Traditional anaerobic digestion (AD) is a well-established technology that converts organic matter into biogas. However, its performance is highly sensitive to substrate composition, which can lead to low methane production and high sensitivity to toxic compounds. To overcome these limitations, the integration of AD with electrochemical systems has been proposed in recent years, an approach that has increased process efficiency and stability. This makes AD a much more robust system, allowing for the treatment of a wider variety of waste. Currently, the most relevant electrochemical systems coupled with AD are microbial electrolysis cells (MECs), microbial fuel cells (MFCs), and electrodialysis (ED) systems. MEC enhances biogas or hydrogen production and improves methane quality while also reducing organic discard in the effluent. MFCs, when integrated with AD, offer a way to directly generate electricity from organic waste. Recently, ED has been coupled with AD to recover valuable compounds like volatile fatty acids from fermentation, which not only increases treatment efficiency but also obtains industrially valuable products. This review summarizes recent research on the design and configurations of AD combined with these electrochemical systems.

BackgroundVenous thromboembolism (VTE) is the third most common cause of cardiovascular death. Primary Antiphospholipid Syndrome (P-APS) is a chronic systemic autoimmune disorder characterized by thrombotic events and/or obstetric complications in patients carrying antiphospholipid antibodies (aPL) without autoimmune pathology. The prevalence of primary antiphospholipid syndrome (P-APS) in patients with VTE is approximately 9%. However, few studies have evaluated non-criteria antiphospholipid antibodies in the acute phase of VTE.ObjectiveTo assess the role of criteria and non-criteria antiphospholipid antibodies in patients with acute VTE.MethodsA cohort of 181 patients with VTE was followed for 2 years. An age-matched control group of 181 healthy individuals was included for comparison.ResultsCriteria aPL were detected in 8.8% of patients, whereas non-criteria aPL were present in 23.8%. Criteria aPL were independently associated with overall VTE (OR 7.09, p=0.021) and unprovoked VTE (OR 4.61, p=0.021). IgA anti-Beta2 Glycoprotein-1 antibodies (aB2GP1), detected in 16% of patients, were independently associated with VTE (OR 4.31, p=0.014) and unprovoked VTE (OR 3.78, p=0.006). Furthermore, IgA aB2GP1 positivity was also associated with more severe clinical presentation, defined by a Pulmonary Embolism Severity Index scale ≥3 (OR 3.13; p=0.048), and with the development of chronic thromboembolic pulmonary hypertension (OR 5.7; p=0.008).ConclusionIgA aB2GP1 antibodies are independently associated with VTE, particularly unprovoked VTE, and with both severe pulmonary embolism, and subsequent chronic thromboembolic pulmonary hypertension.

Anthracophyllum hirsutum and Stereum hirsutum produce manganese peroxidase (MnP) and laccase to break down lignin, a potential biological pretreatment for lignocellulosic biomass. This work aimed to evaluate the effect of copper (Cu) and manganese (Mn) added to olive mill solid waste (OMSW) inoculated with A. discolor and S. hirsutum on ligninolytic enzyme activity, lignin degradation, and phenolic compound removal. Different optimal metal dosages were determined for each fungal strain. For S. hirsutum , the addition of 6.1 mg Cu kg⁻ 1 and 7.3 mg Mn kg⁻ 1 resulted in 173 ± 5 U·L⁻ 1 MnP activity (an 863% increase compared to no metal addition) and 42 ± 3% lignin degradation (183% higher than with no metal addition, 15 ± 3%). These conditions also led to 65–75% phenol removal efficiencies in OMSW at 25 days and 80–95% in leachates between 20 and 30 days. For A. discolor , 14.6 mg Mn kg⁻ 1 yielded 37 ± 7 U·L⁻ 1 MnP activity (a 142% increase compared to no metal addition) and 38 ± 7% lignin degradation (150% higher than with no metal addition, 15 ± 3%). Under these conditions, A. discolor achieved 80–90% phenol removal in leachates at 20 days. These results demonstrate the positive effect of optimised metal supplementation, highlighting the potential of S. hirsutum and A. discolor for effective lignocellulosic biomass pretreatment and future mycoremediation processes. Graphical Abstract

IntroductionAntiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by thrombotic symptoms (venous, arterial, or small vessels) and/or gestational morbidity in patients carrying antiphospholipid antibodies (aPLs). Criteria aPLs include anti-cardiolipin antibodies, anti-beta 2 glycoprotein I (aB2GPI) antibodies of the IgG or IgM isotypes, and lupus anticoagulant (LA). However, there are aPLs that are associated with APS events but are not included in the criteria (extra-criteria). The aim of this study is to evaluate the prevalence and association of criteria and extra-criteria aPLs with APS clinical events.MethodsA total of 838 patients with clinical manifestations of APS were studied. In total, 715 presented with vascular manifestations, and 130 presented with obstetric morbidity. We measured levels of criteria aPLs, and the extra-criteria aPLs determined were anti-phosphatidylserine/prothrombin (aPS/PT) of IgG and IgM isotypes and aB2GPI IgA.ResultsClassic aPL, aPS/PT, and aB2GPI IgA positivity showed a significant and independent association with thrombosis (OR: 2.40, 2.36, and 2.53 respectively). IgA aB2GP1 was the only aPL significantly associated with the five types of thrombotic events (venous thrombosis, pulmonary embolism, stroke, acute myocardial infarction, and arterial thrombosis). Regarding obstetric APS, the most relevant antibodies were classic aPL of IgM isotype (OR: 36.04) and aPS/PT of both isotypes (OR: 4.4). The other aPL studied did not show association in multivariate analysis.DiscussionThe degree of clinical association for each group of aPLs was different depending on the form of presentation (vascular or obstetric) and the presence or absence of autoimmune diseases. Moreover, a fair level of agreement between LA and aPS/PT positivity was found; therefore, aPS/PT should not be referred to as a surrogate marker of LA.

Thousands of tons of two-phase olive mill solid waste (2P-OMSW) are generated annually, necessitating effective valorization strategies. Composting has been widely explored as a management approach; however, the extended processing time required for these residues poses a significant challenge for the olive industry. In this study, a forced aeration system combined with a semipermeable cover was implemented at a demonstrative scale to enhance the composting process and reduce its duration. Additionally, process optimization was evaluated through a two-stage composting strategy. In stage I, compost preconditioning was carried out using two types of manure (poultry and cow). In stage II, a bioaugmentation process was introduced using the edible fungus Pleurotus eryngii. The composting of 2P-OMSW under forced aeration and a semipermeable cover lasted 90 days. During the composting process, physicochemical parameters, total phenol content, microbial analysis, and phytotoxicity bioassays were measured to evaluate the efficiency and quality of the final compost. In stage I, poultry manure proved to be more effective than cow manure, resulting in a lower C/N ratio (<25%), higher nitrogen, phosphorus, and potassium content, and a greater reduction in total phenol content (>70%). In stage II, bioaugmentation significantly enhanced the removal of heavy metals, particularly zinc (Zn) and copper (Cu). Both final composts, obtained within 90 days, exhibited enriched nutrient content, stabilized nonphytotoxic organic matter, and low heavy metal concentrations. The findings highlight the potential of a forced aeration system combined with a semipermeable cover as an effective strategy for composting 2P-OMSW. This approach facilitates the transformation of 2P-OMSW into high-quality compost, making it suitable for use as an organic amendment or fertilizer in agricultural systems. Furthermore, it allows for the management of this residue within a relatively short time frame.

The anaerobic digestion (AD) of fruit and vegetable waste (FVW) from wholesale markets can be significantly impacted by seasonal variations in feedstock composition. For this reason, this research aimed to evaluate the adaptability of anaerobic reactors to the different disturbances in feedstocks composition that may develop during long-term treatment of FVWs. Results showed that the system could be flexible enough to cope with type feedstock changes with an appropriate gradual adaptation process. Monoterpenes accumulation led to a decline in acetoclastic methanogens, particularly Methanosarcina, resulting in volatile fatty acids (VFAs) accumulation and process acidification. However, monoterpenes content reduction in the feedstock enabled AD process recovery, increased Methanosarcina relative abundance, stabilized methane production at 224 +/- 13 mL CH4/g VS, and decreased VFAs by approximately 20 %. Therefore, it could be concluded that monoterpenes are compounds with a relevant potential impact and their cumulative levels in anaerobic reactors must be carefully monitored.

Two methanogenesis inhibition strategies for enhancing volatile fatty acid (VFA) production through the anaerobic fermentation of alperujo, a byproduct of olive oil production, were evaluated. Methanogenesis inhibition was implemented via two different approaches, one by pH adjustment to 5.0 and another one by chemical inhibition using 2-bromoethanesulfonate (BES) at pH 7. The VFA accumulation at the end of the experiment was 67% higher under the BES condition than under the pH 5 condition. Interestingly, the VFA profiles were similar under both conditions, with acetic acid as the dominant product, followed by propionic and butyric acids. The results demonstrated a 25% increase in alperujo solubilization under the BES condition, compared to under the pH 5 condition. This latest finding, together with the similar VFA profiles on both strategies, suggests that the hydrolysis step in alperujo solubilization was impacted by the pH difference. These findings highlight the effectiveness of chemical inhibition in enhancing solubilization, hydrolysis, and VFA accumulation during anaerobic fermentation of alperujo and, most importantly, the negative effect of pH 5 on the solubilization step.

On -site anaerobic digesters for small agricultural farms typically have feeding schedules that fluctuate according to farm operations. Shocks in feeding, particularly for putrescible waste can disrupt the stable operation of a digester. The effect of intermittent feeding on the anaerobic digestion of rejected raspberries was investigated in four 3L reactors operated in semicontinuous mode for 350 days at 38 C with a hydraulic retention time of 25 days and an organic loading rate (OLR) of 1gVS/L/d. During the acclimatisation period (147 days) the organic loading was 5 feeds per week. The feeding regime of two reactors was then changed while maintaining the same OLR and HRT to one weekly feed event in one reactor and 3 equal feeds per week in another. The feeding regime did not significantly affect specific methane yield (369 +/- 47 L/kgVS on average) despite very different weekly patterns in methane production. Volatile fatty acids (VFA) comprised >83 % of the organics in the effluent, while the rest included non-inhibitory concentrations of phenolic compounds (515-556 mg gallic acid/L). The microbial composition and relative abundance of predominant groups in all reactors were the archaeal genera Methanobacterium and Methanolinea and the bacterial phyla Bacteridota and Firmicutes. Increasing the OLR to 2gVS/L/d on day 238 resulted in failure of all reactors, attributed to the insufficient alkalinity to counterbalance the VFA produced, and the pH decrease below 6. Overall results suggests that optimal digestion of raspberry waste is maintained despite variations in feeding frequency, but acidification can occur with OLR changes.

Monoterpenes are antimicrobial compounds widely distributed in vegetable biomass, whose inhibitory potential for anaerobic digestion is underestimated. In this research, the toxic effect of limonene and fenchone, two of the main monoterpenes present in vegetable biomasses, and those of 4-terpineol, α-terpineol, and p-cymene, compounds described as main metabolites of limonene degradation, have been assessed. Methane production was totally inhibited at dosed of 1000mgL-1 of fenchone and limonene and at 600mgL-1 of p-cymene and 4-terpineol. Based on the methane production rate, the inhibition followed the next trend: α-terpineol << fenchone < limonene ≈ p-cymene < 4-terpineol. Regardless of dosed concentration, monoterpenes were mostly degraded at the end of the experiment (>85%), except p-cymene at 600mgL-1. Therefore, monoterpenes could entail a high risk of inhibition that can be aggravated by the difficulty to accurately follow their concentration and by the scarce information on their effect on anaerobic process.

Microalgae are being proposed as excellent substrates for different biorefinery processes. Anaerobic digestion process of microalgae is one of these interesting processes but has some limitations in deleting cell walls. For this reason, many studies proposed different types of pre-treatments, entailing energy, operation, and investment costs. This work aims to optimize the anaerobic digestion of the microalgae Chlorella sorokiniana and Chlorella sorokiniana (strain S12/S13/S16) without any pre-treatment by selecting the optimal harvesting time. The greatest influence is seen at 5:00 PM in methane production for both microalgae. For Chlorella sorokiniana, it is the most optimal moment for anaerobic digestion, whereas Chlorella sorokiniana (strain S12/S13/S16) is the least optimal. In the other harvesting times, both microalgae present a similar methane production, i.e. 173 +/- 12 mL CH4/g of total volatile solids. The highest methane production rate values were obtained during peak sunlight, 1:00 PM and 8:00 AM, respectively, and lower overnight.

Dry anaerobic digestion (dry-AD) is an attractive process for solid wastes such as agri-food waste. However, some limitations mainly associated to lack of effective mixing, can hinder the methane production capacity of the systems. Bulking agent (BA) has been proposed as a solution to the compaction issues in systems without mechanical agitation, such as leaching bed reactors. However, effects of BA are still not clear, and, thus, the factors to consider for its dose has not been optimized yet. This work studies the effect of BA in dry-AD. Two substrates with different characteristics were proposed as models, bean peel as a lignocellulosic substrate and a mixture of food waste as a readily biodegradable substrate. Inert plastic rings were used as BA at different BA:S ratios. Assessed BA:S ratio did not affect the performance of methane production for the lignocellulosic waste, but it did significantly affect to the easily biodegradable substrate, showing up to a 28% of methane production increase. This result could be due to the presence of lignocellulosic compounds in the bean peel, behaving like a natural BA. In assays with an increased bed height, the compaction of the system was more severe, resulting in the rapid acidification of the processes. At these conditions, the positive effect of BA addition was more marked, allowing methane production and no acidification of the system. Thus, the addition of BA is a suitable strategy for improving methane production or stability in dry-AD systems without requiring the stirring of the systems.

The improvement of mesophilic biomethanisation of recalcitrant sewage sludge derived from urban wastewater treatment through the application of a sonication pretreatment was evaluated in parallel in two pilot-scale anaerobic digesters (two biological replicates: reactors RA and RB). The valorisation process was monitored through a novel and holistic approach that related the biomethanisation yield, and its main batch operational parameters, with the abundance of archaeal and bacterial communities in the anaerobic inocula. Sonication allowed achieving a methane yield coefficient derived from sewage sludge of 240 +/- 20 mLSTPCH4/g VS (volatile solids) at the load range of 0.8-4.0 g VS/L in both reactors. The process was more stable in reactor B, with a wider range of loads being allowed (up to 5.29 g VS/L). Monitoring the presence of Archaea in the mixing liquor revealed a variation in their abundance throughout the process which was directly related to the availability of organic matter and pH. Advanced metagenomic analysis showed the phylogenetic and functional diversity of the complex microbiome involved. While Bacteria were widely distributed in 35 phyla, Archaea fitted in only two. Euryarchaeota was the majoritarian archaeal phylum (99.5 %) and its more abundant families are linked to methanogenic metabolism. Functional analysis revealed several relevant metabolic pathways that followed similar trends in both reactors. "Methane metabolism" clearly diminished at the end of the process in concordance with the exhaust of methane generation, while "ABC transporters" or "two-component systems", involved in bacterial survival to changing environments, followed the opposite pattern. This integrated approach could help to increase the methanogenic valorisation of sewage sludge.

White-rot fungi (WRF) are increasingly recognized for their biotechnological potential due to the wide range of applications of ligninolytic enzymes. The addition of different metals involved in the functioning of ligninolytic enzymes, mainly copper and manganese, has been widely studied to maximize the enzymatic activities of the WRF. This review aims to provide information on the effect of metal-fungi interaction mechanisms that justify the effects of enzymatic activity. The addition of copper is associated with increased laccase activity, with reported improvements in the laccase activity compared to controls without metal addition of up to 100% at doses between 0.5–1 mM. The addition of manganese resulted in an improvement in manganese peroxidase activity with respect to the control at the wide range of 1–18.2 mM. Furthermore, enzymatic activity was generally favored by using substrates with lignocellulosic fibers with respect to synthetic culture medium. Quantifying the concentration of metals in the substrate is required to monitor bioavailable metals for fungi in these assays accurately, making an external contribution less necessary.

Levulinic acid (LA) is a polymer with a vast industrial application range and can be co-produced as a minor by-product during the biological production of polyhydroxyalkanoates (PHA). However, the influence of key parameters as tools for favouring the production of LA over PHA is still unclear. In this study, we investigated how several critical operational conditions, i.e., carbon-nitrogen ratio (C/N), organic loading rate (OLR) and airflow, can be optimised to favour LA accumulation over PHA production by a mixed microbial culture (MMC), using synthetic grape pomace (GP) hydrolysate as the substrate. The results showed that it was possible to direct the MMC towards LA accumulation instead of PHA. The maximum LA yield was 2.7 ± 0.2 g LA/(L·d) using a C/N of 35, an airflow of 5 L/min and an OLR of 4 g sCOD/(L·d). The OLR and, to a lesser extent, the C/N ratio were the main factors significantly and positively correlated with the biological synthesis of LA.

IntroductionInfluenza virus infection can cause a range of clinical symptoms, including respiratory failure (RF) and even death. The mechanisms responsible for the most severe forms of the disease are not yet well understood. The objective is to assess the initial immune response upon admission and its potential impact on infection progression.MethodsWe conducted a prospective observational study of patients with influenza virus infection who required admission to a tertiary hospital in the 2017/18 and 2018/19 flu seasons. Immune markers, surrogate markers of neutrophil activation, and blood levels of DNase I and Apolipoprotein-H (ApoH) were determined in the first serum sample available during hospital care. Patients were followed until hospital discharge or death. Initially, 792 patients were included. From this group, 107 patients with poor evolution were selected, and a random control group was matched by day of admission.ResultsPatients with poor outcomes had significantly reduced ApoH levels, a soluble protein that regulate both complement and coagulation pathways. In multivariate analysis, low plasma levels of ApoH (OR:5.43; 2.21-13.4), high levels of C- reactive protein (OR:2.73: 1.28-5.4), hyperferritinemia (OR:2.83; 1.28-5.4) and smoking (OR:3.41; 1.04-11.16), were significantly associated with a worse prognosis. RF was independently associated with low levels of ApoH (OR: 5.12; 2.02-1.94), while high levels of IL15 behaved as a protective factor (OR:0.30; 0.12-0.71).DiscussionTherefore, in hospitalized influenza patients, a dysregulated early immune response is associated with a worse outcome. Adequate plasma levels of ApoH are protective against severe influenza and RF and High levels of IL15 protect against RF.

Harnessing microbial capabilities for metal recovery from secondary waste sources is an eco-friendly and sustainable approach for the management of metal-containing wastes. Soluble microbial products (SMP) and extracellular polymeric substances (EPS) are the two main groups of extracellular compounds produced by microorganisms in response to metal stress that are of great importance for remediation and recovery of metals. These include various high-, and low, molecular weight components, which serve various functional and structural roles. These compounds often contain functional groups with metal binding potential that can attenuate metal stress by sequestering metal ions, making them less bioavailable. Microorganisms can regulate the content and composition of EPS and SMP in response to metal stress in order to increase the compounds specificity and capacity for metal binding. Thus, EPS and SMP represent ideal candidates for developing technologies for selective metal recovery from complex wastes. To discover highly metal-sorptive compounds with specific metal binding affinity for metal recovery applications, it is necessary to investigate the metal binding affinity of these compounds, especially under metal stressed conditions. In this review we critically reviewed microbial EPS and SMP production as a response to metal stress with a particular emphasis on the metal binding properties of these compounds and their role in altering metal bioavailability. Furthermore, for the first time, we compiled the available data on potential application of these compounds for selective metal recovery from waste streams.

The stability and robustness of long-term anaerobic digestion process of fruit and vegetable waste (FVW) generated in Mediterranean wholesale markets were assessed, monitoring potential inhibitory volatile organic compounds (VOCs) such as volatile fatty acids (VFAs) and/or monoterpenes. Particle size (4 and 10 mm) and organic loading rate (OLR) were evaluated during the experimentation. Anaerobic digestion remained stable at OLR of 1.0 g VS L-1 d-1 (VS, total volatile solids) regardless of the feedstock particle size. At this OLR, methane yield was 254 & PLUSMN; 8 and 229 & PLUSMN; 11 mL CH4 g VS-1 for 4 and 10 mm, respectively. As the OLR increased above 1.0 g VS L-1 d-1, the system rapidly destabilized, and a high accumulation of VFAs was observed. In parallel of to the VFAs accumulation, other VOCs such as fenchone also reached concentrations that contributes to the destabilisation of the process. The destabilization process at an OLR of 3.0 g VS L-1 d-1 also resulted in a drastic reduction in the relative abundance and species diversity of methanogenic archaea in all digesters.

Volatile fatty acids (VFAs) revalorisation from waste products are key in achieving industrial sustainability and circular economic goals. Hence, the objective of this work was to correlate the adaptability of the microbial community in olive mill solid waste (OMSW) anaerobic fermentation processes, to the production of VFAs under different pH conditions, i.e. under acidic (pH 4 &5), neutral (pH 6 & 7) and alkaline conditions (pH 9 & 10). At neutral conditions, anaerobic digestion exhibited minimal accumulation of VFAs, as they were primarily biotransformed to methane, where no significant changes in the microbial community were observed. At acidic conditions, a diverse profile of VFAs were present in the reactors, although the VFA production was limited to around 20 % of fed OMSW. Despite the low accumulation, the VFA profile at pH 5 was more complex than those at alkaline conditions, accounting propionic acid as the main VFA compound produced at pH 5 (60 % of the total VFAs). Acidic conditions entailed a shift in the microbial composition compared to the initial inoculum, although the reactors maintained similar diversity indices. At alkaline conditions, around 50 % of the fed OMSW was accumulated as VFAs, mainly as acetic acid. Overall, a lower diversity and higher dominance corresponded to a less diverse VFAs profile, such as the preponderance of acetic acid correlated with a microbial diversity decrease and the increased dominance of Tissirella.

On-site anaerobic digesters for small agricultural farms typically have feeding schedules that fluctuate according to farm operations. Shocks in feeding, particularly for putrescible waste can disrupt the stable operation of a digester. The effect of intermittent feeding on the anaerobic digestion of rejected raspberries was investigated in four 3L reactors operated in semicontinuous mode for 350 days at 38 °C with a hydraulic retention time of 25 days and an organic loading rate (OLR) of 1gVS/L/d. During the acclimatisation period (147 days) the organic loading was 5 feeds per week. The feeding regime of two reactors was then changed while maintaining the same OLR and HRT to one weekly feed event in one reactor and 3 equal feeds per week in another. The feeding regime did not significantly affect specific methane yield (369 ± 47 L/kgVS on average) despite very different weekly patterns in methane production. Volatile fatty acids (VFA) comprised >83% of the organics in the effluent, while the rest included non-inhibitory concentrations of phenolic compounds (515-556 mg gallic acid/L). The microbial composition and relative abundance of predominant groups in all reactors were the archaeal genera Methanobacterium and Methanolinea and the bacterial phyla Bacteridota and Firmicutes. Increasing the OLR to 2gVS/L/d on day 238 resulted in failure of all reactors, attributed to the insufficient alkalinity to counterbalance the VFA produced, and the pH decrease below 6. Overall results suggests that optimal digestion of raspberry waste is maintained despite variations in feeding frequency, but acidification can occur with OLR changes.