Bacteriocin production by lactic acid bacteria using ice cream co-product as the fermentation substrate.

Ice cream manufacture commonly results in the accumulation of wasted product that contains valuable food-grade quality components, including fat, carbohydrates, and protein. Methods have been developed for recovering the fat from this waste stream, but this results in the generation of a co-product rich in fermentable carbohydrates. This study aimed to investigate the potential for using this co-product as a fermentation substrate for production of antimicrobial peptides, called bacteriocins, by dairy starter cultures. Results showed that Streptococcus thermophilus B59671 and Lactococcus lactis 11454 produced the broad-spectrum bacteriocins thermophilin 110 and nisin, respectively, when the fermentation substrate was melted ice cream, or a co-product generated by a modified butter churning technique. Bacteriocin production varied depending on the brand and variety of vanilla ice cream used in this study. When an alternate enzyme-assisted fat extraction technique was used, S. thermophilus metabolism was impaired within the resulting co-product, and thermophilin 110 production was not observed. Lactococcus lactis was still able to grow in this co-product, but antimicrobial activity was not observed. Results from this study suggest the co-product generated when using the churning technique is a better choice to use as a base medium for future studies to optimize bacteriocin production.

A prevalence of dynamo-generated magnetic fields in the cores of intermediate-mass stars.

Magnetic fields play a part in almost all stages of stellar evolution. Most low-mass stars, including the Sun, show surface fields that are generated by dynamo processes in their convective envelopes. Intermediate-mass stars do not have deep convective envelopes, although 10 per cent exhibit strong surface fields that are presumed to be residuals from the star formation process. These stars do have convective cores that might produce internal magnetic fields, and these fields might survive into later stages of stellar evolution, but information has been limited by our inability to measure the fields below the stellar surface. Here we report the strength of dipolar oscillation modes for a sample of 3,600 red giant stars. About 20 per cent of our sample show mode suppression, by strong magnetic fields in the cores, but this fraction is a strong function of mass. Strong core fields occur only in red giants heavier than 1.1 solar masses, and the occurrence rate is at least 50 per cent for intermediate-mass stars (1.6-2.0 solar masses), indicating that powerful dynamos were very common in the previously convective cores of these stars.

Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars.

A knowledge of stellar ages is crucial for our understanding of many astrophysical phenomena, and yet ages can be difficult to determine. As they become older, stars lose mass and angular momentum, resulting in an observed slowdown in surface rotation. The technique of 'gyrochronology' uses the rotation period of a star to calculate its age. However, stars of known age must be used for calibration, and, until recently, the approach was untested for old stars (older than 1 gigayear, Gyr). Rotation periods are now known for stars in an open cluster of intermediate age (NGC 6819; 2.5 Gyr old), and for old field stars whose ages have been determined with asteroseismology. The data for the cluster agree with previous period-age relations, but these relations fail to describe the asteroseismic sample. Here we report stellar evolutionary modelling, and confirm the presence of unexpectedly rapid rotation in stars that are more evolved than the Sun. We demonstrate that models that incorporate dramatically weakened magnetic braking for old stars can--unlike existing models--reproduce both the asteroseismic and the cluster data. Our findings might suggest a fundamental change in the nature of ageing stellar dynamos, with the Sun being close to the critical transition to much weaker magnetized winds. This weakened braking limits the diagnostic power of gyrochronology for those stars that are more than halfway through their main-sequence lifetimes.

SoilTemp: A global database of near-surface temperature.

Current analyses and predictions of spatially explicit patterns and processes in ecology most often rely on climate data interpolated from standardized weather stations. This interpolated climate data represents long-term average thermal conditions at coarse spatial resolutions only. Hence, many climate-forcing factors that operate at fine spatiotemporal resolutions are overlooked. This is particularly important in relation to effects of observation height (e.g. vegetation, snow and soil characteristics) and in habitats varying in their exposure to radiation, moisture and wind (e.g. topography, radiative forcing or cold-air pooling). Since organisms living close to the ground relate more strongly to these microclimatic conditions than to free-air temperatures, microclimatic ground and near-surface data are needed to provide realistic forecasts of the fate of such organisms under anthropogenic climate change, as well as of the functioning of the ecosystems they live in. To fill this critical gap, we highlight a call for temperature time series submissions to SoilTemp, a geospatial database initiative compiling soil and near-surface temperature data from all over the world. Currently, this database contains time series from 7,538 temperature sensors from 51 countries across all key biomes. The database will pave the way toward an improved global understanding of microclimate and bridge the gap between the available climate data and the climate at fine spatiotemporal resolutions relevant to most organisms and ecosystem processes.

Do people care about pine invasions? Visitor perceptions and willingness to pay for pine control in a protected area.

Tree invasions are increasing globally, causing major problems for biodiversity, ecosystem services and human well-being. In South America, conifer invasions occur across many ecosystems and while numerous studies address the ecological consequences of these invasions, little is known about social perceptions and people's attitudes toward their control. The social perceptions on the effect of invasive conifers can include recreational, cultural and conservation dimensions. This study, conducted in the Malalcahuello National Reserve, aims to assess visitor's perception about invasive pines (Pinus spp.) and their effects on the endangered Araucaria araucana forests and determine their willingness to pay for pine control. We used a questionnaire to survey visitors to the reserve in both winter and summer (n = 138 for each season). When confronted with six images of araucaria and pine forests with and without snow, visitors consistently preferred landscapes without pines and disliked those completely dominated by pines the most. Almost half, 46.5%, of the visitors expressed their willingness to pay (WTP) for pine control and after given a brief explanation about pine impacts, this number rose to 79%. Visitors who said they were unwilling to pay argue ethical, aesthetic and pragmatic considerations relating closely to a number of social value systems and beliefs. Our study shows that there is a high variation in how people assess the threat of invasive pine species in natural areas, but education even in a very brief format can help to increase awareness of the problem and build social and financial support for its control.

Fast core rotation in red-giant stars as revealed by gravity-dominated mixed modes.

When the core hydrogen is exhausted during stellar evolution, the central region of a star contracts and the outer envelope expands and cools, giving rise to a red giant. Convection takes place over much of the star's radius. Conservation of angular momentum requires that the cores of these stars rotate faster than their envelopes; indirect evidence supports this. Information about the angular-momentum distribution is inaccessible to direct observations, but it can be extracted from the effect of rotation on oscillation modes that probe the stellar interior. Here we report an increasing rotation rate from the surface of the star to the stellar core in the interiors of red giants, obtained using the rotational frequency splitting of recently detected 'mixed modes'. By comparison with theoretical stellar models, we conclude that the core must rotate at least ten times faster than the surface. This observational result confirms the theoretical prediction of a steep gradient in the rotation profile towards the deep stellar interior.

Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars.

Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include uncertainties in the amount of mass lost at the surface before helium ignition and the amount of internal mixing from rotation and other processes. Progress is hampered by our inability to distinguish between red giants burning helium in the core and those still only burning hydrogen in a shell. Asteroseismology offers a way forward, being a powerful tool for probing the internal structures of stars using their natural oscillation frequencies. Here we report observations of gravity-mode period spacings in red giants that permit a distinction between evolutionary stages to be made. We use high-precision photometry obtained by the Kepler spacecraft over more than a year to measure oscillations in several hundred red giants. We find many stars whose dipole modes show sequences with approximately regular period spacings. These stars fall into two clear groups, allowing us to distinguish unambiguously between hydrogen-shell-burning stars (period spacing mostly ∼ 50 seconds) and those that are also burning helium (period spacing ∼ 100 to 300 seconds).

The relationship between extent of hemoglobin purification and the performance characteristics of a blood-based flocculant.

BACKGROUND: Whole blood is a highly complex substance. Hemoglobin, the most abundant blood protein, can function as a flocculant; most of the other blood components exhibit poor flocculant activity. For the purpose of processing raw whole blood into a flocculant product, the practical value of hemoglobin purification is uncertain. RESULTS: This study compares the flocculant performance of whole blood to that of three different semi-purified hemoglobin preparations. The whole blood is processed to remove the plasma proteins, the solid cell components, or both. The flocculant performance of whole blood and each hemoglobin preparation is compared over wide ranges of flocculant dose and suspension pH. The clarified liquids are examined for increases in chemical oxygen demand and Kjeldahl nitrogen. Hemoglobin preparations that excluded plasma gave peak flocculation performance at approximately 30 mg solids per gram of suspended kaolin, and gave greatly reduced performance at higher doses; preparations that included plasma gave very similar peak performance, but also maintained relatively high performance at doses up to at least 200 mg g-1 . CONCLUSION: It is shown that removal of the plasma and the cell solids does not improve the flocculant performance or lessen the residual pollutants in the treated water. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Influence of Methylation and Polymerization on Flocculant Properties of Bovine Blood.

Flocculants are used in the primary step of wastewater treatment to precipitate solids. Bovine blood is a slaughterhouse byproduct, and there is limited evidence in the literature demonstrating that it can be used as a flocculant. In this study, native bovine blood (NBB) and three types of chemically modified blood (methylated bovine blood (MeBB), polymerized bovine blood (PolyBB), and polymerized & methylated bovine blood (PMBB)) were tested against suspensions of negatively charged kaolin or positively charged hematite. The methylation reaction had the expected effect of increasing the apparent isoelectric point of MeBB and PMBB relative to that of the NBB starting material, and the polymerization reaction had the intended effect of increasing the average molar mass. NBB and PolyBB performed well with kaolin suspensions at pH ≤5.5, and MeBB showed high and consistent performance, across the pH range of 4.5-8.5. Relative to NBB, MeBB had improved potency and pH independence but also the disadvantage of increased sensitivity to overdosing. The performance of PolyBB was very similar to that of NBB. PMBB had performance enhancements similar to those of MeBB, with a modest improvement in its overdose sensitivity. The performances of MeBB and PMBB with hematite suspensions were poor at all tested doses (2-100 mg/g hematite), whereas a 30 mg/g dose of PolyBB showed 81% precipitation in an hour. The results show that simple chemical treatments can improve the utility of blood as a flocculant for negatively charged solids.

GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star.

Ultrashort-period (USP) exoplanets have orbital periods shorter than 1 day. Precise masses and radii of USP exoplanets could provide constraints on their unknown formation and evolution processes. We report the detection and characterization of the USP planet GJ 367b using high-precision photometry and radial velocity observations. GJ 367b orbits a bright (V-band magnitude of 10.2), nearby, and red (M-type) dwarf star every 7.7 hours. GJ 367b has a radius of 0.718 ± 0.054 Earth-radii and a mass of 0.546 ± 0.078 Earth-masses, making it a sub-Earth planet. The corresponding bulk density is 8.106 ± 2.165 grams per cubic centimeter­close to that of iron. An interior structure model predicts that the planet has an iron core radius fraction of 86 ± 5%, similar to that of Mercury's interior.

Modification of chiral dimethyl tartrate through transesterification: immobilization on POSS and enantioselectivity reversal in sharpless asymmetric epoxidation.

Modification of dimethyl tartrate has been investigated through transesterification with aminoalcohols to provide reactive functionalities for the covalent bonding of chiral tartrate to polyhedral oligomeric silsesquioxanes. The transesterification of dimethyl tartrate has been widely studied using different catalytic systems and reaction conditions. Through the proper selection of both the catalytic system and the reaction conditions, it is possible to achieve monosubstituted or bis-substituted tartrate derivatives as sole products. All the intermediate chiral tartrate-derived ligands were successfully used in the homogeneous enantioselective epoxidation of allylic alcohols providing moderate enantiomeric excess over the products. Attached amine groups have been used to support the modified tartrate ligands on to a haloaryl-functionalized silsesquioxane moiety. This final chiral tartrate ligand displays reverse enantioselectivity in the asymmetric epoxidation of allylic alcohols with regard to the starting dimethyl tartrate ligand, both molecules having the same chiral sign. However, the POSS-containing ligand can be easily recovered in almost quantitative yield and reused in asymmetric epoxidation reactions. In addition, recovered silsesquioxane-pendant ligand, though displaying decreasing catalytic activity in recycling epoxidation tests, showed very stable enantioselective behavior.

The non-nutritional performance characteristics of peptones made from rendered protein.

Economic considerations require the use of inexpensive feedstocks for the fermentative production of moderate-value products. Our previous work has shown that peptones capable of supporting the growth of various microorganisms can be produced from inexpensive animal proteins, including meat and bone meal, feather meal, and blood meal, through alkaline or enzymatic hydrolysis. In this work, we explore how these experimental peptones compare to commercial peptones in terms of performance characteristics other than chemical make-up; these characteristics can impact fermentation operating cost. It is shown that experimental peptone powders produced through enzymatic hydrolysis are highly hygroscopic and that their physical form is not stable to humid storage conditions; those produced through alkaline hydrolysis and commercial peptones are less hygroscopic. When used in growth medium, all peptones contribute haze to the solution; experiments show that the source of haze is different when using enzyme- versus alkali-hydrolyzed peptones. Alkali-hydrolyzed peptones and all peptones made from blood meal are stronger promoters of media foaming than the commercial peptones; some enzyme-hydrolyzed peptones support very little foam formation and are superior to the commercial peptones in this sense. Alkali-hydrolyzed peptones are roughly equivalent to commercial peptones in the coloration they contribute to media, while enzyme-hydrolyzed peptones contribute intense coloration to media. No peptone caused a significant change in the viscosity of media. The experimental peptones studied here may be acceptable low-cost substitutes for commercial peptones, but none is equivalent to the commercial products in all respects.

Enhancing Biosludge Dewaterability with Hemoglobin from Waste Blood as a Bioflocculant.

Synthetic polymers are widely used in the treatment of biosludge (waste activated sludge) to enhance its dewaterability. This paper discusses the results of a systematic study using hemoglobin (Hb) from animal blood and methylated hemoglobin (MeHb), a derivative in which a methyl group replaces the hydrogen carboxyl groups, to replace synthetic polymers to improve the dewatering efficiency of biosludge. With regular hemoglobin, no improvement in biosludge dewatering was found. With 10% of methylated hemoglobin per total solids content, however, the dry solids content of biosludge increased from 10.2 (±0.3) wt% to 15.0 (±1.0) wt%. Zeta potential measurements showed a decrease in the negative surface charge of the particles in biosludge from -34.3 (±3.2) mV to -19.0 (±2.1) mV after the treatment with methylated hemoglobin. This, along with an unchanged particle size distribution after conditioning, suggests that charge neutralization is likely the main cause of particle flocculation. With charges neutralized, the extracellular polymeric substances (EPS) around the biosludge flocs become loose, releasing the trapped water, thus increasing dewaterability.

Performance and mechanism of polypeptidylated hemoglobin (Hb)/iron oxide magnetic composites for enhanced dye removal.

Composites of polypeptidylated hemoglobin supported on different iron oxide weights (0.5:1 and 1:1) were developed and demonstrated to function as efficient adsorbents for Eriochrome black-T dye removal. The synthesis of these adsorbents were performed through N-carboxyanhydride (NCA) polymerization at low temperature (4 °C) and near-neutral pH for 24 h followed by chemical co-precipitation. The synthesized adsorbents were found to exhibit BET surface area (54-87 m2/g), pore volume (0.30-0.35 cm3/g), average pore diameter (160-218 Å) and average pore width (136-171 Å). The developed adsorbents were tested in a batch dye adsorption system. Adsorption was found to follow pseudo-second order kinetics and the Langmuir adsorption capacities were 123, 204 and 217 mg/g for Fe3O4, 0.5:1 and 1:1 adsorbent samples, respectively. Chemical regeneration was successfully carried out using methanol and the reusability of the adsorbents were demonstrated with a decrease in adsorption capacities from ∼49 to ∼33 mg/g after the fourth reuse.

Ab-initio Study of Citrate Ion as an Oxygen-Rich Complexing Agent.

Theoretical studies on conformational analysis, geometry optimizations and frequencies for citrate at the MP2/LANL2DZ level portrait it as a promising candidate for a complexing agent for cadmium (II) ion (Cd2+) and cadmium sulfide (CdS). Natural Bond Orbital (NBO) charges, Delocalization Indices, HOMO/LUMO gaps and surfaces along with absolute electronegativity values were employed to analyze the interactions among the configurations obtained. The most stable structures involved the interaction between the LUMO of Cd2+/CdS and the most dense region of the HOMO of the citrate ion.

Phytochemical profiles and classification of Agave syrups using 1H-NMR and chemometrics.

BACKGROUND: Agave syrups are natural sweeteners that are highly desirable for human consumption because they have low glycemic index. In this work, we explored the potential of 1H-NMR-Chemometrics as a useful tool in the identification and differentiation of Agave syrups. Also, we evaluated the phytochemical screening and antioxidant capacity of Agave syrup compared to other natural sweeteners. RESULTS: The phytochemical screening stands out for Agave syrups containing higher levels of metabolites with antioxidant activity, mainly saponins, glycosides, and terpenoids. Agave syrup antioxidant activity was in a range from 10% to 53%, while the total phenolic content was from 24 to 300 EAG/100 g, and condensed tannins were between 240 and 1,900 mg CE/g. Additionally, 1H-NMR spectroscopy was used to characterize syrup profiles and chemometrics. PCA group analyses allowed the sweeteners' classification by origin and kind of Agave. CONCLUSION: Thus, we conclude that 1H-NMR and chemometrics can be used for identifying, differentiating, and classifying Agave syrups. Besides, Agave syrups contain significant amounts of antioxidative components and can be considered as an effective source of antioxidant.

Producing docosahexaenoic acid (DHA)-rich algae from biodiesel-derived crude glycerol: effects of impurities on DHA production and algal biomass composition.

Crude glycerol is the primary byproduct of the biodiesel industry. Producing docosahexaenoic acid (DHA, 22:6 n-3) through fermentation of the alga Schizochytrium limacinum on crude glycerol provides a unique opportunity to utilize a large quantity of this byproduct. The objective of this work is to investigate the effects of impurities contained in the crude glycerol on DHA production and algal biomass composition. Crude glycerol streams were obtained from different biodiesel refineries. All of the glycerol samples contained methanol, soaps, and various elements including calcium, phosphorus, potassium, silicon, sodium, and zinc. Both methanol and soap were found to negatively influence algal DHA production; these two impurities can be removed from culture medium by evaporation through autoclaving (for methanol) and by precipitation through pH adjustment (for soap). The glycerol-derived algal biomass contained 45-50% lipid, 14-20% protein, and 25% carbohydrate, with 8-13% ash content. Palmitic acid (C16:0) and DHA were the two major fatty acids in the algal lipid. The algal biomass was rich in lysine and cysteine, relative to many common feedstuffs. Elemental analysis by inductively coupled plasma showed that boron, calcium, copper, iron, magnesium, phosphorus, potassium, silicon, sodium, and sulfur were present in the biomass, whereas no heavy metals (such as mercury) were detected in the algal biomass. Overall, the results show that crude glycerol was a suitable carbon source for algal fermentation. The crude glycerol-derived algal biomass had a high level of DHA and a nutritional profile similar to that of commercial algal biomass, suggesting a great potential for using crude glycerol-derived algae in omega-3-fortified food or feed.

Subcutaneous transposition of the superficial femoral artery for arterioarterial hemodialysis: technique and results.

We report the use of subcutaneous transposition of the femoral artery (STFA) for placement of both inflow and outflow needles in 14 hemodialysis (HD) adult patients with difficult access. Follow-up time was 318 months during which a total of 3215 arterioarterial HD sessions were done. Kt/V values ranged between 0.71 and 1.59. Elevated access recirculation and dialysis outflow pressures were common findings to all patients. Complications were: (i) two episodes of bleeding secondary to puncture-related arterial wall laceration, repaired by stitching; (ii) three episodes of thrombosis in two patients, all successfully declotted; (iii) three puncture-related complications needing placement of a vein interposition graft, namely, aneurysm, pseudoaneurysm, and arterial stenosis; and (iv) one case of arterial ligation because of suppurative puncture site infection, without subsequent distal ischemia signs or claudication. The use of STFA should only be reserved for patients in urgent need for vascular access with no remaining options.

Efficient removal of dyes from aqueous solutions using a novel hemoglobin/iron oxide composite.

Magnetic particles entrapped in different matrices that display high thermal stability, low toxicity, interactive functions at the surface, and high saturation magnetization are of great interest. The objective of this work was to synthesize a novel hemoglobin/iron oxide composite (Hb/Fe3O4) for the removal of different dyes (indigo carmine, naphthol blue black, tartrazine, erythrosine, eriochrome black T and bromophenol blue) from aqueous solutions. The Hb/Fe3O4 composite was characterized using scanning electron microscopy (SEM), laser diffraction particle size analysis, FT-IR spectroscopy, isoelectric point determination and thermogravimetric analysis (TGA). The Hb/Fe3O4 composite showed high removal efficiency toward all the different classes of dyes studied and the mechanism of adsorption was dominated by electrostatic interaction. Adsorption was found to follow pseudo-second order kinetic model and Langmuir isotherm. The Langmuir monolayer adsorption capacities for all the dyes range from 80 to 178 mg/g. The Hb/Fe3O4 composite possesses extra advantage of being easily isolated from aqueous suspension using an external magnet. The stability of the prepared Hb/Fe3O4 composite was also demonstrated.

Correction: Landscape drivers of recent fire activity (2001-2017) in south-central Chile.

[This corrects the article DOI: 10.1371/journal.pone.0201195.].