Untangling the interplay of dissolved organic matters variation with microbial symbiotic network in sludge anaerobic fermentation triggered by various pretreatments.

Various pretreatments are commonly adopted to facilitate dissolved organic matter (DOM) release from waste activated sludge (WAS) for high-valued volatile fatty acids (VFAs) promotion, while the interplay impact of DOM dynamics transformation on microbial population and metabolic function traits is poorly understood. This work constructed "DOM-microorganisms-metabolism-VFAs" symbiotic ecologic networks to disclose how DOM dynamics variation intricately interacts with bacterial community networks, assembly processes, and microbial traits during WAS fermentation. The distribution of DOM was altered by different pretreatments, triggering the release of easily biodegradable compounds (O/C ratio > 0.3) and protein-like substance. This alteration greatly improved the substrates biodegradability (higher biological index) and upregulated microbial metabolism capacity (e.g., hydrolysis and fatty acid synthesis). In turn, microbial activity modifications augment substance metabolism level and expedite the conversion of highly reactive compounds (proteins-like DOM) to VFAs, leading to 1.6-4.2 fold rise in VFAs generation. Strong correlations were found between proteins-like DOM and topological properties of DOM-bacteria associations, suggesting that high DOM availability leads to more intricate ecological networks. A change in the way communities assemble, shifting from stronger uniform selection in pH10 and USp reactors to increased randomness in heat reactor, was linked to DOM composition alterations. The ecologic networks further revealed metabolic synergy between hydrolytic-acidogenic bacteria (e.g., Bacteroidota and Firmicutes) and biodegradable DOM (e.g., proteins and amino sugars) leading to higher VFAs generation. This study provides a deeper knowledge of the inherent connections between DOM and microbial traits for efficient VFAs biosynthesis during WAS anaerobic fermentation, offering valuable insights for effective WAS pretreatment strategies.

Tannic Acid Modulation of Substrate Utilization, Microbial Community, and Metabolic Traits in Sludge Anaerobic Fermentation for Volatile Fatty Acid Promotion.

Anaerobic fermentation is a crucial route to realize effective waste activated sludge (WAS) resource recovery and utilization, while the overall efficiency is commonly restrained by undesirable disruptors (i.e., chemical dewatering agents). This work unveiled the unexpectedly positive effects of biodewatering tannic acid (TA) on the volatile fatty acids (VFAs) biosynthesis during WAS anaerobic fermentation. The total VFAs yield was remarkably increased by 15.6 folds with enriched acetate and butyrate in TA-occurred systems. TA was capable to disintegrate extracellular polymeric substances to promote the overall organics release. However, TA further modulated the soluble proteins structure by hydrogen bonding and hydrophobic interactions, resulting in the decrease of proteins bioavailability and consequential alteration of metabolic substrate feature. These changes reshaped the microbial community and stimulated adaptive regulatory systems in hydrolytic-acidogenic bacteria. The keystone species for carbohydrate metabolism (i.e., Solobacterium and Erysipelotrichaceae) were preferentially enriched. Also, the typical quorum sensing (i.e., enhancing substrate transport) and two-component systems (i.e., sustaining high metabolic activity) were activated to promote the microbial networks connectivity and ecological cooperative behaviors in response to TA stress. Additionally, the metabolic functions responsible for carbohydrate hydrolysis, transmembrane transport, and intracellular metabolism as well as VFA biosynthesis showed increased relative abundance, which maintained high microbial activities for VFAs biosynthesis. This study underscored the advantages of biodewatering TA for WAS treatment in the context of resource recovery and deciphered the interactive mechanisms.

Polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes syndrome with dilated cardiomyopathy: A case report.

BACKGROUND: Polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes (POEMS) syndrome is a rare paraneoplastic syndrome that encompass multiple systems. The most common clinical symptoms of POEMS syndrome are progressive sensorimotor polyneuropathy, organ enlargement, endocrine disorders, darkening skin, a monoclonal plasma cell proliferative disorder, and lymph node hyperplasia. The organomegaly consists of hepatosplenomegaly and/or lymphadenopathy; cases of cardiomyopathy are rare. Diagnoses are often delayed because of the atypical nature of the syndrome, exposing patients to possibly severe disability. Therefore, identifying atypical symptoms can improve the prognosis and quality of life among POEMS syndrome patients. CASE SUMMARY: Herein, we report the case of a 59-year-old woman with POEMS syndrome that involved dilated cardiomyopathy. The patient presented to the hospital with complaints of shortness of breath and discomfort in the chest. The patient reported previous experiences of limb numbness. During hospitalization, the brain natriuretic peptide levels were 3504.0 pg/mL. Color doppler echocardiography showed an enlarged left side of the heart, along with ventricular wall hypokinesis and compromised functioning of the same side of the heart. Abdominal color ultrasonography revealed that the patient's spleen was enlarged. Observations from cardiac magnetic resonance imaging showed that the left side of the heart was enlarged. Slight myocardical fibrosis was also observed. Electromyography was described as a symmetric sensorimotor demyelinating polyneuropathy. Further immunoelectrophoresis of the serum showed the presence of a monoclonal IGA λ M protein. The vascular endothelial growth factor levels were 622.56 pg/mL. Flow cytometric and immunohistochemical staining of the bone marrow detected no monoclonal plasma cells. Finally, the patient was diagnosed with POEMS syndrome associated with dilated cardiomyopathy. The chest-related discomfort and the shortness of breath resolved after the administration of lenalidomide and dexamethasone. CONCLUSION: When patients with cardiomyopathy have systemic manifestations such as numb limbs and darkening skin, the POEMS syndrome is the most possible diagnosis.

Simultaneous volatile fatty acids promotion and antibiotic resistance genes reduction in fluoranthene-induced sludge alkaline fermentation: Regulation of microbial consortia and cell functions.

The impact and mechanism of fluoranthene (Flr), a typical polycyclic aromatic hydrocarbon highly detected in sludge, on alkaline fermentation for volatile fatty acids (VFAs) recovery and antibiotic resistance genes (ARGs) transfer were studied. The results demonstrated that VFAs production increased from 2189 to 4272 mg COD/L with a simultaneous reduction of ARGs with Flr. The hydrolytic enzymes and genes related to glucose and amino acid metabolism were provoked. Also, Flr benefited for the enrichment of hydrolytic-acidifying consortia (i.e., Parabacteroides and Alkalibaculum) while reduced VFAs consumers (i.e., Rubrivivax) and ARGs potential hosts (i.e., Rubrivivax and Pseudomonas). Metagenomic analysis indicated that the genes related to cell wall synthesis, biofilm formation and substrate transporters to maintain high VFAs-producer activities were upregulated. Moreover, cell functions of efflux pump and Type IV secretion system were suppressed to inhibit ARGs proliferation. This study provided intrinsic mechanisms of Flr-induced VFAs promotion and ARGs reduction during alkaline fermentation.

Dynamic microbiome disassembly and evolution induced by antimicrobial methylisothiazolinone in sludge anaerobic fermentation for volatile fatty acids generation.

In the post-COVID-19 pandemic era, various antimicrobials have emerged and concentrated in waste-activated sludge (WAS), affecting the biological treatment of WAS. However, there is still a knowledge gap in the dynamic response and adaptive mechanism of anaerobic microbiome under exogenous antimicrobial stress. This study found that methylisothiazolinone (MIT, as a typic antimicrobial) caused an interesting lag effect on the volatile fatty acids (VFAs) promotion in the WAS anaerobic fermentation process. MIT was effective to disintegrate the extracellular polymeric substances (EPS), and those functional anaerobic microorganisms were easily exposed and negatively impacted by the MIT interference after the loss of protective barriers. Correspondingly, the ecological interactions and microbial metabolic functions related to VFA biosynthesis (e.g., pyruvate metabolism) were downregulated at the initial stage. The syntrophic consortia gradually adapted to the interference and attenuated the MIT stress by activating chemotaxis and resistance genes (e.g., excreting, binding, and inactivating). Due to the increased bioavailable substrates in the fermentation systems, the dominant microorganisms (i.e., Clostridium and Caloramator) with both VFAs production and MIT-tolerance functions have been domesticated. Moreover, MIT disrupted the syntrophic interaction between acetogens and methanogens and totally suppressed methanogens' metabolic activities. The VFA production derived from WAS anaerobic fermentation was therefore enhanced due to the interference of antimicrobial MIT stress. This work deciphered dynamic changes and adaptive evolution of anaerobic syntrophic consortia in response to antimicrobial stress and provided guidance on the evaluation and control of the ecological risks of exogenous pollutants in WAS treatment.

Disinfectant sodium dichloroisocyanurate synergistically strengthened sludge acidogenic process and pathogens inactivation: Targeted upregulation of functional microorganisms and metabolic traits via self-adaptation.

Harmless and resourceful treatment of waste activated sludge (WAS) have been the crucial goal for building environmental-friendly and sustainable society, while the synergistic realization approach is currently limited. This work skillfully utilized the disinfectant sodium dichloroisocyanurate (NaDCC) to simultaneously achieve the pathogenic potential inactivation (decreased by 60.1 %) and efficient volatile fatty acids (VFAs) recovery (increased by 221.9 %) during WAS anaerobic fermentation in rather cost-effective way (Chemicals costs:0.4 USD/kg VFAs versus products benefits: 2.68 USD/kg chemical). Mechanistic analysis revealed that the C=O and NCl bonds in NaDCC could spontaneously absorb sludge (binding energy -4.9 kJ/mol), and then caused the sludge disintegration and organic substrates release for microbial utilization due to the oxidizability of NaDCC. The disruption of sludge structure along with the increase of bioavailable fermentation substrates contributed to the selectively regulation of microbial community via enriching VFAs-forming microorganisms (e.g., Pseudomonas and Streptomyces) and reducing VFAs-consuming microorganisms, especially aceticlastic methanogens (e.g., Methanothrix and Methanospirillum). Correspondingly, the metabolic functions of membrane transport, substrate metabolism, pyruvate metabolism, and fatty acid biosynthesis locating in the central pathway of VFAs production were all upregulated while the methanogenic step was inhibited (especially acetate-type methanogenic pathway). Further exploration unveiled that for those enriched functional anaerobes were capable to activate the self-adaptive systems of DNA replication, SOS response, oxidative stress defense, efflux pump, and energy metabolism to counteract the unfavorable NaDCC stress and maintain high microbial activities for efficient VFAs yields. This study would provide a novel strategy for synergistic realization of harmless and resourceful treatment of WAS, and identify the interrelations between microbial metabolic regulations and adaptive responses.

Distinct effects of chemical- and bio- flocculants on the sludge acidogenic fermentation for volatile fatty acids production by affecting the acidogenic steps, microbial community structure and metabolic functions.

Flocculants play crucial roles in sludge treatment, while the specific impact of chemical and bio-flocculants on sludge anaerobic fermentation was unknown. This study unveiled the contrasting effects of chitosan (CTS) and poly­aluminum chloride (PAC) on volatile fatty acids (VFAs) generation during sludge fermentation. CTS supplementation resulted in 17.2 % increase in VFAs production, while PAC exposure led to 7.6 % reduction compared to the control. Further investigation revealed that CTS facilitated sludge solubilization and hydrolysis, thus providing sufficient organic substrates for VFAs generation. Additionally, environmental-friendly CTS exposure positively influenced the abundance and activity of functional anaerobes, as well as the expression of genes associated with VFAs biosynthesis. In contrast, PAC exposure resulted in the formation of larger sludge flocs, which hindered WAS solubilization and hydrolysis. Meanwhile, its potential microbial toxicity also impeded the microbial metabolic activity (i.e., genetic expressions), resulting in unsatisfactory VFAs production.

Nitrogen-doped graphene for tetracycline removal via enhancing adsorption and non-radical persulfate activation.

Nitrogen-doped graphene (NG) was synthesized via direct thermal annealing treatment. The obtained NG showed outstanding removal ability for tetracycline (TC) ascribed to enhanced adsorption and persulfate activation. The maximum TC adsorption capacity calculated from the Langmuir model of NG was 227.3 mg/g, which was 1.66 times larger than nitrogen-free graphene. The coexistence of NG and persulfate (PS) exhibited complete degradation of TC within 120 min attributed to the successful modification of nitrogen. Further analysis demonstrated that non-radical electron transfer was the dominant degradation pathway, which was different from the widely acknowledgeable radical mechanism. An electron donor-mediator-acceptor system was introduced, in which TC, NG, and PS performed as electron donor, mediator, and acceptor, respectively. The potential intermediates in the TC degradation process were detected and toxicity assessment was also performed. In addition, more than 75.8% of total organic carbon was removed, and excellent reusability was manifested in multiple adsorption and degradation experiments.

Phenanthrene regulates metabolic pathways for hydrogen accumulation in sludge alkaline dark fermentation.

The influence of phenanthrene (PHE), a general polycyclic aromatic hydrocarbon in waste activated sludge, on sludge alkaline dark fermentation for hydrogen accumulation was investigated prospectively. The yield of hydrogen was 16.2 mL/g TSS with 50 mg/kg TSS PHE, which was 1.3-fold greater than that of the control. Mechanism research demonstrated that hydrogen production and the abundance of functional microorganisms were facilitated, whereas those of homoacetogenesis were reduced. The activity of pyruvate ferredoxin oxidoreductase in the conversion of pyruvate to reduced ferredoxin for hydrogen production was promoted by 57.2%, and that of carbon monoxide dehydrogenase and formyltetrahydrofolate synthetase, closely associated with hydrogen consumption, was suppressed by 60.5% and 55.9%, respectively. Moreover, the encoding genes involved in pyruvate metabolism were significantly up-regulated, while genes related to consuming hydrogen to reduce carbon dioxide and produce 5-methyltetrahydrofolate were down-regulated. This study notably illustrates the effect of PHE on hydrogen accumulation from metabolic pathways.

Can visceral fat parameters based on computed tomography be used to predict occult peritoneal metastasis in gastric cancer?

BACKGROUND: The preoperative prediction of peritoneal metastasis (PM) in gastric cancer would prevent unnecessary surgery and promptly indicate an appropriate treatment plan. AIM: To explore the predictive value of visceral fat (VF) parameters obtained from preoperative computed tomography (CT) images for occult PM and to develop an individualized model for predicting occult PM in patients with gastric carcinoma (GC). METHODS: A total of 128 confirmed GC cases (84 male and 44 female patients) that underwent CT scans were analyzed and categorized into PM-positive (n = 43) and PM-negative (n = 85) groups. The clinical characteristics and VF parameters of two regions of interest (ROIs) were collected. Univariate and stratified analyses based on VF volume were performed to screen for predictive characteristics for occult PM. Prediction models with and without VF parameters were established by multivariable logistic regression analysis. RESULTS: The mean attenuations of VFROI 1 and VFROI 2 varied significantly between the PM-positive and PM-negative groups (P = 0.044 and 0.001, respectively). The areas under the receiver operating characteristic curves (AUCs) of VFROI 1 and VFROI 2 were 0.599 and 0.657, respectively. The mean attenuation of VFROI 2 was included in the final prediction combined model, but not an independent risk factor of PM (P = 0.068). No significant difference was observed between the models with and without mean attenuation of VF (AUC: 0.749 vs 0.730, P = 0.339). CONCLUSION: The mean attenuation of VF is a potential auxiliary parameter for predicting occult PM in patients with GC.

Ultrasonic-assisted hypochlorite activation accelerated volatile fatty acids production during sewage sludge fermentation: Critical insights on solubilization/hydrolysis stages and microbial traits.

The effective disruption of extracellular polymeric substances using appropriate pretreatment is critical to achieving resource recovery from sewage sludge (SS) by anaerobic fermentation. This work proposed an ultrasonic-assisted hypochlorite activation strategy for enhanced production of volatile fatty acids (VFAs) during SS fermentation. The results demonstrated that after individual ultrasonic and hypochlorite pretreatment, the maximum VFAs yield improved by 8 and 107% with that in control, respectively, while a combination of both techniques led to an improvement of 119%, indicating their synergistic effects on SS fermentation. This method enhanced the solubilization and hydrolysis efficiencies and contributed to the increased biodegradable substrates, which would be beneficial in enhancing microbial activity for VFAs production. The functional anaerobes, metabolic pathways, and gene expressions involved in VFAs biosynthesis were effectively improved. This work would bring a novel insight into the disposal of municipal solid waste for resource recovery.

Zinc pyrithione induced volatile fatty acids promotion derived from sludge anaerobic digestion: Interrelating the affected steps with microbial metabolic regulation and adaptive responses.

The massive use of zinc pyrithione (ZPT, as broad-spectrum bactericides) resulted in its high levels in waste activated sludge (WAS) and affected subsequent WAS treatment. This work revealed the effects of ZPT on the volatile fatty acids (VFAs) during WAS anaerobic digestion, in which VFAs yield was enhanced by approximately 6-9 folds (from 353 mg COD/L in control to 2526-3318 mg COD/L with low level of ZPT (20-50 mg/g TSS)). The ZPT occurred in WAS enabled the acceleration of solubilization, hydrolysis and acidification processes while inhibited the methanogenesis. Also, the low ZPT contributed to the enrichment of functional hydrolytic-acidifying microorganisms (e.g., Ottowia and Acinetobacter) but caused the reduction of methanogens (e.g., Methanomassiliicoccus and Methanothrix). Meta-transcriptomic analysis demonstrated that the critical genes relevant to extracellular hydrolysis (i.e. CLPP and ZapA), membrane transport (i.e. gltI, and gltL), substrates metabolisms (i.e. fadj, and acd), and VFAs biosynthesis (i.e. porB and porD) were all upregulated by 25.1-701.3% with low level of ZPT. Specifically, the ZPT stimulus on amino acids metabolism for VFAs transformation was prominent over carbohydrates. Moreover, the functional species enabled to regulate the genes in QS and TCS systems to maintain favorable cell chemotaxis to adapt the ZPT stress. The cationic antimicrobial peptide resistance pathway was upregulated to blunt ZPT with the secretion of more lipopolysaccharide and activate proton pumps to maintain ions homeostasis to antagonize the ZPT toxicity for high microbial activities, the abundance of related genes was up-regulated by 60.5 to 524.5%. This work enlightened environmental behaviors of emerging pollutants on WAS anaerobic digestion process with interrelations of microbial metabolic regulation and adaptive responses.

Proteomic profiling of robust acetoclastic methanogen in chrysene-altered anaerobic digestion: Global dissection of enzymes.

Methanogen is a pivotal player in pollution treatment and energy recovery, and emerging pollutants (EPs) frequently occur in methanogen-applied biotechnology such as anaerobic digestion (AD). However, the direct effect and underlying mechanism of EPs on crucial methanogen involved in its application still remain unclear. The positive effect of chrysene (CH) on semi-continuous AD of sludge and the robust methanogen was dissected in this study. The methane yield in the digester with CH (100 mg/kg dry sludge) was 62.1 mL/g VS substrate, much higher than that in the control (46.1 mL/g VS substrate). Both methane production from acetoclastic methanogenesis (AM) and the AM proportion in the methanogenic pathway were improved in CH-shaped AD. Acetoclastic consortia, especially Methanosarcina and functional profiles of AM were enriched by CH in favor of the corresponding methanogenesis. Further, based on pure cultivation exposed to CH, the methanogenic performance, biomass, survivability and activity of typical Methanosarcina (M. barkeri) were boosted. Notably, iTRAQ proteomics revealed that the manufacturing (transcription and translation), expression and biocatalytic activity of acetoclastic metalloenzymes, particularly tetrahydromethanopterin S-methyltransferase and methyl-coenzyme M reductase with cobalt/nickel-cofactor (F430 and cobalamin), and acetyl-CoA decarbonylase/synthase with cobalt/nickel-active site, of M. barkeri were upregulated significantly with fold changes in the range of 1.21-3.20 due to the CH presence. This study shed light on EPs-affecting industrially crucial methanogen at the molecular biology level during AD and had implications in the technical relevance of methanogens.

Microbial Enterotypes Shape the Divergence in Gut Fermentation, Host Metabolism, and Growth Rate of Young Goats.

Enterotypes can be useful tools for studying the gut microbial community landscape, which is thought to play a crucial role in animal performance. However, few studies have been carried out to identify enterotypes and their associations with growth performance in young goats. In this study, two enterotypes were categorized in 76 goats: cluster 1 (n = 39) and cluster 2 (n = 37). Compared to cluster 2, cluster 1 had greater growth rates, the concentrations of acetate, propionate, valerate, and total volatile fatty acids (VFA) in the gut. Several serum glycolipid metabolism parameters, including glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), were also increased in cluster 1, while serum IgG was decreased in cluster 1. Using α-diversity analysis, we found a microbiome with lower richness and diversity in cluster 1. Some gut bacteria, including Succinivibrio and several members of the Prevotellaceae family, were enriched in cluster 1, while Christensenellaceae R-7 group, Romboutsia, and Clostridium sensu stricto 1 were enriched in cluster 2. A co-occurrence network analysis revealed that the differential interaction patterns existed in two enterotypes, and microbial function prediction suggested that some nutrient metabolism-related pathways, including amino acid biosynthesis and starch and sucrose metabolism, were enriched in cluster 1. Furthermore, a correlation analysis showed that enterotype-related bacteria were closely correlated with gut fermentation, serum biochemistry, and growth rate. Overall, our data provide a new perspective for understanding enterotype characteristics in goats, offering insights into important microbial interaction mechanisms for improving the growth performance of ruminant animals. IMPORTANCE The intricate relationships between a host animal and its resident gut microbiomes provide opportunities for dealing with energy efficiency and production challenges in the livestock industry. Here, we applied the enterotype concept to the gut microbiome in young goats and found that it can be classified into two enterotypes which are apparently associated with divergences in gut fermentation, blood biochemistry, and goat growth rates. The microbial co-occurrence networks and function predictions differed between the two enterotypes, suggesting that the formation of host phenotype may be modified by different bacterial features and complex bacterial interactions. The characteristics of enterotypes related to growth performance in young goats may enable us to improve long-term production performance in goat industry by modulating the gut microbiome during early life.

Metagenomic insight of fluorene-boosted sludge acidogenic fermentation: Metabolic transformation of amino acids and monosaccharides.

Fluorene (Flu) occurs widely in various environments and its toxicity to organisms is well-known. However, the impact of Flu on complicated biochemical processes involving functional microbial community has been reported rarely. In this study, the facilitation of Flu on the volatile fatty acids (VFAs) generation executed by acidogenic microbial population during sludge acidogenic fermentation (37 °C, SRT = 8 d, pH = 10.0) was investigated. The accumulation of VFAs (particularly acetic acid) increased initially and then declined with the increasing of Flu concentration (0-500 mg/kg dry sludge), which reached a maximum (3211.1 mg COD/L) as Flu content was 200 mg/kg dry sludge. The Flu-enhanced VFAs production was primarily attributed to the shift of hydrolysis/acidification, as well as the corresponding functional microbial community and the activity of enzymes. Based on the metagenomics analysis, the conversion of organic substrates, i.e. amino acid and monosaccharide, into VFAs embraced in hydrolysis/acidification shaped by Flu was constructed at the genetic level. The relative abundances of genes included in aminotransfer and deamination process of amino acid and glycolysis of monosaccharide into VFA-precursors (pyruvate, acetyl-CoA and propionyl-CoA), and the further formation of VFAs were improved due to the Flu presence. This study shed light on the Flu-affected microbial processes at the molecular biology level during acidogenic fermentation and was of great significance in resource recovery of sludge containing persistent organic pollutants.

Dioctyl phthalate enhances volatile fatty acids production from sludge anaerobic fermentation: Insights of electron transport and metabolic functions.

As one of the most widely used phthalate plasticizers, dioctyl phthalate (DOP) has been detected in wastewater and accumulates in sludge through wastewater treatment, which may adversely affect further sludge treatment. However, the role of DOP on sludge anaerobic fermentation and its mechanism are not yet clear. Therefore, this study focused on the effect of DOP on the volatile fatty acids (VFAs) generation via the anaerobic fermentation of sludge. The results demonstrated that the presence of DOP had a considerable contribution to the generation of VFAs, and the maximum production of VFAs reached 4769 mg COD/L at 500 mg/kg DOP, which was 1.57 folds that of the control. Mechanistic investigation showed that DOP mainly enhanced the hydrolysis, acidification and related enzymes activities of sludge. VFAs-producing microorganisms (e.g., Clostridium and Conexibacter) were also enriched under DOP exposure. Importantly, the presence of DOP increased the electron transfer activity by 26 %, consequently facilitating the organics conversion and fermentation process. Notably, the functional gene expressions involved in substrate metabolism and VFAs biosynthesis were enhanced with DOP, resulting in increased VFAs production from sludge. The results obtained in this study offered a new strategy for the control of pollutants and the recycling of valuable products from sludge.

Polycyclic aromatic hydrocarbons stimulate acidogenesis, acetogenesis and methanogenesis during anaerobic co-digestion of waste activated sludge and food waste.

Polycyclic aromatic hydrocarbons (PAHs) have been reported to influence acetic acid production during anaerobic treatment. However, investigations of the impacts of PAHs on the anaerobic co-digestion of waste activated sludge and food waste are limited. Therefore, the effects of PAHs on anaerobic co-digestion were explored in this study. Four kinds of PAHs all exhibited positive contributions to methane production, especially phenanthrene. Mechanism exploration revealed that acidogenesis, acetogenesis, and methanogenesis were improved in the presence of phenanthrene, and acetotrophic methanogenesis had the greatest improvement with 69.4%. Dominant bacteria and archaea related to acetic acid and methane accumulation were changed by phenanthrene. Moreover, extracellular polymeric substances, coenzyme F420, and McrA gene copy number were promoted by phenanthrene, which was beneficial for the generation of acetic acid and methane. Overall, this study provides new insights into the role of organic pollutants in the anaerobic co-digestion of solid wastes.

Sulfadiazine inhibits hydrogen production during sludge anaerobic fermentation by affecting pyruvate decarboxylation.

The overuse and random discharge of antibiotics can cause serious environmental pollution. Sludge acts as a repository for antibiotics, its anaerobic fermentation process will inevitably be affected. This study investigated the effects of a typical antibiotic contaminant, sulfadiazine (SDZ), on the anaerobic fermentation of sludge for hydrogen production. Results demonstrated that the production of hydrogen was significantly inhibited by SDZ, and the inhibition was enhanced with increasing SDZ content. Within 5 days, the cumulative amount of hydrogen with 500 mg SDZ/kg dry sludge was 8.5 mL, which was only 32.2% of that in the control (26.4 mL). Mechanistic investigation showed that the reduced hydrogen production when SDZ existed was mainly attributed to the suppression of pyruvate decarboxylation during the hydrogen production stage, and the diversity of microorganisms, especially the abundance of microorganisms and the activities of key enzymes closely related to hydrogen production were inhibited with SDZ, resulting in less hydrogen accumulation.

Nitric Oxide: A Neglected Driver for the Conjugative Transfer of Antibiotic Resistance Genes among Wastewater Microbiota.

The dissemination of plasmid-borne antibiotic resistance genes (ARGs) in wastewater is becoming an urgent concern. Previous studies mainly focused on the effects of coexisting contaminants on plasmid conjugation, but ignored the potential contribution of some byproducts inevitably released from wastewater treatment processes. Herein, we demonstrate for the first time that nitric oxide (NO), an intermediate of the wastewater nitrogen cycle, can significantly boost the conjugative transfer of plasmid RP4 from Escherichia coli K12 to different recipients (E. coli HB101, Salmonella typhimurium, and wastewater microbiota). Phenotypic and genotypic tests confirmed that NO-induced promotion was not attributed to the SOS response, a well-recognized driver for horizontal gene transfer. Instead, NO exposure increased the outer membrane permeability of both the donor and recipient by inhibiting the expression of key genes involved in lipopolysaccharide biosynthesis (such as waaJ), thereby lowering the membrane barrier for conjugation. On the other hand, NO exposure not only resulted in the accumulation of intracellular tryptophan but also triggered the deficiency of intracellular methionine, both of which were validated to play key roles in regulating the global regulatory genes (korA, korB, and trbA) of plasmid RP4, activating its encoding transfer apparatus (represented by trfAp and trbBp). Overall, our findings highlighted the risks of NO in spreading ARGs among wastewater microbiota and updated the regulation mechanism of plasmid conjugation.

Clinical and imaging features of carcinosarcoma of the uterus and cervix.

AIM: The purpose of our study was to analyze the clinical and imaging features of uterine carcinosarcoma (UCS) and cervical carcinosarcoma (CCS), and to explore the diagnostic and staging accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) examinations. METHODS: 41 patients including 37 with UCS and 4 with CCS from July 2011 to September 2020 were enrolled in the study. Of the 37 UCS cases, 7 had CT images, 27 had MRI images, and 3 had both CT and MRI images. The Clinical data, CT or MRI imaging findings were analyzed. Diagnosis and staging accuracy of CT and MRI images were also analyzed. RESULTS: Carcinosarcoma usually occurs in postmenopausal women (40/41), with the typical clinical symptom being vaginal bleeding (33/41). The CA125 degree was significantly different between the two invasion depth groups (p = 0.011). Most uterine carcinosarcomas showed unclear boundaries, uneven density, low or equal signal on T1WI, high or mixed signal on T2WI, uneven high signal on diffusion-weighted image (DWI), and mild enhancement. The diagnostic accuracies of CT and MRI for carcinosarcoma were 0% and 3.33%, respectively. The diagnostic accuracy for malignant tumors on CT and MRI was 50% and 83.33%, respectively. CONCLUSIONS: Carcinosarcoma lesions presented with huge mass filling in the cavity, and some presented with small polypoid lesions or endometrial thickening. Evaluation of lymph node metastasis is a significant challenge for imaging staging.