Antibody responses after first and second Covid-19 vaccination in patients with chronic lymphocytic leukaemia

B-cell chronic lymphocytic leukaemia (CLL) is associated with immunosuppression and patients are at increased clinical risk following SARS-CoV-2 infection. Covid-19 vaccines offer the potential for protection against severe infection but relatively little is known regarding the profile of the antibody response following first or second vaccination. We studied spike-specific antibody responses following first and/or second Covid-19 vaccination in 299 patients with CLL compared with healthy donors. 286 patients underwent extended interval (10-12 week) vaccination. 154 patients received the BNT162b2 mRNA vaccine and 145 patients received ChAdOx1. Blood samples were taken either by venepuncture or as dried blood spots on filter paper. Spike-specific antibody responses were detectable in 34% of patients with CLL after one vaccine (n = 267) compared to 94% in healthy donors with antibody titres 104-fold lower in the patient group. Antibody responses increased to 75% after second vaccine (n = 55), compared to 100% in healthy donors, although titres remained lower. Multivariate analysis showed that current treatment with BTK inhibitors or IgA deficiency were independently associated with failure to generate an antibody response after the second vaccine. This work supports the need for optimisation of vaccination strategy in patients with CLL including the potential utility of booster vaccines.

A magnetic-void-porous MnFe2O4/carbon microspheres nano-catalyst for catalytic ozonation: Preparation, performance and mechanism

Wastewater treatment is essential to guarantee human health and ecological security. Catalytic ozonation with nanocatalysts is a widely studied and efficient treatment technology. However, this method has always been limited by nanocatalysts disadvantages such as easily loss, difficult to separate and reuse, and catalytic ability decay caused by aggregation, which could cause severe resources waste and potential risk to human health and ecosystem. To remedy these challenges, a magnetic-void-porous MnFe₂O₄/carbon microsphere shell nanocatalyst (CMS-MnFe₂O₄) was successfully synthesized using renewable natural microalgae. The separation test showed CMS-MnFe₂O₄ was rapidly separated within 2 min under an external magnetic field. In catalytic ozonation of oxalic acid (OA), CMS-MnFe₂O₄ showed efficient and stable catalytic efficiency, reaching a maximum total organic carbon removal efficiency of 96.59 % and maintained a 93.88 % efficiency after 4 cycles. The stable catalytic efficiency was due to the supporting effects of the carbon microsphere shell, which significantly enhanced CMS-MnFe₂O₄ chemical stability and reduced the metal ions leaching to 10-20 % of MnFe₂O₄ through electron transfer. To explore the catalytic mechanism, radical experiments were conducted and a new degradation pathway of OA involving superoxide anions rather than hydroxyl radicals was proposed. Consequently, this study suggests that an efficient, recyclable, stable, and durable catalyst for catalytic ozonation could be prepared.

[Analysis of PARP inhibitors induced anemia in advanced and relapsed epithelial ovarian cancer]

Objective: To explore the clinical features of poly ADP-ribose polymerase (PARP) inhibitor-related anemia in advanced and relapsed epithelial ovarian cancer (EOC). Methods: Patients diagnosed with advanced or relapsed EOC and treated with PARP inhibitor at National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College between January 2015 to October 2020 were accrued. The data included PARP inhibitors, treatment details, and lab tests before treatment and during treatment were collected and the clinical characteristics of PARP inhibitor-related anemia were analyzed. Results: (1) A total of 98 patients with a median age of 56.5 years old (30-82 years old) were enrolled in this study. All patients were treated with PARP inhibitor (65 cases of olaparib, 17 cases of niraparib, and 16 cases of fluzoparib). The median treatment duration was 37.5 weeks (4-119 weeks). (2) The anemia rate was 40% (39/98), including 5% (5/98) of grade Ⅰ, 14% (14/98) of grade Ⅱ, 11% (11/98) of grade Ⅲ, and 9% (9/98) of grade Ⅳ. Fourteen patients with pre-treatment grade Ⅰ anemia had a higher rate of anemia events than the 80 patients without pre-treatment anemia, 7/14 vs 35% (28/80; χ²=4.281, P=0.039). (3) The median anemia occurrence time was 7.0 weeks (1-52 weeks), including 41% (16/39) of anemia cases occurred in 1-4 weeks, 26% (10/39) occurred in 5-8 weeks, 13% (5/39) occurred in 9-12 weeks, 3% (1/39) occurred in 13-16 weeks, 10% (4/39) occurred in 17-20 weeks, 8% (3/39) occurred ≥21 weeks. At the time of the lowest hemoglobulin tested, the median value of mean corpuscular volume (MCV) was 106 fl,which was higher than the up limit of normal range (100 fl), 74% (29/39) of anemia patients had an elevated MCV level; the median value of mean corpuscular hemoglobin (MCH) was 36 pg, 54% (21/39) of anemia patients had an elevated MCH level; the median value of mean corpuscular hemoglobin concentration (MCHC) was 320 g/L, 69% (27/39) of anemia patients had a higher MCHC level; 92% (36/39) of anemia patients had a normal level of serum iron; 79% (31/39) of anemia patients had a normal level of transferrin. 74% (29/39) of the anemia patients were macrocytic orthochromatic anemia. (4) Among the 39 patients with anemia, 20 patients (51%, 20/39) withhold the treatment of PARP inhibitor due to grade Ⅲ or Ⅳ anemia, including 10 patients (50%, 10/20) who resumed the PARP inhibitor treatment by suppling iron, folate, and vitamin B₁₂. The median stopping time of PARP inhibitor was 5.5 weeks (2-10 weeks), while the other 10 patients terminated the PARP inhibitor treatment for not recovering from severe anemia. Conclusions: One of the common adverse effects of PARP inhibitors is anemia, which mostly happened in the first 3 months of treatment. In the treatment of EOC, PARP inhibitor-related anemia mainly manifest as macrocytic orthochromatic anemia, and most patients with normal serum iron and transferrin.

Stable nitrogen removal by anammox process after rapid temperature drops: Insights from metagenomics and metaproteomics

This study investigated the impacts of rapid temperature drops on anammox process performance and the metabolism of its core microbial populations through proteomic analysis. Over a 50-day period, the temperature of an up-flow granular bed anammox reactor was stepwise decreased from 35 °C to 15 °C and resulted in repeated transient increases in effluent nitrite concentrations. At 15 °C, a nitrogen removal rate of 2.71 ± 0.23 gN/(L·d) was maintained over 100 days operation. Total AnAOB population abundance (20.9%±4.9%) and AnAOB protein abundances (75.7% ± 3.3%) remained stable with decreased temperature. Key proteins of Ca. Brocadia for nitrogen metabolism, as well as for carbohydrate metabolism and primary metabolite biosynthesis were less expressed at 15 °C than 35 °C, while several proteins of heterotrophic Chloroflexi spp. involved in carbohydrate and metabolites metabolisms were expressed to a higher degree at 15 °C. Overall, metabolism of AnAOB responded at a higher degree to low temperatures than that of heterotrophs.

Maintenance treatment in advanced HER2-negative gastric cancer

Survival for patients with advanced gastric cancer (GC) remains poor. Systemic chemotherapy which has reached a plateau stays the standard first-line (1L) treatment for advanced human epidermal growth-factor receptor 2 (HER2)-negative GC. To maximize the benefit of 1L treatment, the concept of maintenance treatment is constantly being explored. In advanced HER2-negative GC, current clinical guidelines do not recommend a standard maintenance therapy strategy. In addition to the monotherapy maintenance with fluorouracil after 4-6 cycles of 1L chemotherapy, some agents that are active against novel targets have been evaluated in clinical trials for maintenance treatment. Whereas most of these trials do not reach their primary endpoints, they open new horizons for the 1L treatment of advanced HER2-negative GC. Therefore, we reviewed the clinical trials in the field of maintenance treatment in advanced HER2-negative GC and discussed some of the problems in clinical trials.

In situ elimination of nitrite inhibition on AnAOB by acetate dosing in an up-flow granular anammox reactor

The inhibition of over-accumulated nitrite on anaerobic ammonium oxidation (anammox) activity has been widely reported and intensively studied. Surprisingly, there are limited researches on the strategy to deal with nitrite inhibition. In this work, to eliminate nitrite inhibition in an up-flow granular anammox reactor, acetate dosing (600 mg COD L^-1) and simultaneous acetate and denitrifying sludge dosing (600 mg COD L^-1 and 1.4 g dry weight L^-1) were implemented to temporarily activate microbial denitrification to reduce nitrite, respectively. In two strategies, reactor nitrogen removal and extracellular ATP were resumed to initial levels, while the recovery ratios of intracellular ATP and nitrite removal rate (67.1% and 15.6 mg N h^-1) of the former were higher than those (52.5% and 11.2 mg N h^-1) of the latter, indicating acetate dosing was more qualified to nitrite removal. Meanwhile, although a decrease of the dominated Ca. Brocadia from 30.7 to 25.8% was not reversed through high-throughput sequencing, acetate dosing did not cause denitrifiers proliferation. As easily implemented acetate dosing was as effective as direct discharge of inhibitory nitrite as the control strategy, it was recommended when nitrite inhibition happened. Additionally, an irregular behavior of nitrate overproduction via nitrite oxidation and the drastic increase of extracellular ATP were detected and proposed as the response of AnAOB to nitrite inhibition.

Phytoplankton distribution characteristics and its relationship with bacterioplankton in Dianchi Lake

Phytoplankton and bacterioplankton perform important ecological functions in lake ecosystem. In this paper, the abundance and composition of phytoplankton and bacterioplankton at 13 sites of Dianchi lake during the wet and dry seasons were monitored, and the relationship between phytoplankton and bacterioplankton in this plateau lake was studied. Phytoplankton community structure analysis was carried out by ocular method, and bacterioplankton was investigated by high-throughput 16S rRNA gene Illumina sequencing. The relationship between phytoplankton and bacterioplankton was observed using redundancy analysis. The results showed that 87 species of phytoplankton belonging to 5 phyla and 29 genera were identified in Dianchi lake. Phytoplankton diversity and richness were higher in the wet season than those in the dry season. In the wet season, Cyanophyta was the dominant phylum whose density was 2.01 × 10⁸ cells/L, accounting for more than 90% of the total algae, then followed by Chlorophyta, Bacillariophyta, Chrysophyta, and Cryptophyta. The spatial distribution of phytoplankton in the wet season and dry seasons showed significant differences. In the dry season, the north-central part of Dianchi lake was dominated by Limnothrix redekei and Microcystis minutissima of Cyanophyta, while Pseudanabaena moniliformis and Coelosphaerium nagelianum of Cyanophyta mainly was dominated in the south of Dianchi lake. In the wet season, Microcystis minutissima of Cyanophyta was the dominant species all the area, while Limnothrix redekei of Cyanophyta was second dominant. Proteobacteria and Bacteroidetes were the dominant phyla among bacterioplankton. The community structure of bacterioplankton was influenced by Cyanophyta and Bacillariophyta. Cyanophyta had a major influence on Pseudomonas, Acinetobacter of Proteobacteria, and Flavobacterium of Bacteroidetes. Bacillariophyta showed a strong correlation with Gemmobacter, Stenotrophomonas, and Aeromonas of Proteobacteria. Cyanophyta and Bacillariophyta produced the most significant impact on predicted functional genes of bacterioplankton, and the predicted functional genes of the samples were different in different seasons. Cell densities of Cyanophyta were positively related to metabolism-predicted functional genes of bacterioplankton. Bacillariophyta and Cryptophyta had an impact on most of the cellular processes and signaling predicted functional genes. Bacterioplankton-predicted functional gene information storage and processing were significantly affected by cell densities of Chlorophyta. Therefore, the analysis of the phytoplankton community and the bacterioplankton-predicted functional gene in Dianchi lake exerts a great significance in revealing the ecosystem function of plateau lakes and harmful algal bloom control.

The split-off terahertz radiating dipoles on thermally reduced α-V2O5 (001) surface

The trapped electron states on a pliable lattice have different localization and physical chemistry characteristics. Here, terahertz time-domain measurements suggest that the formation of vanadyl oxygen defect, in the presence of the surface potential traps and mobile charge carriers, leads to a transient charge distribution that forms terahertz radiating dipoles in V2O5. The emergence of radiating dipoles is evidenced by terahertz responses with a two-valley feature of the thermally reduced α-V2O5 (001) thin films in the temperature range of 300-700 K. The two photoconductance valleys on a several millielectron volts interval are related to two emergent split-off traps, which originate from the VO6 octahedra distortion upon the vanadyl oxygen desorption on the surface. The pliable surface lattices plays a decisive role. So long as the α-V2O5 (001) thin films are covered by a 30 nm-thick Al2O3 capping layer, the distinct two-valley feature disappears completely in the full temperature range. The terahertz radiating dipoles with a fine energy structure is potentially a new measure for charge dynamics on the α-V2O5 (001) surface.

Intravitreal conbercept for branch retinal vein occlusion induced macular edema: one initial injection versus three monthly injections

Background

To compare the efficacy of one initial intravitreal injection of conbercept (IVC) versus three monthly IVCs in patients with macular edema (ME) after branch retinal vein occlusion (BRVO). Both options were followed by a pro re nata (PRN) retreatment regimen.

Methods

This study retrospectively investigated and followed 60 patients with acute ME secondary to BRVO for over a year. 30 subjects received one initial injection (1 + PRN group); while, 30 received three monthly injections (3 + PRN group). The functional and anatomic outcomes were assessed during each follow-up.

Results

The general characteristics of the 60 subjects were as follows: mean [SD] age, 57.43 [13.06] years; 33 [55%] female; 36 [60%] non-ischemic form. Both groups showed a stable gain in visual acuity (VA) with similar logMAR (mean ± SD) (1 + PRN group 0.308 ± 0.399, 3 + PRN group 0.34 ± 0.352) during the first 12 months. Additionally, both groups exhibited a significant reduction in central foveal thickness (CFT) with no statistically significant difference between them (1 + PRN group 222.1 μm ± 197.1 μm, 3 + PRN group 228.4 μm ± 200.2 μm). Both treatment groups had similar improvements in logMAR and anatomic outcomes over time. The stratified analysis showed that patients with the non-ischemic form and those with the ischemic form had similar improvements in VA (0.346 ± 0.366 VS 0.29 ± 0.39, P = 0.575) during the 12 months follow-ups. The number of injections was lower in the 1 + PRN group (4.0 ± 1.6) than in the 3 + PRN group (4.7 ± 1.3) (P = 0.068). No adverse effects or unexpected safety issues were reported in either group.

Conclusions

Conbercept yielded significant improvements in VA and CFT among patients with BRVO induced ME, independent of their retinal ischemia status. The results showed that the 3 + PRN regimen do not lead to better functional outcomes or lower treatment needs in clinical practice as compared to the 1 + PRN regimen.

Long-term, selective production of caproate in an anaerobic membrane bioreactor

Fermentative caproate production from wastewater is attractive but is currently limited by the low product purity and concentration. In this work, continuous, selective production of caproate from acetate and ethanol, the common products of wastewater anaerobic fermentation, was achieved in an anaerobic membrane bioreactor (AnMBR). The reactor was continuously operated for over 522 days without need for chemical cleaning. With an ethanol-to-acetate ratio of 3.0, the effluent caproate concentration was 2.62 g/L on average and the caproate ratio in liquid products reached 74%. Further raising the influent ethanol content slightly increased the effluent caproate level but lowered the product selectivity and resulted in microbial inhibition. The Clostridia (the major caproate-producing bacteria) and Methanobacterium species (which consume hydrogen to alleviate microbial inhibition) was significantly enriched in the acclimated sludge. Our results imply a great potential of utilizing AnMBR to recover caproate from the effluent of wastewater acidogenic fermentation process.

Two-stage anaerobic digestion of food waste coupled with in situ ammonia recovery using gas membrane absorption: Performance and microbial community

A two-stage GAs Membrane Absorption anaerobic Reactor (GAMAR) was developed by combining the gas membrane absorption (GMA) system with two-stage anaerobic digestion. The two-stage configuration consisted of an acidogenic reactor (AR) and a methanogenic reactor (MR) with GMA. With the application of GMA, the ammonia concentration of MR was maintained at 2200 mgN L^-1 to alleviate potential ammonia inhibition. The setup of AR enhanced hydrolysis and acidogenesis of FW and alleviated volatile fatty acids (VFA) accumulation in MR. Two-stage GAMAR could be operated stably at 6.1 kg VS m^-3 d^-1 and the volumetric biogas production rate was 3.21 m³ m^-3 d^-1. The different environmental conditions caused a significant shift in the microbial community. Lactobacillus and Aeriscardovia became predominant in AR under low pH, while Syntrophomonas was dominant in MR when the reactor was stable. The dominant archaea genus in MR was Methanothrix and it greatly decreased when MR was acidified.

Enhanced nitrite accumulation under mainstream conditions by a combination of free ammonia-based sludge treatment and low dissolved oxygen: reactor performance and microbiome analysis

Partial nitritation under mainstream conditions is one of the major bottlenecks for the application of deammonification processes to municipal wastewater treatment plants. This study aimed at evaluating the combination effect of a side-stream free ammonia (FA) treatment and low dissolved oxygen (0.2 ± 0.1 mg L⁻¹) on inhibiting nitrite oxidizing bacteria (NOB) from enhancing nitrite accumulation in long-term lab-scale experiments. Two continuous floccular sludge reactors treating low-strength synthetic wastewater (60 mg N–NH₄⁺ L⁻¹ without COD) with a fixed nitrogen loading rate of 0.22 ± 0.03 g N per L per day were operated in a varied temperature range of 7–31 °C, with one acting as the experimental reactor and the other as the control. Side-stream sludge treatment with a stepwise elevation of FA concentration (65.2–261.1 mg NH₃ L⁻¹) was carried out every day in the experimental reactor; the nitrite accumulation ratio (NAR, (NO₂–N/(NO₂⁻–N + NO₃⁻–N) × 100%)) in the experimental reactor was always about twice that in the control one. Quantitative PCR (q-PCR) and high-throughput sequencing analyses showed the dominant NOB was mostly Nitrobacter, while there was an alternating trend between Nitrobacter and Nitrospira. Even though the whole microbial communities of each experimental stage between the two reactors were relatively clustered due to an incomplete NOB washout, three abundant metabolisms (amino acid metabolism, pyruvate metabolism and nitrogen metabolism) and key functional genes of nitrification predicted by PICRUSt in the experimental reactor were enriched, providing a better understanding of nitrite accumulation. These results have demonstrated that the positive hybrid effects of FA side-stream sludge treatment and a low DO could enhance nitrite accumulation. It is expected that a complete washout of NOB would be achieved after further process optimization.

An introduction of the combination of side-stream sludge treatment using FA and low DO could more effectively enhance nitrite accumulation than single low DO.

Enhanced biogas production and in situ ammonia recovery from food waste using a gas-membrane absorption anaerobic reactor

A novel GAs-Membrane Absorption anaerobic Reactor (GAMAR) was developed by combining gas-membrane absorption system with anaerobic digestion. A gas-permeable expanded polytetrafluoroethylene (ePTFE) membrane was submerged in the anaerobic reactor. Free ammonia could transfer through the gas-permeable membrane and be recovered by acidic solution. The free ammonia concentration was lower than 40 mgN L^-1 in GAMAR, which alleviated ammonia inhibition. Meanwhile free ammonia concentration up 70 mgN L^-1 in the reference reactor inhibited methanogens and led to unstable operation. The volumetric biogas production rate of GAMAR was 2.83 m³ m^-3 d^-1, and 58% higher than the reference reactor. Long term use of membrane led to membrane fouling and hydrophobicity loss. The contact angle of membrane decreased from 105.9 ± 1.2° to 97.6 ± 6.3° after 43 d. The abundance of methanogens in GAMAR was 1.8-2.1 times higher than that in the reference reactor, which was in accordance with the higher biogas production rate in GAMAR.

Carbon dioxide fixation coupled with ammonium uptake by immobilized Scenedesmus obliquus and its potential for protein production

In this study, immobilized Scenedesmus obliquus (S. obliquus) was proposed to simultaneously alleviate the carbon dioxide (CO₂) and ammonium (NH₄⁺-N). Two trophic modes of autotrophy and mixotrophy were conducted by batch experiments with a period of 5 days. The results shown that NH₄⁺-N could be removed more efficiently if algal cells were immobilized, and the trophic mode change had no significant effect on immobilized S. obliquus to NH₄⁺-N removal under 5% CO₂ sparging. Specifically, immobilized S. obliquus could remove NH₄⁺-N completely at initial concentrations of 30 and 50 mg/L and reached about 80% removal rate of NH₄⁺-N at the concentration of 70 mg/L under both trophic modes. The protein synthesis was its main removal mechanism and the dominant amino acid components including glutamic acid (Glu), cystine (Cys), arginine (Arg), methionine (Met) and lysine (Lys) were sensitive to NH₄⁺-N assimilation.

Ozonation reactivity characteristics of dissolved organic matter in secondary petrochemical wastewater by single ozone, ozone/H2O2, and ozone/catalyst

Advanced oxidation methods (e.g., ozonation systems) are used for control of recalcitrant pollutants in secondary petrochemical wastewater. For the selection of the optimal wastewater treatment method, we compared the reactivity characteristics of dissolved organic matter (DOM) in three common ozone treatment processes: single ozone, ozone/H₂O₂, and ozone/catalyst. The raw and ozonated DOM were fractionated into six fractions using ion exchange resins. Fluorescence spectroscopy and size exclusion chromatography were employed to characterize the fractions. The results showed that the single ozone system transformed hydrophobic components into hydrophilic components, but exhibited low mineralization ability. By contrast, the increase in hydrophilic acid fractions transformed from other fractions in the ozonation process were further mineralized in the ozone/H₂O₂ and ozone/catalyst systems. Ozone/H₂O₂ preferentially reduced hydrophobic bases, whereas ozone/catalyst preferentially reduced hydrophilic neutral components. However, ozone/H₂O₂ exhibited low selectivity in degrading organic compounds of different molecular weights. The highest total organic carbon (TOC) removal efficiency was achieved in the ozone/catalyst system, which promoted the transformation from fulvic acid- and humic acid-like substances into aromatic proteins and soluble microbial by-product-like substances. The single ozone system transformed high-molecular-weight compounds into low-molecular-weight compounds, resulting in an unsatisfactory TOC removal efficiency. By contrast, the ozone/catalyst system selectively removed the residual low-molecular-weight compounds in the reaction with ozone. This might have contributed to the high TOC removal efficiency of the ozone/catalyst treatment. These results can be used by other researchers and engineers to inform the selection of optimal ozone treatment based on wastewater characteristics.

Effects of residual ozone on the performance of microorganisms treating petrochemical wastewater

This study investigated the effects of residual ozone on the performance of microorganisms treating petrochemical wastewater using batch experiments with low and high ozone dosages (5.0 mg/L and 50.0 mg/L, respectively). The results indicated that the low residual ozone concentration significantly increased COD removal by 24.21% in the biological process compared to control group with no ozone residual, while the high residual ozone concentration showed the opposite effect. In the reactor with low residual ozone concentration (0.45 mg/L), the amount of loosely bound (LB)-extracellular polymeric substances (EPS) in the activated sludge decreased by 23.23%, while the amount of tightly bound (TB)-EPS increased by 129.16% compared to the none-ozone residual reactor. In addition, the low residual ozone was found to improve the bioactivity of activated sludge by 139.73% in the first 30 min of the biological process. In the reactor with high residual ozone concentration (0.91 mg/L), both LB- and TB-EPS of the activated sludge increased, while bioactivity decreased. This implies that low residual ozone in a bio-reactor can enhance microbial activity by increasing contact between the pollutants and cells by removing LB-EPS covering the outer layer of the sludge. The microorganisms in the sludge samples could be classified into three groups representing those that are susceptible to ozone, tolerant to low dose of residual ozone, and resistant to high dose of residual ozone. The resistant bacteria Gemmatimonadaceae uncultured became predominant, with a relative abundance of 11.37%, under low residual ozone conditions, while it decreased at high ozone concentrations. The results showed that a certain amount of residual ozone could stimulate the activity of microorganisms by altering the EPS fraction and structure of the microbial community, and thus it is important for the removal of refractory organics from wastewater in the ozone-biological process.

High variations of methanogenic microorganisms drive full-scale anaerobic digestion process

Anaerobic digestion is one of the most successful waste management strategies worldwide, wherein microorganisms play an essential role in reducing organic pollutants and producing renewable energy. However, variations of microbial community in full-scale anaerobic digesters, particularly functional groups relevant to biogas production, remain elusive. Here, we examined microbial community in a year-long monthly time series of 3 full-scale anaerobic digesters. We observed substantial diversification in community composition, with only a few abundant OTUs (e.g. Clostridiales, Anaerolineaceae and Methanosaeta) persistently present across different samples. Similarly, there were high variations in relative abundance of methanogenic archaea and methanogenic genes, which were positively correlated (r² = 0.530, P < 0.001). Variations of methanogens explained 55.7% of biogas producing rates, much higher than the explanatory percentage of environmental parameters (16.4%). Hydrogenotrophic methanogens, especially abundant Methanomicrobiales taxa, were correlated with biogas production performance (r = 0.665, P < 0.001) and nearly all methanogenic genes (0.430 < r < 0.735, P < 0.012). Given that methanogenic archaea or genes are well established for methanogenesis, we conclude that high variations in methanogenic traits (e.g. taxa or genes) are responsible for biogas production variations in full-scale anaerobic digesters.

Genomic dynamics of full-scale temperature-phased anaerobic digestion treating waste activated sludge: Focusing on temperature differentiation

A robust microbial community is essential for the overall stability and performance of the anaerobic digestion process. In this study, two digesters of a full-scale temperature-phased anaerobic digestion plant treating waste activated sludge were sampled for one year. The acidogenesis reactor (AR) was run at 45 ± 2 °C for six months in Period I and was run at 38 ± 2 °C for six months in Period II. While the methanogenesis reactor (MR) was run at 36 ± 3 °C throughout the year. 16S rRNA amplicon sequencing and GeoChip 5.0 results showed that samples were clearly differentiated by reactors and periods. The elevated temperature in AR during Period I improved the effects of phase separation between the AR and MR. In AR, Fervidobacterium, assigned to Class Thermotogae, had a higher relative abundance of 8.9% in Period I. The abundance of genes involved with carbon degradation was significantly higher in Period I than Period II. In MR, the relative abundance of Methanosarcina increased from 19.8% in Period I to 30.6% in Period II. In addition, the influent characteristics, reactor performance, and operating parameters were determined as the key variables shaping the microbial community, contributing to a total of 76.3% and 69.5% of the variance of the AR and MR, respectively. Combined, this study enriches our understanding of genomic dynamics in full scale temperature-phased anaerobic digestion process.

Performance and microbial community of an expanded granular sludge bed reactor in the treatment of cephalosporin wastewater

In this study, the anaerobic treatment and microbial characteristics of high-concentration cephalosporin wastewater were studied. A pilot-scale expanded granular sludge bed (EGSB) reactor was designed to treat cephalosporin wastewater, whose diameter, height and effective volume were 0.5 m, 4.9 m, 0.92 m³, respectively. With mixed high-concentration cephalosporin wastewater and municipal wastewater as a substrate, the anaerobic reactor was started and operated 414 days. An average COD removal efficiency of 72% was achieved at an organic loading rate (OLR) of 9.96 kg COD/(m³·d), with a hydraulic retention time (HRT) of 25 h. The average methane content reached 82%. Methanobacterium and Methanomassiliicoccus were predominant archaea in the granular sludge for each of the organic loading rates, and the predominant methane-producing pathway was hydrogenotroph and methylotroph. Those results demonstrated that the EGSB reactor could treat high-concentration cephalosporin wastewater with a unique methane-producing pathway.

Realizing stable operation of anaerobic ammonia oxidation at low temperatures treating low strength synthetic wastewater

The low activity of Anammox bacteria at low temperatures and competition from nitrite oxidation bacteria (NOB) when treating low strength wastewater have been major bottlenecks in implementing Anammox in mainstream wastewater treatment. By intermittent high strength feeding (IHSF) and stepwise temperature reduction, stable operation of a granular Anammox reactor was realized at low temperatures (down to 15°C) for 28days when treating low strength synthetic wastewater. The nitrogen loading rate reached 1.23-1.34kgN/m³/day, and the total nitrogen removal rate reached 0.71-0.98kgN/m³/day. The IHSF enriched the Anammox sludge in high strength cycles and compensated for sludge loss in low strength cycles, and the high concentration of ammonium in high strength cycles inhibited NOB. The 16SrRNA gene sequencing results revealed that Candidatus Kuenenia was predominant in the reactor at low temperatures.