Search Results (161)

Anaerobic digestion is a widely adopted technique for biologically converting organic biomass to biogas under oxygen-limited conditions. However, several factors, including the properties of biomass and its complex structure, make it challenging to degrade biomass effectively, thereby reducing the overall efficiency of anaerobic digestion. This review examines the recent advancements in commonly used pretreatment techniques, including physical, chemical, and biological methods, and their impact on the biodegradability of organic waste for anaerobic digestion. Furthermore, this review explores integrated approaches that utilize two or more pretreatments to achieve synergistic effects on biomass degradation. This article highlights various additives and their physicochemical characteristics, which play a vital role in stimulating direct interspecies electron transfer to enhance biomethanation reaction rates. Direct electron interspecies transfer is a crucial aspect that accelerates electron transfer among syntrophic microbial communities during anaerobic digestion, thereby enhancing biomethane formation. Finally, this article reviews potential approaches, identifies research gaps, and outlines future directions to strengthen and develop advanced pretreatment strategies and novel additives to improve anaerobic digestion processes for generating high-value biogas. Full article

In personalized nutrition, dietary guidelines must be adapted to the physiological and developmental needs of individuals across the lifespan, especially during childhood and adolescence. These should account for nutritional status, health conditions, and early-life risk factors, including those that emerge during pregnancy. This narrative review synthesizes recent evidence (2020–2025) on the biological value of protein sources in supporting pediatric growth and development. While adequate protein intake is essential for physical and cognitive development in individuals under nineteen, excessive intake may accelerate growth and increase the long-term risks of overweight and obesity. Compared to animal-based proteins (ABPs), plant-based proteins (PBPs) carry a higher risk of nutrient deficiencies in vulnerable populations due to lower digestibility and incomplete amino acid profiles. Although plant-based diets are encouraged for environmental reasons—particularly to reduce the ecological impact of livestock—protein intake must remain appropriate for age, sex, health status, and context. Nutritional strategies must ensure an adequate supply of essential amino acids and proper micronutrient supplementation, regardless of whether children follow diets rich in ABPs, PBPs, or a combination of both. Attention to these factors is vital to balancing nutritional adequacy with long-term health and sustainability goals. Full article

Research on energy demand is advancing, with the addition of nanomaterials in anaerobic digestion increasing stability, accelerating hydrolysis, and reducing microbial inhibition. However, further research is needed to determine the mechanisms, ideal dosages, and long-term impacts. This work used continuous stir tank reactors (CSTRs) to experimentally examine the biocompatibility of iron oxide nanoparticles (Fe₃O₄-NPs) at a concentration of 75 mg/L at various organic loading rates (OLRs) of 0.3, 0.8, and 1.3 gVS/L.d (CSTRs). The efficiency of the reactors was observed by considering various parameters, such as pH, soluble chemical oxygen demand (sCOD), TVFA formation and degradation, total solids (TS), and volatile solids (VS) removal, as well as methane (CH₄) generation. Hence, it was found that the reactor with added NPs (R1) yielded an optimum 725.9 mL/gVS of CH₄ and this was achieved at the lowest OLR of 0.3 gVS/Ld. However, another reactor (R2, without NPs), exhibited more stabilized results, ranging from 372.8 to 424.4 mL/gVS at 0.3 to 1.3 gVS/Ld of OLR, respectively. Therefore, in R1, the maximum removal of sCOD, TVFAs, and VS was achieved at 90%, 74%, and 93%, respectively, as compared to R2. Full article

Anaerobic digestion (AD) is a sustainable strategy for converting hazardous wastes into renewable energy while supporting Sustainable Development Goals (SDGs). This study aimed to evaluate the effect of inoculum on optimizing biogas production from sewage sludge (SS) and cattle manure (CM). Bench-scale digesters were fed with 0, 20, and 40% inoculum prepared at a 1:3 SS:CM ratio. Substrate and digestate were analyzed for physicochemical properties, and biogas production data were fitted using nonlinear models. Kinetic parameters ranged from 0.0770 to 0.4691 L·kg⁻¹ for Y_max, from 1.0263 to 2.1343 L·kg⁻¹·week⁻¹ for μ_max, and from 0.8168 to 8.0114 weeks for λ, depending on the ratio. The 1:3 SS:CM with 40% inoculum significantly improved biogas production by reducing the lag phase and increasing weekly yield, with the Gompertz model showing the best fit to the digestion kinetics. This was particularly evident due to the favorable conditions for microbial adaptation and efficient substrate degradation. The results reinforce the concept of optimization as defined in this study, wherein the application of inoculum enhances the performance of AD by improving the physicochemical conditions of the substrate and accelerating microbial activity, thereby resulting in increased methane (CH₄) generation and overall biogas yield. Full article

The construction of an anaerobic digester coupled with post-digestion low-level aeration for agricultural wastewater treatment is described. The digester employs underwater speakers to accelerate the anaerobic digestion process while retaining solids to reduce the strength of the effluent. The effluent is sent to a holding tank and fed at a low flow rate to an aeration tank to effect partial nitrification of the wastewater. The outlet of this tank is sent to a settling tank to retain biomass that developed in the aeration tank, and the effluent is sent to a small constructed wetland to further reduce wastewater nitrogen and phosphorus. The wetland was planted with the broadleaf cattail, Typha latifolia, and hence led to the formation of a retention basin. The system has reduced energy consumption due to the use of underwater sonic treatment and low-level aeration that is not designed to achieve full nitrification/denitrification but rather to achieve a mixture of ammonium, nitrite, and nitrate that might foster the development of a consortium of organisms (i.e., nitrifiers and Anammox bacteria) that can remediate wastewater ammonium at low cost. The system is meant to serve as a complex where various technologies and practices can be evaluated to improve the treatment of agricultural wastewater. Preliminary data from the system are presented. Full article

Anaerobic digestion (AD) converts organic waste into methane-rich biogas but often faces performance issues due to organic acid and ammonium nitrogen accumulation. This hinders methanogen growth and reduces methane production. Recent studies show that incorporating conductive materials (CMs) into the AD matrix can mitigate these issues by facilitating electron transfer between microorganisms. This process accelerates the oxidation of organic acids and ammonium ions, enhancing methane recovery. The effectiveness of CMs depends on their type, porosity, surface morphology, and conductivity, which foster a symbiotic microbial community. This comprehensive review paper aimed to (i) describe the influence of CMs on the growth and enrichment of the AD microbial community, (ii) quantify the enhancement of biodegradation and methane generation, and (iii) observe syntrophic interactions and interspecies electron transfer. The review also summarized the impact of different conductive materials on methane generation and the effect of operational parameters, e.g., dose, size, and external voltage application, on the conductive electrodes. The study summarized that the different conductive materials have different influences, and their application in the AD matrix has to be realistic based on availability and economic benefits. Full article

Clinopodium bolivianum (Benth.) Kuntze, commonly known as muña, inca muña or koa, has traditionally been used for its medicinal properties in digestive disorders. Some studies have revealed its antioxidant potential and antibacterial activity. This study determined the volatile components, evaluated the antioxidant capacity of C. bolivianum essential oil and its incorporation into three hair cosmetic formulations: shampoo, combing cream, and capillary lotion. Gas Chromatography–Mass Spectrometry (GC–MS) confirmed pulegone as the main component, accounting for 66.85% of the essential oil. The antioxidant activity was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, with Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) as a reference compound. The essential oil exhibited significant radical scavenging activity, with IC₅₀ values of 1344.0 ± 12.23 µg/mL for DPPH and 40.125 ± 1.25 µg/mL for ABTS. Among the formulated cosmetic products, the combing cream containing 0.5% of the essential oil demonstrated the highest antioxidant activity, with IC₅₀ values of 0.72 µg/mL (DPPH) and 0.068 µg/mL (ABTS). In contrast, the shampoo and capillary lotion showed lower antioxidant potential. The stability evaluation confirmed that all formulations maintained their physicochemical properties under accelerated conditions. These findings highlight the potential application of C. bolivianum essential oil as a natural antioxidant in cosmetic formulations, contributing to its protective and functional properties. Full article

Anaerobic digestion is an important technology for energy recovery from organic waste. However, methanogenesis is restricted by some barriers, such as the low-speed bottleneck of interspecies electron transfer (IET), the low hydrogen partial pressure limitation, trace element deficiency, etc., resulting in poor system stability and low methane production. Recently, multiple iron accelerants have been employed to overcome the above challenges and have been proven effective in enhancing methanogenesis. This study reviews the effects of iron accelerants (Fe⁰, Fe₃O₄ and magnetite, Fe₂O₃ and hematite, iron salts and other iron accelerants) on anaerobic digestion in terms of methane production, process stability and the microbial community and elaborates the mechanisms of iron accelerants in mediating the direct interspecies electron transfer (DIET) of the syntrophic methanogenic community, strong reducibility promoting methanogenesis, provision of nutrient elements for microorganisms, etc. The potential engineering application of iron accelerants in anaerobic digestion and the current research advances regarding the environmental impacts and the recovery of iron accelerants are also summarized. Although iron accelerants exhibit positive effects on anaerobic digestion, most of the current research focuses on laboratory and small-scale investigations, and its large-scale engineering application should be further verified. Future research should focus on elucidating the mechanisms of iron accelerants for enhancing anaerobic digestion, developing diverse application methods for different types of anaerobic systems, optimizing large-scale engineering applications, and exploring the environmental impacts and high-efficiency recovery strategies of iron accelerants. Full article

The issue of antibiotic-resistant bacterial infections, coupled with the rise in viral pandemics and the slow development of new antibacterial and antiviral treatments, underscores the critical need for novel strategies to mitigate the spread of drug-resistant pathogens, enhance the efficacy of existing therapies, and accelerate the discovery and deployment of innovative antimicrobial and antiviral solutions. One promising approach to address these challenges is the dietary supplementation of non-digestible oligosaccharides (NDOs). NDOs, including human milk oligosaccharides (HMOs), play a vital role in shaping and sustaining a healthy gut microbiota. Beyond stimulating the growth and activity of beneficial gut bacteria, NDOs can also interact directly with pathogenic bacteria and viruses. Their antiviral and antibacterial properties arise from their unique interactions with pathogens and their ability to modulate the host’s immune system. NDOs can function as decoy receptors, inhibit pathogen growth, bind to bacterial toxins, stimulate the host immune response, exhibit anti-biofilm properties, and enhance barrier protection. However, a notable gap exists in the comprehensive assessment of in vivo and clinical data on this topic. This review aims to provide an in-depth overview of the in vivo evidence related to the antiviral and antibacterial effects of various NDOs and HMOs, with a focus on discussing their possible mechanisms of action. Full article

Sewage sludge was treated with nanoscale zero-valent iron (nZVI) to enhance biogas and methane (CH₄) production, and the influence of key parameters on the material’s anaerobic digestion (AD) efficiency was analyzed using sigmoidal mathematical models. In this study, three dosages of nZVI (0.5%, 1.5% and 3%) were added to the anaerobic sludge digestion system to enhance and accelerate the sludge decomposition process. The results showed that cumulative biogas yield after 41 days of digestion increased by 23.9% in the reactor with a nZVI dosage of 1.5%. Correspondingly, the highest CH₄ production enhancement by 21.5% was achieved with a nZVI dosage of 1.5% compared to the control. The results indicated that this nZVI dosage was optimal for the AD system, as it governed the highest biogas and CH₄ yields and maximum removal of total and volatile solids. Additionally, to predict biogas and CH₄ yields and evaluate kinetic parameters, eight kinetic models were applied. According to the results of the modified Gompertz, Richards and logistic models, the nZVI dosage of 1.5% shortened the biogas lag phase from 11 to 5 days compared to the control. The Schnute model provided the best fit to the experimental biogas and CH₄ data due to highest coefficients of determination (R²: 0.9997–0.9999 at 1.5% and 3% nZVI dosages), as well as the lowest Akaike’s Information Criterion values and errors. This demonstrated its superior performance compared to other models. Full article

As a type of high-water-content agricultural waste, vegetable waste (VW) is extremely prone to spoilage and environmental pollution. Anaerobic digestion (AD) technology can accelerate the degradation of VW; however, its direct reaction might encounter the risk of termination due to excessive acidification. How to effectively prevent excessive acidification and further accelerate the degradation and maturity of VW remains a significant challenge at present. This paper employed the methods of AD of biogas and aerobic treatment (AT) of biogas slurry (BS) to develop a set of three groups of coupled devices for thermostatic anaerobic and aerobic processes with temperature control by solar collectors. The reaction process was further facilitated by adopting a mixture of raw materials and exogenous additives. In Lanzhou, a comparative experiment was carried out to examine the impacts of a blank group (BG) (additive-free), a 1 g/L urea group (UG), and a 1 g/L plant ash group (PG) on the decomposition process of the mixture of cow dung and tomato stems and leaves. The thermostatic batch wet AD stage of the mixed raw materials at (26 ± 2 °C) lasted for 49 days. The substrate after digestion underwent aerobic aeration treatment for 8 h at different temperatures and different aeration rates. The results show that the system could be initiated smoothly and maintain stable operation in winter under the temperature control of the solar collector; adding additives during AD significantly boosted biogas and methane production during the first 28 days, with urea being the most effective. During the subsequent aerobic phase, UG demonstrated the highest bio-effectiveness under optimized conditions of (30 ± 1 °C) and an aeration rate of 12 L/min. Comprehensive analysis revealed that the optimal operation strategy was identified as the use of UG with a 29-day reaction cycle. The research results have significant referential value for the rapid decomposition of high-water-content agricultural and livestock waste in cold regions. Full article

Background: Tear fluid, rich in proteins, is a promising source of novel biomarkers for ocular and systemic health. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the primary method for biomarker discovery. Still, factors such as limited sample volume, extracellular protein contamination, and reflex tearing can significantly impact results. Glass microcapillary tubes minimize these issues. Schirmer strips remain the most common collection method due to existing LC-MS/MS protocol optimization. Methods: In this study, we evaluated multiple digestion protocols for the shotgun quantitative LC-MS/MS analysis of small-volume tear fluid samples collected using glass capillary tubes. Protocol optimization was performed using pooled samples and then compared with the analysis of individual samples. Results: Using the optimized protocol, one μL samples were processed using a timsTOF Pro 2 mass spectrometer (Bruker) coupled online with an Evosep One liquid chromatography system (Evosep), leading to the identification of an average of 361 ± 63 proteins in pooled samples and 525 ± 123 proteins in individual small-volume tear fluid samples. Conclusions: This protocol highlights the practicality of using glass capillary tubes for comprehensive LC-MS/MS-based tear proteomics analysis, paving the way for detailed proteomics characterization of individual tear fluid samples rather than pooled samples. By shifting from pooled to individual samples, this approach greatly accelerates tear biomarker discovery, advancing precision and personalized medicine. Full article

Knowledge of how novel antigens or dietary stimuli affect stomach development and function in pigs remains limited. This study aimed to investigate stomach characteristics, parietal cell numbers, and the expression of genes essential to the functioning of the fundic and pyloric gland regions at weaning compared to seven days post-weaning and to examine whether maternal probiotic supplementation or piglet dietary tryptophan (Trp) levels influence these stomach parameters. This study has a 2 × 3 factorial design, with 48 sows assigned to one of two diets: basal or basal supplemented with Bacillus subtilis and Bacillus amyloliquefaciens. Their litters received creep diets containing 0.22, 0.27, or 0.33% standardized ileal digestible (SID) Trp. In total, 96 pigs were sacrificed for gastric sampling, 48 on the day of weaning and 48 on day 7 post-weaning. At 7 days post-weaning, pigs had an increased number of parietal cells and expression of parietal cell activity and digestive enzyme (PGA5 and CHIA) genes in the fundic gland region (p < 0.05), although the expression of signaling molecules involved in the regulation of acid secretion was unchanged in the fundic gland region (p > 0.05) and reduced in the pyloric gland region (p < 0.05), compared to the day of weaning. Overall, maternal probiotic supplementation had a significant impact on gene expression in the fundic gland region of the offspring, elevating several genes related to parietal cell activity (CLIC6, HRH2, KCNE1, KCNQ1, CHRM3, CCKBR, and SSTR2) (p < 0.05). Additionally, there were time × maternal interactions, where certain acid secretion pathway (ATP4A and HDC), chitinase enzyme (CHIA), and ghrelin (GHRL) genes were increased in offspring from probiotic sows compared to control sows at weaning (p < 0.05), but not at 7 days post-weaning (p > 0.05). Maternal probiotic supplementation did not influence growth performance pre-weaning or during the 7-day post-weaning period. There was a limited effect of creep Trp level or maternal × creep interactions on performance, gene expression, or parietal cell counts. Low pre-weaning creep intake may have confounded this analysis. In conclusion, maternal probiotic supplementation accelerated the maturation of the offspring’s stomach, particularly in terms of the expression of genes linked to acid secretion from parietal cells. Full article

Solid-state anaerobic digestion (SS-AD) is a promising technology for treating organic waste and producing renewable energy. This study explores the feasibility of using 3D printing to rapidly design cost-effective laboratory-scale digesters for optimization experiments. Batch reactors were designed using fused deposition modeling (FDM) with polylactic acid (PLA) and stereolithography (SLA) with High Temp V2 resin. PLA had a negligible impact on methane yields, while raw SLA resin positively influenced methanogenic potential, likely due to residual isopropanol used in post-processing, causing a 19% increase in CH4 yield. The performance of the 3D-printed reactors was compared to that of a conventionally machined PMMA reactor using cattle manure as a substrate, showing comparable methane yields and process stability. Three-dimensional printing technologies have demonstrated remarkable efficiency in designing laboratory-scale digesters, with a 70% cost reduction for SLA technology and an 80% reduction in design time compared to conventional reactors designed by plastics processing, while maintaining comparable biogas production. FDM technologies with PLA have shown that they are not suitable for these uses. This study demonstrates the potential of additive manufacturing to accelerate SS-AD research and development. However, care must be taken in material selection and post-processing to avoid introducing experimental bias. Full article

Malaria, a severe vector-borne disease, affects billions of people globally and claims over half a million lives annually. Climate change can impact lifespan and the development of vectors. There is a gap in organized, multidisciplined research on climate change’s impact on malaria incidence and transmission. This review assesses and summarizes research on the effects of change in climate on human health, specifically on malaria. Results suggest that higher temperatures accelerate larval development, promote reproduction, enhance blood feed frequency, increase digestion, shorten vector life cycles, and lower mortality rates. Rainfall provides aquatic stages, extends mosquitoes’ lifespans, and increases cases. Mosquito activity increases with high humidity, which facilitates malaria transmission. Flooding can lead to increased inhabitation development, vector population growth, and habitat diversion, increasing breeding sites and the number of cases. Droughts can increase vector range by creating new breeding grounds. Strong storms wash Anopheles’ eggs and reproduction habitat. It limits reproduction and affects disease outbreaks. The Indian Ocean Dipole (IOD) and El Nino Southern Oscillation (ENSO) indirectly alter malaria transmission. The study recommends strengthening collaboration between policymakers, researchers, and stakeholders to reduce malaria risks. It also suggests strengthening control mechanisms and improved early warnings. Full article