Digestion Mixture Research Articles

ASSESSING A MODIFIED CARBONATE DIGESTION PROTOCOL FOR INCREASED CARBON DIOXIDE RECOVERY DURING CREMATED BONE PRETREATMENT

ABSTRACT Cremated bones are a commonly preserved material and often found in burial environments where unburned bone may not be preserved. As such direct radiocarbon dating of cremated bone could be essential in determining the chronology of an event. Pretreatment of cremated bone exploits the structural carbonate component of the bone which survives cremation. However, due to the low abundance (ca. 0.1%) of this component, the extraction of an amount of endogenous carbon sufficient for radiocarbon dating may represent a challenge. Here we investigate two modifications to the phosphoric acid digestion protocol used during the preparation of cremated bones at the Oxford Radiocarbon Accelerator Unit (ORAU). The first of these was to use ultrasonication to release evolved CO2 from the viscous phosphoric acid and cremated bone mixture that is formed during digestion. The second was to double the amount of time during which evolved CO2 was removed from the reaction vessel by transfer into a cryogenically cooled ampoule. Ultrasonication of the digestion mixture failed to produce a significantly higher carbon yield, while double-time collection resulted in an average 21.5±13.8% increase of C yield without affecting the measured age. Extending the collection time can better enable reliable dating of small (less than 1 g) samples.

Enhanced biological phosphorus removal from wastewater with synergistic treatment via anaerobic digestion and micro electrolysis

Anaerobic digestion coupled with micro electrolysis was employed to enhance biological anaerobic phosphorus removal. The anaerobic reactor with the micro electrolysis material maintained a relatively lower total phosphorus (TP) in the digestion mixture and a higher PH3 content in the digestion gas than the control system with no filler, which facilitated phosphorus removal due to PH3 formation. The PH3 release was positively correlated with indicators such as H2 content, COD concentration, and activity of the electron transfer system. The addition of Fe-C and Fe-Mn-C fillers promoted the biochemical metabolism of organic substrates, and the digestion systems had lower chemical oxygen demand, total nitrogen, and TP during continuous operation. The average TP in the control system was 7.0 mg L−1 from 11 d to 40 d; however, the mean values in the Fe-C and Fe-Mn-C systems were 5.1 and 4.7 mg L−1, respectively. In a conventional anaerobic digestion system, electrons and hydrogens preferentially transfer to sulfate to produce H2S, resulting in a decrease in reducing power. As micro electrolysis material was added to the wastewater, the dissolved Fe2+ or Mn2+ ions combined with sulfur ions to form sulphide precipitates, mitigating the biological toxicity derived from H2S and reducing the consumption of reactive hydrogen. Hence, electrons and hydrogen accumulate and subsequently facilitate the reduction of PH3 formation and methane synthesis. This study provides new insights into the biological dephosphorisation of wastewater.

Preparation of magnetic carbon nitride composite toward phosphopeptide enrichment

Protein phosphorylation plays an important role in cellular signaling and disease development. Advances in mass spectrometry-based proteomics have enabled qualitative and quantitative phosphorylation studies as well as in-depth biological explorations for biomarker discovery and signaling pathway analysis. However, the dynamic changes that occur during phosphorylation and the low abundance of target analytes render direct analysis difficult because mass spectral detection offers no selectivity, unlike immunoassays such as Western blot and enzyme-linked immunosorbent assay (ELISA). The present study aimed to solve one of the key problems in the specific and efficient isolation of phosphorylated peptides. A method based on a magnetic carbon nitride composite coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was developed for the enrichment and analysis of phosphopeptides with low abundance in complex samples. Magnetic carbon nitride composite was synthesized and characterized by electron microscopy, infrared spectroscopy, and X-ray diffractometry. The composite showed a well-distributed two-dimensional layered structure and functional groups with excellent paramagnetic performance. Two classical phosphoproteins, namely, α- and β-caseins, were selected as model phosphorylated samples to assess the performance of the proposed enrichment technique. The magnetic carbon nitride composite exhibited high selectivity and sensitivity for phosphopeptide enrichment. The limit of detection was determined by MALDI-TOF-MS analysis to be 0.1 fmol. The selectivity of the method was investigated using the digest mixtures of α-casein, β-casein, and bovine serum albumin (BSA) with different mass ratios (1∶1∶1000, 1∶1∶2000, and 1∶1∶5000). Direct analysis of the samples revealed the dominance of spectral signals from the abundant peptides in BSA. After enrichment with the magnetic carbon nitride composite, the high concentration of background proteins was washed away and only the signals of the phosphopeptides were captured. The signals from the casein proteins were clearly observed with little background noise, indicating the high selectivity of the composite material. The robustness of the method was tested by assessing the reusability of the same batch of magnetic carbon nitride materials over 20 cycles of enrichment. The composite showed nearly the same enrichment ability even after several cycles of reuse, demonstrating its potential applicability for a large number of clinical samples. Finally, the method was applied to the analysis of phosphopeptides from several commonly used phosphoprotein-containing samples, including skimmed milk digest, human serum, and human saliva; these samples are significant in the analysis of food quality, disease biomarkers, and liquid biopsies for cancer. Without enrichment, no phosphopeptide was detected because of the high abundance of nonphosphopeptide materials dominating the spectral signals obtained. After pretreatment with the developed magnetic carbon nitride composite, most of the phosphosites were identified with high selectivity and sensitivity via MALDI-TOF-MS. These results revealed the practicality of the developed approach for clinical applications. In addition, our method may potentially be employed for phosphoproteomics with real complex biological samples.

Study on phosphonylation and modification characteristics of organophosphorus nerve agents on multi-species and multi-source albumins

Protein adducts are vital targets for exploring organophosphorus nerve agents (OPNAs) exposure and identification, that can be used to characterize the chemical burden and initiate chemical safety measures. However, the use of protein adducts as biomarkers of OPNA exposure has developed slowly. To further promote the development of biomarkers in chemical forensics, it is crucial to expand the range of modified peptides and active sites, and describe the characteristics of OPNA adducts at specific reaction sites. This study utilized multi-species and multi-source albumins as the protein targets. We identified 56 peptides in albumins from various species (including human, horse, rat and pig), that were modified by at least two OPNAs. Diverse modification characteristics were observed in response to certain agents: including (1) multiple sites on the same peptide modified by one or more agents, (2) different reactivities at the same site in homologous albumins, and (3) different preferences at the same active sites associated with differences in the biological matrix during exposure. Our studies provided an empirical reference with rationalized underpinnings supported by estimated conformation energetics through molecular modeling.We employed different peptide markers for detection of protein adducts, as (one would do) in forensic screening for identification and quantification of chemical damage. Three characteristic peptides were screened and analyzed in human albumin, including Y287ICENQDSISSK, K438VPQVS443TPTLVEVSR, and Y162LY164EIAR. Stable fragment ions with neutral loss were found from their tandem MS/MS spectra, which were used as characteristic ions for identification and extraction of modified peptides in enzymatic digestion mixtures. Coupling these observations with computer simulations, we found that the structural stability of albumin and albumin-adduct complexes (as well as the effective force that promotes stability of different adducts) changes in the interval before and after adduct formation. In pig albumin, five active peptides existed stably in vivo and in vitro. Most of them can be detected within 30 min after OPNA exposure, and the detection window can persist about half a month. These early findings provided the foundation and rationale for utilizing pig albumin as a sampling target for rapid analysis in future forensic work.

Graphene oxide as inhibitor on the hydrolysis of fats under simulated in vitro duodenal conditions

Obesity is a global pandemic, thus novel developments that reduce the absorption of fats is of interest. We have evaluated the effect of graphene oxide (GO) on the lipase catalyzed hydrolysis of fats (tributyrin, sunflower and olive oil) under simulated duodenal conditions. Results indicate that the presence of GO in the digestion mixture can inhibit lipase activity up to a 90% of the initial reaction rate, and this inhibition lasts even during 2 h of digestion. The inhibition mechanism seems non competitive and could be opposite to the effect of bile salts, although the direct interaction between GO and the enzyme cannot be discarded. The inhibition is found also in alimentary fats suggesting that GO could be a strong inhibitor for fat hydrolysis.

Quality Assessment of Some Herbal Aphrodisiac Instant Coffee Premix Products Marketed in Kaduna, Nigeria

Aphrodisiac refers to any substance (food, drink or drug) or practice that is believed to stimulate sexual desire or enhance sexual pleasure and performance. There have been reports indicating lack of good manufacturing practices and adulteration of herbal aphrodisiac with phosphodiestrate-5 (PDE-5) inhibitors without consideration of public safety. The aim of this study is to assess the quality of three herbal aphrodisiac instant coffee premix products, through physicochemical analysis, elemental analysis, quantification of caffeine, detection and quantification of undeclared adulterants. Physicochemical properties of the three samples of herbal aphrodisiac products were determined using the methods described by World Health Organization 2011, while elemental analysis was conducted using nitric acidhydrochloric acid (1:3) digestion mixtures and subsequent analysis for the presence of lead, copper, cadmium, zinc and iron using micro plasma atomic emission spectrophotometer (MP-AES). Iodometric titration was used for quantification of caffeine levels in the samples while fourier transform infrared (FTIR) and ultraviolet (UV) spectroscopy were used for the detection and quantification of undeclared adulterants respectively. Moisture content (2.33 %, 2.83 % and 1.60 %) and ash value (10.50 %, 11.67 % and 0.98 %) of the samples A, B and C respectively were found to be within the official permissible limit. The samples were found to be rich in iron and zinc; however, the levels of lead, cadmium, and copper were above the WHO permissible limits. The concentrations of caffeine in the samples were less than the acceptable WHO limit of 400 mg/day. However, sildenafil was detected in two of the products (151.45 mg and 82.15 mg), while tadalafil was detected in one of the products (36.13 mg). The herbal aphrodisiacs were adulterated with either sildenafil or tadalafil, and contained relatively high levels of lead, cadmium, and copper. However, moisture content, ash value, and caffeine content met the WHO requirements.

Co-stimulatory pathway competitive assay development using Liquid chromatography–tandem mass spectrometry (LC-MS/MS)

T-cells play a significant role in the development of autoimmune diseases. The CD28-B7 costimulatory pathway is crucial for activating T-cells, and blocking this pathway is essential for treating autoimmune diseases. Therapeutic antibodies and fusion proteins that target costimulatory molecules like CD80, CD86, CTLA-4, and CD28 have been developed to explore the costimulation process and as targeted treatments. To advance our understanding of costimulation in autoimmunity and the inhibition of the costimulatory pathway, it is crucial to have an accurate, precise, and direct method for detecting and quantifying the soluble form of these molecules in body fluids and various biological systems. Herein, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying the four costimulatory proteins depending on the signature peptides derived from the soluble isoform of these proteins in multiple reaction monitoring (MRM) mode. The method was validated using the US FDA guidelines. The LOQ was determined as ∼0.5 nM for the four analytes, with quantification extended to 20 nM with a correlation coefficient of R2>0.998. The developed MRM method was used to analyze on-bead digested protein mixtures to establish a competitive assay for the CD28-B7 costimulatory pathway using CTLA4-Ig (Abatacept ™) as an FDA-approved drug for rheumatoid arthritis. The IC50 was determined to be 2.99 and 159.8 nM for sCD80 and sCD86, respectively. A straightforward MRM-based competitive assay will advance the knowledge about the costimulatory role in autoimmunity and the autoimmune therapeutic drug discovery, with the need for broad application on different in vitro and in vivo models to discover new targeted inhibitors.

Investigating the Merits of Microfluidic Capillary Zone Electrophoresis-Mass Spectrometry (CZE-MS) in the Bottom-Up Characterization of Larger RNAs.

Established bottom-up approaches for the characterization of nucleic acids (NAs) rely on the strand-cleavage activity of nucleotide-specific endonucleases to generate smaller oligonucleotides amenable to gas-phase sequencing. The complexity of these hydrolytic mixtures calls for the utilization of a front-end separation to facilitate full mass spectrometric (MS) characterization. This report explored the merits of microfluidic capillary zone electrophoresis (CZE) as a possible alternative to common liquid chromatography techniques. An oligonucleotide ladder was initially employed to investigate the roles of fundamental analyte features and experimental parameters in determining the outcome of CZE-MS analyses. The results demonstrated the ability to fully resolve the various rungs into discrete electrophoretic peaks with full-width half-height (FWHH) resolution that was visibly affected by the overall amount of material injected into the system. Analogous results were obtained from a digestion mixture prepared by treating yeast tRNAPhe (75 nt) with RNase T1, which provided several well-resolved peaks in spite of the increasing sample heterogeneity. The regular shapes of such peaks, however, belied the fact that most of them contained sets of comigrating species, as shown by the corresponding MS spectra. Even though it was not possible to segregate each species into an individual electrophoretic peak, the analysis still proved capable of unambiguously identifying a total of 29 hydrolytic products, which were sufficient to cover 96% of the tRNAPhe's sequence. Their masses accurately reflected the presence of modified nucleotides characteristic of this type of substrate. The analysis of a digestion mixture obtained from the 364 nt HIV-1 5'-UTR proved to be more challenging. The electropherogram displayed fewer well-resolved peaks and significantly greater incidence of product comigration. In this case, fractionating the highly heterogeneous mixture into discrete bands helped reduce signal suppression and detection bias. As a result, the corresponding MS data enabled the assignment of 248 products out of the possible 513 predicted from the 5'-UTR sequence, which afforded 100% sequence coverage. This figure represented a significant improvement over the 36 total products identified earlier under suboptimal conditions, which afforded only 57% coverage, or the 83 observed by direct infusion nanospray-MS (72%). These results provided a measure of the excellent potential of the technique to support the bottom-up characterization of progressively larger NA samples, such as putative NA therapeutics and mRNA vaccines.

Estimating In Vitro Protein Digestion and Protein Digestibility Corrected Amino Acid Score of Chicken Breasts Affected by White Striping and Wooden Breast Abnormalities.

An understanding regarding impacts of growth-related myopathies, i.e., white striping (WS) and wooden breast (WB), on the quality of dietary protein from cooked chicken breast is still limited. This study aimed at comparing protein content and in vitro protein digestion and estimating the in vitro protein digestibility corrected amino acid score (PDCAAS) of cooked chicken meat exhibiting different abnormality levels (i.e., normal, WS, and WS + WB). The results show that the WS + WB samples exhibited lower protein content, greater cooking loss, and greater lipid oxidation than those of normal samples (p < 0.05). No differences in protein carbonyls or the myofibril fragmentation index were found (p ≥ 0.05). Cooked samples were hydrolyzed in vitro using digestive enzyme mixtures that subsequently mimicked the enzymatic reactions in oral, gastric, and intestinal routes. The WS + WB samples exhibited greater values of free NH2 and degree of hydrolysis than the others at all digestion phases (p < 0.05), suggesting a greater proteolytic susceptibility. The in vitro PDCAAS of the WS + WB samples was greater than that of the other samples for pre-school children, school children, and adults (p < 0.05). Overall, the findings suggest that the cooked chicken breast with the WS + WB condition might provide greater protein digestibility and availability than WS and normal chicken breasts.

Innovative organic waste pretreatment approach for efficient anaerobic bioconversion: Effect of recirculation ratio at pre-processing in vortex layer apparatus on biogas production

Agricultural waste, called biomass, is of great interest as a renewable energy source. The purpose of this work was to determine the optimal recirculation rate (RR) values of the solid digestate when applying a new approach to the intensification of anaerobic conversion, providing a high quality biogas yield. This approach includes solid digestate recirculation and pre-processing a mixture of raw waste and solid digestate in a vortex layer apparatus. For this, the operation of an experimental biogas plant without recirculation and with recirculation was considered, starting from very low RR values, from 0.034 to 1, to ensure a high methane production rate (MPR) and methane yield (MY). From the point of view of MPR and MY, the recirculation ratios of 0.034 and 0.071 look the most attractive, however, with a recirculation ratio of 0.5, the content of hydrogen sulfide de-creased to 14 ppm with a simultaneous increase in MPR by 12 % compared to the control.

Dissolved organic material changes during combined treatment of a mixture of landfill leachate and anaerobic digestate using deammonification and chemical coagulation.

The current study investigates the combined treatment of wastewater of anaerobic digestate and landfill leachate, using deammonification and coagulation/flocculation processes. The deammonification section studies the performance of a full-scale deammonification plant in nitrogen and chemical oxygen demand (COD) removal, monitored over 2 years. For further COD reduction from the deammonification effluent (DE) to meet the environmental regulatory standards, coagulation/flocculation using three different Al-based coagulants was used to treat the DE. Results revealed that the deammonification plant showed 80% average ammonium removal from the mixed feed over the study period. Additionally, 30% of the feed COD was removed in the deammonification plant. COD analysis after treatment using coagulants revealed that the polyaluminum chloride modified with Fe had the best performance in reducing COD to meet the environmental standards. Excitation-emission matrix-parallel factor analysis (EEM-PARAFAC) of the dissolved organic material (DOM) samples indicated that fluorescents were the compounds mostly affected by the coagulant types. DOM analysis using 2D correlation Fourier-transform infrared spectroscopy revealed that the applied coagulants showed minor differences in removing different functional groups, despite having different COD reduction performance. Wastewater elemental analysis indicated elevated metal concentrations in low pH conditions (<6) due to re-stabilization of the flocs using coagulants.

Variations of theKjeldahlmethod for assessing nitrogen concentration in tropical forages

AbstractNitrogen (N) is one of the most important components of feeds and its quantification allows estimating protein equivalents, an important characteristic for diet formulation in ruminant nutrition. We aimed to evaluate N recovery in tropical forages using the Kjeldahl method with modifications involving a pre‐digestion step with salicylic acid and, or a partial replacement of copper sulfate by titanium dioxide as a catalyst. Forty‐eight study materials (i.e., tropical forages) were evaluated. Kjeldahl standard procedure was based on acid digestion with sodium sulfate and copper sulfate (20:1), followed by steam distillation in sodium hydroxide and titration with hydrochloric acid. The Kjeldahl variations were: salicylic acid as pre‐treatment before digestion, titanium dioxide replacing 50% of copper sulfate as catalyst in the digestion mixture, and salicylic acid and titanium as described above. The Dumas method was used as standard method to verify N recovery through Kjeldahl procedures. The N concentrations of the study materials (Dumas method) ranged from 1.9 to 28.3 g/kg as‐is. We found that all the methods were strongly and positively associated with each other (p &lt; .01). All Kjeldahl methods produced N concentrations different from those obtained by the Dumas method (p &lt; .01). The N recovery ranged from 0.971 to 0.980 for the different Kjeldahl methods. However, we did not find any difference between the different Kjeldahl methods regarding N concentrations (p≥ .89). The N recovery of the Kjeldahl method is not influenced by a pre‐digestion with salicylic acid or by the partial replacement of copper sulfate with titanium dioxide as a catalyst.

Development and Evaluation of Polyherbal Formulation with Carminative Effect

Carminative drugs, which reduce or prevent gastrointestinal flatulence and colic and have historically been used to enhance human health, is examined in this study. The carminative qualities of spices like clove, coriander, cardamom, fennel, nutmeg, black pepper, and ajowan are highlighted in particular. Numerous health benefits, including anti-inflammatory, antiseptic, anti-hypertensive, and myorelaxant qualities, are demonstrated by these spices. To enhance their effects, formulations were made utilizing a geometrical approach and different weights of these powders were combined and evaluated. To confirm the quality and safety of the carminative powder, organoleptic evaluation, physicochemical characteristics, rheological evaluation, and carminative potential were evaluated. The carminative powder, had a pH of 6.5, is free-flowing, non-sticky, and aesthetically pleasing, according to the results. Given the rising popularity of natural treatments and holistic healthcare, the future of carminative herbal medications is bright. Due to their digestive advantages, many herbs and mixtures have grown in popularity, and this pattern is predicted to continue. New carminative herbs and novel formulations may be found as a result of research and development in herbal medicine in the upcoming years. The market for carminative herbal medicines is projected to grow as consumer interest in plant-based treatments for digestive problems rises.

Separation of lactic acid from fermented residual resources using membrane technology

Lactic acid can be derived from microbial fermentation and be used as a platform chemical in various industrial applications. This study aims to investigate the challenges involved in combining a low-cost, heterogeneous feedstock, such as a mixture of candy-waste and digestate, with an optimized downstream strategy to achieve maximum recovery of high-purity lactic acid, targeting low energy consumption. To achieve this goal, four membrane separation technologies, namely microfiltration, nanofiltration, monopolar, and bipolar electrodialysis, were combined to design two purification processes. Microfiltration served as the pre-purification step, followed by either process A, which combined nanofiltration and bipolar electrodialysis, or process B, a combination of monopolar and bipolar electrodialysis. The findings emphasized the importance of pH as a control factor. Nanofiltration at pH 2.8 and monopolar electrodialysis at pH 4.0 led to increased lactic acid recovery. Moreover, it was observed that process B resulted in 1.09-fold higher lactic acid recovery than process A. However, process A had a 1.19-fold lower specific energy consumption, and the presence of ions in the final solution was reduced by 5-fold. In both processes lactic acid was separated from sugars and organic acids. Overall, the findings of this study suggest that membrane separation technology is a viable method for separating lactic acid produced from a mixture of residual candy-waste and digestate.

THE EFFECT OF AN INNOVATIVE FERTILIZER OF DIGESTATE AND WOOD ASH MIXTURES ON WINTER GARLIC PRODUCTIVITY

Garlic (Allium sativum L.) is a widespread crop in vegetable production. The popularity of garlic is due to its bactericidal and antioxidant properties. Digestate and wood ash are the by-products of cogeneration plants. The digestate is rich in nutrients, can provide a large part of the nutrients needed by the plant during the growing season, as well as improves the soil structure. Wood ash contains small amounts of phosphorus and potassium and is strongly alkaline (pH 8–12) due to the oxides in its composition, mostly calcium carbonate. The purpose of the study was to determine the effect of fertilizer rates of the digestate and wood ash mixtures on winter garlic productivity and harvest quality. Field trials with the winter garlic variety 'Lubaša' were established in sod clay, loamy soil. In the garlic plantation, different variants of fertilizer mixtures were used – they contained pig or cattle manure or plant residue digestate, and wood ash. The ratio of digestate and wood ash in the mixtures was 3:1; fertilizer rates for winter garlic were 15 and 30 t ha-1. In the study, the different types of fertilizers showed different effects on the yield and quality of winter garlic.

THE EFFICIENCY OF USING ALTERNATIVE FERTILIZERS IN POTATO PLANTATIONS

Field trials with the two potato variety were carried out in sod stagnogley soil. Soil agrochemical parameters: pHKCl 6.7 organic matter (OV) content in soil 2.3%, phosphorus (P2O5) content - 149 mg kg-1 and potassium (K2O) content - 200 mg kg-1 in soil. Potato plantations were created using different variants of fertilizer mix with pig (from SIA “Latvi Dan Agro”) and cattle (from SIA “Ziedi JP”) manure digestate and wood ash (from SIA“Gren Jelgava”) in different ratio (digestate :wood ash ratio used: 4:1and 3:1). The rates of innovative mixed fertilizer for pig and cattle manure digestates for potatoes were 15 and 30 t ha-1. Both norms for digestate manure from pure pigs and cattle were used as control options. The potato production norm was 3.0 t ha-1. The placement of the variants in the trial was randomized, in triplicate. In the study, the two types of fertilizer had different effects on potato tuber yield. Using mixtures of pig manure digestate and wood ash in different ratios, the average yield was 34.2 t ha-1, but using mixtures of cattle manure digestate and wood ash, the average yield was 27.8 t ha-1. In the studied variants, its content in potato dry matter varied in the range of 9.15-11.42%. The amount of dry matter affects the culinary properties of the tubers. The application of fertilizer mixtures increased the dry matter content by an average of 1.7–2.7%. Fertilizer variants with higher tuber yield or higher starch content provided the highest starch yield. In general, the use of mixtures of wood ash and biogas digestate to fertilize crops and improve soil fertility can be an efficient way to process both products and can be an environmentally friendly alternative to fertilizers. The objective of the research was to study the influence of digestate and wood ash mixtures fertilizer rates on potato productivity and quality.

A nitrogen-doped graphene tube composite based on immobilized metal affinity chromatography for the capture of phosphopeptides

A novel immobilized metal affinity chromatography (IMAC) functional composite, mNi@N-GrT@PDA@Ti4+, was fabricated based on ultrathin magnetic nitrogen-doped graphene tube (mNi@N-GrT) after chelated Ti4+ with polydopamine, following as a magnetic solid-phase extraction sorbent for rapidly selective enrichment and mass spectrometry identification of phosphorylated peptides. After optimized, the composite exhibited high specificity in the enrichment of phosphopeptides from the digest mixture of β-casein and bovine serum albumin (BSA). The robust method presented the low detection limits (1 fmol, 200 μL) and excellent selectivity (1:100) in the molar ration mixture of β-casein and BSA digests. Furthermore, the selective enrichment of phosphopeptides in the complex bio-samples, was successfully carried out. The results showed that 28 phosphopeptides were finally detected in mouse brain, and 2087 phosphorylated peptides were identified in the HeLa cells extracts with specific selectivity of 95.6%. The enrichment performance of mNi@N-GrT@PDA@Ti4+ was satisfactory, suggesting that the functional composite provided a potential application in the enrichment of trace phosphorylated peptides from the complex biological matrix.

Variability of Micro- and Macro-Elements in Anaerobic Co-Digestion of Municipal Sewage Sludge and Food Industrial By-Products.

The main aim of this study was to evaluate the effect of the addition of selected industrial food wastes on the fate of micro- and macro-elements within an anaerobic digestion process (AD), as well as define the relationship between their content and AD efficiency. Orange peels, (OP), orange pulp (PL) and brewery spent grain (BSG) were used as co-substrates, while municipal sewage sludge (SS) was applied as the main component. The introduction of co-substrates resulted in improvements in feedstock composition in terms of macro-elements, with a simultaneous decrease in the content of HMs (heavy metals). Such beneficial effects led to enhanced methane production, and improved process performance at the highest doses of PL and BSG. In turn, reduced biogas and methane production was found in the three-component digestion mixtures in the presence of OP and BSG; therein, the highest accumulation of most HMs within the process was also revealed. Considering the agricultural application of all digestates, exceedances for Cu, Zn and Hg were recorded, thereby excluding their further use for that purpose.

Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar

Biological treatments focused on stabilizing and detoxifying olive mill wastewater facilitate agronomic reuse for irrigation and fertilization. Anaerobic digestion is particularly attractive in view of energy recovery, but is severely hampered by the microbial toxicity of olive mill wastewater. In this work, the addition of biochar to the digestion mixture was studied to improve the stability and efficiency of the anaerobic process. Kinetics and yields of biogas production were evaluated in batch digestion tests with biochar concentrations ranging from 0 to 45 g L−1. The addition of biochar reduced sensibly the lag phase for methanogenesis and increased the maximum rate of biogas generation. Final yields of hydrogen and methane were not affected. Upon addition of biochar, soluble COD removal increased from 66% up to 84%, and phenolics removal increased from 50% up to 95%. Digestate phytotoxicity, as measured by seed germination tests, was reduced compared to raw wastewater. Addition of biochar further reduced phytotoxicity and, furthermore, a stimulatory effect was observed for a twenty-fold dilution. In conclusion, biochar addition enhances the anaerobic digestion of olive mill wastewaters by effectively reducing methanogenesis inhibition and digestate phytotoxicity, thus improving energy and biomass recovery.

Soil Fertility Improvement with Mixtures of Wood Ash and Biogas Digestates Enhances Leaf Photosynthesis and Extends the Growth Period for Deciduous Trees.

In the context of climate change, it is necessary to establish forest management by balancing more products, using less area, and minimizing environmental impacts. The use of different industrial bio-based by-products as soil conditioners in the last few decades has gain more interest, because it leads to an extended use time of these products and supports the circular economy. The aim of this study was to determine the effect of fertiliser made from cattle and pig manure biogas fermentation digestate and wood ash from two cogeneration plants, applied in different mixture ratios, to test its suitability for fertilisation of deciduous trees, using the physiological, morphological, and chemical parameters of the leaves as an indicator. We selected two poplar clones: foreign 'OP42' (syn. Hybrid 275) and local 'AUCE' annual shoot stem cuttings as planting materials. A negative control group with acidic forest mineral soil as substrate and four fertilised groups with different applied digestate and wood ash ratio mixtures to forest soil was established (ash:digestate 0:0 (Control), 1:1, 2:1, 3:1, 4:1). Mixture application improved growing conditions because all fertilised group poplars had longer growth periods and photosynthetic rates in August than the control group. Both local and foreign clones showed a good response to fertilisation in terms of leaf parameters. Poplar is a suitable culture to fertilise with bio-waste biogenic products, because of its capacity to absorb nutrients and fast response to fertilisation.