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Aiming at the drawbacks of conventional methods for the digestion of total dissolved phosphorus (TDP) in water, a novel ozone-based photoactivated synergistic oxidative digestion device based on a high-voltage discharge ozone generator with an oxygen source and a jacketed bubbling reactor was presented. The effects of reaction temperature, reaction time, ozone flow, initial pH of solution, common inorganic anions (Cl–, , ), and total nitrogen on the digestion efficiency were investigated. Combining the improved ammonium molybdate spectrophotometric method, proposed the new determination method for TDP and verified its performance within the range of 0.1–2.0 mg/L. Results showed that this method has good linearity (R2 = 0.9997), precision (0.40%), accuracy (–0.50%), and a low limit of detection (0.0042 mg/L) under the optimized digestion process conditions (reaction temperature of 40°C, reaction time of 20 min, ozone flow of 0.6 L/min, initial pH of 5). This method provides a promising approach for routine analysis or online monitoring of TDP in water. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine the total iodine content in Korean abalone (Haliotis discus hannai) and to investigate the bioavailability of iodine using an in vitro method. This research paper focuses on total iodine quantification in abalone (Haliotis discus hannai) and its components (viscera and muscle) using inductively coupled plasma mass spectrometry (ICP-MS). Additionally, an in vitro bioavailability study explored iodine absorption potential. Abalone pretreatment involved both the European standard method (ES) and microwave-assisted extraction method (MAE). The limits of detection (LOD) were 0.11 ng/g for both ES and MAE, with a limit of quantification (LOQ) of 5.4 ng/g for MAE. Accuracy, assessed using a reference material (fish muscle, ERM—BB422), showed values of 1.5 ± 0.010 mg/kg for ES and 1.6 ± 0.066 mg/kg for MAE, within an acceptable range of 1.4 ± 0.42 mg/kg. Precision, evaluated using the Horwitz ratio (HorRat) with a reference material, was determined to be 0.45 for ES and 0.27 for MAE. Therefore, total iodine contents were estimated as 74 ± 2.2 µg/g for abalone viscera and 17 ± 0.77 µg/g for abalone muscle with ES, and 76 ± 1.0 µg/g for abalone viscera and 17 ± 0.51 µg/g for abalone muscle with MAE. Recovery tests demonstrated an acceptable range of 90–110%. In the in vitro bioavailability assessment, digestion efficiency yielded ranges of 42–50.2% for viscera and 67–115% for muscle. Absorption efficiency variations were determined as 37–43% for viscera and 48–75% for muscle. [ABSTRACT FROM AUTHOR]

Trace element abundances in organic-rich sediments are widely used in various fields of the geosciences, yet few contributions discuss the effectiveness of low-cost benchtop acid digestion techniques for such samples. Here, we tested three different sample preparation methods (acid digestion in closed and open vessels, and fusion) on twelve powder aliquots of organic-rich sediment, standard reference material NIST 2702. Comparison of newly obtained ICP-MS and LA-ICP-MS results with their respective certificate values, facilitates the assessment of digestion efficiency and the effects of vessel size, acid mixture, and other parameters on the recoveries of 29 trace elements. Our results show that benchtop digestion of organic-rich sediment in closed 7 mL PFA vessels using HF+HNO3+HClO4 mixture is more efficient compared with open vessel digestion treated with the same acid mixture (± HCl), with closed or open vessel digestions without HClO4, and with LA-ICP-MS measurements on fused glass discs. [ABSTRACT FROM AUTHOR]

The anaerobic digestion of sewage sludge in South Korean wastewater treatment plants is affected by seasonal factors and other influences, resulting in lower digestion efficiency and gas production, which cannot reach optimal yields. The aim of this study was to improve the digestion efficiency and gas production of sludge anaerobic digestion in a wastewater treatment plant (WWTP) by using data mining techniques to adjust operational parameters. Through experimental data obtained from the WWTP in Daegu City, South Korea, an artificial neural network (ANN) technology was used to adjust the range of the organic loading rate (OLR) and hydraulic retention rate (HRT) to improve the efficiency and methane gas production from anaerobic sludge digestion. Data sources were normalized, and data analysis including Pearson correlation analysis, multiple regression analysis and an artificial neural network for optimal results. The results of the study showed a predicted 0.5% increase in digestion efficiency and a 1.3% increase in gas production at organic loads of 1.26–1.46 kg/m3 day and an HRT of 26–30 days. This shows that the ANN model that we established is feasible and can be used to improve the efficiency and gas production of sludge anaerobic digestion. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine the total iodine content in Korean abalone (Haliotis discus hannai) and to investigate the bioavailability of iodine using an in vitro method. This research paper focuses on total iodine quantification in abalone (Haliotis discus hannai) and its components (viscera and muscle) using inductively coupled plasma mass spectrometry (ICP-MS). Additionally, an in vitro bioavailability study explored iodine absorption potential. Abalone pretreatment involved both the European standard method (ES) and microwave-assisted extraction method (MAE). The limits of detection (LOD) were 0.11 ng/g for both ES and MAE, with a limit of quantification (LOQ) of 5.4 ng/g for MAE. Accuracy, assessed using a reference material (fish muscle, ERM—BB422), showed values of 1.5 ± 0.010 mg/kg for ES and 1.6 ± 0.066 mg/kg for MAE, within an acceptable range of 1.4 ± 0.42 mg/kg. Precision, evaluated using the Horwitz ratio (HorRat) with a reference material, was determined to be 0.45 for ES and 0.27 for MAE. Therefore, total iodine contents were estimated as 74 ± 2.2 µg/g for abalone viscera and 17 ± 0.77 µg/g for abalone muscle with ES, and 76 ± 1.0 µg/g for abalone viscera and 17 ± 0.51 µg/g for abalone muscle with MAE. Recovery tests demonstrated an acceptable range of 90–110%. In the in vitro bioavailability assessment, digestion efficiency yielded ranges of 42–50.2% for viscera and 67–115% for muscle. Absorption efficiency variations were determined as 37–43% for viscera and 48–75% for muscle.

Simple Summary: Trypsin is frequently employed to cleave proteins ahead of mass spectrometry characterization. Traditionally, enzyme digestion involves overnight incubation of proteins at 37 °C, which is time consuming though still may yield poor digestion efficiency. While raising the temperature should theoretically accelerate the digestion, it also destabilizes the enzyme and promotes trypsin de-activation. We therefore questioned whether elevated temperature is beneficial for improving tryptic digestion. Here, we quantify protein digestion kinetics at elevated temperatures for calcium-stabilized trypsin and enforce the critical importance of calcium ions to preserve the enzyme. We quantitatively demonstrate that 1 h at 47 °C provides a superior digest when compared to conventional (overnight, 37 °C) processing of the proteome. The practical impact of our enhanced digestion protocol is shown through bottom-up mass spectrometry analysis of a complex proteome mixture. Bottom-up proteomics relies on efficient trypsin digestion ahead of MS analysis. Prior studies have suggested digestion at elevated temperature to accelerate proteolysis, showing an increase in the number of MS-identified peptides. However, improved sequence coverage may be a consequence of partial digestion, as higher temperatures destabilize and degrade the enzyme, causing enhanced activity to be short-lived. Here, we use a spectroscopic (BAEE) assay to quantify calcium-stabilized trypsin activity over the complete time course of a digestion. At 47 °C, the addition of calcium contributes a 25-fold enhancement in trypsin stability. Higher temperatures show a net decrease in cumulative trypsin activity. Through bottom-up MS analysis of a yeast proteome extract, we demonstrate that a 1 h digestion at 47 °C with 10 mM Ca2+ provides a 29% increase in the total number of peptide identifications. Simultaneously, the quantitative proportion of peptides with 1 or more missed cleavage sites was diminished in the 47 °C digestion, supporting enhanced digestion efficiency with the 1 h protocol. Trypsin specificity also improves, as seen by a drop in the quantitative abundance of semi-tryptic peptides. Our enhanced digestion protocol improves throughput for bottom-up sample preparation and validates the approach as a robust, low-cost alternative to maximized protein digestion efficiency. [ABSTRACT FROM AUTHOR]

The anaerobic digestion of sewage sludge in South Korean wastewater treatment plants is affected by seasonal factors and other influences, resulting in lower digestion efficiency and gas production, which cannot reach optimal yields. The aim of this study was to improve the digestion efficiency and gas production of sludge anaerobic digestion in a wastewater treatment plant (WWTP) by using data mining techniques to adjust operational parameters. Through experimental data obtained from the WWTP in Daegu City, South Korea, an artificial neural network (ANN) technology was used to adjust the range of the organic loading rate (OLR) and hydraulic retention rate (HRT) to improve the efficiency and methane gas production from anaerobic sludge digestion. Data sources were normalized, and data analysis including Pearson correlation analysis, multiple regression analysis and an artificial neural network for optimal results. The results of the study showed a predicted 0.5% increase in digestion efficiency and a 1.3% increase in gas production at organic loads of 1.26–1.46 kg/m3 day and an HRT of 26–30 days. This shows that the ANN model that we established is feasible and can be used to improve the efficiency and gas production of sludge anaerobic digestion.

Trypsin digestion plays a pivotal role in successful bottom-up peptide characterization and quantitation. While denaturants are often incorporated to enhance protein solubility, surfactants are recognized to inhibit enzyme activity. However, several reports have suggested that incorporating surfactants or other solvent additives may enhance digestion and MS detection. Here, we assess the impacts of ionic surfactants on cumulative trypsin activity and subsequently evaluate the total digestion efficiency of a proteome mixture by quantitative MS. Although low surfactant concentrations, such as 0.01% SDS or 0.2% SDC, significantly enhanced the initial trypsin activity (by 14 or 42%, respectively), time course assays revealed accelerated enzyme deactivation, evident by 10- or 40-fold reductions in trypsin activity half-life at these respective surfactant concentrations. Despite enhanced initial tryptic activity, quantitative MS analysis of a common liver proteome extract, digested with various surfactants (0.01 or 0.1% SDS, 0.5% SDC), consistently revealed decreased peptide counts and signal intensity, indicative of a lower digestion efficiency compared to a nonsurfactant control. Furthermore, including detergents for digestion did not improve the detection of membrane proteins, nor hydrophobic peptides. These results stress the importance of assessing cumulative enzyme activity when optimizing the digestion of a proteome mixture, particularly in the presence of denaturants.

The digestion of biogenic organic matter is an essential step of sample preparation within microplastic analyses. Organic residues hamper the separation of polymer particles especially within density separation or polymer identification via spectroscopic and staining methods. Therefore, a concise literature survey has been undertaken to identify the most commonly applied digestion protocols with a special focus on water and sediments samples. The selected protocols comprise different solutions, concentrations, and reaction temperatures. Within this study we tested acids (nitric acid and hydrochloric acid), bases (sodium hydroxide and potassium hydroxide), and oxidizing agents [hydrogen peroxide, sodium hypochlorite and Fenton's reagent (hydrogen peroxide 30% in combination with iron(II)sulfate 0.27%)] at different concentrations, temperature levels, and reaction times on their efficiency of biogenic organic matter destruction and the resistance of different synthetic polymers against the applied digestion protocols. Tests were carried out in three parallels on organic material (soft tissue—leaves, hard tissue—branches, and calcareous material—shells) and six polymers (low-density polyethylene, high-density polyethylene, polypropylene, polyamide, polystyrene, and polyethylene terephthalate) in two size categories. Before and after the application of different digestion protocols, the material was weighed in order to determine the degree of digestion efficiency and polymer resistance, respectively. The efficiency of organic matter destruction is highly variable. Calcareous shells showed no to very low reaction to oxidizing agents and bases, but were efficiently dissolved with both tested acids at all concentrations and at all temperatures. Soft and hard tissue were most efficiently destroyed by sodium hypochlorite. However, the other reagents can also have good effects, especially by increasing the temperature to 40–50°C. The additional temperature increase to 60–70°C showed a further but less effective improvement, compared to the initial temperature increase. The resistance of tested polymer types can be rated as good except for polyamide and polyethylene terephthalate. Increasing the concentrations and temperatures, however, results in accelerated degradation of all polymers. This is most evident for polyamide and polyethylene terephthalate, which show losses in weight between 15 and 100% when the digestion temperature is increased. This effect is most pronounced for polyamide in the presence of acids and for polyethylene terephthalate digested with bases. As a concluding recommendation the selection of the appropriate digestion method should be specifically tested within initial pre-tests to account for the specific composition of the sample matrix and the project objectives.

Abstract In group-living animals, social context is known to modulate physiology, behaviour and reproductive output as well as foraging and nutritional strategies. Here we investigate the digestive efficiency of 38 individuals belonging to different social categories of a semi-feral and individually marked flock of greylag geese (Anser anser). During 9 consecutive days in winter 2017, when the ground was fully covered with snow (i.e. no grass or other natural forage available) and the accessible food was standardized, 184 individual droppings were collected and analysed to estimate the apparent digestibility of organic matter (ADOM). Lignin was used as an indigestible internal marker in the food and droppings. The digestive efficiency was higher in pairs with offspring as compared to pairs without offspring or unpaired birds. Furthermore, individuals with high ADOM were more likely to breed successfully in the following season than those with low ADOM. Our findings demonstrate that social status modulates digestive efficiency, probably via a chain of physiological mechanisms including a dampened stress response in individuals enjoying stable social relationships with and social support by their family members (i.e. their own pair-partner and offspring). Our findings underline the importance of the social network in modulating physiology, such as digestive efficiency, and ultimately reproductive success.

As an energy‐saving and effective physical method, ultrasound technologies are gaining research attention for the production of modified starches. Corn starch–caffeic acid complexes are prepared via ultrasound process, and the effect of ultrasound power on the physicochemical properties and in vitro digestion of the complexes is investigated. The results of Fourier‐transform infrared spectroscopy and the amount of complexes analysis indicate that ultrasound can help with the formation of starch–caffeic acid complexes, and the amount of caffeic acid in complexes depended on the ultrasound power. Scanning electron microscopy shows starch–caffeic acid complexes exhibit obvious dense network structure with increasing ultrasound power. X‐ray diffraction results indicate the presence of V‐type crystalline polymorph between starch and caffeic acid under high power of ultrasound irradiation. The starch–caffeic acid complexes can significantly inhibit the swelling power of starch granules at high temperature and increase the solubility of starch granules. Furthermore, the in vitro digestion of starch–caffeic acid complexes is estimated, and the result shows that the resulting complexes from ultrasound have lower digestion properties. Taken together, it is proposed that ultrasound technology is an effective method for preparation of starch complexes with potential as a functional food and drug delivery system. [ABSTRACT FROM AUTHOR]

In this study the mixing quality of turbine impellers with blade angles of 30°, 45°, and 60° was studied on the anaerobic digestion efficiency using a new model based on mixing time, energy consumption, biogas compounds, and slurry characterizations. Study on the mixing process using a single indicator system based image processing technique showed a mixing for 5 and 10 min and pausing for 5 h. The results showed that (i) the impeller with blade angle of 30° and mixing time of 5 min consumed the least energy whereas produced the most CH 4 amounts associated with more TS, T.VS, C, and N degradation, (ii) the impeller with blade angle of 60° produced the least CO amounts associated with more COD and BOD removal, and (iii) the suitable mixing time decreased the CO and H 2 S production. The results confirmed that the significant effects of the impeller blade angle and mixing time on biogas compounds were because of changing the slurry characterizations during the mixing process. Using the new model for efficiency evaluation, the impeller with blade angle of 30° in mixing time of 5 min had the highest efficiency among the researched cases documented its favorite for better digestion in higher efficiency. • Suitable TIBA and t mix were determined based energy efficiency and digestion quality. • Increase N s from 30 to 100 rpm, reduced t mix <1.2 times but increased the P w > 37 times. • Suitable t mix , determined by image processing method, can affect CO and H 2 S compounds. • TIBA of 60° had the least CO and 30° had the most CH 4 related to removal slurry properties. • The efficiency-based new model showed TIBA = 30°, t mix = 5min had the highest efficiency. [ABSTRACT FROM AUTHOR]

Clarification of whether suspension-feeding infaunal bivalves are able to utilize benthic diatoms as food is essential for understanding coastal food webs. Although many benthic diatoms possess hard thickly siliceous cell walls (frustules), no study has examined if bivalves can effectively break their frustules to digest and assimilate the cell contents. In the present study, feeding rates and digestion efficiencies of the Manila clam fed on three benthic and a planktonic diatom species with different mechanical strengths (hardness) of frustules were compared to determine if the clam can efficiently break benthic diatoms with relatively hard frustules. Fragments of diatom frustules in the gut were observed using a scanning electron microscope. Although digestion efficiencies of the Manila clam were significantly different among the diatom species, the efficiencies were all above 90% for all four diatom species indicating that the Manila clam can efficiently crush hard diatom frustules of benthic species. The mechanism for crushing diatom cells in the gut appears to rely on the density of diatom cells ingested into the clam's stomach. By the rotation of the crystalline style, densely packed diatom cells in the stomach are agitated leading to attrition with each other, and subsequently the frustules are ruptured. The results of the present study indicate that when benthic diatoms are suspended in the water column the Manila clam can effectively utilize benthic diatoms as a major food source irrespective of the hardness of the diatom's frustules. [ABSTRACT FROM AUTHOR]

Abstract: Evolutionary morphological and physiological differences between browsers and grazers contribute to species‐specific digestion efficiency of food resources. Rumen microbial community structure of browsers is supposedly adapted to characteristic nutrient composition of the diet source. If this assumption is correct, domesticated ruminants, or grazers, are poor model animals for assessing the nutritional value of food consumed by browsing game species. In this study, typical spring and summer foods of the European moose (Alces alces) were combined with rumen fluid collected from both dairy cows (Bos taurus) and from moose, with the aim of comparing fermentation efficiency and microbial community composition. The nutritional value of the food resources was characterized by chemical analysis and advanced in vitro measurements. The study also addressed whether or not feed evaluation based on in vitro techniques with cattle rumen fluid as inoculum could be a practical alternative when evaluating the nutritional value of plants consumed by wild browsers. Our results suggest that the fermentation characteristics of moose spring and summer food are partly host‐specific and related to the contribution of the bacterial phyla Firmicutes and Bacteriodetes to the rumen microbial community. Host‐specific adaptations of the ruminal microbial community structure could be explained from the evolutionary adaptations related to feeding habitats and morphophysiological differences between browsers and grazers. However, the observed overall differences in microbial community structure could not be related to ruminal digestion parameters measured in vitro. The in vitro evaluation of digestion efficiency reveals that equal amounts of methane were produced across all feed samples regardless of whether the ruminal fluid was from moose or dairy cow. The results of this study suggested that the nutritional value of browsers' spring and summer food can be predicted using rumen fluid from domesticated grazers as inoculum in in vitro assessments of extent of digestion when excluding samples of the white water lily root, but not of fermentation characteristics as indicated by the proportions of individual fermentation fatty acids to the total of volatile fatty acids. [ABSTRACT FROM AUTHOR]

By-products from the food industry can be valuable ingredients in animal feeds. One example is olive cake (OC), generated in large amounts by the olive oil industry, which contains oil with a high proportion of oleic acid and polyphenols. An experiment was performed using pigs to determine the nutritional value of crude (COC) and partially defatted (PDOC) olive cake, and to evaluate their effect on nutrient balance, slurry properties and potential ammonia (NH 3 ) and methane (CH 4 ) emissions. Five experimental feeds were designed; a basal diet and another four diets produced by substituting 100 or 200 g/kg of the basal diet with either COC or PDOC. Thirty finishing male pigs (76.1 ± 4.2 kg initial BW) were used in the experiment (6 animals/treatment). After a 14-day adaptation period, faeces and urine were collected separately for 7 days to measure nutrient digestibility and the excretory patterns of nitrogen. Potential NH 3 and CH 4 emissions were measured in reconstituted slurry samples over 11 and 100 days, respectively. The dry matter (DM), crude protein (CP), cellulose, starch and energy coefficients of total tract apparent digestibility (CTTAD) were negative and linearly (P < 0.05) affected by OC inclusion level. However, the type of OC did not influence any of the digestion efficiencies studied. The energy digestibility of the ingredients tested, estimated by substitution, were 0.479 (±0.040, SEM) and 0.327 (±0.049) for COC and PDOC, respectively. Overall, the results indicate a digestible energy (DE) value from COC and PDOC that account respectively for around 80 or 60% of the DE provided by barley grain in pigs. Faecal content of cellulose, polyphenols and gross energy (GE) increased linearly with OC inclusion, whereas ash content decreased. The total N content of urine decreased linearly with OC inclusion, but benzoic and hippuric acid contents increased, which resulted in lower pH values for the OC diets. The ratio between faecal and urine N excretion decreased from 2.48 in the basal diet to 1.01 on average in the 200 g/kg OC diets. As a result, increasing both COC and PDOC levels in diets resulted in lower NH 3 emissions per volume of slurry and in a lower biochemical CH 4 potential. Although slurry excretion increased with OC inclusion, daily NH 3 emissions still decreased with increasing OC inclusion. However, potential CH 4 emissions per animal increased. A global perspective throughout the production chain is needed to assess the impact of including OC in pig diets on gaseous emissions. [ABSTRACT FROM AUTHOR]

Huge variation of drug transporter abundance was seen in the literature, making PBPK prediction difficult when transporters play a major role. Among multiple factors such as membrane fraction, digestion, and peptide selection that contributed to such variation, peptide selection is the least discussed. Herein, a strategy was established by using a small amount of purified protein standard to select a peptide with near 100% digestion efficiency for quantitation of a transporter protein MDR1. The impact of native membrane protein's tertiary structure on the digestion efficiency of surrogate peptides of MDR1 was investigated. Peptides in more solvent accessible regions are found to be digested much more efficiently than those in large stretches of helical structures. The concentration of peptide EALDESIPPVSFWR(EAL) in the most solvent accessible linker region of MDR1 was found closest to the true protein concentration. When using EAL for MDR1 quantitation, the abundance is over 10 times higher than previously reported, indicating the importance of peptide selection for transporter quantitation. In addition, this study also proposes a screening strategy to select peptides appropriate for relative quantitation for in vitro- in vivo extrapolation in the absence of any protein standard. [ABSTRACT FROM AUTHOR]

Trypsin is the most widely used enzyme in proteomic research due to its high specificity. Although the in-solution digestion is predominantly used, it has several drawbacks, such as long digestion times, autolysis, and intolerance to high temperatures or organic solvents. To overcome these shortcomings trypsin was covalently immobilized on solid support and tested for its proteolytic activity. Trypsin was immobilized on bridge-ethyl hybrid silica sorbent with 300 Å pores, packed in 2.1 × 30 mm column and compared with Perfinity and Poroszyme trypsin columns. Catalytic efficiency of enzymatic reactors was tested using N α -Benzoyl- l -arginine 4-nitroanilide hydrochloride as a substrate. The impact of buffer pH, mobile phase flow rate, and temperature on enzymatic activity was investigated. Digestion speed generally increased with the temperature from 20 to 37 °C. Digestion speed also increased with pH from 7.0 to 9.0; the activity of prototype enzyme reactor was highest at pH 9.0, when it activity exceeded both commercial reactors. Preliminary data for fast protein digestion are presented. [ABSTRACT FROM AUTHOR]

This research aimed to investigate effects of protein source in practical diets on nutrient excretion and potential emissions of ammonia (NH 3 ) and methane (CH 4 ) in pigs. Three experimental feeds were designed to substitute a mixture of soybean meal and soybean hulls (SB diet) with sunflower meal (SFM) or wheat DDGS (WDDGS). The proportion of other ingredients was also modified in order to maintain similar nutrient contents across diets. Changes in protein source led to differences in dietary content of neutral detergent insoluble crude protein, soluble fibre (SF) and acid detergent lignin. Twenty-four pigs (8 per diet), weighing 52.3 or 60.8 kg at the first and second batch, respectively, were housed individually in metabolic pens to determine during a 7-day period dry matter (DM) balance, coefficients of total tract apparent digestibility (CTTAD) of nutrients, and faecal and urine composition. Representative slurry samples from each animal were used to measure NH 3 and CH 4 emissions over an 11 and/or 100-day storage period, respectively. Neither DM intake, nor DM or energy CTTAD differed among experimental diets, but type of feed affected ( P < 0.001) crude protein (CP) digestibility, which was highest for SFM (0.846) than for SB (0.775) diet, with WDGGS-based diet giving an intermediate value (0.794). Faecal DM composition was influenced ( P < 0.001) accordingly, with the lowest CP concentration found for diet SFM and the highest for SB. The ratio of N excreted in urine or faeces decreased from SFM (1.63) to SB diet (0.650), as a consequence of both lower urine and higher faecal losses, with all the faecal N fractions increasing in parallel to total excretion. This result was parallel to a decrease of potential NH 3 emission (g/kg slurry) in diet SB with respect to diet SFM (from 1.82 to 1.12, P < 0.05), giving slurry from WDGGS-based diet an intermediate value (1.58). Otherwise, SF and insoluble neutral detergent fibre (aNDFom) CTTAD were affected ( P < 0.001 and P = 0.002, respectively) by type of diet, being lower for SFM than in SB-diet; besides, a higher content of aNDFom (491 vs 361 g/kg) on faecal DM was observed for SFM with respect to SB, with WDDGS-based diet being intermediate. Degree of lignification of aNDFom of faeces decreased in the order SFM > WDDGS > SB (from 0.171 to 0.109 and 0.086, respectively) in parallel to a decrease of potential CH 4 emission per g of OM of slurry (from 301 to 269 and 256 mL, respectively). When both gaseous emissions were expressed per animal and day, differences followed the same trend, but did not reach significant levels. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish the relationships between faecal fat concentration and gaseous emissions from pig slurry. Five diets were designed to meet essential nutrient requirements: a control and four experimental feeds including two levels (35 or 70 g/kg) of calcium soap fatty acids distillate (CSP) and 0 or 200 g/kg of orange pulp (OP) combined in a 2 × 2 factorial structure. Thirty growing pigs (six per treatment) were used to measure dry matter (DM) and N balance, coefficients of total tract apparent digestibility (CTTAD) of nutrients, faecal and urine composition and potential emissions of ammonia (NH 3 ) and methane (CH 4 ). Increasing dietary CSP level decreased DM, ether extract (EE) and crude protein (CP) CTTAD (by 4.0, 11.1 and 3.5%, respectively, P < 0.05), but did not influence those of fibrous constituents. It also led to a decrease (from 475 to 412 g/kg DM, P < 0.001) of faecal concentration of neutral detergent fibre (aNDFom) and to an increment (from 138 to 204 g/kg, P < 0.001) of EE in faecal DM that was related to greater CH 4 emissions, both per gram of organic matter ( P = 0.021) or on a daily basis ( P < 0.001). Level of CSP did not affect N content in faeces or urine, but increased daily DM ( P < 0.001), and N ( P = 0.031) faecal excretion with no effect on urine N excretion. This resulted in lesser ( P = 0.036) NH 3 potential emission per kg of slurry. Addition of OP decreased CTTAD of EE (by 7.9%, P = 0.044), but increased ( P < 0.05) that of all the fibrous fractions. As a consequence, faecal EE content increased (from 165 to 177 g/kg DM; P = 0.012), and aNDFom decreased greatly (from 483 to 404 g/kg DM, P < 0.001), which in all resulted in a lack of effect of OP on CH 4 potential emission. Inclusion of OP in the diet also led to a significant decrease of CP CTTAD (by 6.85%, P < 0.001), and to an increase of faecal CP concentration (from 174 to 226 g/kg DM, P < 0.001), with no significant influence on urine N content. These effects resulted in higher N faecal losses, especially those of the undigested dietary origin, without significant effects on potential NH 3 emission. No significant interactions between CSP and OP supplementation were observed for the gaseous emissions measured. [ABSTRACT FROM AUTHOR]

An experiment was conducted to investigate the effects of increasing the level of two sources of fibrous by-products, orange pulp (OP) and carob meal (CM), in iso-NDF growing-finishing pig diets on nutrient balance, slurry composition and potential ammonia (NH 3 ) and methane (CH 4 ) emissions. Thirty pigs (85.4 ± 12.3 kg) were fed five iso-nutritive diets: a commercial control wheat/barley (C) and four experimental diets including two sources of fibrous by-products (OP and CM) and two dietary levels (75 and 150 g/kg) in a 2 × 2 factorial arrangement. After a 14-day adaptation period, faeces and urine were collected separately for 7 days to measure nutrient digestibility and the excretory patterns of N from pigs (6 replicates per diet) housed individually in metabolic pens. For each animal, the derived NH 3 and CH 4 emissions were measured in samples of slurry over an 11- and 100-day storage periods, respectively. Source and level of the fibrous by-products affected digestion efficiency in a different way as the coefficients of total tract apparent digestibility (CTTAD) for dry matter (DM), organic matter (OM), fibre fractions and gross energy increased with OP but decreased with CM ( P < 0.05). Crude protein CTTAD decreased with the inclusion of both sources of fibre, being lower at the highest dietary level. Faecal concentration of fibre fractions increased ( P < 0.05) with the level of inclusion of CM but decreased with that of OP ( P < 0.01). High dietary level for both sources of fibre increased ( P < 0.02) CP faecal content but urine N content decreased (from 205 to 168 g/kg DM, P < 0.05) in all the fibre-supplemented compared to C diet. Additionally, the proportions of undigested dietary, water soluble, and bacterial and endogenous debris of faecal N excretion were not affected by treatments. The initial slurry characteristics did not differ among different fibre sources and dietary levels, except pH, which decreased at the highest by-product inclusion levels. Ammonia emission per kg of slurry was lower in all the fibre-supplemented diets than in C diet (from 2.44 to 1.81 g, P < 0.05). Additionally, slurries from the highest dietary level of by-products tended ( P < 0.06) to emit less NH 3 per kg of initial total Kjeldahl N and showed a lower B 0 , independently of the fibre source. Thus, the fibre sources and their dietary levels affected pig nutrient digestion and composition of urine and faeces, showing potential to decrease NH 3 and CH 4 emissions at high levels of inclusion, independently of type of fibre. [ABSTRACT FROM AUTHOR]

Many prey organisms reduce their activity to reduce predation risk. A common argument is that a reduction in activity is one of the highest costs of defence. I exposed predator-induced and predator-naïve morphs to a short-term predator environment and recorded behavioural, life-historical, physiological, and morphological responses. In contrast to expectation, reduced activity was not one of the highest costs of responding to predators. Predator-exposed tadpoles ingested the same amount of food with less feeding effort and evacuated food from their guts at a higher rate. Despite these advantages, predator-exposed tadpoles still paid costs in responding to predators, in decreased development rate. They did not have reduced survival or reduced growth. Costs in responding to predators are probably caused by physiological factors, such as reduced conversion rates, increased metabolic rates or by allocation to morphological defences, such as increased tail depth. My results show that feeding activity is not linked to the amount of food ingested and that physiological mechanisms, such as gut evacuation, decouple feeding activity and ingestion from growth, development and survival. There was no adaptive response in gut morphology. My study improves the understanding of the underlying internal and physiological mechanisms mediating the trade-off between activity and costs of predator-induced defences. [Copyright &y& Elsevier]

We investigated the mechanism and efficiency of digestion of two types of pollen, maize, Zea mays, and sunflower, Helianthus annuus, by the spotted maize beetle, Astylus atromaculatus (Melyridae). We found similar and high extraction efficiencies, but different mechanisms of digestion. Osmotic shock was apparently involved in digestion of the large and thin-walled maize pollen grains. In the anterior midgut most maize pollen grains were already ruptured, in contrast with the intact exines of sunflower pollen, which suggests another mechanism of digestion for the latter, such as enzymatic action. We investigated the effect of osmotic shock on maize pollen in vitro by looking at the behavior of pollen grains in varying osmotic concentrations. Maize pollen grains burst in both distilled water and sugar solutions of various concentrations, and the amount of rupturing decreased with an increase in sugar concentration. Digestion of maize pollen was much slower in honeybees than in spotted maize beetles. Maize pollen bursts early in the midgut of maize beetles, but remains intact in honeybees: this suggests that osmotic shock may not be as important for honeybees as previously suggested. [Copyright &y& Elsevier]

[Display omitted] • The intrinsic drawbacks of WAS for efficient AD process are disclosed. • The main inhibitory mechanisms of interfering pollutants for WAS AD were analyzed. • Potential strategies for mitigating the restrictions on WAS digestion are revealed. • The future directions for the improvement of WAS digestion are proposed. Anaerobic digestion (AD) is an effective approach for waste activated sludge (WAS) disposal with substantial recovery of valuable substrates. Previous studies have extensively explored the correlations of common operational parameters with AD efficiency, but the impacts of intrinsic characteristics of WAS on the AD processes are generally underestimated. This study focused on disclosing the association of intrinsic drawbacks in WAS with AD performance, and found that the cemented WAS structure, low fraction of biomass and various high levels of inhibitory pollutants (e.g. , organic pollutants and heavy metals), as the integral parts of WAS all greatly restricted the AD performance. The main potential strategies and underlying mechanisms to mitigate the restrictions for efficient WAS digestion, including the practical pretreatment methods, bioaugmentation and aided substances addition, were critically analyzed. Also, future directions for the improvement of WAS digestion were proposed from the perspectives of technical, management and economic aspects. [ABSTRACT FROM AUTHOR]

[Display omitted] • The functional microbes play critical roles in the anaerobic digestion of organics. • The shift of microbial community associated with operational factors is disclosed. • The Firmicutes and hydrogenotrophic methanogens are more adaptive in AD. • The research gaps for the evolution principles of anaerobic species are proposed. Anaerobic digestion (AD) processes are promising to effectively recover resources from organic wastes or wastewater. As a microbial-driven process, the functional anaerobic species played critical roles in AD. However, the lack of effective understanding of the correlations of varying microbial communities with different operational factors hinders the microbial regulation to improve the AD performance. In this paper, the main anaerobic functional microorganisms involved in different stages of AD processes were first demonstrated. Then, the response of anaerobic microbial community to different operating parameters, exogenous interfering substances and digestion substrates, as well as the digestion efficiency, were discussed. Finally, the research gaps and future directions on the understanding of functional microorganisms in AD were proposed. This review provides insightful knowledge of distribution patterns of functional microbial community in anaerobic digesters, and gives critical guidance to regulate and enrich specific functional microorganisms to accumulate certain AD products. [ABSTRACT FROM AUTHOR]

Based on a synergistic digestion method of ultraviolet combined with ozone (UV/O3), this article investigates the reaction characteristics of nitrogen-containing compounds (N-compounds) in water and the influence of ions on digestion efficiency. In this respect, a novel and efficient AOPs-based dual-environmental digestion method for the determination of total dissolved nitrogen (TDN) in waters with complex components is proposed, in the hopes of improving the detection efficiency and accuracy of total nitrogen via online monitoring. The results show that inorganic and organic N-compounds have higher conversion rates in alkaline and acidic conditions, respectively. Meanwhile, the experimental results on the influence of Cl−, CO32−, and HCO3− on the digestion process indicate that Cl− can convert to radical reactive halogen species (RHS) in order to promote digestion efficiency, but CO32− and HCO3− cause a cyclic reaction consuming numerous •OH, weakening the digestion efficiency. Ultimately, to verify the effectiveness of this novel digestion method, total dissolved nitrogen samples containing ammonium chloride, urea, and glycine in different proportions were digested under the optimal conditions: flow rate, 0.6 L/min; reaction temperature, 40 °C; pH in acidic conditions, 2; digestion time in acidic condition, 10 min; pH in alkaline conditions, 11; digestion time in alkaline conditions, 10 min. The conversion rate (CR) of samples varied from 93.23% to 98.64%; the mean CR was greater than 95.30%. This novel and efficient digestion method represents a potential alternative for the digestion of N-compounds in the routine analysis or online monitoring of water quality. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar sustained high digestion performance and low membrane fouling of AnMBRs. • Electron transfer system activity and VFAs degradation were enhanced by biochar. • Biochar improved the sludge filtration property and decreased the hydrophobic DOM. • Biochar decreased the cake/gel foulants ratio by mitigating cake layer formation. The enhancement effects of biochar to an anaerobic membrane bioreactor (AnMBR) treating sewage at low temperatures was investigated in this study through analyzing organics removal, digestion performance, mixed liquor properties, membrane resistance, and foulant compositions. The chemical oxygen demand (COD) removal efficiency and the COD converted to methane rate increased by more than 12.5% at 10 °C, mainly because of the promotion of biochar to volatile fatty acids degradation. Although biochar caused higher dissolved organic matter (DOM) concentration in the AnMBR, it improved the filtration property of the bulk sludge and absorbed the hydrophobic DOM. The decreased filtration resistance assisted by biochar leads to a prolonged membrane operation duration over 200%. Surface foulants, especially cake foulants, were largely mitigated by the enhanced scouring intensity of mixed liquor at the membrane surface, and hence, decreasing the cake/gel foulants ratio. [ABSTRACT FROM AUTHOR]

• Leather fleshing waste was co-digested with food waste leachate. • Characteristics of substrate affected microbial community structure. • The changes of microbial communities influenced biogas production performance. • High lipid content in co-substrate was related to high biogas production yield. • Protein rich characteristic of co-substrate exhibited fast biogas production rate. In this study, leather fleshing waste (LFW) and a complementary substrate (food waste leachate; FWL) were co-digested. The main focus of research was to study effects on biogas production caused by interactions between co-substrates when combined in different mixing ratios and changes on microbial community structures. Due to a positive effect of co-digestion (i.e. , establishing nutrient equilibrium), the adjusted substrates for optimum C/N ratio by blending LFW and FWL resulted in significantly higher biodegradability and biomethane production (375.5–520.8 mL CH 4 g−1 VS) than the mono-digestion of each substrate. According to co-digestion of LFW and FWL, microbial communities became more diverse and the changes of microbial structure influenced the biomethane production performance. Among the co-digesting conditions, the biomethane production yield and rate of the samples were in reverse order and the results were firmly associated with the relative richness of lipids (yield-related) and proteins (rate-related) in the co-substrates. [ABSTRACT FROM AUTHOR]

Over the past two decades, the alkaline persulfate oxidation (PO) with thermal and/or ultraviolet (UV) assisted digestion method has been widely used for digestion of nitrogen containing compounds (N-compounds) in water quality routine analysis in laboratory or on-line analysis, due to its simple principle, high conversion rate, high percent recovery, low-cost. However, this digestion method still has some inevitable problems such as complex operations, high contamination potential, batch N blanks, higher reaction temperature (120–124 °C) and time-consuming (30–60 min). In this study, ozone (O3) was selected as the oxidant for digestion of N-compounds through analysis and comparison firstly. Secondly, we proposed and compared the UV and/or ultrasound (US) combined with ozone (UV/O3, US/O3 and UV/US/O3) synergistic digestion methods based on O3 with sole O3 oxidation method on digestion efficiency (digestion time and conversion rate) of standard N-compounds. Simultaneously, the influence of reaction temperature, pH of water sample, concentration of O3 and mass flow rate, UV intensity, US frequency and power on digestion efficiency were investigated, and then the optimum parameters for digestion system were obtained. Experimental results indicated that UV radiation can effectively induce and promote the decomposition and photolysis of O3 in water to generate hydroxyl radicals (•OH), while US can promote the diffusion and dissolution of O3 in water and intensify the gas-liquid mass transfer process for the reaction system. Meanwhile, results showed that the UV/US/O3 synergistic digestion method had the best digestion efficiency under the optimum conditions: water sample volume, 10 mL; pH of water sample, 11; O3 mass flow rate, 3200 mg/h; reaction temperature, 30 °C; digestion time, 25 min; UV lamp power, 18 W; distance between UV lamp and reactor, 2 cm; US frequency, 20 kHz; US power, 75 W. The conversion rate (CR) of synthetic wastewater samples varied from 99.6% to 101.4% for total dissolved nitrogen (TDN) in the range of 1.0~4.0 mg/L. The UV/US/O3 synergistic digestion method would be an effective and potential alternative for digestion of N-compounds in water quality routine analysis in laboratory or on-line analysis. [ABSTRACT FROM AUTHOR]

All shotgun proteomics experiments rely on efficient proteolysis steps for sensitive peptide/protein identification and quantification. Previous reports suggest that the sequential tandem LysC/trypsin digest yields higher recovery of fully tryptic peptides than single-tryptic proteolysis. Based on the previous studies, it is assumed that the advantageous effect of tandem proteolysis requires a high sample denaturation state for the initial LysC digest. Therefore, to date, all systematic assessments of LysC/trypsin proteolysis are done in chaotropic environments such as urea. Here, sole trypsin is compared with LysC/trypsin and it is shown that tandem digestion can be carried with high efficiency in Mass Spectrometry-compatible detergents, thereby resulting in higher quantitative yields of fully cleaved peptides. It is further demonstrated that higher cleavage efficiency of tandem digests has a positive impact on absolute protein quantification using intensity-based absolute quantification (iBAQ) values. The results of the examination of divergent urea tandem conditions imply that beneficial effects of the initial LysC digest do not depend on the sample denaturation state, but, are mainly caused by different target specificities of LysC and trypsin. The observed detergent compatibility enables tandem digestion schemes to be implemented in efficient cellular solubilization proteomics procedures without the need for buffer exchange to chaotropic environments., (© 2019 The Authors. Proteomics published by Wiley-VCH Verlag GmbH & Co. KGaA.)