring, ionizable probes can be added to the formulation. Optical probes (dyes) have shown dramatic ionization changes in lyophilized products, but it is unclear whether the pH indicator is uniform throughout the matrix and whether the change in the pH indicator actually mirrors drug ionization changes. In solid-state NMR (SSNMR) spectroscopy, the chemical shift of the carbonyl carbon in carboxylic acids is very sensitive to the ionization state of the acid. Therefore, SSNMR can be used to measure ionization changes in a lyophilized matrix by employing a small quantity of an isotopically-labeled carboxylic acid species in the formulation. This paper compares the apparent pH of six trehalose-containing lyophilized buffer systems using SSNMR and UV-Vis diffuse reflectance spectroscopy (UVDRS). Both SSNMR and UVDRS results using two different ionization probes (butyric acid and bromocresol purple, respectively) showed little change in apparent acidity compared to the pre-lyophilized solution in a sodium citrate buffer, but a greater change was observed in potassium phosphate, sodium phosphate, and histidine buffers. While the trends between the two methods were similar, there were differences in the numerical values of equivalent pH (pHeq) observed between the two methods. The potential causes contributing to the differences are discussed.

Impact of mobile and stationary phases on siRNA duplex stability in liquid chromatography

Nucleic acid duplexes are typically analyzed in non-denaturing conditions. Melting temperature (Tm) is the property used to measure duplex stability; however, it is not known how the chromatographic conditions and mobile phase composition affect the duplex stability. We employed differential scanning calorimetry (DSC) method to measure the melting temperature of chemically modified silencing RNA duplex (21 base pairs, 0.15 mM duplex concentration) in mobile phases commonly used in reversed-phase, ion-pair reversed-phase, size exclusion and hydrophilic interaction chromatography. We investigated mobile phases consisting of ammonium acetate, alkylammonium ion-pairing reagents, alkali-ion chlorides, magnesium chloride, and additives including methanol, ethanol, acetonitrile and hexafluoroisopropanol. Increasing buffer concentration enhanced the duplex stability (Tm was 67.1 – 78.2 °C for 10–100 mM [Na+] concentration). The melting temperature decreases with the increase in cation size (70.2 °C in 10 mM [Li+], 68.1 °C in 10 mM [NH4+], 65.6 °C in 10 mM [Cs+], and 56.6 °C in 10 mM [triethylammonium+] solutions). Inclusion of 20 % of organic solvent in buffer reduced the melting temperature by 1–3 °C, and denaturation power increases in the order MeOH<EtOH<MeCN. Next, we investigated the RNA duplex melting using selected chromatographic techniques and within the 10–90 °C column temperature range. Melting temperature obtained with size exclusion chromatography in 25 mM sodium phosphate buffer was ∼ 70 °C, about 5 °C lower compared to DSC values. The apparent melting temperature for a reversed-phase chromatography experiment was < 10 °C for 10 mM ammonium acetate mobile phase with acetonitrile eluent. Ion-pair reversed-phase with 10 mM triethylamine, 100 mM hexafluoroisopropanol and MeCN as eluent yielded Tm 49.3–54.9 °C. Hydrophilic interaction chromatography experiments with 10 mM ammonium acetate and ∼ 50 % acetonitrile mobile phase showed high duplex stability (Tm ∼ 80 °C). The observed chromatographic Tm values suggest that the formation of an organic/aqueous solvent layer on the chromatographic sorbent surface affects the duplex stability more significantly than the composition of the mobile phase alone.

Validated green and white RP-HPLC method for the estimation of Zolmitriptan in marketed dosage form

To develop and validate a rapid, accurate, economical, effective and greenery RP-HPLC method for the determination of Zolmitriptan in tablet dosage form. RP-HPLC method was developed using Luna (C18) (4.6×250mm, 5μm) column and Sodium phosphate buffer (pH 4.7): Methanol [75: 25, v/v] was used as mobile phase at a flow rate of 1.0mL/min. The detection was carried out at 227nm. Further, eco-friendliness, productivity and performance of the optimized analytical method were assessed by green and white tools. The retention time of Zolmitriptan was found to be 3.25min with acceptable chromatographic parameters. The optimized RP-HPLC method was more eco-friendly, efficient, throughput and practicable than the reported methods as confirmed by AES, AGREE, GAPI and RGB tools. Further, the proposed analytical method showed all the validation parameters within the acceptance limit of ICH Q2 R1 guidelines. The linear regression analysis indicated a good linear response in the 10 to 120μg/mL concentration range with R2 of 0.99998. The percentage content and percentage assay of Zolmitriptan in Zomig-5mg tablet was found to be 103.36±0.356% and 97.86±0.693%. The developed and validated method has several advantages compared to the reported HPLC methods and is useful in the systematic analysis of Zolmitriptan in its dosage form.

First report of Triticum mosaic virus infecting oat crop in the United States.

Triticum mosaic virus (TriMV, genus Poacevirus, family Potyviridae) was first reported in 2006 (Seifers et al. 2008) to infect wheat, and since then, it has been established as a constraint for US wheat production (Byamukama et al. 2013). In the field, TriMV often exists as a coinfection with wheat streak mosaic virus (WSMV), and these two viruses interact synergistically to produce severe symptoms and greater yield loss (Byamukama et al. 2012; Tatineni et al. 2022). Both TriMV and WSMV are transmitted by wheat curl mites (Aceria tosichella Keifer) (McMechan et al. 2014). Wheat is the primary host reported for TriMV in the field, but Seifers et al. (2010) established oat, rye, barley, and several other cereals and grasses as hosts under controlled conditions. However, there are no documented cases of TriMV infecting oats in the field. Between 10-25 June, 2023, a total of 273 field oat plants showing foliar yellowing, yellow flecking, and streaking symptoms were collected from four different fields in Nebraska (Big Springs: 41.1029° N, 102.1451° W; Mead: 41.2292° N, 96.4938° W; Odell: 40.0459° N, 96.7984° W; Stumf: 40.5048° N, 101.4223° W). Total RNA was extracted using the MagMax Plant RNA Isolation kit (Thermo Fisher Scientific) and the KingFisher Flex Magnetic Particle Processor (Thermo Fisher Scientific) (Mondal et al. 2023). Sample RNA was assayed with a single-step multiplex reverse transcription polymerase chain reaction (RT-PCR) to determine presence of WSMV and TriMV. Out of 273 symptomatic oat plants, 254 (93.04%) tested positive for at least one virus. Out of total positive samples, 238 were positive for WSMV (93.70 %), 12 plants tested positive for both TriMV and WSMV (4.70%), and 4 plants were infected with TriMV alone (1.60%). As a secondary confirmation, amplified fragments from the TriMV single infection were gel purified using a gel extraction kit (QIAquick) and sequenced (Eurofins Genomics). The nucleotide sequences were analysed using the BlastN program, compiled, and edited in the BioEdit software (Hall 1999). Sequences were deposited in the NCBI GenBank database (accession number PP475806). Nucleotide BLAST searches of the target coat protein (CP) gene showed > 98% identity to the corresponding sequences in TriMV accession MK318274. For further validation, virus inoculum was prepared by grinding field-collected plant material from plants with only TriMV present in 20 mM sodium phosphate buffer, pH 7.0, and then mechanically inoculating two-week-old oats (cv. Shaw n=8) and wheat (cv. Sattler, n=8) plants. Three weeks post-inoculation, all the eight wheat plants exhibited mild yellowing and streaking symptoms, while oat plants did not show obvious foliar symptoms. All wheat and oat plants were further tested positive with DAC-ELISA (antibodies produced against TriMV CP at the USDA-ARS facility in Lincoln, NE) and with RT-PCR. The specific attribution of these symptoms to TriMV in oats is not possible as none produced prominent symptoms. Asymptomatic oat infection from symptomatic field-collected oat samples could be due to oat cultivar differences. Although the prevalence of TriMV in wheat has been established across the Great Plains of the United States, to our knowledge, this is the first report of TriMV infection in US oat fields. Our finding warrant further investigation into the incidence and impact of the virus in oat crop and its potential for serving as a asymptomatic virus reservoir.

Enhancement of growth media for extreme iron limitation in Escherichia coli.

Iron is an essential nutrient for microbial growth and bacteria have evolved numerous routes to solubilize and scavenge this biometal, which is often present at very low concentrations in host tissue. We recently used a MOPS-based medium to induce iron limitation in Escherichia coli K-12 during the characterization of novel siderophore-conjugated antibiotics. In this study we confirm that growth media derived from commercially available M9 salts are unsuitable for studies of iron-limited growth, probably through the contamination of the sodium phosphate buffer components with over 100 µM iron. In contrast, MOPS-based media that are treated with metal-binding Chelex resin allow the free iron concentration to be reduced to growth-limiting levels. Despite these measures a small amount of E. coli growth is still observed in these iron-depleted media. By growing E. coli in conditions that theoretically increase the demand for iron-dependent enzymes, namely by replacing the glucose carbon source for acetate and by switching to a microaerobic atmosphere, we can reduce background growth even further. Finally, we demonstrate that by adding an exogeneous siderophore to the growth media which is poorly used by E. coli, we can completely prevent growth, perhaps mimicking the situation in host tissue. In conclusion, this short study provides practical experimental insight into low iron media and how to augment the growth conditions of E. coli for extreme iron-limited growth.

Comparing Conventional and Modern Methods for The Phycocyanin Extraction from Spirullina sp

Spirulina platensis, a blue-green algae abundant in tropical regions, is rich in minerals, vitamins, fibers, and pigments, with low nucleic acid content. It has unique chromoproteins called phycobiliproteins, notably phycocyanin, used in various applications. This study aims to optimize phycocyanin extraction using different solvents (distilled water and sodium phosphate buffer pH 6.7) and methods (freeze-thaw and sonication). Spirulina platensis biomass was extracted in both solvents, then some of them was freeze for 24 and 48 hours followed by thawing overnight. The other was sonicated for 2.5 minutes, 50 Hz then soaked for 1, 2, and 3 hours. All of the samples were centrifuged at 6000 rpm for 10 minutes and the absorbance was measured using a UV-Vis spectrophotometer at wavelengths of 280, 620, and 650 nm. with freeze-thawing for 48 hours yielded the highest phycocyanin concentration (0.55%), with a yield of 11.07 and purity of 0.21. Sonication improved phycocyanin concentration, yield, and purity significantly, yielding 1.108, 25.85, and 0.26, respectively.

RP-HPLC Method Development and Validation for Simultaneous Determination of Sofosbuvir and Ledipasvir: A Pharmaceutical Application Study

The objective of the present work was to develop a simple, precise, accurate, reproducible, and specific reversed-phase high performance liquid chromatographic method for the simultaneous determination of sofosbuvir and ledipasvir in pharmaceutical dosage form. The HPLC system (Shimadzu, LC-2030) consisted of Hypersil ODS - C18 (250 mm, 4.6 mm, 5 μm- Thermo Scientific) was used for the isocratic elution using mobile phase composed of sodium phosphate buffer (pH 3.5) and acetonitrile in the ratio of 40:60% (v/v). Both sofosbuvir and ledipasvir were detected at 260 nm with a flow rate of 1 mL/min. The mean retention time of sofosbuvir was 3.094, whereas ledipasvir was 6.22 minutes. A linear relationship was found in the concentration ranged from 0.54 to 162 μg/mL for sofosbuvir (r2 = 0.9993) and 0.14 to 42 μg/mL for ledipasvir (r2 = 0.9994). The RSD values for recovery test were found 0.99% for sofosbuvir and 0.22% for ledipasvir. The lower limit of detection (LOD) were 0.054 mcg/mL and 0.012 mcg/mL, and the limit of quantification (LOQ) were 0.135 mcg/mL and 0.030 mcg/mL for sofosbuvir and ledipasvir, respectively. The method was successfully applied to the assay and in-vitro dissolution studies of sofosbuvir and ledipasvir in tablet dosage form and all the results were found within the acceptance limits.

Determination of the Nucleic Acid Constituents in Edible Mushrooms by High-Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD)

Nucleosides and nucleobases in edible mushrooms collected from the Tekirdağ region of Turkey were determined by high performance liquid chromatography (HPLC). Separation of compounds was accomplished by gradient elution on a C18 column. A mixture of methanol (MeOH):50 mM sodium phosphate buffer (1:99, v/v) at pH 3.70 and methanol:50 mM sodium phosphate buffer (20:80) at pH 6.20 was used as the solvent. Two methods were used to treat the lyophilized mushrooms: ultrasound-assisted solid-liquid extraction (US-SLE) and pressurized (accelerated) solid-liquid extraction (PSLE). Deionized water was used as the extraction solvent. The extraction temperature and time were optimized. Fourteen nucleosides and nucleobases were simultaneously monitored at 254 nm within 25 min. Ultrasound-assisted solid-liquid was demonstrated to be more effective, perhaps because the pressurized liquid extraction system is a closed system and the matrix-solvent interaction may be insufficient. Adenosine, guanosine and uridine were the most abundant compounds in all studied mushrooms.

β-galactosidase immobilization on ceramic ultrafiltration membrane for simultaneous lactose hydrolysis and protein separation

Protein and lactose of cheese whey can be separated using ultrafiltration membranes and lactose can be hydrolyzed by β-galactosidase. This study investigated the integration of ultrafiltration and enzymatic hydrolysis for simultaneous protein concentration and lactose hydrolysis. β-galactosidase was immobilized on ceramic membrane via surface activation with gelatin and subsequent enzyme cross-linking with glutaraldehyde. Membrane geometries, buffer types, gelatin and enzyme concentrations were optimized. The optimal results yielded a 63 % enzyme immobilization efficiency and a 93 % lactose hydrolysis rate by using disc membrane, sodium acetate buffer (pH 4.8), sodium phosphate buffer (pH 7.5), 0.1 g/L gelatin concentration, and 5.0 g/L enzyme concentration. The optimized enzymatic membrane was evaluated with synthetic and real whey. In synthetic whey, 85 % lactose hydrolysis and 89 % protein rejection were achieved. While in real whey, 72 % lactose hydrolysis and 83 % protein recovery were obtained. This approach offers a single-step, efficient, and scalable method for whey valorization with potential for industrial applications.

Formation of left-handed helices by C2'-fluorinated nucleic acids under physiological salt conditions.

Recent findings in cell biology have rekindled interest in Z-DNA, the left-handed helical form of DNA. We report here that two minimally modified nucleosides, 2'F-araC and 2'F-riboG, induce the formation of the Z-form under low ionic strength. We show that oligomers entirely made of these two nucleosides exclusively produce left-handed duplexes that bind to the Zα domain of ADAR1. The effect of the two nucleotides is so dramatic that Z-form duplexes are the only species observed in 10 mM sodium phosphate buffer and neutral pH, and no B-form is observed at any temperature. Hence, in contrast to other studies reporting formation of Z/B-form equilibria by a preference for purine glycosidic angles in syn, our NMR and computational work revealed that sequential 2'F…H2N and intramolecular 3'H…N3' interactions stabilize the left-handed helix. The equilibriumbetween B- and Z- forms is slow in the 19F NMR time scale (≥ms), and each conformation exhibited unprecedented chemical shift differences in the 19F signals. This observation led to a reliable estimation of the relative population of B and Z species and enabled us to monitor B-Z transitions under different conditions. The unique features of 2'F-modified DNA should thus be a valuable addition to existing techniques for specific detection of new Z-binding proteins and ligands.

Electrolyte‐gated organic field‐effect transistors with high operational stability and lifetime in practical electrolytes

AbstractA key component of organic bioelectronics is electrolyte‐gated organic field‐effect transistors (EG‐OFETs), which have recently been used as sensors to demonstrate label‐free, single‐molecule detection. However, these devices exhibit limited stability when operated in direct contact with aqueous electrolytes. Ultrahigh stability is demonstrated to be achievable through the utilization of a systematic multifactorial approach in this study. EG‐OFETs with operational stability and lifetime several orders of magnitude higher than the state of the art have been fabricated by carefully controlling a set of intricate stability‐limiting factors, including contamination and corrosion. The indacenodithiophene‐co‐benzothiadiazole (IDTBT) EG‐OFETs exhibit operational stability that exceeds 900 min in a variety of widely used electrolytes, with an overall lifetime exceeding 2 months in ultrapure water and 1 month in various electrolytes. The devices were not affected by electrical stress‐induced trap states and can remain stable even in voltage ranges where electrochemical doping occurs. To validate the applicability of our stabilized device for biosensing applications, the reliable detection of the protein lysozyme in ultrapure water and in a physiological sodium phosphate buffer solution for 1500 min was demonstrated. The results show that polymer‐based EG‐OFETs are a viable architecture not only for short‐term but also for long‐term biosensing applications.

Interaction of Lyophilic Zinc(II) Porphyrins with Bovine Serum Albumin

Palladium-catalyzed heterylation of monobromophenyl-substituted zinc(II) porphyrin with small heterocycles (benzothiazole, benzoxazole, and N-methylbenzimidazole) was carried out. As a result, unsymmetrical heterylphenyl-substituted zinc(II) porphyrins soluble in organic solvents were obtained. The interaction of heteryl-substituted zinc(II) porphyrins with alpha-helical proteins was studied by spectral methods using bovine serum albumin in aqueous organic solvents. It was found that the titration of the zinc(II) porphyrins with albumin in a sodium phosphate buffer involves a number of equilibria including complexation and aggregation. In the case of porphyrins containing N-methylbenzimidazole and benzoxazole residues, self-aggregation processes initiated by absorption of organic solvent molecules by the protein predominate. It was found that more hydrophobic nature of zinc(II) porphyrin with benzothiazole residue promotes the complex formation with the protein. The photochemical properties of zinc(II) porphyrin with a benzothiazole residue, capacity for the photooxidation of the alpha-helical protein, and the high affinity of protein to this porphyrin make it a promising candidate for the potential applicability for photodynamic inactivation.

Development and Validation of a Simple and Reliable HPLC-UV Method for Determining Gemcitabine Levels: Application in Pharmacokinetic Analysis.

Background and Objectives: Gemcitabine has been used to treat various solid cancers, including, since 1997, metastatic pancreatic cancer. Here, we developed an HPLC-UV method to determine serum gemcitabine levels and use it in pharmacokinetic studies. Materials and Methods: The analysis was performed after a single protein precipitation step on a reversed-phase column, isocratically eluted with sodium phosphate buffer and methanol. For the pharmacokinetic study, NOD/SCID mice received a single dose of gemcitabine at 100 mg/kg by either subcutaneous (SC) or intraperitoneal (IP) administration. Blood samples were collected at 5, 15, and 30 min and 1, 2, 4, and 6 h after the administration of gemcitabine for further analysis. Results: The duration of the analysis was ~12.5 min. The calibration curve was linear (r2 = 0.999) over the range of 1-400 μM. The mean recovery of GEM was 96.53% and the limit of detection was 0.166 μΜ. T1/2, Tmax, Cmax, AUC0-t, and clearance were 64.49 min, 5.00 min, 264.88 μmol/L, 9351.95 μmol/L*min, and 0.0103(mg)/(μmol/L)/min, respectively, for the SC administration. The corresponding values for the IP administration were 59.34 min, 5.00 min, 300.73 μmol/L, 8981.35 μmol/L*min and 0.0108(mg)/(μmol/L)/min (not statistically different from the SC administration). Conclusions: A simple, valid, sensitive, and inexpensive method for the measurement of gemcitabine in serum has been developed. This method may be useful for monitoring gemcitabine levels in cancer patients as part of therapeutic drug monitoring.

Probing Chemical Equilibrium in Frozen Sodium Phosphate Buffer Solution by 31P Solid-State NMR.

Phosphate buffers are crucial for cryopreservative stability in pharmaceuticals, food processing, biomedical sciences, and biology. However, their freeze concentrates lack quantitative characterization, especially regarding the physicochemical properties of phosphate salt species in equilibrium at subzero temperatures. This study employs 31P solid-state NMR (ssNMR) to analyze frozen sodium phosphate (NaP) solutions, providing insights into phase composition, ionic strength, and pH. For the first time, we have directly quantified phosphate species in frozen NaP buffer, including crystallized disodium phosphate dodecahydrate (Na2HPO4·12H2O) content and the concentrations of H2PO4- and HPO42- in the freeze concentrate. This enabled the calculation of the pH as well as the ionic strength in the freeze concentrate. Trehalose effectively mitigated pH shifts in buffer solutions by preventing the selective crystallization of salt, a spectroscopic phenomenon not previously observed experimentally.

Effect of the Oligosaccharid Fraction of Fusarium oxysporum f. sp. vasinfectum on the Activity of Phenolic Metabolism Enzymes in Cotton Leaves

The synthesis of secondary metabolites, notably phenolic compounds, is part of the plant's defense reactions. The enzymes of phenolic metabolism can constitute a parameter of measurement of the defense of the plants. The aim of this work is to evaluate the activity of phenolic metabolism enzymes and an antioxidant enzyme after treatment of cotton plants with a fungal elicitor. Cotton plants obtained from the cultivar Y764AG3 were treated with the oligosaccharide fraction (FOS) of Fusarium oxysporum f. sp. Vasinfectum (FOV). The extraction of the enzymes is carried out cold by grinding the leaves in extraction buffer in the presence of PVP (0.5 %) and 0.1 M sodium phosphate buffer. The supernatant obtained after centrifugation of the filtrate was purified with Dowex-2 in order to obtain the purified enzymatic fraction. This fraction was used for the determination of enzyme activity by reading the absorbances. The results showed that the activity of ammonia-lyase activity was higher in the treated plants than in the control. This reflects an increase in the biosynthesis of phenolic compounds in the treated plants. On the other hand, oxidoreductase activity was higher in control plants than in treated plants. This indicates a decrease in the degradation of phenolic compounds in the treated plants. This study revealed the existence of an active phenolic metabolism in the FOS-treated plants. Thus defence mechanisms are activated in plants treated with the oligosaccharide fraction of Fusarium oxysporum f. sp. Vasinfectum.

Identification and characterization of a PL35 GAGs lyase with 4-O-sulfated N-acetylgalactosamine (A-type)-rich structures producing property

Glycosaminoglycan (GAG) lyases are important tools for investigating the structure of GAGs and preparing low-molecular-weight GAGs. The PL35 family, a recently established polysaccharide lyase family, should be further investigated. In this study, we discovered a new GAG lyase, CHa1, which belongs to the PL35 family. When expressed heterologously in Escherichia coli (BL21), CHa1 exhibited high expression levels and solubility. The optimal activity was observed in Tris-HCl buffer (pH 7.0) or sodium phosphate buffer (pH 8.0) at 30 °C. The specific activities towards HA, CSA, CSC, CSD, CSE, and HS were 3.81, 13.03, 36.47, 18.46, 6.46, and 0.50 U/mg protein, respectively. CHa1 digests substrate chains randomly that acting as an endolytic lyase and shows a significant preference for GlcA-containing structures, prefers larger oligosaccharides (≥UDP8) and can generate a series of oligosaccharides composed mainly of the A unit when digesting CSA. These oligosaccharides include ΔC-A, ΔC-A-A, ΔC-A-A-A, ΔC-A-A-A-A, and ΔC-A-A-A-A-A. The residues Tyr257 and His421 play crucial roles in the catalytic process, and Ser211, Asn212, Asn213, Trp214, Gln216, Lys360, Arg460 and Gln462 may participate in the binding process of CHa1. This study on CHa1 contributes to our understanding of the PL35 family and provides valuable tools for investigating the structure of GAGs.

Using isopropanol as the hydrogen donor to achieve by-product-free biological hydrogenation in water with carbonyl reductase

In this study, the reaction equilibrium was broken using isopropanol as a co-substrate, which was different from previous glucose as a co-substrate for furfural reduction, solving the problems of many by-products, low selectivity, and the addition of sodium phosphate buffers. The volatility of isopropanol and acetone prevented the production of by-products to the reaction system, improving the conversion and selectivity. 10 g/L furfural could be converted into furfuryl alcohol in pure water, and the furfural conversion was 90%, furfuryl alcohol selectivity was 100%, and the concentration of furfuryl alcohol could reach more than 20 g/L through accumulation reaction. No by-products were produced in this reaction system, and a single furfuryl alcohol product was obtained in the water catalytic system, which was convenient for downstream separation and purification. At the same time, based on the theory of the NADH coenzyme cycle system, this catalytic method could complete the conversion of various aldehydes into the corresponding alcohols, and it could be expanded to various biological hydrogenation projects, which has important industrial development and production prospects.

Cadmium Toxicity Induced Changes on Antioxidative Enzymes Level in Fresh Water Catfish Channa Punctatus (Bloch)

Aquatic ecosystem of India is being affected by various heavy metals. In present, cadmium contamination in aquatic organism as well as its accumulation in food chain has become a global environmental concern. Cadmium exposure to fishes alter the various enzymatic and histopathologic profiles. Such alteration can be act as a bioindicator for aquatic environment. The present study has been planned to observe the effect of cadmium chloride on commercially important fish _Channa punctatus _(body weight 27.04±0.19 g and length 16.7±0.20 cm). For Invitro assessment of cadmium effect in term of enzymatic and nonenzymatic assay have been done. Fishes were acclimatized and treated separately with different concentration of CdCl2. Dissected out the liver and homogenized in 0.1 M sodium phosphate buffer (pH 7.4). Biochemical analysis was done for lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and protein estimation. The results were shown as mean and standard error (Mean± SEM). The analysis of variance (ANOVA) was analysed and significantly applied for the Dunnett test for multiple comparison of groups against the control which determine the significant differences among the groups. This study is for academic importance and will provide valuable information regarding cadmium toxicity. At the same time, it will address the public health issue as for as consumption of the fishes from contaminated water is concerned.

Cadmium Toxicity-Induced Changes in Antioxidative Enzyme Levels in Freshwater Catfish Channa Punctatus (Bloch)

Present study has been planned to observe the effect of Cadmium chloride on the locally available economically important edible fish _Channa punctatus _(body weight 27.04±0.19 g and length 16.7±0.20 cm). To assess the effect of cadmium in terms of enzymatic and non-enzymatic assays, laboratory studies have been done. Fish were acclimatized and treated separately with concentrations of 35 mg/L and 70 mg/L of CdCl2. The livers were dissected out and homogenized in 0.1 M sodium phosphate buffer (pH 7.4). Biochemical analyses were done for lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and protein estimations. The results were shown as mean and standard error (Mean ± SEM). The analyses of variance (ANOVAs) were analysed and significantly applied for the Dunnett test for multiple comparisons of groups against the control, which determined the significant differences among the groups. This study is of academic importance and will provide valuable information regarding cadmium toxicity. At the same time, it will address the public health issue as far as consumption of fishes from contaminated water is concerned.