A combined small‐angle X‐ray and neutron scattering study of the structure of purified soluble gastrointestinal mucins

The structures of purified soluble porcine gastric (Muc5ac) and duodenal (Muc2) mucin solutions at neutral and acidic pH were examined using small‐angle X‐ray scattering and small‐angle neutron scattering experiments. We provide evidence for the morphology of the network above the semidilute overlap concentration and above the entanglement concentration. Furthermore, we investigated the gelation of both types of mucin solutions in response to a reduction in pH, where we observed the formation of large‐scale heterogeneities within the polymer solutions, typical of microphase‐separated gels. The concentration dependence of the inhomogeneity length scale (Ξ) and the amplitude of the excess scattering intensity [I_ex(0)] are consistent with previously studied gelled synthetic polymeric systems. The persistence lengths of the chains were found to be similar for both Muc5ac and Muc2 from Kratky plots of the neutron data (8 ± 2 nm). © 2014 Wiley Periodicals, Inc. Biopolymers 101: 1154–1164, 2014.     

Double-stranded helix of xanthan: Rigidity in 0.01M aqueous sodium chloride containing 0.01 N hydrochloric acid

Six samples of Na xanthan in 0.01M aqueous NaCl containing 0.01 N HCl (pH = 2) were studied by light scattering and viscosity. This study was motivated by the finding that the intrinsic viscosity [η] fairly sharply decreased when the pH of the solvent was lowered from about 6 to 2 by adding HCl to 0.01M aqueous NaCl in which Na xanthan dissolves as rigid dimers having a double-helical structure. The data for weight-average molecular weight, radius of gyration, and [η] showed that Na xanthan at pH = 2 remains a dimer behaving as a semiflexible chain. Data analysis in terms of known theories for unperturbed wormlike chains yielded 0.47 ± 0.02, 2.0 ± 0.6, and 68 ± 7 nm for the contour length h per main-chain residue, diameter d, and persistence length q of the dimer, respectively. these h and d values agreed with the pitch per main-chain residue and the diameter of the double helix of Na xanthan in 0.01 or 0.1M aqueous NaCl. However, the q value, which was close to the intrinsic persistence length q₀ ( = q in the absence of electrostatic interaction) of Na xanthan at pH = 2, was much smaller than the q₀ (106 nm) of this helix. We concluded that the xanthan dimer at pH = 2 assumes a double-helical structure, which is geometrically the same as, but is more flexible than, that at neutral pH.     

Effects of supplementing the diets of Mugil liza Valenciennes, 1836 juveniles with citrus pectin

The aim of this study was to evaluate whether increasing the levels of citrus pectin has anti‐nutritional effects when included in the diets of Mugil liza juveniles, including its effects on hepatic metabolism and modulation of the microbial community. Fish (mean weight 0.38 g ± 0.01) were stocked at a density of 15 fishes per tank and fed for 60 days with either a control diet or one of three diets containing different levels of pectin (4, 8 and 12%), in triplicates. The temperature, dissolved oxygen, pH, salinity and alkalinity during the trial were, respectively, 25.0°C ± 0.1, 6.82 ± 0.02 mg L^?1, 8.10 ± 0.06 and 147 mg ± 12.93 CaCO₃. The total ammonia‐nitrogen (TAN) in PC4, PC8 and PC12 treatments were, respectively, 0.69 ± 0.38; 0.57 ± 0.35; 0.64 ± 0.39 and 0.45 ± 0.23 mg L^?1. The increasing diet viscosity with pectin inclusion did not cause significant differences in growth. Fish fed with pectin demonstrated a reduction in their percentage body dry matter, crude protein and ash. Hepatic glycogen levels were elevated in the group fed with 12% pectin, while there were no effects in cholesterol and triglycerides levels. Citrus pectin did not exert any modulatory effect on the microbial community. Although the pectin‐supplemented fish showed enteritis during the experimental period, this did not impair animal performance. However, the use of this polysaccharide as a binder in mullet (Mugil liza) diets for longer periods should be considered with caution.     

Sensitivity of organic matter decomposition to warming varies with its quality

The relationship between organic matter (OM) lability and temperature sensitivity is disputed, with recent observations suggesting that responses of relatively more resistant OM to increased temperature could be greater than, equivalent to, or less than responses of relatively more labile OM. This lack of clear understanding limits the ability to forecast carbon (C) cycle responses to temperature changes. Here, we derive a novel approach (denoted Q_10?q) that accounts for changes in OM quality during decomposition and use it to analyze data from three independent sources. Results from new laboratory soil incubations (labile Q_10?q=2.1 ± 0.2; more resistant Q_10?q=3.8 ± 0.3) and reanalysis of data from other soil incubations reported in the literature (labile Q_10?q=2.3; more resistant Q_10?q=3.3) demonstrate that temperature sensitivity of soil OM decomposition increases with decreasing soil OM lability. Analysis of data from a cross‐site, field litter bag decomposition study (labile Q_10?q=3.3 ± 0.2; resistant Q_10?q=4.9 ± 0.2) shows that litter OM follows the same pattern, with greater temperature sensitivity for more resistant litter OM. Furthermore, the initial response of cultivated soils, presumably containing less labile soil OM (Q_10?q=2.4 ± 0.3) was greater than that for undisturbed grassland soils (Q_10?q=1.7 ± 0.1). Soil C losses estimated using this approach will differ from previous estimates as a function of the magnitude of the temperature increase and the proportion of whole soil OM comprised of compounds sensitive to temperature over that temperature range. It is likely that increased temperature has already prompted release of significant amounts of C to the atmosphere as CO₂. Our results indicate that future losses of litter and soil C may be even greater than previously supposed.     

Eleven‐year Prevalence Trends of Obesity in Greek Children: First Evidence that Prevalence of Obesity Is Leveling Off

We examined 11‐year (1997–2007) trends in underweight, overweight, and obesity in Greek children. Population data derived from a yearly, school‐based health survey carried out between 1997 and 2007 in >80% of all Greek schools. Height and weight measurements from 651,582 children, aged 8–9 years (boys: 51.2%) were analyzed. The gender‐ and age‐specific BMI cutoff points by the International Obesity Task Force (IOTF) were used in order to define underweight, normal weight, overweight, and obesity. Trend analysis showed an increase in the prevalence of obesity from 7.2 ± 0.2% in 1997 to 11.3 ± 0.2% in 2004 for girls (P < 0.001) and from 8.1 ± 0.2% in 1997 to 12.3 ± 0.2% in 2004 for boys (P < 0.001). An apparent leveling off in obesity rates was observed during 2004–2007 for both boys and girls. The prevalence of overweight rose between 1997 and 2007 from 20.2 ± 0.2% to 26.7 ± 0.2% for girls (P < 0.001) and from 19.6 ± 0.2% to 26.5 ± 0.2% for boys (P < 0.001). The overall prevalence of thinness in the same period remained constant in both sexes. The presented population‐based data revealed that the prevalence of overweight and obesity among 8‐ to 9‐year‐old Greek children is alarmingly elevated, with the overweight rates rising continuously. However, an apparent leveling off in obesity rates for the past 4 consecutive years was documented for the first time in both genders.     

Influence of Physico-Chemical Factors on the Oligomerization and Biological Activity of Bacteriocin AS-48

Bacteriocin AS-48 forms a mixture of monomers and oligomers in aqueous solutions. Such oligomers can be clearly differentiated by SDS-PAGE after formaldehyde crosslinking, and we have verified that these associates are stable to acid treatment after fixation. In addition, they show antimicrobial activity and are recognized by anti-AS-48 antibodies. AS-48 oligomers can be dissociated by the detergents SDS and Triton X-100. The degree of oligomerization of AS-48 depends on the pH of the solution and the protein concentration. At pH below 5, AS-48 is in the monomeric state at protein concentrations below 0.55.mg ml⁻¹, but it also forms dimers above this protein concentration. This bacteriocin forms oligomers at pH values above 5, in agreement with the observation that it is also more hydrophobic at neutral pH. AS-48 is stable to mild heat treatments irrespectively of pH. At 120°C it is more heat resistant under acidic conditions, but it inactivates at neutral pH. Activity of AS-48 against E. faecalis is highest at neutral pH, but it is highest at pH 4 for E. coli. The influence of pH on bacteriocin activity could be owing to changes in the conformation/oligomerization of the bacteriocin peptide as well as to changes in the surface charge of the target bacteria. Received: 3 July 2000\t/\tAccepted: 11 August 2000     

Structure and mechanism of action of riboflavin-binding protein: Small-angle X-ray scattering,sedimentation, and circular dichroism studies on the holo- and apoproteins

Riboflavin-binding protein, a transport protein occurring in egg whites, binds riboflavin tightly at pH values above 4.5 but releases it readily at pH values below 4.0. Structural aspects of this biologically important binding were studied by several methods. Analysis of sedimentation equilibrium data gave an average molecular weight of 32,500 ± 1000 for all forms of the protein and showed the absence of changes in quaternary structure when riboflavin was bound at neutral pH or released at pH 3.7. Sedimentation velocity showed no change in tertiary structure on binding at pH 7.0 but revealed a significant change in sedimentation constant at pH 3.7. While circular dichroism showed no appreciable change in secondary structure, it gave evidence of a marked change in the aromatic region at the lower pH. Small-angle X-ray scattering, going from the holoprotein at neutral pH to the apoprotein at low pH, showed a small but significant increase in radius of gyration (19.8 ± 0.2 vs 20.6 ± 0.1 Å) with slightly decreased anisotropy and with substantial increases in molecular volume (55,600 ± 530 vs 66,500 ± 240 ų), surface (11,840 ± 120 vs 13,470 ± 140 Å), and hydration (0.27 ± 0.01 vs 0.38 ± 0.01 g H₂O/g dry protein). Hydration values were obtained from small-angle X-ray scattering in two different ways for comparison with those calculated from sedimentation coefficients by way of frictional coefficients (derived from two different dimensionless ratios based independently on the structural small-angle X-ray scattering data). For either form of the protein, the surface calculated from an ellipsoidal model could account for only about 62% of the surface found experimentally. The excess surface was ascribed to topographic features of the molecule. Relative changes in this new parameter, together with the circular dichroism data and the known association of riboflavin binding with aromatic residues, suggested the opening of an aromatic-rich cleft concomitant with the release of riboflavin as a consequence of lowered pH.     

Acid-induced unfolding of didecameric keyhole limpet hemocyanin: detection and characterizations of decameric and tetrameric intermediate states

Keyhole limpet hemocyanin (KLH) is widely used as an immune stimulant and hapten carrier derived from a marine mollusc Megathura crenulata. To provide details of the stability and equilibrium of KLH, different intermediate species were investigated with a series of biophysical techniques: circular dichroism, binding of hydrophobic dye, 1-anilino-8-naphthalene sulfonic acid, acrylamide-induced fluorescence quenching, thermal stability and dynamic light scattering. KLH in its native state at pH 7.4 exists in the stable didecameric form with hydrodynamic radii (R _h) of 28.22 nm, which is approximately equal to a molecular mass of 8.8 ± 0.6 MDa. The experimental results demonstrated the presence of two structurally distinct species in the conformational transition of KLH under acidic conditions. One species populates at pH 2.8, characterized as decameric (4.8 ± 0.2 MDa; R _h = 22.02 nm), molten globule-like state, while the other accumulates at pH 1.2 and is characterized as a tetramer (2.4 ± 0.8 MDa; R _h = 16.47 nm) with more organized secondary and tertiary structures. Our experimental manipulation of the oligomeric states of KLH has provided data that correlate well with the known oligomeric forms obtained from total KLH formed in vivo and extends our understanding of multimer formation by KLH. The results are of particular interest in light of the important role of the mechanistic pathway of pH-dependent structural changes of Hc stability in the biochemical and medical applications of these respiratory proteins.     

Toxicity of 2,3,5,6-tetrachlorophenol to willow trees (Salix viminalis)

Chlorinated phenols have been intensively investigated from an eco-toxicological point of view, however almost nothing is known about toxicity of tetrachlorophenol (TeCP) to higher terrestrial plants. This article applied the willow tree acute toxicity test to study the toxicity of 2,3,5,6-TeCP to willows Salix viminalis (S. viminalis) at neutral and acidic conditions (roughly pH 7 and 4) with inhibition of transpiration as toxic endpoint. At neutral pH the EC₅₀ was >10 mg L^?1 while the EC₅₀ at acidic conditions was 0.32 ± 0.17 mg L^?1, clearly indicating that toxicity is exerted by the non-ionic chemical fraction. Standard tests running at neutral pH are therefore not capturing the full toxicity of weak acids and bases.     

Evaluation of agomelatine stability under different stress conditions using an HPLC method with fluorescence detection: application to the analysis of tablets and human plasma

A simple and highly sensitive stability‐indicating HPLC method was developed and validated for the determination of the new antidepressant agent, agomelatine (AGM). Separation of AGM from its stress‐induced degradation products was achieved on a BDS Hypersil phenyl column (250 mm × 4.6 mm i.d., 5 µm particle size) using methanol–0.05 M phosphate buffer of pH 2.5 (35: 65, v/v) as a mobile phase with fluorescence detection at 230/370 nm. Naproxen was used as an internal standard. The method satisfied all the validation requirements, as evidenced by good linearity (correlation coefficient of 0.9999, over the concentration range 0.4–40.0 ng/mL), accuracy (recovery average 99.55 ± 0.90%), precision (intra‐day RSD 0.54–1.35% and inter‐day RSD 0.93–1.26%), robustness and specificity. The stability of AGM was investigated under different ICH recommended stress conditions including acidic, alkaline, neutral, oxidative and photolytic. AGM was found to be labile to acidic and alkaline degradation and a kinetic study was conducted to explore its degradation behavior. First‐order degradation rate constants and half‐life times were calculated in each case. The proposed method was applied for the determination of AGM in tablets and spiked human plasma with mean percentage recoveries of 99.87 ± 0.31 (n = 3) and 102.09 ± 5.01 (n = 5), respectively. Hence, the proposed method was successfully applied for the determination of AGM in human volunteer plasma. The results were compared statistically with those obtained by a comparison HPLC method revealing no significant differences between the two methods regarding accuracy and precision. Copyright © 2014 John Wiley & Sons, Ltd.     

Bcl‐xL overexpression does not enhance specific erythropoietin productivity of recombinant CHO cells grown at 33°C and 37°C

Overexpression of bcl‐xL in recombinant Chinese hamster ovary (rCHO) cells has been known to suppress apoptotic cell death and thereby extend culture longevity during batch culture. However, its effect on specific productivity (q) of rCHO cells is controversial. This study attempts to investigate the effect of bcl‐xL overexpression on q of rCHO cells producing erythropoietin (EPO). To regulate the bcl‐xL expression level, the Tet‐off system was introduced in rCHO cells producing EPO (EPO‐off‐bcl‐xL). The bcl‐xL expression level was tightly controlled by doxycycline concentration. To evaluate the effect of bcl‐xL overexpression on specific EPO productivity (q_EPO) at different levels, EPO‐off‐bcl‐xL cells were cultivated at the two different culture temperatures, 33°C and 37°C. The q_EPO at 33°C and 37°C in the presence of 100 ng/mL doxycycline (without bcl‐xL overexpression) were 4.89 ± 0.21 and 3.18 ± 0.06 μg/10⁶cells/day, respectively. In the absence of doxycycline, bcl‐xL overexpression did not affect q_EPO significantly, regardless of the culture temperature, though it extended the culture longevity. Taken together, bcl‐xL overexpression showed no significant effect on the q_EPO of rCHO cells grown at 33°C and 37°C. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009     

Study on interactions of aminoglycoside antibiotics with calf thymus DNA and determination of calf thymus DNA via the resonance Rayleigh scattering technique

A simple and sensitive resonance Rayleigh scattering (RRS) spectra method was developed for the determination of calf thymus DNA (ctDNA). The enhanced RRS signals were based on the interactions between ctDNA and aminoglycoside antibiotics (AGs) including kanamycin (KANA), tobramycin (TOB), gentamicin (GEN) and neomycin (NEO) in a weakly acidic medium (pH 3.3–5.7). Parameters influencing the method were investigated. Under optimum conditions, increments in the scattering intensity (?I) were directly proportional to the concentration of ctDNA over certain ranges. The detection limit ranged from 12.2 to 16.9 ng/mL. Spectroscopic methods, including RRS spectra, absorption spectra and circular dichroism (CD) spectroscopy, coupled with thermo‐denaturation experiments were used to study the interactions, indicating that the interaction between AGs with ctDNA was electrostatic binding mode. Copyright © 2015 John Wiley & Sons, Ltd.     

The exogenous application of AtPGLR,an endo‐polygalacturonase,triggers pollen tube burst and repair

Plant cell wall remodeling plays a key role in the control of cell elongation and differentiation. In particular, fine‐tuning of the degree of methylesterification of pectins was previously reported to control developmental processes as diverse as pollen germination, pollen tube elongation, emergence of primordia or elongation of dark‐grown hypocotyls. However, how pectin degradation can modulate plant development has remained elusive. Here we report the characterization of a polygalacturonase (PG), AtPGLR, the gene for which is highly expressed at the onset of lateral root emergence in Arabidopsis. Due to gene compensation mechanisms, mutant approaches failed to determine the involvement of AtPGLR in plant growth. To overcome this issue, AtPGLR has been expressed heterologously in the yeast Pichia pastoris and biochemically characterized. We showed that AtPGLR is an endo‐PG that preferentially releases non‐methylesterified oligogalacturonides with a short degree of polymerization (< 8) at acidic pH. The application of the purified recombinant protein on Amaryllis pollen tubes, an excellent model for studying cell wall remodeling at acidic pH, induced abnormal pollen tubes or cytoplasmic leakage in the subapical dome of the pollen tube tip, where non‐methylesterified pectin epitopes are detected. Those leaks could either be repaired by new β‐glucan deposits (mostly callose) in the cell wall or promoted dramatic burst of the pollen tube. Our work presents the full biochemical characterization of an Arabidopsis PG and highlights the importance of pectin integrity in pollen tube elongation.     

Lake responses to long‐term disturbances and management practices

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Potential Aqueous Two‐Phase Processes for the Primary Recovery of Colored Protein from Microbial Origin

The primary recovery of c‐phycocyanin and b‐phycoerythrin from Spirulina maxima and Porphyridium cruentum, respectively, using an established extraction strategy was selected as a practical model system to study the generic application of polyethylene glycol (PEG)‐phosphate aqueous two‐phase systems (ATPS). The generic practical implementation of ATPS extraction was evaluated for the recovery of colored proteins from microbial origin. A comparison of the influence of system parameters, such as PEG molecular mass, concentration of PEG as well as salt, system pH and volume ratio, on the partition behavior of c‐phycocyanin and b‐phycoerythrin was carried out to determine under which conditions target colored protein and contaminants concentrate to opposite phases. One‐stage processes are proposed for the primary recovery of the colored proteins. PEG1450‐phosphate ATPS extraction (volume ratio (V_R) equal to 0.3, tie‐line length (TLL) of 34 % w/w and system pH 7.0) for the recovery of c‐phycocyanin from Spirulina maxima resulted in a primary recovery process that produced a protein purity of 2.1 ± 0.2 (defined as the relationship of 620 nm to 280 nm absorbance) and a product yield of 98 % [w/w]. PEG1000‐phosphate ATPS extraction (i.e., V_R = 1.0, PEG 1000, TLL 50 % w/w and system pH 7.0) was preferred for the recovery of b‐phycoerythrin from Porphyridium cruentum, which resulted in a protein purity of 2.8 ± 0.2 (defined as the relationship of 545 nm to 280 nm absorbance) and a product yield of 82 % [w/w]. The purity of c‐phycocyanin and b‐phycoerythrin from the crude extract increased 3‐ and 4‐fold, respectively, after ATPS. The results reported herein demonstrated the benefits of the practical generic application of ATPS for the primary recovery of colored proteins from microbial origin as a first step for the development of purification processes.     

Influence of lactic acid bacteria on stereoselective degradation of theta‐cypermethrin

The purpose of this study was to investigate the influence of four kinds of Lactic acid bacteria (LAB) on stereoselective degradation of theta‐cypermethrin (CYP), including Lactobacillus plantarum, Lactobacillus casei, Lactobacillus delbrueckii, and Streptococcus thermophilus. An effective analytical method for (±)‐theta‐CYP in medium was developed by high‐performance liquid chromatography with cellulose tris‐(3,5‐dimethylphenylcarbamate) chiral stationary phase. theta‐Cypermethrin was spiked to LAB medium with different inoculation rates and sampled at 0, 2, 8, 24, 36, 48, 72, 120, 168, and 240 hours. The results showed that LAB influenced the half‐lives and enantiomer fractions of theta‐CYP enantiomers, which lead a closer degradation rate between the 2 stereoisomers, and no obvious difference was found among 4 LABs. Besides, the stereoselective degradation of theta‐CYP was closely related to pH. The lower the pH (pH of 3, 5, 7, and 9), the lower the enantiomer fraction (from 4.88 to 6.69). At pH of 3, 7, and 9, significant differences of half‐lives between enantiomers were observed. (?)‐theta‐Cypermethrin decreased faster than (+)‐theta‐CYP under pH of 3, while opposite results were indicated under pH of 7 and 9. Moreover, the acidic condition contributed to the higher chiral configuration stability of (±)‐theta‐CYP. (+)‐Enantiomer was influenced by pH in a greater degree than (?)‐enantiomer.     

Diatom Diversity in Chronically versus Episodically Acidified Adirondack Streams

The relationship between algal species richness and diversity, and pH is controversial. Furthermore, it is still unknown how episodic stream acidification following atmospheric deposition affects species richness and diversity. Here we analyzed water chemistry and diatom epiphyton dynamics and showed their contrasting behavior in chronically vs. episodically acidic streams in the Adirondack region. Species richness and diversity were significantly higher in the chronically acidic brown water stream, where organic acidity was significantly higher and the ratio of inorganic to organic monomeric aluminum significantly lower. Conversely, in the episodically acidic clear water stream, the inorganic acidity and pH were significantly higher and the diatom communities were very species‐poor. This suggests that episodic acidification in the Adirondacks may be more stressful for stream biota than chronic acidity. Strong negative linear relationships between species diversity, Eunotia exigua, and dissolved organic carbon against pH were revealed after the influence of non‐linear temporal trends was partialled out using a novel way of temporal modeling. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Insights into the binding of paclitaxel to human serum albumin: multispectroscopic studies

The interaction of paclitaxel with human serum albumin (HSA) was studied using fluorescence, resonance light scattering, ultraviolet‐visible, circular dichroism and Fourier transform infrared spectroscopy at pH 7.4. Fluorescence data revealed that the fluorescence quenching of HSA by paclitaxel was a static quenching procedure. Time‐resolved fluorescence data also confirmed the quenching mode, which present a constant decay time of about 5 ns. The binding sites were approximately 1 and the binding constant suggested a weak association (324/M at 298 K), which is helpful for the release of the drug to targeted organs. The thermodynamic parameters, ΔG^○, ΔH° and ΔS° were calculated as – 1.06 × 10⁴ J/mol, 361 J/mol per K and 9.7 × 10⁴ J/mol respectively at 298 K, suggesting that binding was spontaneous and was driven mainly by hydrophobic interactions. The binding distance between HSA and paclitaxel was determined to be 2.23 nm based on the Förster theory. Analysis of circular dichroism, ultraviolet‐visible, three‐dimensional fluorescence, Fourier transform infrared and resonance light scattering spectra demonstrated that HSA conformation was slightly altered in the presence of paclitaxel and dimension of the individual HSA molecules were larger after interacting with paclitaxel. These results were confirmed by a molecular docking study. Copyright © 2013 John Wiley & Sons, Ltd.     

Basal Endothelial Nitric Oxide Release Is Preserved in Overweight and Obese Adults

Objective: Impaired basal nitric oxide release is associated with a number of cardiovascular disorders including hypertension, arterial spasm, and myocardial infarction. We determined whether basal endothelial nitric oxide release is reduced in otherwise healthy overweight and obese adult humans. Research Methods and Procedures: Seventy sedentary adults were studied: 32 normal weight (BMI <25 kg/m²), 24 overweight (BMI ≥ 25 < 30 kg/m²), and 14 obese (BMI ≥ 30 kg/m²). Forearm blood flow (FBF) responses to intra‐arterial infusions of N^g‐monomethyl‐l ‐arginine (5 mg/min), a nitric oxide synthase inhibitor, were used as an index of basal nitric oxide release. Results: N^g‐monomethyl‐l ‐arginine elicited significant reductions in FBF in the normal weight (from 4.1 ± 0.2 to 2.7 ± 0.2 mL/100 mL tissue/min), overweight (4.1 ± 0.1 to 2.8 ± 0.2 mL/100 mL tissue/min), and obese (3.9 ± 0.3 to 2.7 ± 0.2 mL/100 mL tissue/min) subjects. Importantly, the magnitude of reduction in FBF (～30%) was similar among the groups. Discussion: These results indicate that the capacity of the endothelium to release nitric oxide under basal conditions is not compromised in overweight and obese adults.     

Cost-effective and concurrent production of industrially valuable xylano-pectinolytic enzymes by a bacterial isolate Bacillus pumilus AJK

Simultaneous production of xylanase and pectinase by Bacillus pumilus AJK under submerged fermentation was investigated in this study. Under optimized conditions, it produced 315?±?16 IU/mL acidic xylanase, 290?±?20 IU/mL alkaline xylanase, and 88?±?9 IU/mL pectinase. The production of xylano-pectinolytic enzymes was the highest after inoculating media (containing 2% each of wheat bran and Citrus limetta peel, 0.5% peptone, 10?mM MgSO₄, pH 7.0) with 2% of 21-hr-old culture and incubated at 37°C for 60?hr at 200?rpm. Xylanase retained 100% activity from pH 6.0 to10.0 after 3?hr of incubation, while pectinase showed 100% stability from pH 6.0 to 9.0 even after 6?hr of incubation. Cost-effective and concurrent production of xylanase and pectinase by a bacterial isolate in the same production media suggests its potential for various biotechnological applications. This is the first report of simultaneous production of industrially important extracellular xylano-pectinolytic enzymes by B. pumilus.