ABSTRACT
The effects of typical organic compounds including easily degradable organic matters sodium acetate, yeast and methanol, and refractory organic matter (ROM) humic acid on anaerobic ammonium oxidation (anammox) systems in short-term and medium-term exposure time were studied. During short-term experiments, nitrogen removal activity (NRA) was inhibited at sodium acetate level of 150 mg L-1 total organic carbon (TOC) and methanol level of 30-150 mg L-1 TOC, but humic acid and yeast (≤150 mg L-1 TOC) enhanced nitrogen removal in anammox systems. The greatest NRA of 30.10 mg TN g-1 VSS h-1 was recorded at yeast level of 90 mg L-1 TOC. In medium-term experiments, organics significantly inhibited the nitrogen removal ability. As a ROM, humic acid enhanced sludge aggregation and biological diversity, but decreased the bioactivity and extracellular polymeric substances levels. Due to the endogenous denitrification, the relative abundance of anammox bacteria (AnAOB) was decreased. Candidatus Kuenenia is still dominant in sludge with methanol and humid acid, but AnAOB are not dominant due to the addition of sodium acetate and yeast. This research would be beneficial for the full-scale application of the anammox process in treating real wastewater with organics and ammonia.
ABSTRACT
Drug resistance poses a high risk to human health. Extensive use of non-antibiotic drugs contributes to antibiotic resistance genes (ARGs) transfer. However, how they affect the spread of broad-host plasmids in complex biological systems remains unknown. This study investigated the effect of metoprolol on the transfer frequency and host range of ARGs in both intrageneric and intergeneric pure culture systems, as well as in anammox microbiome. The results showed that environmental concentrations of metoprolol significantly promoted the intrageneric and intergeneric conjugative transfer. Initially, metoprolol induced excessive oxidative stress, resulting in high cell membrane permeability and bacterial SOS response. Meanwhile, more pili formation increased the adhesion and contact between bacteria, and the abundance of conjugation-related genes also increased significantly. Activation of the electron transport chain provided more ATP for this energy-consuming process. The underlying mechanism was further verified in the complex anammox conjugative system. Metoprolol induced the enrichment of ARGs and mobile genetic elements. The enhanced bacterial interaction and energy generation facilitated the high conjugative transfer frequency of ARGs. In addition, plasmid-borne ARGs tended to transfer to opportunistic pathogens. This work raises public concerns about the health and ecological risks of non-antibiotic drugs.
Subject(s)
Conjugation, Genetic , Metoprolol , Plasmids , Plasmids/genetics , Conjugation, Genetic/drug effects , Drug Resistance, Multiple, Bacterial/genetics , Drug Resistance, Multiple, Bacterial/drug effects , Adrenergic beta-Antagonists/pharmacology , Gene Transfer, Horizontal , Bacteria/genetics , Bacteria/drug effects , Bacteria/metabolism , Anti-Bacterial Agents/pharmacology , Genes, MDR/genetics , Microbiota/drug effectsABSTRACT
Ectopic transplantation of the hand remains a rare, innovative yet valuable operation in select cases of trauma and amputation. We aim to describe a novel technique of complex hand reconstruction using a two-stage ectopic implantation of the contralateral upper limb. A male patient with a near complete avulsion amputation of the right upper limb at the level of the mid-forearm and a crushing injury to his left hand was admitted after a farming accident. The right palm was ectopically transplanted to the left lower limb and both upper limbs underwent debridement with vacuum assisted dressings (VACs). There was eventual dieback of the left thumb, ring and little finger with a large palmar soft tissue defect that was eventually reconstructed using segments of the ectopically transplanted limb in two separate operations. The patient made an uneventful postoperative recovery and managed to regain protective sensation and gross motor function of his reconstructed hand.
Subject(s)
Amputation, Traumatic , Hand Injuries , Plastic Surgery Procedures , Humans , Male , Hand Injuries/surgery , Amputation, Traumatic/surgery , Plastic Surgery Procedures/methods , Adult , Crush Injuries/surgeryABSTRACT
The extremely slow growth rate of anaerobic ammonia oxidation (anammox) bacteria limits full-scale application of anammox process worldwide. In this study, extracellular polymeric substances (EPS)-coated polypropylene (PP) carriers were prepared for biofilm formation. The biomass adhesion rate of EPS-PP carrier was 12 times that of PP carrier, and EPS-PP achieved significant enrichment of E. coli BY63. The 120-day continuous flow experiment showed that the EPS-PP carrier accelerated the formation of anammox biofilm, and the nitrogen removal efficiency increased by 10.5 %. In addition, the abundance of Candidatus Kuenenia in EPS-PP biofilm was 27.1%. Simultaneously, amino acids with high synthesis cost and the metabolites of glycerophospholipids related to biofilm formation on EPS-PP biofilm were significantly up-regulated. Therefore, EPS-PP carriers facilitated the rapid formation of anammox biofilm and promoted the metabolic activity of functional bacteria, which further contributed to the environmental and economic sustainability of anammox process.
Subject(s)
Biofilms , Extracellular Polymeric Substance Matrix , Oxidation-Reduction , Extracellular Polymeric Substance Matrix/metabolism , Ammonia/metabolism , Polypropylenes , Nitrogen/metabolism , Microbial Consortia/physiology , Bacteria/metabolism , Anaerobiosis/physiology , Biomass , Escherichia coli/metabolismABSTRACT
Anaerobic ammonium oxidation (anammox), an energy-efficient deamination biotechnology, faces operational challenges in low-temperature environments. Enhancing the metabolic activity of anammox bacteria (AnAOB) is pivotal for advancing its application in mainstream municipal wastewater treatment. Inspired by the metabolic adaptability of AnAOB and based on our previous findings, this work investigated the enhancement of intracellular ATP and NADH synthesis through the exogenous supply of reduced humic acid (HAred) and H2O2 redox couple, aiming to augment AnAOB activity under low-temperature conditions. Our experimental setup involved continuous dosing of 0.0067 µmol g-1 volatile suspended solid of H2O2 and 10 mg g-1 volatile suspended solid of HAred into a mainstream anammox reactor operated at 15 °C with an influent TN content of 60 mg/L. The results showed that HAred / H2O2 couple succeeded in maintaining the effluent TN at 10.72 ± 0.91 mg l-1. The specific anammox activity, ATP and NADH synthesis levels of sludge increased by 1.34, 2.33 and 6.50 folds, respectively, over the control setup devoid of the redox couple. High-throughput sequencing analysis revealed that the relative abundance of Candidatus Kuenenia after adding HAred / H2O2 couple reached 3.65 % at the end of operation, which was 5.14 folds higher than that of the control group. Further metabolomics analysis underscored an activation in the metabolism of amino acids, nucleotides, and phospholipids, which collectively enhanced the availability of ATP and NADH for the respiratory processes. These findings may provide guidance on strategy development for improving the electron transfer efficiency of AnAOB and underscore the potential of using redox couples to promote the mainstream application of anammox technology.
Subject(s)
Oxidation-Reduction , Sewage , Sewage/microbiology , Bioreactors , Ammonium Compounds/metabolism , Anaerobiosis , Hydrogen Peroxide/metabolism , Waste Disposal, Fluid/methods , Bacteria/metabolism , NAD/metabolismABSTRACT
Anaerobic biological treatment technology, especially denitrification and anaerobic ammonia oxidation (anammox) technology as mainstream process, played dominant role in the field of biological wastewater treatment. However, the above process was prone to sludge floating during high load operation and thereby affecting the efficient and stable operation of the system. Excessive production of extracellular polymeric substance (EPS) was considered to be the main reason for anaerobic granular sludge flotation, but the summaries in this area were not comprehensive enough. In this review, the potential mechanisms of denitrification and anammox sludge floatation were discussed from the perspective of granular sludge structural characteristics, nutrient transfer, and microbial flora change respectively, and the corresponding control strategies were also summarized. Finally, this paper indicated that future research on sludge flotation should focus on reducing the negative effects of EPS in sludge particles.
Subject(s)
Denitrification , Nitrogen , Sewage , Waste Disposal, Fluid , Sewage/microbiology , Waste Disposal, Fluid/methods , Anaerobiosis , Nitrogen/metabolism , Oxidation-Reduction , Bioreactors/microbiologyABSTRACT
The widespread use of surfactants raise challenges to biological wastewater treatment. Anaerobic ammonium oxidation (anammox) process has the potential to treat wastewater containing anionic surfactants, but the response of anammox consortia at the molecular level under long-term exposure is unclear. Using high-throughput sequencing and gene quantification, combined with molecular docking, the effect of sodium dodecyl sulfonate (SDS) on anammox consortia were investigated. Levels of reactive oxygen species (ROS) might be lower than the threshold of oxidative damage, while the increase of lactate dehydrogenase (LDH) represented the cell membrane damage. Decreased abundance of functional genes (hdh, hzsA and nirS) indicated the decrease of the anammox bacterial abundance. Trace amounts of N-acyl homoserine lactone (AHL, C6-HSL, C8-HSL and C12-HSL) contained in influent could induce endogenous quorum sensing (QS), which could regulate the correlation between functional bacteria to optimize the microbial community and strengthen the resistance of anammox consortia to SDS. In addition, the proliferation of disinfectant resistance genes might increase the environmental pathogenicity of sewage discharge. This work highlights the potential response mechanism of anammox consortium to surfactants and provides a universal microbial-friendly bioenhancement strategy based on QS.
Subject(s)
Quorum Sensing , Surface-Active Agents , Waste Disposal, Fluid , Surface-Active Agents/metabolism , Waste Disposal, Fluid/methods , Wastewater/microbiology , Oxidation-Reduction , Anaerobiosis , Ammonium Compounds/metabolism , Molecular Docking Simulation , Microbial Consortia/physiologyABSTRACT
To improve nitrogen removal efficiency (NRE) and achieve homogenous distribution of anammox sludge and substrate, a new substrate equalization theory and a cumulative overload index was proposed for multifed upflow anaerobic sludge bed (MUASB) reactors with mature anammox granules. The performance and flow patterns of MUASB reactors were investigated under various influent conditions. The results showed that the nitrogen removal performance and stability of MUASB reactors could be optimized by minimizing the cumulative load. The NRE gradually increased from 83.3 ± 2.2 %, 86.8 ± 4.2 % to 89.3 ± 4.1 % and 89.7 ± 1.6 % in feeding flow tests and feeding port tests, respectively. Furthermore, the flow patterns were compared based on residence time distribution and computational fluid dynamics, indicating that a better equilibrium distribution of microorganisms and substrates could be achieved in the MUASB reactors under the lowest cumulative load. Therefore, substrate equalization theory can be used to optimize the nitrogen removal performance of MUASB reactors with low-carbon footprints.
Subject(s)
Bioreactors , Nitrogen , Sewage , Sewage/microbiology , Anaerobiosis , Nitrogen/metabolism , Oxidation-Reduction , HydrodynamicsABSTRACT
Ciprofloxacin (CIP) poses a high risk of resistance development in water environments. Therefore, comprehensive effects and recovery strategies of CIP in anaerobic ammonia oxidation (anammox) process were systematically elucidated from consortia and pure strains perspectives. The anammox consortia was not significantly affected by the stress of 10 mg L-1 CIP, while the higher concentration (20 mg L-1) of CIP caused a dramatic reduction in the nitrogen removal performance of anammox system. Simultaneously, the abundances of dominant functional bacteria and corresponding genes also significantly decreased. Such inhibition could not be mitigated by the recovery strategy of adding hydrazine and hydroxylamine. Reducing nitrogen load rate from 5.1 to 1.4 kg N m-3 d-1 promoted the restoration of three reactors. In addition, the robustness and recovery of anammox systems was evaluated using starvation and shock strategies. Simultaneously, antibiotic resistance genes and key metabolic pathways of anammox consortia were upregulated, such as carbohydrate and energy metabolisms. In addition, 11 pure stains were isolated from the anammox system and identified through phylogenetic analysis, 40 % of which showed multidrug resistance, especially Pseudomonas. These findings provide deep insights into the responding mechanism of anammox consortia to CIP stress and promote the application of anammox process for treating wastewater containing antibiotics.
Subject(s)
Anti-Bacterial Agents , Ciprofloxacin , Ciprofloxacin/pharmacology , Oxidation-Reduction , Ammonia/metabolism , Anaerobiosis , Bioreactors/microbiology , Bacteria/metabolism , Bacteria/genetics , Microbial Consortia , Nitrogen/metabolism , Wastewater/microbiologyABSTRACT
The treatment of pretreated printed circuit board (PCB) wastewater by anaerobic ammonium oxidation (anammox) process has been rarely reported. This study sought to investigate the performance of the anammox process during various phases of pretreated PCB wastewater treatment. The nitrogen removal efficiency (NRE) reached 90 ± 10% at a Cu2+ concentration of 2.5 mg·L-1, but declined to 22 ± 11% as the Cu2+ level increased to 10.3 mg·L-1. During phase III, there was a 38% increase in the relative abundance of Candidatus Kuenenia compared to phase I. By adjusting the substrate concentration and introducing synthetic wastewater into the reactor, the anammox performance was nearly restored to that of phase I. These findings underscore the potential of the anammox process for treating pretreated PCB wastewater and expanding its practical applications to industrial wastewater treatment.
Subject(s)
Ammonium Compounds , Wastewater , Anaerobiosis , Feasibility Studies , Denitrification , Bioreactors , Oxidation-Reduction , Nitrogen , SewageABSTRACT
Nonphotosynthetic microorganisms are typically unable to directly utilize light energy, but light might change the metabolic pathway of these bacteria indirectly by forming intermediates such as reactive oxygen species (ROS). This work investigated the role of light on nitrogen conversion by anaerobic ammonium oxidation (anammox) consortia. The results showed that high intensity light (>20000 lx) caused ca. 50% inhibition of anammox activity, and total ROS reached 167% at 60,000 lx. Surprisingly, 200 lx light was found to induce unexpected promotion of the nitrogen conversion rate, and ultraviolet light (<420 nm) was identified as the main contributor. Metagenomic and metatranscriptomic analyses revealed that the gene encoding cytochrome c peroxidase was highly expressed only under 200 lx light. 15N isotope tracing, gene abundance quantification, and external H2O2 addition experiments showed that photoinduced trace H2O2 triggered cytochrome c peroxidase expression to take up electrons from extracellular nonfermentative organics to synthesize NADH and ATP, thereby expediting nitrogen dissimulation of anammox consortia. External supplying reduced humic acid into a low-intensity light exposure system would result in a maximal 1.7-fold increase in the nitrogen conversion rate. These interesting findings may provide insight into the niche differentiation and widespread nature of anammox bacteria in natural ecotopes.
Subject(s)
Anaerobic Ammonia Oxidation , Cytochrome-c Peroxidase , Electrons , Hydrogen Peroxide , Reactive Oxygen Species , NitrogenABSTRACT
In this work, chiroptical crystalline complexes of PEI/Tart (P/T) consisting of linear poly(ethylemeimine) (PEI) and an enantiomeric excess (ee) of tartaric acid (Tart) were used as chiral catalytic templates in the hydrolytic condensation of titanium bislactates and co-condensation of titanium bislactates and tetramethoxysilane for the preparation of chiral titania (TiO2) and chiral titania/silica (TiO2/SiO2) hybrid. Different from the general case of enantiopure templates excelling in chiral transformation when compared to enantiomeric excess ones, P/T systems with different enantiomer ratios exhibited each activity in the transformation of their chiral information to the resulting minerals titania and titania/silica. Especially, the P/T complexes with ee only by ±4% (D/L = 52/48 or 48/52), which is near the racemic state (D/L = 50/50), served as excellent chiral catalytic templates to generate chiroptical titania and titania/silica with mirror relation of the CD signals. By means of DSC, XRD, SEM and DRCD techniques, the crystalline complexes of PEI/Tart (P/T), the as-prepared TiO2@P/T and TiO2/SiO2@P/T, and the calcined TiO2 and TiO2/SiO2 were thoroughly investigated and the mechanism of the chiral transformation from the enantiomeric excess of P/T to minerals was proposed.
ABSTRACT
Human oocyte maturation arrest represents one of the severe conditions for female patients with primary infertility. However, the genetic factors underlying this human disease remain largely unknown. The spindle assembly checkpoint (SAC) is an intricate surveillance mechanism that ensures accurate segregation of chromosomes throughout cell cycles. Once the kinetochores of chromosomes are correctly attached to bipolar spindles and the SAC is satisfied, the MAD2L1BP, best known as p31comet, binds mitosis arrest deficient 2 (MAD2) and recruits the AAA+-ATPase TRIP13 to disassemble the mitotic checkpoint complex (MCC), leading to the cell-cycle progression. In this study, by whole-exome sequencing (WES), we identified homozygous and compound heterozygous MAD2L1BP variants in three families with female patients diagnosed with primary infertility owing to oocyte metaphase I (MI) arrest. Functional studies revealed that the protein variants resulting from the C-terminal truncation of MAD2L1BP lost their binding ability to MAD2. cRNA microinjection of full-length or truncated MAD2L1BP uncovered their discordant roles in driving the extrusion of polar body 1 (PB1) in mouse oocytes. Furthermore, the patient's oocytes carrying the mutated MAD2L1BP resumed polar body extrusion (PBE) when rescued by microinjection of full-length MAD2L1BP cRNAs. Together, our studies identified and characterized novel biallelic variants in MAD2L1BP responsible for human oocyte maturation arrest at MI, and thus prompted new therapeutic avenues for curing female primary infertility.
Subject(s)
Adaptor Proteins, Signal Transducing , Cell Cycle Proteins , Infertility, Female , Nuclear Proteins , Animals , Female , Humans , Mice , Adaptor Proteins, Signal Transducing/genetics , Cell Cycle Checkpoints , Cell Cycle Proteins/genetics , Exome Sequencing , Infertility, Female/genetics , Mad2 Proteins , Nuclear Proteins/genetics , Oocytes/cytology , Young Adult , Adult , MeiosisABSTRACT
BACKGROUND: Facing the 0.7-22% incidence rate of hepatocellular carcinoma (HCC) with inferior vena cava tumor thrombus (IVCTT), there are usually no obvious symptoms and signs when the tumor thrombus completely blocks the IVCTT in the early stage.1.J Gastroenterol. 29:41-46;2.Hepatogastroenterology. 41:154-157;3.Clin Cardiol. 19:211-213; Once diagnosed, it is the end-stage manifestation without unified treatment for HCC with IVCTT, bringing poor prognosis. Without active treatment, the median survival time is only 3 months. Previous scholars believed that patients with IVCTT should not adopt active surgical treatment. With the advance of technology, active surgical treatment has significantly lengthened the survival time with IVCTT.4.Ann Surg Oncol. 20:914-22;5.World J Surg Oncol. 11:259;6.Hepatogastroenterology. 58:1694-1699; However, for patients with HCC and IVCTT, open surgery was always selected in the past by opening the diaphragm through the combined thoracoabdominal incision to block the superior and subhepatic vena cava, leading long incision and huge trauma. With the development of minimally invasive techniques, laparoscopy thoracoscopy has showed great advantages in the treatment of HCC with IVCTT. A patient underwent laparoscopic with thoracoscopic resection of tumor and cancer thrombectomy after neoadjuvant therapy and then survived after follow-up.7.Ann Surg Oncol. 29:5548-5549 Therefore, it used as a first reported case of robot-assisted laparoscopic with thoracoscopic treatment of HCC complicated inferior vena cava cancer thrombectomy. METHODS: A 41-year-old man had a liver space-occupying lesion discovered during his medical examination 2 months ago. The diagnosis of HCC with IVCTT was confirmed by enhanced CT and biopsy specimen in the first hospitalization. A combination of TACE, targeted therapy, and immunotherapy plan was applied for the patient after multidisciplinary treatment (MDT). Specifically, Lenvatinib was taken orally 8 mg daily and 160 mg of toripalimab was given intravenously every 3 weeks. His reexamination CT showed that the tumor was more advanced after 2 months of treatment. The surgical operation was performed based on comprehensive consideration. The patient was placed in the left lateral decubitus position, and a thoracoscopic prefabricated the inferior vena cava above diaphragm blocking device was pulled out of the incision. The patient was switched to a supine position with the head of the bed raised 30 degrees. The gallbladder was removed first after entering the abdominal cavity, then prefabricated first hilar blocking band. Sterile rubber glove edges and hemo-lock were used to fabricate the blocking device. The novel hepatic inflow occlusion device is a safe, reliable, and convenient technique that is associated with favorable perioperative outcomes and low risk of conversion.8.Surg Endosc. 34:2807-2813 The liver along the middle hepatic vein was cut to expose the anterior wall of the inferior vena cava, then prefabricated posterior inferior vena cava blocking belt and right hepatic vein blocking belt. Finally, the first portal of liver, right hepatic vein, retrohepatic inferior vena cava, and inferior vena cava above diaphragm were blocked in sequence, so that accomplishing tumor resection and thrombectomy of inferior vena cava. It should be emphasized that before the inferior vena cava is completely sutured, the retrohepatic inferior vena cava blocking device should be released to allow blood flow to flush the inferior vena cava. Moreover, transesophageal ultrasound is required to real-time monitor inferior vena cava blood flow and IVCTT. Some images of the operation are shown in Fig. 1. Fig. 1 (a) Layout of the trocar. â Make a 3cm small incision between the right anterior axillary line and the midaxillary line, parallel to the fourth and fifth intercostal spaces; a puncture hole in the next intercostal space for endoscope; â¡2cm above the intersection of umbilicus horizontal line and axillary front line; â¢Intersection of right clavicular midline and umbilical horizontal line; â£Superior margin of umbilicus; â¤The midpoint of '⣠& â¥'; â¥2cm below the intersection of left clavicular midline and left costal margin. (b) Prefabricated the inferior vena cava blocking device above diaphragm by thoracoscopic. (c) The smooth tumor thrombus protruding into the inferior vena cava RESULTS: It took 475 min to finish the operation, and the loss of blood was estimated as 300 ml. The patient was discharged from hospital 8 days after the operation without postoperative complication. HCC was confirmed by postoperative pathology. CONCLUSIONS: Robot surgical system reduces the limitations of laparoscopic surgery by offering a stable three-dimensional view, 10-times-enlarged image, restored eye-hand axis, and excellent dexterity with the endowristed instruments, which has several advantages over open operation such as diminished blood loss, reduced morbidity, and shorter hospital stay.9.Chirurg. 88:7-11;10.BMC Surg. 11:2;11.Minerva Chir. 64:135-146; Furthermore, it could favor the operative feasibility of difficult resections reducing the conversion rate and playing a role to extend the indications of liver resection to minimally invasive approaches. It may provide new curative options in patients deemed inoperable with conventional surgery, such as HCC with IVCTT.12.Biosci Trends. 16:178-188;13.J Hepatobiliary Pancreat Sci. 29:1108-1123.
Subject(s)
Carcinoma, Hepatocellular , Laparoscopy , Liver Neoplasms , Robotics , Venous Thrombosis , Male , Humans , Adult , Carcinoma, Hepatocellular/pathology , Vena Cava, Inferior/surgery , Vena Cava, Inferior/pathology , Liver Neoplasms/pathology , Laparoscopy/methods , Venous Thrombosis/pathology , ThoracoscopyABSTRACT
RESEARCH QUESTION: What are the clinical outcomes and safety implications of early cumulus cell removal after short-term insemination combined with early rescue intracytoplasmic sperm injection (ICSI) in preventing fertilization failure? DESIGN: In this retrospective study, a total of 14,360 cycles were divided into four groups based on insemination method and fertilization ability: conventional IVF group (nâ¯=â¯5519); early cumulus cell removal group (nâ¯=â¯4107); conventional ICSI group (nâ¯=â¯4215); and early rescue ICSI group (where failed or low fertilization was predicted, nâ¯=â¯519). Fertilization outcomes, pregnancy outcomes, neonatal outcomes and birth defects were analysed by comparing the early cumulus cell removal group with the conventional IVF group, and the early rescue ICSI group with the conventional ICSI group. RESULTS: There were no significant differences in the outcomes of fertilization, pregnancy, neonates or birth defects between the conventional IVF group and the early cumulus cell removal group (P > 0.05). When compared with the conventional ICSI group, the early rescue ICSI group had similar rates of two pronuclei (2PN) at fertilization, clinical pregnancy, miscarriage, ectopic pregnancy, live birth, sex, mean gestational age, very low birthweight, macrosomia and birth defects (P > 0.05) but a higher polyploidy rate, lower high-quality embryo rate (both P < 0.001), lower twin pregnancy rate (P < 0.01), lower rate of low birthweight, and a higher rate of normal birthweight (both Pâ¯=â¯0.024). CONCLUSIONS: Early cumulus cell removal combined with early rescue ICSI led to good pregnancy and neonatal outcomes without an increase in birth defects. This approach could therefore be an effective and safe method for patients with fertilization failure in conventional IVF.
Subject(s)
Fertilization in Vitro , Sperm Injections, Intracytoplasmic , Pregnancy , Infant, Newborn , Female , Humans , Male , Sperm Injections, Intracytoplasmic/methods , Fertilization in Vitro/methods , Retrospective Studies , Cumulus Cells , Birth Weight , Semen , Pregnancy Rate , FertilizationABSTRACT
Anaerobic ammonium oxidation (anammox) is a low-carbon biological nitrogen removal process, that has been widely applied to treat high-strength wastewater. However, the practical application of mainstream anammox treatment is limited due to the slow growth rate of anammox bacteria (AnAOB). Therefore, it is important to provide a comprehensive summary of the potential impacts and regulatory strategies for system stability. This article systematically reviewed the effects of environmental fluctuations on anammox systems, summarizing the bacterial metabolisms and the relationship between metabolite and microbial functional effects. To address the shortcoming of mainstream anammox process, molecular strategies based on quorum sensing (QS) were proposed. Sludge granulation, gel encapsulation and carrier-based biofilm technologies were adopted to enhance the QS function in microbial aggregation and reduction of biomass loss. Furthermore, this article discussed the application and progress of anammox-coupled processes. Valuable insights were provided for the stable operation and development of mainstream anammox process from the perspectives of QS and microbial metabolism.
Subject(s)
Ammonium Compounds , Quorum Sensing , Anaerobic Ammonia Oxidation , Oxidation-Reduction , Ammonium Compounds/metabolism , Bioreactors/microbiology , Sewage/microbiology , Bacteria/metabolism , Nitrogen/metabolism , Anaerobiosis , DenitrificationABSTRACT
The widespread use of antibiotics has created an antibiotic resistance genes (ARGs)-enriched environment, which causes high risks on human and animal health. Although antibiotics can be partially adsorbed and degraded in wastewater treatment processes, striving for a complete understanding of the microbial adaptive mechanism to antibiotic stress remains urgent. Combined with metagenomics and metabolomics, this study revealed that anammox consortia could adapt to lincomycin by spontaneously changing the preference for metabolite utilization and establishing interactions with eukaryotes, such as Ascomycota and Basidiomycota. Specifically, quorum sensing (QS) based microbial regulation and the ARGs transfer mediated by clustered regularly interspaced short palindromic repeats (CRISPR) system and global regulatory genes were the principal adaptive strategies. Western blotting results validated that Cas9 and TrfA were mainly responsible for the alteration of ARGs transfer pathway. These findings highlight the potential adaptative mechanism of microbes to antibiotic stress and fill gaps in horizontal gene transfer pathways in the anammox process, further facilitating the ARGs control through molecular and synthetic biology techniques.
Subject(s)
CRISPR-Cas Systems , Quorum Sensing , Animals , Humans , Lincomycin/pharmacology , Multiomics , Anaerobic Ammonia Oxidation , Anti-Bacterial Agents/pharmacologyABSTRACT
Physiological changes with the assist role of soluble microbial products (SMP) of preserved denitrifying sludge (DS) undergoing long-term stress of starvation under different storage temperature is extremely important. In this study, SMP extracted from DS were added into DS in starvation condition under room temperature (15-20 °C), 4 °C and -20 °C with three different bio-augmentation phases of 10, 15 and 30 days. Experimental results showed that added SMP in room temperature was optimal for preservation of DS under starvation stress with optimized dosage of 2.0 mL mL-1 sludge and bio-augmentation phase of 10 d. SMP was more effective in maintaining the specific denitrification activity of DS, and it was nearly boosted to 94.1 % of control one due to assist of 2 times SMP addition with 10 days interval of each. Under assist of SMP, extracellular polymeric substances (EPS) secretion was enhanced as the defense layer to withstand starvation stress, and the protein may be utilized as an alternative substrate to gain energy, accelerate electron transport and transfer during denitrification process. This investigation revealed the feasibility of SMP as an economical and robust strategy for preservation of DS.
Subject(s)
Denitrification , Sewage , Sewage/chemistry , Extracellular Polymeric Substance Matrix , Proteins , BioreactorsABSTRACT
The hybrid vesicle AuNP@LCCV, in which a large number of AuNPs with an average size of about 2.8 nm were densely and uniformly distributed in an isolated state throughout the corona of the unusual polymer vesicle, was prepared via in situ reduction of Au3+ ions, which were encapsulated in advance in the unique polymer vesicle (LCCV) consisting of a hydrophobic membrane of poly(2-phenyl-2-oxazoline) and a hydrophilic loop-cluster corona of polyethyleneimine. The vesicle was formed via self-assembly from a comb-like block copolymer in which a polystyrenic main chain was grafted densely with diblock polyethyleneimine-b-poly(2-phenyl-2-oxazoline) and acted as a reactor for the reduction of Au3+. The hybrid vesicle AuNP@LCCV showed powerful catalytic ability in the reduction of nitrophenols (NPs). Interestingly, the reduction reactions of NPs showed a remarkably long induction time, which could be shortened dramatically from 60 min to 1-2 min by greatly increasing the concentration of NaBH4. It is revealed that the oxygen adsorbed on the AuNPs significantly inhibited the reduction, causing the induction time. Once the oxygen is chemically cleaned from the surface of the AuNPs, the reduction of 4-NP proceeds gradually for a while and then completes suddenly. The reduction mechanism accompanying the oxygen-dependent induction time is proposed from the view of the strong oxygen affinity of the catalyst AuNP@LCCV.
ABSTRACT
Chiral mesoporous silica (mSiO2) nanomaterials have gained significant attention during the past two decades. Most of them show a topologically characteristic helix; however, little attention has been paid to the molecular-scale chirality of mSiO2 frameworks. Herein, we report a chiral amide-gel-directed synthesis strategy for the fabrication of chiral mSiO2 nanospheres with molecular-scale-like chirality in the silicate skeletons. The functionalization of micelles with the chiral amide gels via electrostatic interactions realizes the growth of molecular configuration chiral silica sols. Subsequent modular self-assembly results in the formation of dendritic large mesoporous silica nanospheres with molecular chirality of the silica frameworks. As a result, the resultant chiral mSiO2 nanospheres show abundant large mesopores (â¼10.1 nm), high pore volumes (â¼1.8 cm3·g-1), high surface areas (â¼525 m2·g-1), and evident CD activity. The successful transfer of the chirality from the chiral amide gels to composited micelles and further to asymmetric silica polymeric frameworks based on modular self-assembly leads to the presence of molecular chirality in the final products. The chiral mSiO2 frameworks display a good chiral stability after a high-temperature calcination (even up to 1000 °C). The chiral mSiO2 can impart a notable decline in ß-amyloid protein (Aß42) aggregation formation up to 79%, leading to significant mitigation of Aß42-induced cytotoxicity on the human neuroblastoma line SH-ST5Y cells in vitro. This finding opens a new avenue to construct the molecular chirality configuration in nanomaterials for optical and biomedical applications.