Interaction effects of MTHFR C677T and A1298C polymorphisms with maternal glycated haemoglobin levels on adverse birth outcomes.

AIMS: The role of maternal genetic factors in the association between high glycated haemoglobin (HbA1c) levels and adverse birth outcomes remains unclear. MATERIALS AND METHODS: In this study, the maternal HbA1c levels of 5108 normoglycemic pregnant women in China were measured, and A1298C and C677T polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene were genotyped. RESULTS: Elevated HbA1c levels during the second trimester were associated with increased risks of macrosomia, large-for-gestational age (LGA), preterm birth (PTB), and reduced gestational age (p < 0.05). Pregnant women with MTHFR A1298C AA or C677T CT + TT genotypes were susceptible to adverse pregnancy outcomes related to HbA1c levels. Among pregnant women with the A1298C AA genotype, each standard deviation (SD) increase in HbA1c levels increased the risk of PTB by 1.32-times and reduced the gestational age by 0.11 weeks (p < 0.05). For MTHFR C677T CC + TT genotype carriers, higher HbA1c levels were associated with 1.49-, 1.24-, and 1.23-times increased risks of macrosomia, LGA, and PTB, respectively (p < 0.05). A U-shaped curve for PTB risk in relation to HbA1c levels was observed among the C677T CC + TT participants, with a cut-off value of 4.58%. Among subjects with the A1298C AA genotype combined with the C677T CT + TT genotype, each SD increase in HbA1c levels was associated with 1.40 and 1.37-times increased risks of LGA and PTB, respectively. CONCLUSIONS: Our findings highlight the importance of glycaemic control during pregnancy and the potential impact of genetic factors on birth outcomes. However, further large-scale studies are required to confirm these findings.

Ubiquity of Synthetic Phenolic Antioxidants in Children's Cerebrospinal Fluid from South China: First Evidence for Their Penetration across the Blood-Cerebrospinal Fluid Barrier.

Synthetic phenolic antioxidants (SPAs) and relevant transformation products (TPs) are potentially neurotoxic pollutants to which humans are widely exposed. However, their penetration behavior across the brain barrier and associated exposure to the central nervous system (CNS) remain unknown. This study is the first to investigate a wide range of 30 SPAs and TPs, including emerging SPAs, in matched serum and cerebrospinal fluid (CSF) samples from children in Guangzhou, China. Sixty-two children of either sex aged <14 years with nonbloody CSF and complete clinical information were included. The findings demonstrated the ubiquitous occurrence of many SPAs and TPs, particularly BHT, 2,4-di-tert-butylphenol (DBP), AO 1010, AO 1076, BHT-Q, and BHT-quinol, not only in serum but also in the CSF. Median total concentrations of SPAs and TPs were up to 22.0 and 2.63 ng/mL in serum and 14.5 and 2.11 ng/mL in CSF, respectively. On calculating the penetration efficiencies across the blood-CSF barrier (BCSFB) (RCSF/serum, CCSF/Cserum) for selected SPAs and TPs, their RCSF/serum values (median 0.52-1.41) were highly related to their physicochemical properties, indicating that passive diffusion may be the potential mechanism of BCSFB penetration. In addition, the RCSF/serum values were positively correlated with the barrier permeability index RAlb (AlbuminCSF/Albuminserum), indicating that barrier integrity is an important determinant of BCSFB penetration. Overall, these results will improve our perception of human internal exposure to SPAs and lay a solid foundation for assessing the risk of CNS exposure to various SPAs.

Ipsilateral orolingual angioedema following rhTNK-tPA administration for acute ischemic stroke.

Recombinant human tenecteplase tissue-type plasminogen activator (rhTNK-tPA), a genetically modified variant of conventional alteplase with longer half-life and higher fibrin specificity, has now emerged as a reasonable choice for thrombolytic treatment of acute ischemic stroke (AIS) in China. Orolingual angioedema is a rare but potentially life-threatening complication of intravenous thrombolysis. Currently, there is no documented evidence of orolingual angioedema occurring after thrombolysis with rhTNK-tPA. In this report, we present a unique case of a 75-year-old Chinese man who developed ipsilateral orolingual angioedema following the administration of rhTNK-tPA for AIS. Our case emphasizes the need for caution when using rhTNK-tPA due to its potential to induce ipsilateral orolingual angioedema.

Maternal pre-pregnancy BMI, MTHFR polymorphisms, and the risk of adverse pregnancy outcomes in pregnant women from South China: a retrospective cohort study.

BACKGROUND: Increasing evidence suggests an association between maternal pre-pregnancy body mass index (pre-BMI) and adverse pregnancy outcomes. However, the effects of methylenetetrahydrofolate reductase (MTHFR) polymorphisms on these relationships require further investigation. This study aimed to investigate whether the relationship between pre-BMI and the risk of adverse pregnancy outcomes was influenced by MTHFR gene polymorphisms. METHODS: A total of 5614 mother-fetus pairs were included in the study. The odds ratios (OR) of adverse pregnancy complications, including gestational diabetes mellitus (GDM), gestational hypertension (GHT), cesarean delivery (CS), and premature rupture of membranes (PROM), were estimated using adjusted logistic regression models and subgroup analysis. RESULTS: Pregnant women with higher pre-BMI values were positively related to the risk of GDM, GHT, and CS. In the subgroup analysis, underweight BMI was associated with a decreased risk of CS and GDM in pregnant women with the MTHFR A1298C AA or C677T CC genotype, while overweight/obese BMI was associated with an increased risk of GDM and CS in different MTHFR variants. Moreover, pregnant women with MTHFR A1298C AC + CC or C667T CC were found to have an increased risk of GHT in the MTHFR A1298C AA or C667T CT + TT genotype. A remarkable association was observed between the obesity group with MTHFR A1298C AC + CC (OR = 6.49, CI: 2.67-15.79) and the overweight group with the C667T CC genotype (OR = 4.72, CI: 2.13-10.45). CONCLUSIONS: MTHFR gene polymorphisms exert a modifying effect on the association between maternal pre-BMI and the risk of GHT, CS, and GDM. Pregnant women with a high pre-BMI with specific MTHFR genotypes should be considered for GHT development.

Blood-cerebrospinal fluid barrier permeability of metals/metalloids and its determinants in pediatric patients.

Concerns regarding adverse effects of metal/metalloids exposure on brain development and neurological disorders among children are increasing. However, the transport patterns of metals/metalloids across the blood-cerebrospinal fluid barrier (BCSFB) need to be clarified in children. A total of 99 Chinese pediatric patients were enrolled from February 2020 to August 2021, with a median age of 6.76 months. We detected 16 metal/metalloid levels in matched serum and cerebrospinal fluid (CSF) samples using inductively coupled plasma mass spectrometry. The BCSFB permeability of metals/metalloids were estimated and the potential effects of biomedical parameters were explored. Most metals/metalloids were detectable among > 80.0% of CSF samples. Significant correlations were observed between strontium (Sr, r = 0.46), molybdenum (Mo, r = 0.50), and cadmium (Cd, r = 0.24) concentrations in serum and CSF (P < 0.05). Ratios of metal/metalloid levels in CSF to serum (Rmetal) ranged from 0.02 to 0.74, and hazardous metals/metalloids including arsenic (As), Cd, lead (Pb), thallium (Tl), and manganese (Mn) showed high transfer efficiencies across the BCSFB (Rmetals > 0.5). With the adjustment of age and sex, albumin, ß2-microglobulin, and total protein levels in CSF were positively associated with copper (Cu) permeability (FDR-adjusted P < 0.05), while glucose in CSF was negatively correlated with calcium (Ca), Cu, Sr, and Mo BCSFB permeability (FDR-adjusted P < 0.05). Q-Alb promoted Cu permeability across the BCSFB (FDR-adjusted P < 0.001), while C-reactive protein levels in serum were positively associated with selenium (Se) permeability (FDR-adjusted P = 0.046). For the first time, our findings provided data for the BCSFB permeability of 16 metals/metalloids in children, and indicated that some biomedical parameters could influence the transformation of metals/metalloids from serum to CSF. Metals/metalloids with strong BCSFB permeability warrant attention for their potential neurotoxicity.

Molecular Characterization of Distinct Fungal Communities in the Soil of a Rare Earth Mining Area.

The exploitation of ion-absorbed rare earth elements (REEs) has caused serious ecological destruction and environmental pollution. Effects on soil fungal structure and diversity exerted by mining activities are usually ignored, although fungus is one of the most important components in soil ecosystems. In the present research, quantitative polymerase chain reaction (qPCR) and high-throughput Illumina MiSeq sequencing were conducted to characterize fungal community composition and structure in soil of a rare earth mining area after in situ leaching. Statistical analyses, network, and FUNGuild were used to conduct in-depth analyses. Ascomycota, Basidiomycota, and Glomeromycota were the most abundant phyla in the mining soils. Fungal community structures were stable after leaching practice, but nutrition contents (organic matter, TC, and TN) significantly and positively contributed to fungal abundances and diversities. Saprotrophs in phyla Ascomycota and Basidiomycota were the dominant fungal trophic mode, and they played critical roles in nutrient cycling, transformation processes, and reducing REE toxicity. Symbiotrophs of phyla Glomeromycota contributed to soil aggregation and slowing down nutrient losses after in situ leaching practice. In addition, fungi could regulate the interactions between species to resist the harsh environment of REE toxicity or ammonium caused by in situ leaching practice.

Associations of Prenatal Exposure to Per- and Polyfluoroalkyl Substances with the Neonatal Birth Size and Hormones in the Growth Hormone/Insulin-Like Growth Factor Axis.

Toxicological data suggest a significant developmental toxicity of per- and polyfluoroalkyl substances (PFASs); however, evidence in humans remains inconclusive. Furthermore, the effects of prenatal exposure to PFASs on hormones in the growth hormone (GH)/insulin-like growth factor (IGF) axis of newborns remain largely unclear. We aimed to investigate the associations of prenatal exposure to PFASs with the neonatal birth size, GH, IGF-1, and IGF-binding protein 3 (IGFBP-3). The concentrations of 22 PFASs were measured in the plasma of 224 pregnant women collected within 3 days before delivery (39.3 weeks) in Guangzhou, China, and the anthropometric data were gathered from medical records. Paired cord blood was collected at delivery to determine GH, IGF-1, and IGFBP-3 levels. Multivariable linear regression models revealed the inverse associations of several long-chain PFASs with birth weight and ponderal index as well as the significant associations of perfluorobutanoic acid and perfluorooctanoic acid (PFOA) with IGFBP-3 levels. The Bayesian kernel machine regression confirmed the association of perfluorooctane sulfonate with birth weight and ponderal index and of PFOA with IGFBP-3 and identified an inverse joint effect of exposure to a mixture of multiple PFASs on birth weight. The findings provide the first comprehensive evidence on the individual and joint effects of multiple PFASs on the neonatal birth size and hormones in the GH/IGF axis, which requires further confirmation.

Effects of HRT and Loading Rate on Performance of Carriers-Amended Anammox UASB Reactors.

Effects of hydraulic retention time (HRT) and nitrogen loading rate (NLR) on performance of anammox UASBs amended with spherical plastic and bamboo charcoal carriers were investigated. During the experimental period, the performance of reactors was continuously evaluated by monitoring ammonium-N, nitrite-N, and nitrate-N at HRT of 48, 36, 24, and 12 hours. With HRTs between 24 and 48 hours, the ammonium-N and nitrite-N removal efficiency was higher than 99%, while the total nitrogen (TN) removal efficiency was almost higher than 90%. When HRT decreased to 12 hours with NLR increasing to 0.16 kg N m-3 d-1, ammonium-N, and TN removal efficiency decreased to 87 and 80%, respectively. Moreover, phylogenetic analysis revealed anammox community still existed at the HRT of 12 hours and was most closely related to C. Brocadia sp.40. In addition, different types of carriers had no significant influence on the anammox community.

Zwitterionic Surfactant Modified Acetylene Black Paste Electrode for Highly Facile and Sensitive Determination of Tetrabromobisphenol A.

A electrochemical sensor for the highly sensitive detection of tetrabromobisphenol A (TBBPA) was fabricated based on acetylene black paste electrode (ABPE) modified with 3-(N,N-Dimethylpalmitylammonio) propanesulfonate (SB3-16) in this study. The peak current of TBBPA was significantly enhanced at SB3-16/ABPE compared with unmodified electrodes. To further improve the electrochemical performance of the modified electrode, corresponding experimental parameters such as the length of hydrophobic chains of zwitterionic surfactant, the concentration of SB3-16, pH value, and accumulation time were examined. The peak currents of TBBPA were found to be linearly correlated with its concentrations in the range of 1 nM to 1 µM, with a detection limit of 0.4 nM. Besides, a possible mechanism was also discussed, and the hydrophobic interaction between TBBPA and the surfactants was suggested to take a leading role in enhancing the responses. Finally, this sensor was successfully employed to detect TBBPA in water samples.

The structure and component characteristics of partial nitrification biofilms under autotrophic and heterotrophic conditions.

The differences in the structure and component characteristics of partial nitrification biofilms between autotrophic and heterotrophic conditions were investigated in this work. Three-dimensional excitation-emission matrix fluorescence spectroscopy (EEM), fluorescence staining, and confocal laser scanning microscopy (CLSM) were used to determine differences in the architecture and extracellular polymeric substance (EPS) distribution of the autotrophic and heterotrophic biofilms. Partial nitrification was successfully achieved, and the results demonstrated that an appropriate amount of organic carbon (chemical oxygen demand (COD)/N = 2.6) is advantageous for obtaining better partial nitrification. The final ammoniation and nitrosation rates achieved were 97 and 99 %, respectively. Proteins (PN) and polysaccharides (PS) were dominant in the tightly bound EPS (TB-EPS) of autotrophic and heterotrophic biofilms, with PN/PS ratios of 0.96 and 0.69, respectively. Proteins, lipids, α-D-glucopyranose polysaccharides, and nucleic acids were mostly present within the layers of biofilms, but they were distributed in the upper-middle portion of the autotrophic biofilm and increased with depth from the upper layer in the heterotrophic biofilms.

High sensitive and selective sensing of hydrogen peroxide released from pheochromocytoma cells based on Pt-Au bimetallic nanoparticles electrodeposited on reduced graphene sheets.

In this study, a high sensitive and selective hydrogen peroxide (H2O2) sensor was successfully constructed with Pt-Au bimetallic nanoparticles (Pt-Au NPs)/reduced graphene sheets (rGSs) hybrid films. Various molar ratios of Au to Pt and different electrodeposition conditions were evaluated to control the morphology and electrocatalytic activity of the Pt-Au bimetallic nanoparticles. Upon optimal conditions, wide linear ranges from 1 µM to 1.78 mM and 1.78 mM to 16.8 mM were obtained, with a detection limit as low as 0.31 µM. Besides, due to the synergetic effects of the bimetallic NPs and rGSs, the amperometric H2O2 sensor could operate at a low potential of 0 V. Under this potential, not only common anodic interferences induced from ascorbic acid, uric acid and dopamine, but also the cathodic interference induced from endogenous O2 could be effectively avoided. Furthermore, with rat pheochromocytoma cells (PC 12) as model, the proposed sensor had been successfully used in the detection of H2O2 released from the cancer cells. This method with wide linear ranges and excellent selectivity can provide a promising alternative for H2O2 monitoring in vivo in the fields of physiology, pathology and diagnosis.

New insights into the structure and dynamics of actinomycetal community during manure composting.

Despite advancing knowledge about the functional role of actinomycetes in degrading lignocellulosic materials, definitive knowledge concerning the diversity and dynamics of the actinomycetal community in composting is still lacking. In this study, real-time polymerase chain reaction (PCR) coupled with denaturing gradient gel electrophoresis (DGGE) and clone library construction were applied to investigate actinomycetal diversity and dynamics in a pilot-scale composting. Quantitative real-time PCR data revealed that actinomycetes accounted for 18-86 % of bacteria and that the fraction peaked during the maturing phase, indicating that Actinobacteria were critical to the compost ecosystem. Qualitatively, actinomycetal communities displayed distinct temporal variations during composting. Fourteen distinct genera of actinomycetes and an unknown group were observed in manure composts. Redundancy analysis indicated that temperature exerted an influence over the actinomycetal communities. Specifically, pathogenic Corynebacterium species dominated in the initial phase, whereas the genera Saccharomonospora and Thermobifida were abundant in the thermophilic phase. In maturing composts, mesophilic Micrococcineae members were most prevalent. The dominant thermophiles along with Micrococcineae may jointly facilitate the degradation of lignocellulosic materials during composting. Together, our research revealed a more detailed ecological and potential functional role for actinomycetes in the compost ecology.

Characterization and energy potential of food waste from catering service in Hangzhou, China.

Safe disposal of food waste is becoming an impending issue in China with the rapid increase of its production and the promotion of environmental awareness. Food waste from catering services in Hangzhou, China, was surveyed and characterized in this study. A questionnaire survey involving 632 units across the urban districts showed that 83.5% of the food waste was not properly treated. Daily food waste production from catering units was estimated to be 1184.5 tonnes. The ratio of volatile solid to total solid, easily biodegradable matter (including crude fat, crude protein and total starch) content in total solid and the ratio of total organic carbon to nitrogen varied in ranges of 90.1%-93.9%, 60.9%-72.1%, and 11.9-19.9, respectively. Based on the methane yield of 350 mL g VS(-1) in anaerobic batch tests, annual biogas energy of 1.0 × 10(9) MJ was estimated to be recovered from the food waste. Food waste from catering services was suggested to be an attractive clean energy source by anaerobic digestion.

[Research progress in microbial anaerobic oxidation coupled to denitrification--a review].

The process of denitrifying anaerobic methane oxidation (DAMO), which uses methane as electron donor for denitrification, can achieve nitrogen remove of wastewater and simultaneously reduce the emission of methane. The research of DAMO mechanism focuses on two pathways - the reverse methanogenesis coupled denitrification and the nitrite-dependent anaerobic methane oxidation (n-damo). Considering that DAMO process makes a significant contribution to global carbon and nitrogen cycling, our review summarizes the progresses of DAMO in recent years and focuses on the enrichment culture of microorganism, especially the microbiological characteristic of enrichment containing M. oxyfera. The microbiological mechanisms and parameters of the process are also reviewed. On this basis, some practical problems and prospects in the engineering application of the process are also discussed.

Metagenomics coupled with thermodynamic analysis revealed a potential way to improve the nitrogen removal efficiency of the aerobic methane oxidation coupled to denitrification process under the hypoxic condition.

Aerobic methane (CH4) oxidation coupled to denitrification (AME-D) is a promising wastewater treatment process for CH4 utilization and nitrogen removal. However, it is unclear which CH4-derived carbons are suitable for the AME-D process and how these organics are metabolized. In this study, metagenomics coupled with a thermodynamic model were used to explore the microorganisms and their metabolic mechanisms in an AME-D membrane biofilm reactor (MBfR) with high nitrogen removal efficiency. Results revealed that the aerobic methanotrophs of Methylomonas with the CH4-based fermentation potential were highly enriched and played an important role in CH4 conversion in the MBfR. Bacteria of Xanthomonadaceae, Methylophilaceae, Bacteroidetes, Rhodocyclaceae, Hyphomicrobium were the main denitrifiers. C1 compounds (methanol, formaldehyde and formate) and CH4-based fermentation products are promising cross-feeding intermediates of the AME-D. Specially, by means of integrating the CH4-based fermentation with denitrification, the minimum amount of CH4 required to remove per mole of nitrate can be further reduced to 1.25 mol-CH4 mol-1-NO3-, even lower than that of methanol. Compared to the choice to secrete methanol, type I aerobic methanotrophs require a 15 % reduction in the amount of oxygen required to secrete fermentation metabolites, but a 72 % increase in the amount of CH4-C released. Based on this trade-off, optimizing oxygen supply strategies will help to construct engineered microbiomes focused on aerobic methanotrophs with CH4-based fermentation potential. This study gives an insight into C and N conversions in the AME-D process and highlights the role of CH4-based fermentation in improving the nitrogen removal efficiency of the AME-D process.

Release characteristics of volatile organic compounds at residential garbage collection points: a case study of Hangzhou, China.

With the implementation of garbage classification, perishable waste has become increasingly concentrated. This has led to a significant change in the VOC release characteristics at residential garbage collection points, posing a potential risk with unknown characteristics. This study investigated the release characteristics, odor pollution, and health risks of VOCs at garbage collection points under different classification effectiveness, seasons, garbage drop-off periods, and garbage collection point types. The results showed that the average concentration of VOCs released from the garbage sorting collection points (SPs) was 341.43 ± 261.16 µg/m3, and oxygenated compounds (e.g., ethyl acetate and acetone) were the main VOC components. The VOC concentration increased as the community classification effectiveness improved, and it was higher in summer (followed by spring, autumn, and winter). Moreover, the VOC concentrations were higher in the evenings than in the mornings and at centralized garbage collection points (CPs) than at SPs. Further, odor activity value (OAV) assessments indicated that acrolein, styrene, and ethyl acetate were the critical odorous components, with an average OAV of 0.87 ± 0.85, implying marginal odor pollution in some communities. Health risk assessments further revealed that trichloroethylene, benzene, and chlorotoluene were the critical health risk substances, with an average carcinogenic risk (CR) value of 10-6-10-4, and a non-carcinogenic risk (HI) value < 1. These results indicated that HIs were acceptable, but potential CRs existed in the communities. Therefore, VOC pollution prevention and control measures should be urgently strengthened at the garbage collection points in high pollution risk scenarios.

Pilot-scale study of innovative mechanically-enhanced dynamic composting for treating kitchen waste.

This study introduced a novel mechanically-enhanced dynamic composting (MEDC) method for treating kitchen waste (KW) through partial-mixing and stratified fermentation. A pilot test varied aeration frequencies (AF) to refine control parameters and explore the maturation mechanism. Results showed that a moderate AF (10 min/4 h) achieved optimal efficiency, with a compost germination index of 123 % within 15 d. Moderate AF enhanced the growth of Corynebacterium_1 (25.4 %) and Saccharomonospora (10.5 %) during the low-temperature stage and Bacillus growth (91.3 %) during the maturation stage. Moreover, it enhanced microbial interactions (with an average degree of 19.9) and promoted substrate degradation and transformation, expediting heating and maturation. Multivariate dimensionality reduction analysis showed the MEDC accomplished rapid composting through stratified composting, dividing the reactor into distinct functional zones: feeding, low-temperature, high-temperature, and maturation. This enabled efficient microorganism enrichment and material degradation, expediting KW decomposition and maturation. This study offers a promising alternative for accelerated KW composting.

Association between maternal lipid profiles and vitamin D status in second trimester and risk of LGA or SGA: a retrospective study.

Background: Accumulating evidence has linked dyslipidemia during pregnancy to the risk of delivering infants born either large for gestational age (LGA) or small for gestational age (SGA). However, the effects of the vitamin D status on these relationships require further investigation. This study investigated whether the relationship between lipid profiles and the risk of LGA or SGA was influenced by vitamin D levels during the second trimester. Methods: Maternal lipid profile levels, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and vitamin D levels, were measured in a cohort of 6,499 pregnant women during the second trimester. Multivariate regression models and subgroup analyses were employed to evaluate the potential associations between maternal lipid profiles, vitamin D levels, and the risk of LGA or SGA. Results: The prevalence of SGA infants was 9.8% (n=635), whereas that of LGA infants was 6.9% (n=447). Maternal TG levels were found to be positively associated with the risk of LGA (odds ratio [OR] = 1.41, 95% confidence interval [CI]:1.17-1.70), whereas a negative association was observed between maternal TG, TC, LDL-C levels, and risk of SGA. Additionally, mothers with higher HDL-C levels were less likely to give birth to an LGA infant (OR=0.58, 95% CI:0.39-0.85). Importantly, associations between TG, TC, LDL-c, and SGA as well as between TG and LGA were primarily observed among pregnant women with insufficient vitamin D levels. As for HDL-C, the risk of LGA was lower in mothers with sufficient vitamin D (OR = 0.42, 95% CI:0.18-0.98) compared to those with insufficient vitamin D (OR = 0.65, 95% CI:0.42-0.99). Conclusion: Vitamin D status during the second trimester exerts a modifying effect on the association between lipid profiles and the risk of LGA and SGA infants.

Insight into the effects of biochar on manure composting: evidence supporting the relationship between N2O emission and denitrifying community.

Although nitrous oxide (N2O) emissions from composting contribute to the accelerated greenhouse effect, it is difficult to implement practical methods to mitigate these emissions. In this study, the effects of biochar amendment during pig manure composting were investigated to evaluate the inter-relationships between N2O emission and the abundance of denitrifying bacteria. Analytical results from two pilot composting treatments with (PWSB, pig manure + wood chips + sawdust + biochar) or without (PWS, pig manure + wood chips + sawdust) biochar (3% w/w) demonstrated that biochar amendment not only lowered NO2(-)-N concentrations but also lowered the total N2O emissions from pig manure composting, especially during the later stages. Quantification of functional genes involved in denitrification and Spearman rank correlations matrix revealed that the N2O emission rates correlated with the abundance of nosZ, nirK, and nirS genes. Biochar-amended pig manure had a higher pH and a lower moisture content. Biochar amendment altered the abundance of denitrifying bacteria significantly; less N2O-producing and more N2O-consuming bacteria were present in the PWSB, and this significantly lowered N2O emissions in the maturation phase. Together, the results demonstrate that biochar amendment could be a novel greenhouse gas mitigation strategy during pig manure composting.