Habitat- and lifestyle-dependent structural and functional characteristics of viruses in mangrove wetlands of different functional zonings.

Mangrove wetlands, as one of the natural ecosystems with the most ecological services, have garnered widespread attention about their microbial driven biogeochemical cycling. Urbanization have led to different spatial patterns of environmental conditions and microbial communities in mangroves. However, viruses, as the pivotal drivers of biogeochemical cycling in mangroves, remain inadequately explored in terms of how their ecological potential and complex interactions with host respond to functional zonings. To address this knowledge gap, we conducted a comprehensive investigation on the structural and functional properties of temperate and lytic viruses in mangrove wetlands from different functional zonings by jointly using high-throughput sequencing, prokaryotic and viral metagenomics. Multiple environmental factors were found to significantly influence the taxonomic and functional composition, as well as lysogen-lysis decision-making of mangrove viruses. Furthermore, enriched auxiliary metabolic genes (AMGs) involved in methane, nitrogen and sulfur metabolism, and heavy metal resistance were unveiled in mangrove viruses, whose community composition was closely related to lifestyle and host. The virus-host pairs with different lifestyles were also discovered to react to environmental changes in different ways, which provided an empirical evidence for how virus and bacteria dynamics were specific to viral lifestyles in nature. This study expands our comprehension of the intricate interactions among virus, prokaryotic host and the environment in mangrove wetlands from multiple perspectives, including viral lifestyles, virus-host interactions, and habitat dependence. Importantly, it provides a new ecological perspective on how mangrove viruses are adapted to the stress posed by urbanization.

Intake of tobacco nitrosamines of smokers in various provinces of China and their cancer risk: A meta-analysis.

Nitrosamines are a class of carcinogens which have been detected widely in food, water, some pharmaceuticals as well as tobacco. The objectives of this paper include reviewing the basic information on tobacco consumption and nitrosamine contents, and assessing the health risks of tobacco nitrosamines exposure to Chinese smokers. We searched the publications in English from "Web of Science" and those in Chinese from the "China National Knowledge Infrastructure" in 2022 and collected 151 literatures with valid information. The content of main nitrosamines in tobacco, including 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosonornicotine (NNN), N-nitrosoanatabine (NAT), N-nitrosoanabasine (NAB), total tobacco-specific nitrosamines (TSNA), and N-nitrosodimethylamine (NDMA) were summarized. The information of daily tobacco consumption of smokers in 30 provinces of China was also collected. Then, the intakes of NNN, NNK, NAT, NAB, TSNAs, and NDMA via tobacco smoke were estimated as 1534 ng/day, 591 ng/day, 685 ng/day, 81 ng/day, 2543 ng/day, and 484 ng/day by adult smokers in 30 provinces, respectively. The cancer risk (CR) values for NNN and NNK inhalation intake were further calculated as 1.44 × 10-5 and 1.95 × 10-4. The CR value for NDMA intake via tobacco smoke (inhalation: 1.66 × 10-4) indicates that NDMA is similarly dangerous in tobacco smoke when compared with the TSNAs. In China, the CR values caused by average nitrosamines intake via various exposures and their order can be estimated as the following: smoke (3.75 × 10-4) > food (1.74 × 10-4) > drinking water (1.38 × 10-5). Smokers in China averagely suffer 200% of extra cancer risk caused by nitrosamines in tobacco when compared with non-smokers.

Spatial and Seasonal Patterns of Sediment Bacterial Communities in Large River Cascade Reservoirs: Drivers, Assembly Processes, and Co-occurrence Relationship.

Sediment bacteria play an irreplaceable role in promoting the function and biogeochemical cycle of the freshwater ecosystem; however, little is known about their biogeographical patterns and community assembly mechanisms in large river suffering from cascade development. Here, we investigated the spatiotemporal distribution patterns of bacterial communities employing next-generation sequencing analysis and multivariate statistical analyses from the Lancang River cascade reservoirs during summer and winter. We found that sediment bacterial composition has a significant seasonal turnover due to the modification of cascade reservoirs operation mode, and the spatial consistency of biogeographical models (including distance-decay relationship and covariation of community composition with geographical distance) also has subtle changes. The linear regression between the dissimilarity of bacterial communities in sediments, geographical and environmental distance showed that the synergistic effects of geographical and environmental factors explained the influence on bacterial communities. Furthermore, the environmental difference explained little variations (19.40%) in community structure, implying the homogeneity of environmental conditions across the cascade reservoirs of Lancang River. From the quantification of the ecological process, the homogeneous selection was recognized as the dominating factor of bacterial community assembly. The co-occurrence topological network analyses showed that the key genera were more important than the most connected genera. In general, the assembly of bacterial communities in sediment of cascade reservoirs was mediated by both deterministic and stochastic processes and is always dominated by homogeneous selection with the seasonal switching, but the effects of dispersal limitation and ecological drift cannot be ignored.

Seasonality Determines the Variations of Biofilm Microbiome and Antibiotic Resistome in a Pilot-Scale Chlorinated Drinking Water Distribution System Deciphered by Metagenome Assembly.

Understanding the biofilm microbiome and antibiotic resistome evolution in drinking water distribution systems (DWDSs) is crucial to ensure the safety of drinking water. We explored the 10 month evolution of the microbial community, antibiotic resistance genes (ARGs), mobile gene elements (MGEs) co-existing with ARGs and pathogenic ARG hosts, and the ARG driving factors in DWDS biofilms using metagenomics assembly. Sampling season was critical in determining the microbial community and antibiotic resistome shift. Pseudomonas was the primary biofilm colonizer, and biofilms diversified more as the formation time increased. Most genera tended to cooperate to adapt to an oligotrophic environment with disinfectant stress. Biofilm microbial community and antibiotic resistome assembly were mainly determined by stochastic processes and changed with season. Metagenome assembly provided the occurrence and fates of MGEs co-existing with ARGs and ARG hosts in DWDS biofilms. The abundance of ARG- and MGE-carrying pathogen Stenotrophomonas maltophilia was high in summer. It primarily harbored the aph(3)-IIb, multidrug transporter, smeD, and metallo-beta-lactamase ARGs, which were transferred via recombination. The microbial community was the most crucial factor driving the antibiotic resistance shift. We provide novel insights about the evolution of pathogens and ARGs and their correlations in DWDS biofilms to ensure the safety of drinking water.

Seasonal variations of microbial community and antibiotic resistome in a suburb drinking water distribution system in a northern Chinese city.

Antibiotic resistance genes (ARGs) are an emerging issue for drinking water safety. However, the seasonal variation of ARGs in drinking water distribution systems (DWDS) is still unclear. This work revealed the tempo-spatial changes of microbial community, ARGs, mobile genetic elements (MGEs) co-occurring with ARGs, ARG hosts in DWDS bulk water by means of metagenome assembly. The microbial community and antibiotic resistome varied with sampling season and site. Temperature, ammonia, chlorite and total plate count (TPC) drove the variations of microbial community structure. Moreover, environmental parameters (total organic carbon (TOC), chlorite, TPC and hardness) shifted antibiotic resistome. ARGs and MGEs co-occurring with ARGs showed higher relative abundance in summer and autumn, which might be attributed to detached pipe biofilm. In particular, ARG-bacitracin and plasmid were the predominant ARG and MGE, respectively. ARG hosts changed with season and site and were more diverse in summer and autumn. In winter and spring, Limnohabitans and Mycobacterium were the major ARG hosts as well as the dominant genera in microbial community. In addition, in summer and autumn, high relative abundance of Achromobacter and Stenotrophomonas were the hosts harboring many kinds of ARGs and MGEs at site in a residential zone (0.4 km from the water treatment plant). Compared with MGEs, microbial community had a greater contribution to the variation of antibiotic resistome. This work gives new insights into the dynamics of ARGs in full-scale DWDS and the underlying factors.

Anaerobic sulfamethoxazole-degrading bacterial consortia in antibiotic-contaminated wetland sediments identified by DNA-stable isotope probing and metagenomics analysis.

Anaerobic degradation has been demonstrated as an important pathway for the removal of sulfonamide (SA) in contaminated environments, and identifying the microorganisms responsible for the degradation of SA is a key step in developing bioaugmentation approaches. In this study, we investigated the anaerobic degradation activity of three SA [sulfadiazine (SDZ), sulfamethazine (SMZ) and sulfamethoxazole (SMX)] and the associated bacterial community in wetland sediments contaminated by aquaculture (in Fujian Province, coded with FJ), livestock farming (in Sichuan Province, coded with SC), or rural wastewaters (in Guangdong Province, coded with GD). Additionally, the combination of DNA-stable isotope probing (SIP) with metagenomics was further applied to assess the active SA-degrading microbes using SMX as a model SA. Among SDZ, SMZ and SMX, only SMX could be effectively dissipated, and the degradation of SMX was relatively fast in the microcosms of sediments with higher levels of SA contamination (FJ and SC). The anaerobic biotransformation pathway of SMX was initiated by hydrogenation with the cleavage of the N-O bond on the isoxazole ring. DNA-SIP revealed that the in situ active anaerobic SMX-degraders (5, 18 and 3 genera in sediments FJ, SC and GD respectively) were dominated by Proteobacteria in sediments FJ and SC, but by Firmicutes (two Family XVIII members) in sediment GD. Mycobacterium, unclassified Burkholderiaceae and Rhodocyclaceae were identified as the dominant active SMX-degrading bacteria in both sediments FJ and SC. Higher proportions of antibiotic resistance gene and genes involved in various functional categories were observed in sediments FJ and SC.

In-situ active Bisphenol A-degrading microorganisms in mangrove sediments.

Bisphenol A (BPA), as both an endocrine disrupting compound and an important industrial material, is broadly distributed in coastal regions and may cause adverse effects on mangrove ecosystems. Although many BPA degraders have been isolated from various environments, the in-situ active BPA-degrading microorganisms in mangrove ecosystem are still unknown. In this study, DNA-based stable isotope probing in combination with high-throughput sequencing was adopted to pinpoint the microbes actually involved in BPA metabolism in mangrove sediments. Five bacterial genera were speculated to be associated with BPA degradation based on linear discriminant analysis (LDA) effect size (LEfSe) analysis, including Truepera, Methylobacterium, Novosphingobium, Rhodococcus and Rhodobacter. The in-situ BPA degraders were different between mudflat and forest sediments. The Shannon index of microbes in heavy fractions was significantly lower than that in light fractions. Besides, phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) demonstrated that the functional genes relevant to cytochrome P450, benzoate degradation, bisphenol degradation and citrate cycle were up-regulated significantly in in-situ BPA-degrading microbes. These findings greatly expanded the knowledge of indigenous BPA metabolic microorganisms in mangrove ecosystems.

Metagenomic insights into the profile of antibiotic resistomes in sediments of aquaculture wastewater treatment system.

To meet the rapidly growing global demand for aquaculture products, large amounts of antibiotics were used in aquaculture, which might accelerate the evolution of antibiotic-resistant bacteria (ARB) and the propagation of antibiotic genes (ARGs). In our research, we revealed the ARGs profiles, their co-occurrence with mobile genetic elements (MGEs), and potential hosts in sediments of a crab pond wastewater purification system based on metagenomic analysis. The residual antibiotic seems to increase the propagation of ARGs in the crab pond, but there was no clear relationship between a given antibiotic type and the corresponding resistance genes. The effect of aquaculture on sediment was not as profound as that of other anthropogentic activities, but increased the relative abundance of sulfonamide resistance gene. A higher abundance of MGEs, especially plasmid, increased the potential ARGs dissemination risk in crab and purification ponds. Multidrug and sulfonamide resistance genes had greater potential to transfer because they were more frequently carried by MGEs. The horizontal gene transfer was likely to occur among a variety of microorganisms, and various ARGs hosts including Pseudomonas, Acinetobacter, Escherichia, and Klebsiella were identified. Bacterial community influenced the composition of ARG hosts, and Proteobacteria was the predominant hosts. Overall, our study provides novel insights into the environmental risk of ARGs in sediments of aquaculture wastewater treatment system.

Review on corrosion and corrosion scale formation upon unlined cast iron pipes in drinking water distribution systems.

The qualified finished water from water treatment plants (WTPs) may become discolored and deteriorated during transportation in drinking water distribution systems (DWDSs), which affected tap water quality seriously. This water stability problem often occurs due to pipe corrosion and the destabilization of corrosion scales. This paper provides a comprehensive review of pipe corrosion in DWDSs, including corrosion process, corrosion scale formation, influencing factors and monitoring technologies utilized in DWDSs. In terms of corrosion process, corrosion occurrence, development mechanisms, currently applied assays, and indices used to determine the corrosion possibility are summarized, as well as the chemical and bacterial influences. In terms of scale formation, explanations for the nature of corrosion and scale formation mechanisms are discussed and its typical multilayered structure is illustrated. Furthermore, the influences of water quality and microbial activity on scale transformation are comprehensively discussed. Corrosion-related bacteria at the genus level and their associated corrosion mechanism are also summarized. This review helps deepen the current understanding of pipe corrosion and scale formation in DWDSs, providing guidance for water supply utilities to ensure effective measures to maintain water quality stability and guarantee drinking water safety.

Inflammatory cytokines derived from peripheral blood contribute to the modified electroconvulsive therapy-induced cognitive deficits in major depressive disorder.

Little is known about the pathophysiology of memory deficits in patients with major depressive disorder (MDD) treated with modified electroconvulsive therapy (MECT). This study examined the profiles of cytokines, the memory function, and their association in MECT-treated MDD patients. Forty first-episode, drug-free MDD patients and 40 healthy controls were recruited. MECT was started with antidepressant treatment at a stable initial dose. The Wechsler Memory Scale (WMS) and Hamilton Rating Scale for Depression 17 (HRSD-17) were used to assess the cognitive function. MDD patients were divided into the memory impairment group (WMS < 50) and the non-memory impairment group (WMS ≥ 50) based on the total WMS scores after MECT. The levels of NOD-like receptor 3 (NLRP3) inflammasome, interleukin-18 (IL-18) and nuclear factor kappa-B (NF-κB) in the serum were measured. MDD patients showed significantly higher levels of NLRP3 inflammasome, IL-18 and NF-κB than that in the controls prior to MECT, and the levels also significantly increased after MECT. In MDD patients, the serum levels of these inflammatory cytokines were negatively associated with the total WMS scores and likely contributed to the scores independently. The receiver operating characteristic curve showed that the serum levels of these inflammatory cytokines may predict the cognitive impairment risk in MDD patients receiving MECT. Abnormal levels of NLRP3 inflammasome, IL-18 and NF-κB reflecting the disturbed balance of pro-inflammatory and anti-inflammatory mechanisms likely contribute to the MECT-induced cognitive deficits in MDD patients.

Sequential Functionalization of meta-C-H and ipso-C-O Bonds of Phenols.

The use of a template as a linchpin motif in directed remote C-H functionalization is a versatile yet relatively underexplored strategy. We have developed a template-directed approach to realizing one-pot sequential palladium-catalyzed meta-selective C-H olefination of phenols, and nickel-catalyzed ipso-C-O activation and arylation. Thus, this bifunctional template converts phenols to synthetically useful 1,3-disubstituted arenes.

Heavy metal spill influences bacterial communities in freshwater sediments.

Bacteria are highly abundant in freshwater sediments and play a crucial role in biogeochemical cycling. Bacterial assemblage is known to be sensitive to heavy metal pollution. However, the shift in freshwater sediment bacterial community after a sudden exposure to heavy metal spill remains unknown. The present study explored the impact of metal (metalloid) spill on sediment bacterial community in a freshwater reservoir. Although sediment bacterial abundance was relatively insensitive to metal (metalloid) spill, bacterial richness, diversity and community structure displayed considerable temporal variations. In addition, the proportions of Proteobacteria Chloroflexi, Nitrospirae, Acidobacteria and Bacteroidetes drastically declined, while a significant enrichment of Firmicutes was observed.

Intramolecular dehydrogenative C-S bond coupling of thioamides to form 1,3-benzothiazines under metal-free conditions.

A novel HTIB-promoted direct intramolecular dehydrogenative C-S bond coupling reaction of thioamides has been developed to provide 1,3-benzothiazine derivatives in good yields. The reaction proceeds smoothly to reach completion at room temperature within 1 min under metal-free conditions. This protocol provides a mild and efficient strategy for the synthesis of six-membered N,S-containing heterocycles. Preliminary mechanistic studies indicate that a spirocyclic intermediate might be involved.

Association of Exposure to Ambient Fine Particulate Matter Constituents With Semen Quality Among Men Attending a Fertility Center in China.

Ambient fine particulate matter (PM2.5) exposure has been linked to decreased semen quality, but the associations between PM2.5 constituent exposures and semen quality remain unknown. We enrolled 1081 men whose partners underwent assisted reproductive technology procedures in Wuhan, China in 2014-2015, and examined their semen quality. Daily average concentrations of PM2.5 constituents including 10 metals/metalloid elements and 4 water-soluble ions were continuously determined for 1 week per month at 2 fixed monitoring stations. Linear mixed models were used to examine the associations of exposures to PM2.5 and its constituents with semen quality. Each interquartile range (36.5 µg/m3) increase in PM2.5 exposure was significantly associated with 8.5% (95% CI: 2.3%, 14.4%) and 8.1% (95% CI: 0.7%, 15.0%) decrease in sperm concentration and total sperm number, respectively. Antimony, cadmium, lead, manganese, and nickel exposures were significantly associated with decreased sperm concentration, whereas manganese exposure was also significantly associated with decreased total motility. Nonsmokers were more susceptible to PM2.5 constituent exposures, especially for antimony and cadmium (all P for effect modification <0.05). These findings suggest that PM2.5 and certain constituents may adversely affect semen quality, especially sperm concentration, and provide new evidence to formulate pollution abatement strategies for male reproductive health.

Toxicity of perfluorooctane sulfonate on Phanerochaete chrysosporium: Growth, pollutant degradation and transcriptomics.

As a persistent organic pollutant listed in the Stockholm Convention, perfluorooctane sulfonate (PFOS) is extremely refractory to degradation under ambient conditions. Its potential ecotoxicity has aroused great concerns and research interests. However, little is known about the toxicity of PFOS on fungus. In this study, the white rot fungus Phanerochaete chrysosporium (P. chrysosporium) was adopted to assess the toxicity of PFOS in liquid culture. The addition of 100 mg/L PFOS potassium salt significantly decreased the fungal biomass by up to 76.4% comparing with un-amended control during the incubation period. The hyphostroma of P. chrysosporium was wizened and its cell membrane was thickened, while its vesicle structure was increased, based on the observation with scanning electron microscope (SEM) and transmission electron microscope (TEM). Nevertheless, the PFOS dosage of below 100 mg/L did not show a considerable damage to the growth of P. chrysosporium. The degradation of malachite green (MG) and 2,4-dichlorophenol (2,4-DCP) by P. chrysosporium was negatively affected by PFOS. At the initial dosage of 100 mg/L PFOS, the decolorization efficiency of MG and the degradation efficiency of 2,4-DCP decreased by 37% and 20%, respectively. This might be attributed to the inhibition of PFOS on MnP and LiP activities. The activities of MnP and LiP decreased by 20.6% and 43.4%, respectively. At a high dosage PFOS (100 mg/L), P. chrysosporium could show a high adsorption of MG but lose its pollutant degradation ability. Transcriptome analysis indicated that PFOS contamination could lead to the change of gene expression in the studied white rot fungus, and the genes regulating membrane structure, cell redox process, and cell transport, synthesis and metabolism were impacted. Membrane damage and oxidative damage were the two main mechanisms of PFOS' toxicity to P. chrysosporium.

Impacts of sulfanilamide and oxytetracycline on methane oxidation and methanotrophic community in freshwater sediment.

Methanotrophs are of great significance for the abatement of methane emission from anoxic environments. Antibiotics are ubiquitous in the environment and can affect microbial activity and community density and composition. However, information about the effect of antibiotics on methanotrophs is still lacking. The current study explored the influences of sulfonamides and tetracyclines on methane oxidation potential (MOP) and methanotrophic density and community structure in freshwater sediment microcosms. The addition of both sulfanilamide (SA) and oxytetracycline (OTC) could increase MOP and particulate methane monooxygenase subunit A (pmoA) gene density but decrease the number of pmoA transcripts. Both SA and OTC could also have impacts on sediment methanotrophic community structure. The antibiotic effects on MOP and methanotrophs were found to depend on the dosage and type of antibiotics. This work could provide some new insights towards the links between methane oxidation and antibiotics.

Evaluating the response of anaerobic ammonium-oxidizing bacteria to heavy metal spill in freshwater sediment.

Anaerobic ammonium-oxidizing (anammox) bacteria can play an important role in nitrogen elimination in the environment. However, the effect of heavy metals on anammox bacteria in aquatic ecosystem remains largely unknown. The present study investigated the variability of anammox bacterial community in a freshwater reservoir after a severe heavy metal spill. The richness (Chao1 richness estimator = 2-18), diversity (Shannon index = 0.26-2.04) and community structure of anammox bacteria changed considerably with sampling date, while anammox bacterial abundance (from 1.38 × 105 to 3.09 × 105 anammox bacterial 16S rRNA gene copies per gram dry sediment) was less responsive to metal spill. Anammox bacterial communities were mainly composed of Brocadia- and Anammoxoglobus-like bacteria as well as novel phylotype, however, there relative abundance varied among sampling dates. This work could add the knowledge of the response of anammox bacteria to heavy metal contamination.

Response of ammonia-oxidizing archaea to heavy metal contamination in freshwater sediment.

It has been well-documented that the distribution of ammonia-oxidizing bacteria (AOB) and archaea (AOA) in soils can be affected by heavy metal contamination, whereas information about the impact of heavy metal on these ammonia-oxidizing microorganisms in freshwater sediment is still lacking. The present study explored the change of sediment ammonia-oxidizing microorganisms in a freshwater reservoir after being accidentally contaminated by industrial discharge containing high levels of metals. Bacterial amoA gene was found to be below the quantitative PCR detection and was not successfully amplified by conventional PCR. The number of archaeal amoA gene in reservoir sediments were 9.62 × 102-1.35 × 107 copies per gram dry sediment. AOA abundance continuously decreased, and AOA richness, diversity and community structure also considerably varied with time. Therefore, heavy metal pollution could have a profound impact on freshwater sediment AOA community. This work could expand our knowledge of the effect of heavy metal contamination on nitrification in natural ecosystems.

Biofilm and planktonic bacterial communities in a drinking water distribution system supplied with untreated groundwater.

It is known that both disinfection and water quality can influence the bacterial communities in a drinking water distribution system (DWDS). Here, we hypothesized that bacterial communities in a DWDS with untreated groundwater with no prior purification and disinfection might differ from those in a DWDS with disinfected surface water. The present study applied Illumina MiSeq sequencing to investigate biofilm and planktonic bacterial communities in a DWDS fed with untreated groundwater (receiving no prior purification and disinfection). Considerable differences in bacterial richness (Chao1 richness estimator: 389-745 for water and 392-485 for biofilm), diversity (Shannon diversity index: 2.70-3.77 for water and 2.53-3.66 for biofilm) and community structure existed among both DWDS waters and biofilms. Biofilm and planktonic bacterial communities had distinct structures. The service time of DWDS could affect biofilm bacterial richness, diversity and community structure. Moreover, planktonic bacterial diversity and community structure might be influenced by NO2- concentration, while planktonic bacterial richness was related to NO3- concentration. Proteobacteria dominated in both biofilm and planktonic bacterial communities. Higher concentrations of NO2- favored the deltaproteobacterial proportion, but lowered the gammaproteobacterial proportion in drinking water. Overall, our study indicates that bacterial communities in a DWDS could be influenced by a variety of factors, such as habitats (water or biofilm), DWDS service time, and water chemistry.

Aerobic and anaerobic methanotrophic communities in urban landscape wetland.

Both aerobic methane-oxidizing bacteria (MOB) and nitrite-dependent anaerobic methane oxidation (n-damo) organisms can be important methane sinks in a wetland. However, the influences of the vegetation type on aerobic MOB and n-damo communities in wetland, especially in constructed wetland, remain poorly understood. The present study investigated the influences of the vegetation type on both aerobic MOB and n-damo organisms in a constructed urban landscape wetland. Sediments were collected from eight sites vegetated with different plant species. The abundance (1.19-3.27 × 107 pmoA gene copies per gram dry sediment), richness (Chao1 estimator = 16.3-81.5), diversity (Shannon index = 2.10-3.15), and structure of the sediment aerobic MOB community were found to vary considerably with sampling site. In contrast, n-damo community abundance (8.74 × 105-4.80 × 106 NC10 16S rRNA gene copies per gram dry sediment) changed slightly with the sampling site. The richness (Chao1 estimator = 1-11), diversity (Shannon index = 0-0.78), and structure of the NC10 16S rRNA gene-based n-damo community illustrated slight site-related changes, while the spatial changes of the pmoA gene-based n-damo community richness (Chao1 estimator = 1-8), diversity (Shannon index = 0-0.99), and structure were considerable. The vegetation type could have a profound impact on the wetland aerobic MOB community and had a stronger influence on the pmoA-based n-damo community than on the NC10 16S-based one in urban wetland. Moreover, the aerobic MOB community had greater abundance and higher richness and diversity than the n-damo community. Methylocystis (type II MOB) predominated in urban wetland, while no known type I MOB species was detected. In addition, the ratio of total organic carbon to total nitrogen (C/N) might be a determinant of sediment n-damo community diversity and aerobic MOB richness.