Meta-analysis approaches were used in this first quantitative synthesis of denitrifying woodchip bioreactors. Nitrate removal across environmental and design conditions was assessed from 26 published studies, representing 57 separate bioreactor units (i.e., walls, beds, and laboratory columns). Effect size calculations weighted the data based on variance and number of measurements for each bioreactor unit. Nitrate removal rates in bed and column studies were not significantly different, but both were significantly higher than wall studies. In denitrifying beds, wood source did not significantly affect nitrate removal rates. Nitrate removal (mass per volume) was significantly lower in beds with <6-h hydraulic retention times, which argues for ensuring that bed designs incorporate sufficient time for nitrate removal. Rates significantly declined after the first year of bed operation but then stabilized. Nitrogen limitation significantly affected bed nitrate removal. Categorical and linear assessments found significant nitrate removal effects with bed temperature; a of 2.15 was quite similar to other studies. Lessons from this meta-analysis can be incorporated into bed designs, especially extending hydraulic retention times to increase nitrate removal under low temperature and high flow conditions. Additional column studies are warranted for comparative assessments, as are field-based studies for assessing in situ conditions, especially in aging beds, with careful collection and reporting of design and environmental data. Future assessment of these systems might take a holistic view, reviewing nitrate removal in conjunction with other processes, including greenhouse gas and other unfavorable by-product production.
The performance of wood-based denitrifying bioreactors to treat high-nitrate wastewaters from aquaculture systems has not previously been demonstrated. Four pilot-scale woodchip bioreactors (approximately 1:10 scale) were constructed and operated for 268 d to determine the optimal range of design hydraulic retention times (HRTs) for nitrate removal. The bioreactors were operated under HRTs ranging from 6.6 to 55 h with influent nitrate concentrations generally between 20 and 80 mg NO-N L. These combinations resulted in N removal rates >39 g N m d, which is greater than previously reported. These high removal rates were due in large part to the relatively high chemical oxygen demand and warm temperature (∼19°C) of the wastewater. An optimized design HRT may not be the same based on metrics of N removal rate versus N removal efficiency; longer HRTs demonstrated higher removal efficiencies, and shorter HRTs had higher removal rates. When nitrate influent concentrations were approximately 75 mg NO-N L ( = 6 sample events), the shortest HRT (12 h) had the lowest removal efficiency (45%) but a significantly greater removal rate than the two longest HRTs (42 and 55 h), which were N limited. Sulfate reduction was also observed under highly reduced conditions and was exacerbated under prolonged N-limited environments. Balancing the removal rate and removal efficiency for this water chemistry with a design HRT of approximately 24 h would result in a 65% removal efficiency and removal rates of at least 18 g N m d.
Tile drainage is the major source of nitrate in the upper Midwest, and end-of-tile removal techniques such as wood chip bioreactors have been installed that allow current farming practices to continue, with nitrate removed through denitrification. There have been few multiyear studies of bioreactors examining controls on nitrate removal rates. We evaluated the nitrate removal performance of two wood chip bioreactors during the first 3 yr of operation and examined the major factors that regulated nitrate removal. Bioreactor 2 was subject to river flooding, and performance was not assessed. Bioreactor 1 had average monthly nitrate removal rates of 23 to 44 g N m d in Year 1, which decreased to 1.2 to 11 g N m d in Years 2 and 3. The greater N removal rates in Year 1 and early in Year 2 were likely due to highly degradable C in the woodchips. Only late in Year 2 and in Year 3 was there a strong temperature response in the nitrate removal rate. Less than 1% of the nitrate removed was emitted as NO. Due to large tile inputs of nitrate (729-2127 kg N) at high concentrations (∼30 mg nitrate N L) in Years 2 and 3, overall removal efficiency was low (3 and 7% in Years 2 and 3, respectively). Based on a process-based bioreactor performance model, Bioreactor 1 would have needed to be 9 times as large as the current system to remove 50% of the nitrate load from this 20-ha field.
The aim of this work was to provide recent fatty acids (FA) profiling of chocolates and chocolate products, principally C18:1 trans fatty acids (TFA). 32 samples were analyzed by gas chromatography and FA were quantified. Total TFA content declared in chocolates labelling and real TFA content was compared. TFA ranged from 0.04 to 2.51 g/100 g sample and it was noticed that several manufacturers were underestimating total TFA content in their labelling. Main TFA isomers quantified were C18:1 trans-9 (0.006-0.244%), C18:1 trans-10 (0.009-0.392%) and C18:1 trans-11 (0.013-0.464%), expressed g/100 g sample. Principal Component Analysis was used to discriminate industrial from natural trans fats based on isomeric TFA profile and dairy fat (DF) biomarkers and allowed to group samples in four clusters: high TFA content and high DF content; high TFA content and low DF content, low TFA content and high DF content and low TFA content and low DF content.
Peanut allergy is a major health problem worldwide. Detection of food allergens is a critical aspect of food safety. The VHH domain of single chain antibody from camelids, also known as nanobody (Nb), showed its advantages in the development of biosensors because of its high stability, small molecular size, and ease of production. However, no nanobody specific to peanut allergens has been developed. In this study, we constructed a library with random triplets (NNK) in its CDR regions of a camel nanobody backbone. We screened the library with peanut allergy Ara h 3 and obtained several candidate nanobodies. One of the promising nanobodies, Nb16 was further biochemical characterization by gel filtration, isothermal titration calorimetry (ITC), co-crystallization, and western blot in terms of its interaction with Ara h 3. Nb16 specifically binds to peanut major allergen Ara h 3 with a dissociation constant of 400 nM. Furthermore, we obtained the Ara h 3-Nb16 complex crystals. Structure analysis shows the packing mode is completely different between the Ara h 3-Nb16 complex crystal and the native Ara h 3 crystal. Structural determination of Ara h 3-Nb16 will provide information required to understand the allergenicity of this important peanut allergen. The nanobody Nb16 may have application in the development of biosensors for peanut allergen detection.
In this study, nine pyrimethanil ionic liquids (PILs) were synthesized through acid-bases reaction with nine naturally derived organic acid anions, to improve the physicochemical properties and reduce the environmental adverse impacts. The PILs presented lower volatilization, higher photostability, better soil adsorption capacity, and improved fungicidal activity relative to pyrimethanil. When the length of the carbon chains in the anions was increased, the PILs showed better properties in terms of melting point, water solubility, volatility, and surface tension. The photostabilities and fungicidal activities of the PILs were significantly improved when cyclic compounds were used as the paired anion ions. With enhanced physicochemical properties and better fungicidal activity, PIL7 was selected as the best alternative to pyrimethanil. The intrinsic disadvantages of pyrimethanil could be surmounted using the system developed in the study, thus ILs could have immense potential in the development of eco-friendly and efficient fungicides in the future.
ROS and subsequent oxidative stress are reported to play important roles in chronic metabolic diseases. Plant-derived polyphenols, especially food-derived phenolics, have attracted a lot of attention due to their potential usage against oxidative stress-related diseases. The leaf of Psidium guajava (known as guava) is regarded as a good resource of polyphenols and its products are commercially available in Japan as functional foods against multiple chronic metabolism disorders. In the course of finding novel polyphenols with antioxidative activities from guava leaf, eleven acylated phenolic glycosides (1-11), including five new oleuropeic acid conjugated phenolic glycosides, named guajanosides A-E (1, 2, and 5-7), along with 17 known meroterpenoides (12-28) were isolated and identiﬁed. Their structures were determined by spectroscopic data analysis, chemical degradation and acid hydrolysis. Compounds 1, 2, and 5-11 displayed potent reactive oxygen species (ROS) scavenging activity in LPS-stimulated RAW 264.7 macrophage cells. Western blot revealed that compound 6 markedly increased the expression levels of nuclear factor-erythroid 2-related factor 2 (Nrf2), NAD(P)H quinone dehydrogenase 1 (NQO1) and glutamate-cysteine ligase catalytic subunit (GCLC). The current study revealed the presence of oleuropeic acid-derived phenolic glycosides in guava leaf, and highlighted the potential usage of this type of phenolics against oxidative stress-related metabolic diseases via activation of Nrf2 signaling pathway.
The 4-amion-2,2,6,6-tetramethylpiperidine (Temp) was grafted into the Sodium Lignosulfonate (SL) to obtain the hindered amine modified lignosulfonate (SL-Temp). Then the polymer surfactant (SL-Temp-CTAB) was prepared by using cetyltrimethylammonium bromide (CTAB) and SL-Temp. The obtained SL-Temp-CTAB was used as emulsifier to prepare green Emulsifiable Concentrate (EC) of avermectin (AVM), which shows good emulsifying property and storage stability. The prepared AVM green EC can form AVM-loaded microspheres with nanometer particle size distribution after emulsification in water. After UV irradiation for 70 hours, the AVM retention rate of the green EC prepared using SL-Temp-CTAB was 75.8%, which is much higher than that of commercial EC (0.4%) and the green EC prepared using unmodified SL (31.4%). Moreover, the AVM green EC prepared using SL-Temp-CTAB has slow-release performance, and the release equilibrium time is 5.3 times of the commercial EC. Therefore, the newly prepared AVM green EC using lignin-based functional emulsifier shows good anti-photolysis and slow-release performance compared with the traditional EC.
Recently, we have observed a relationship between poor breadmaking quality and protease activities related to fungal infection. This study aims to identify potential gluten-degrading proteases secreted by fungi and to analyse effects of these proteases on rheological properties of dough and gluten. infected grain was used as a model system. Zymography showed that serine-type proteases secreted by degrade gluten proteins. Zymography followed by LC-MS/MS analyses predicted one serine carboxypeptidase and seven serine endo-peptidases to be candidate fungal proteases involved in gluten degradation. Effects of fungal proteases on the time-dependent rheological properties of dough and gluten were analysed by small amplitude oscillatory shear rheology and large deformation extensional rheology. Our results indicate that fungal proteases degrade gluten proteins not only in the grain itself, but also during dough preparation and resting. Our study give new insight into fungal proteases and their potential role in weakening of gluten.
Tartary buckwheat (Fagopyrum tataricum) seeds are rich in flavonoids. However, the detailed flavonoid compositions and the molecular basis of flavonoid biosynthesis in tartary buckwheat seeds remain largely unclear. Here, we performed a combined metabolite profiling and transcriptome analysis to identify flavonoid compositions and characterize genes involved in flavonoid biosynthesis in the developing tartary buckwheat seeds. In total, 234 flavonoids, including 10 isoflavones, were identified. Of these, 80 flavonoids were significantly differential accumulation during seed development. Transcriptome analysis indicated that most structural genes and some potential regulatory genes of flavonoid biosynthesis were significantly differentially expressed in the course of seed development. Correlation analysis between transcriptome and metabolite profiling shown that the expression patterns of some differentially expressed structural genes and regulatory genes were more consistent with the changes in flavonoids profiles during seed development, and promoted one SG7 subgroup R2R3-MYB transcription factors (FtPinG0009153900.01) was identified as the key regulatory gene of flavonoid biosynthesis. These findings provide valuable information for understanding the mechanism of flavonoid biosynthesis in tartary buckwheat seeds and the further development of tartary buckwheat health products.