Search Results (2,205)

In this study, thermophilic anaerobic digestion (TAD, 60 °C) was evaluated as a downstream waste-to-energy step within a cascading thermophilic biorefinery using four interrelated substrates—primary cafeteria wastes (pCFWs) and primary corn stover wastes (pCSWs) were evaluated without physicochemical pretreatment. Their corresponding secondary substrates, secondary cafeteria waste (sCFW) and secondary corn stover wastes (sCSWs), were residual solids generated after thermophilic bioethanol production and exopolysaccharide production, respectively. To our knowledge, this is the first study to demonstrate sequential thermophilic valorization in which primary wastes are untreated and the remaining biotreated secondary residues are subsequently converted into biomethane, adding each step to bioeconomy. Biomethane potential was quantified to determine how substrate composition and upstream bioprocessing influence methane yield and biodegradability. In the batch, pCFW achieved the highest biodegradability (84% VS reduction) but suffered rapid acidification at higher loadings, whereas pCSW was hydrolysis-limited by lignocellulosic recalcitrance. Upstream bioprocessing (biological pretreatment) improved digestibility, with sCSW exhibiting a 1.8-fold increase in methane yield (300 L CH₄ kg⁻¹ VS) relative to pCSW. All co-digestion treatments outperformed monodigestion, with the best-performing (among the tested) sCFW:sCSW ratio of 3:1 delivering the highest methane yield (413 L CH₄ kg⁻¹ VS) and VS reduction (95.8%). Scale-up in a 40 L fed-batch reactor achieved methane productivities of 49–142 L CH₄ kg⁻¹ VS per feeding cycle, reaching stable operation after two cycles, with cumulative methane production of ~800 L CH₄ kg⁻¹ VS for secondary wastes compared to ~550 L CH₄ kg⁻¹ VS for primary wastes. Microbial analysis revealed dominance of syntrophic acetate-oxidizing bacteria (Acetomicrobium, 22.6%) and hydrogenotrophic methanogens (Methanothermobacter, 72.3%). Therefore, biologically pretreated wastes enabled higher methane recovery and improved solids destruction under thermophilic conditions and demonstrates circular conversion of wastes into renewable biomethane. Full article

Calcium hypochlorite (CH) is a strong oxidant that can be utilized to enhance sludge hydrolysis and anaerobic digestion (AD) performance; however, its suppressive effect on methanogens restricts the development of CH treatment technologies. This laboratory-scale study introduced zero-valent iron (ZVI) into a CH-treated sludge AD system to alleviate the adverse effect, thereby synergistically enhancing biomethane production, and the correlation between methane yield and the two key treatment parameters (ZVI and CH dosages) was explored. The experimental results revealed that the best conditions for the ZVI + CH method were 5 g/L of ZVI plus 0.12 g/g of volatile suspended solids (VSSs) of CH, under which the maximum biomethane yield of 275.8 mL/g VSS was achieved, representing increases of 81.5%, 43.2%, and 28.2% over the control, solo ZVI, and solo CH conditions, respectively. More organic matter in the sludge was found to be degraded during AD by the ZVI + CH treatment compared with the control, solo ZVI, or solo CH conditions. An enzyme activity analysis illustrated that the ZVI + CH treatment not only enhanced the bioactivity of anaerobes but also eliminated the suppression of methanogens by CH. A microbial analysis demonstrated that all functional microbes responsible for sludge AD were enriched by the ZVI + CH treatment, with total abundances of 8.41% and 20.58% in the control and ZVI + CH-treated reactors, respectively. Full article

In conventional anaerobic digestion (AD) of livestock manure, temperature regulation faces an inherent paradox: thermophilic conditions facilitate pathogen inactivation but inhibit methanogenesis, whereas mesophilic conditions enable efficient methane production but are less effective at eliminating pathogens. This study systematically analyzed the methanogenic performance, microbial physiology, and the dynamics of biosafety factors during AD of chicken manure at 4 °C, 35 °C, and 55 °C. Additionally, a ceramic membrane (CM) coupled with ozone micro-nano bubbles (O₃-MNBs) backwashing was configured for advanced digestate purification. Contrary to conventional understanding, mesophilic conditions (35 °C) simultaneously achieved optimal methanogenic efficiency (277.83 mL/gVS) and the efficient removal of viruses (66.65%) and antibiotic resistance genes (ARGs) (>77.11%), supported by a more diverse microbial community. While thermophilic conditions (55 °C) inactivated certain viruses, methanogenic efficiency was significantly inhibited by thermal stress. Moreover, the residual plasmid-borne ARGs were 3.04-fold higher than under mesophilic conditions. The integration of CM filtration with O₃-MNBs backwashing effectively retained and inactivated pathogens while reducing the membrane fouling rate by 83.97%. The integration of mesophilic digestion, membrane filtration, and O₃-MNBs processes synergistically achieved efficient energy recovery and robust pathogen control, providing technical support for the safe treatment and high-value resource utilization of manure. Full article

Background: Antibiotic resistance in Helicobacter pylori is steadily increasing, rendering the treatment of related gastroduodenal diseases increasingly difficult. Lefamulin is a new broad-spectrum antibacterial in the pleuromutilin class, acting by suppressing bacterial protein synthesis. It has the advantages of its unique “induced-fit” mechanism, a low frequency of spontaneous mutations, stepwise development of resistance, stability in acidic environments, and potential for additive or synergistic activity when combined with certain other antibiotics against various facultative anaerobes, including multidrug-resistant isolates. Methods: We investigated, for the first time to the best of our knowledge, the activity of lefamulin against 91 clinical H. pylori isolates from symptomatic adult patients using MIC test strips. Results: Overall, lefamulin MICs₅₀ and MICs₉₀ were 0.25 and 2 mg/L versus 4 and ≥256 mg/L for clarithromycin, and 0.75 and ≥32 mg/L, respectively, for levofloxacin. Lefamulin MICs₅₀ and MICs₉₀ were 0.5 mg/L and 4 mg/L against the 61 clarithromycin-resistant (MICs, >0.25 mg/L) isolates, 0.25 and 0.75 mg/L against the 40 levofloxacin-resistant (MICs, >1 mg/L) isolates, and 0.38 mg/L and 0.75 mg/L, respectively, against the 28 isolates resistant to both agents. Conclusions: Briefly, the new pleuromutilin antibiotic outperformed in vitro both clarithromycin and levofloxacin against H. pylori isolates. Its potential usefulness in treating H. pylori infections resistant to macrolides and fluoroquinolones, and especially those with dual resistance, justifies further investigation. However, some precautions should also be considered. The use of the novel antibiotic lefamulin may offer benefits for H. pylori eradication if our results are confirmed in subsequent studies, including clinical trials. Full article

Resilience and adaptation to extreme climate events have become an urgent necessity. As cities grow denser, increasing numbers of people are exposed to water scarcity, flooding, and power grid disruptions. Immediate action is required to safeguard human lives and property. Residential buildings exert a significant environmental impact throughout their operational phase, contributing to air, land, and water pollution. A more sustainable and proactive approach to building management is essential to reduce the consumption, processing, and disposal of natural resources. This article explores the potential for biogas production from decentralised/on-site wastewater treatment systems through the co-digestion of blackwater (BW) and kitchen waste (KW) for existing residential buildings located in densely populated urban areas using hybrid grids. It addresses the importance of wastewater source separation, the use of BW and KW blends to achieve the best biogas production, and the environmental, economic and social aspects of these systems’ implementation. An extensive literature review and state-of-the-art analysis were conducted to assess the potential, main challenges, and research directions in this field. The results indicate that decentralised anaerobic systems can be technically feasible, reducing grid energy dependence, optimising water use, and valorising digestate as fertiliser—fully aligned with the EU’s Green Deal and the UN Sustainable Development Goals regarding sustainability and circularity. However, few studies address the feasibility of BW (vacuum toilet) and KW co-digestion for combined heat and power generation in hybrid grids. Further pilot- and full-scale research is therefore needed to increase system reliability and social acceptance. Full article

Biochar (BC) is widely utilised to enhance methane production from the anaerobic digestion (AD) process due to its physicochemical properties. This study investigates the influence of biochar pretreatment on its behaviour and performance in AD systems. Pre-treated biochar derived from different feedstocks via slow pyrolysis was applied in Biochemical Methane Potential (BMP) tests at a dosage of 0.25% (w/v), and its impact on both the methane yield and digestion kinetics during cellulose degradation was evaluated. Pre-treatment was performed via steam autoclaving, serving as both a sterilisation and surface-modification step aimed at improving the physicochemical characteristics of biochar, particularly its capacity for microbial immobilisation. The results demonstrated that the effect of autoclave pretreatment on methane production was strongly feedstock-dependent. Autoclaved rice husk biochar (AC-RH550) markedly inhibited methane production, whereas autoclaved softwood biochar (AC-SW550) exhibited the best performance among all biochars tested, achieving the highest methane yield of 382.2 (mL CH₄ g⁻¹ VS), corresponding to an increase of 18.3% compared to non-pretreated SW550 and 9.2% relative to the control. This improvement is attributed to the modifications in biochar surface properties, promoting improved microbial activity and biofilm formation potentially improving direct interspecies electron transfer (DIET). Additionally, biochar may act as a buffering agent and provide adsorption sites for inhibitory intermediates such as VFA. Cell immobilisation experiments further confirmed that autoclaving enhanced biochar porosity and hydrophilicity, encouraging better colonisation and biofilm formation. Scanning electron microscopy (SEM) and microbial analyses verified increased cell attachment on pretreated biochars. Overall, these findings highlight the critical role of pretreatment in optimising biochar functionality for anaerobic digestion applications and cell immobilisation. Full article

The current study aims to assess the effects of coated sodium butyrate (CSB) on the weaning transition of White King pigeons. A total of 336 1-month-old White King pigeons were assigned randomly to four groups, including the Control group fed basal health sandand without CSB and test groups fed the basal health sand with 0.1%, 0.2%, and 0.4% CSB, respectively. The results showed that, compared with the Control group, the average daily feed intake (ADFI) was significantly increased in the 0.1% and 0.2% CSB groups (p < 0.05). The 0.1% CSB group exhibited a higher immune organ index (IOI) than the Control group (p < 0.05). The total protein (TP) and albumin (ALB) levels in the 0.1% CSB and 0.4% CSB groups significantly increased compared with the Control group (p < 0.05). In contrast, the 0.2% CSB group exhibited lower serum ALB, TP, and total cholesterol (TC) levels; TNF-α and IL-6 concentrations were reduced compared with the other groups (p < 0.05), and the 0.4% CSB group showed significantly increased serum TNF-α, IL-6, and D-lactic acid levels (p < 0.05). The ratio of villus height to crypt depth (VH/CD) of the jejunum (p < 0.05) was significantly increased in the 0.2% CSB group. In addition, the CD and VH/CD of the ileum were significantly increased in the 0.1% CSB group (p < 0.05). Firmicutes was the predominant phylum across all treatment groups, while Bacteroidota showed a more sensitive response to CSB supplementation. The 0.1% CSB group showed a significant enrichment of Oscillospiraceae and Muribaculaceae, fiber-fermenting, SCFA-producing taxa, Enterobacterales and Klebsiella, suggesting CSB-mediated alterations in luminal oxygen tension that favor the coexistence of facultative and obligate anaerobic taxa. Collectively, these data revealed that CSB supplementation efficiently improves growth performance and intestinal health of weaning pigeons by ameliorating the intestinal environment. Full article

Effective management of wastewater treatment plants often requires real-time measurements of Biochemical Oxygen Demand (BOD). Conventional methods for determining Biochemical Oxygen Demand (BOD) are often time-consuming, labor-intensive and prone to inaccuracies. Microbial Fuel Cells (MFCs) have emerged as a viable alternative technology for BOD measurement, offering real-time monitoring capability. However, challenges remain in its validity for testing different types of wastewater. This study developed a cost-effective dual-chamber MFC with graphite felt electrodes and a CMI-7000 membrane, inoculated with a microbial consortia grown from anaerobic sludge at optimal conditions (35 °C, pH 7, 1000 Ω external resistance). After one month of biofilm formation, the MFC produced 600 mV. Voltage outputs were measured at six BOD₅ concentrations (36 to 583 mg/L) in synthetic wastewater, showing a strong linear correlation between BOD₅ concentrations and voltage outputs. The MFC was also tested with five domestic wastewater samples with BOD₅ values ranging between 81 and 405 mg/L. The output voltages were inserted into the derived voltage–BOD correlation to obtain BOD₅ values within 2.5% to 11% of conventional laboratory results. These findings confirm the potential of MFC-based biosensors as an efficient and accurate tool for real-time wastewater monitoring. Full article

This study aims to identify microbial strain resources capable of degrading diflufenican and elucidate their degradation characteristics, with the goal of mitigating the phytotoxicity hazards associated with the prolonged use of this persistent herbicide. A degradation strain was isolated, purified, and screened from wheat field soils that had been subjected to diflufenican treatment using an enrichment culture method. The taxonomic classification of the strain was determined through a comprehensive analysis of its morphology, physiology, biochemistry, as well as its 16S rRNA gene sequence. The results demonstrated that the screened bacterial strain 88-1 could utilize diflufenican as its metabolic carbon source and was identified as Enterobacter hormaechei, a facultative anaerobe. The degradation efficiency of strain 88-1 on diflufenican was closely associated with cultivation time, the initial concentration of the herbicide, temperature, pH, and inoculation amount of the strain. Additionally, the degradation rate exhibits a positive correlation with the biomass of the strain. Under optimal conditions (40 mg/L diflufenican, 30 °C, pH 8.0, 10% inoculum), the highest observed degradation efficiency and viable cell density over the 120 h incubation period were 55.11% and 8.05 × 10⁶ CFU/mL, respectively. Furthermore, rapid biotransformation commenced within 24 h, yielding a cascade of metabolites, with 2-(3-(trifluoromethyl)phenoxy)pyridine-3-carboxamide identified as the primary metabolite. These findings suggest that strain 88-1 holds promise for the bioremediation of soils contaminated with diflufenican. Full article

Gynecological malignancies and breast cancer impose substantial health and economic burdens. This review examines how local and systemic microbiota may affect epithelial integrity, inflammation, estrogen metabolism, and immunity. The vaginal ecosystem is the most extensively studied female microbial niche. Cervical cancer serves as the most illustrative clinical example: loss of stable Lactobacillus crispatus dominance and increased prevalence of anaerobic bacteria (anaerobic dysbiosis) are associated with persistent HPV infection, which directly elevates the risk of cervical precancerous lesions. The estrobolome is particularly relevant in endometrial cancer, where intestinal bacterial beta-glucuronidase activity may increase estrogen reabsorption, particularly in obesity and metabolic disease. In ovarian cancer, microbiota is being studied as a possible risk modifier in BRCA1 carriers, but the evidence remains exploratory. In breast cancer, intratumoral bacteria may shape the immune microenvironment, particularly in triple-negative disease. The primary limitation of current research is methodological heterogeneity. Low-biomass samples, such as those from the ovary or endometrium, are highly susceptible to technical contamination. Most studies are cross-sectional and cannot establish causality. Current evidence supports microbiota as a modifier, not a standalone marker or a substitute for standard diagnosis and treatment. Its most plausible near-term role is in multiparameter risk or response models, pending standardized prospective validation. Full article

To explore the effects of different fertilization regimes on physicochemical properties and microbial ecology of greenhouse soil, we set five treatments with original soil (BS) as the control: chemical fertilizer alone (GF), high/low-rate mushroom residue combined with chemical fertilizer (MH, ML), and high/low-rate organic fertilizer combined with chemical fertilizer (OH, OL). Metagenomic sequencing and bioinformatic analyses were adopted to characterize soil nutrients, microbial communities, and C-N-P-S metabolic functions. All treatments increased soil nutrients. MH had the highest organic matter, total nitrogen, nitrate nitrogen, and available phosphorus, while GF contained the most available potassium and ammonium nitrogen. Bacteria dominated the soil microbiota, with Pseudomonadota and Pseudomonas as keystone taxa. Mushroom residue amendments improved microbial richness and diversity. By improving soil physicochemical properties, the combined application of organic fertilizer with chemical fertilizer and mushroom residue with chemical fertilizer both enriched some beneficial microorganisms. Chemical fertilizer alone enhanced anaerobic metabolism, which was reversed by high-rate mushroom residue. Available phosphorus, available potassium, and ammonium nitrogen were key environmental factors driving the differentiation of microbial communities and their functions. Overall, mushroom residue combined with chemical fertilizer is effective for greenhouse soil improvement, with proper dosage and tillage recommended. Full article

High-solid anaerobic digestion (HS-AD) is one of the most efficient and popular solid-waste-treatment and energy-recovery technologies. However, it is significantly influenced by composition and substrate characteristics, with the carbon-to-nitrogen ratio (C/N ratio) and biodegradability being important. In this study, the substrate was adjusted and compounded to investigate the methanogenesis performance with the substrate C/N ratio (2.82–82.72) and biodegradability (refractory and easily degraded) variation during HS-AD. The results showed that the highest methane yield (MY) was achieved with white meat (273.02 mL/g-VS), which was 2.22 times higher than that of substrates with higher C/N ratios. However, this enhanced methane productivity was accompanied by elevated total ammonia nitrogen (TAN) concentrations, which substantially increased the risk of system instability. For a high C/N ratio (>50:1), the difference between the C/N ratio and biodegradability had little influence on MY, and under a low C/N ratio (<5:1), the methane production rate was higher. For low C/N substrates, acetic (14.53–76.82%) accounted for the highest total volatile fatty acids (VFAs) during HS-AD, and for high C/N ratio substrates, propionic (46.44–82.66%) had a higher proportion (r = 0.94). An increased C/N ratio decreased total ammonia nitrogen (TAN) and alkalinity (p < 0.05). Variations in the C/N ratio and biodegradability led to differences in the microbial composition. Full article

Effective management of dairy manure is crucial for reducing environmental and public health risks. This waste material can serve as a viable source of bioenergy via anaerobic digestion. The recalcitrance of lignocellulosic fiber in manure presents challenges for its efficient conversion to methane. Hydrothermal pretreatment of manure fiber improves process performance by deconstructing the lignocellulosic structure. Low-temperature hydrothermal treatment (90–180 °C) of lignocellulosic biomass optimally enhances the AD process performance by limiting the formation of inhibitory compounds such as furfurals. The integration of an optimal hydrothermal pretreatment within an anaerobic digestion system can improve the homogeneity, miscibility, and digestibility of dairy manure, thereby enhancing biogas yield. This review examines the hydrothermal treatment of lignocellulosic biomass, with a focus on dairy manure, the water chemistry involved in pretreatment, relevant process parameters, and the challenges faced in anaerobic digestion. Full article

Intensive dairy farm wastewater (DFW) poses significant environmental challenges due to its high organic loading and complex composition. Anaerobic co-digestion with sewage sludge (SS) offers a promising strategy for simultaneous pollutant removal and bioenergy recovery. However, the optimal inoculation ratio for maximizing both methane production and volatile fatty acid (VFA) accumulation remains unclear for liquid DFW following a solid–liquid separation. This study investigated the effects of three SS addition ratios (0%, 15%, and 45%) on anaerobic co-digestion performance. Daily methane production, cumulative yield, VFA composition, pH, electrical conductivity (EC), ammonium nitrogen (NH₄⁺-N), and chemical oxygen demand (COD) were monitored over 26 days. The 45% SS treatment (S45) achieved the highest cumulative methane yield (2882.60 mL), representing 35.1% and 7.2% increases over S0 and S15. Modified Gompertz modeling confirmed S45 attained the highest methane potential (3056.8 mL) and production rate (569.8 mL/d), with the shortest lag phase (14.47 d). S45 also reached the highest total VFAs peak (2209.02 mg/L) on day 3, advancing acidification by 3 days. Process stability was maintained across all treatments (pH 6.94–8.44), with S45 showing the earliest pH recovery and lowest NH₄⁺-N accumulation. COD removal in S45 exceeded S0 by 25.1% at day 26. These findings indicate that 45% SS addition optimally balances methanogenic performance, acidogenic efficiency, and process stability in DFW anaerobic co-digestion. Full article

Fruit and vegetable wastes can be recycled into value-added fermentation broths (FBs) through anaerobic fermentation, but the characteristics of FBs and the effects on soil ecological processes remain insufficiently understood. This study analyzed FBs produced from 14 wastes and selected five FBs (garlic, tomato, sweet potato, apple, and lettuce) for pot experiments. The results showed significant differences among the FBs in nutrients, enzymes, and microbial communities. Garlic FB had the highest concentrations of ammonium nitrogen (309.81 mg/L), total phosphorus (327.73 mg/L), total potassium (1365.8 mg/L), and organic matter (28.99 g/L), along with the highest activity of acid phosphatase, urease, protease, and catalase (p < 0.05). FB application improved soil nutrient availability and enzyme activities, with garlic FB showing the strongest effects, increasing catalase, urease, acid phosphatase, and β-glucosidase by 83.34%, 180.72%, 112.34%, and 21.95%, respectively. Metagenomic analysis revealed that the soil treated with garlic FB contained beneficial taxa, including Saprospiraceae, Chitinophagaceae, Azotobacter, and Sphingomonas, which are associated with enzyme production and organic matter decomposition. Furthermore, the application of FBs reduced the incidence of downy mildew and leaf spot and promoted the growth of Brassica chinensis. Though chemical fertilizer produced the highest biomass due to immediate nutrient availability, the FB treatments, especially garlic FB, showed advantages concerning soil health, disease suppression, and sustainability, highlighting their potential for organic waste recycling and sustainable agriculture. Full article