19 results match your criteria: "and Environmental Microbiology Research Center at Institute of Microbiology[Affiliation]"

Dirammox (direct ammonia oxidation) to nitrogen (N): discovery, current status, and perspectives.

Curr Opin Microbiol

December 2024

State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266273, China; State Key Laboratory of Microbial Resources, and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address:

Article Synopsis
  • Microbial ammonia oxidation is crucial for nitrogen cycling in various environments, but the specific mechanisms involved remain largely unclear.
  • Dirammox is a new process where ammonia is directly converted to nitrogen gas through hydroxylamine, bypassing nitrite and nitrate, and involves specific genes in Alcaligenes species.
  • The review covers the discovery of dirammox, its genetic and biochemical aspects, ecological implications, and suggests future research directions in this area.
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Both polycyclic aromatic hydrocarbons (PAHs) and heavy metals persist in the environment and are toxic to organisms. Their co-occurrence makes any of them difficult to remove during bioremediation and poses challenges to environmental management and public health. Microorganisms capable of effectively degrading PAHs and detoxifying heavy metals concurrently are required to improve the bioremediation process.

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An oval to rod-shaped, Gram-stain-positive, strictly anaerobic bacterium, designated LFL-14, was isolated from the faeces of a healthy Chinese woman. Cells of the strain were non-spore-forming, grew optimally at 37 °C (growth range 30-45 °C) and pH 7.0 (growth range 6.

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Bacteria capable of direct ammonia oxidation (Dirammox) play important roles in global nitrogen cycling and nutrient removal from wastewater. Dirammox process, NH  → NH OH → N , first defined in Alcaligenes ammonioxydans HO-1 and encoded by dnf gene cluster, has been found to widely exist in aquatic environments. However, because of multidrug resistance in Alcaligenes species, the key genes involved in the Dirammox pathway and the interaction between Dirammox process and the physiological state of Alcaligenes species remain unclear.

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Sulfonamide antibiotics (SAs) are serious pollutants to ecosystems and environments. Previous studies showed that microbial degradation of SAs such as sulfamethoxazole (SMX) proceeds via a sad-encoded oxidative pathway, while the sulfonamide-resistant dihydropteroate synthase gene, sul, is responsible for SA resistance. However, the co-occurrence of sad and sul genes, as well as how the sul gene affects SMX degradation, was not explored.

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The human gastrointestinal tract is inhabited by various microorganisms, including thousands of bacterial taxa that have yet to be cultured and characterized. In this report, we describe the isolation, cultivation, genotypic and phenotypic characterization and taxonomy of five novel anaerobic bacterial strains that were recovered during the massive cultivation and isolation of gut microbes from human faecal samples. On the basis of the polyphasic taxonomic results, we propose two novel genera and five novel species.

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The MocR family transcriptional regulator DnfR has multiple binding sites and regulates Dirammox gene transcription in Alcaligenes faecalis JQ135.

Environ Microbiol

March 2023

Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, China.

Microbial ammonia oxidation is vital to the nitrogen cycle. A biological process, called Dirammox (direct ammonia oxidation, NH →NH OH→N ), has been recently identified in Alcaligenes ammonioxydans and Alcaligenes faecalis. However, its transcriptional regulatory mechanism has not yet been fully elucidated.

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Parkinson's disease (PD) is a complicated neurodegenerative disease, of which gastrointestinal disturbance appears prior to motor symptoms. Numerous studies have shed light on the roles of gastrointestinal tract and its neural connection to brain in PD pathology. In the past decades, the fields of microbiology and neuroscience have become ever more entwined.

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Nonhuman primates (NHPs) such as monkeys are the closest living relatives to humans and are the best available models for causative studies of human health and diseases. Gut microbiomes are intensively involved in host health. In this study, by large-scale cultivation of microbes from fecal samples of monkeys, we obtained previously uncultured bacterial species and constructed a Gut Microbial Biobank (MfGMB).

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sp. nov. and sp. nov., two bacteria from constructed wetland.

Int J Syst Evol Microbiol

March 2022

State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China.

Two Gram-stain-negative, aerobic, non-motile and rod-shaped bacterial strains designated 3A5MI-3 and RSS-23 were isolated from the Dragon-shaped Wetland System in Beijing Olympic Park, PR China. Strain 3A5MI-3 grew at 15–45 °C, pH 5.0–9.

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Non-human primates harbour diverse microbiomes in their guts. As a part of the China Microbiome Initiatives, we cultivated and characterized the gut microbiome of cynomolgus monkeys (). In this report, we communicate the characterization and taxonomy of eight bacterial strains that were obtained from faecal samples of captive cynomolgus monkeys.

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Genetic Foundations of Direct Ammonia Oxidation (Dirammox) to N and MocR-Like Transcriptional Regulator DnfR in Alcaligenes faecalis Strain JQ135.

Appl Environ Microbiol

March 2022

Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural Universitygrid.27871.3b, Nanjing, China.

Article Synopsis
  • Ammonia oxidation is crucial for the nitrogen cycle and engineered ecosystems, with a new pathway called Dirammox recently identified.
  • The study focused on Alcaligenes faecalis strain JQ135, which converts ammonia to nitrous oxide (N) independently of denitrification processes, revealing its genetic regulation.
  • It confirmed that Dirammox is present in various bacteria beyond previously known species, and the regulation involves the MocR-family transcriptional regulator DnfR.
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Article Synopsis
  • Biological foaming in wastewater treatment plants (WWTPs) is primarily caused by the growth of filamentous bulking and foaming bacteria (BFB), which has raised concerns about sludge separation issues.
  • Although research has identified certain foaming bacteria, like Skermania piniformis, there is still a need to understand the wide variety of microbes involved and their roles in foaming.
  • In this study at the Qinghe WWTP in China, a new bacterium called Kaistella beijingensis was isolated and characterized, revealing its ability to produce hydrophobic surfaces and extracellular polymeric substances, contributing to the foaming problem in activated sludge.
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Heterotrophic nitrifiers are able to oxidize and remove ammonia from nitrogen-rich wastewaters but the genetic elements of heterotrophic ammonia oxidation are poorly understood. Here, we isolated and identified a novel heterotrophic nitrifier, Alcaligenes ammonioxydans sp. nov.

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Tropical and temperate wastewater treatment plants assemble different and diverse microbiomes.

Appl Microbiol Biotechnol

January 2021

IMCAS-RCEES joint lab at CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.

The diversity and assembly of activated sludge microbiomes play a key role in the performances of municipal wastewater treatment plants (WWTPs), which are the most widely applied biotechnological process systems. In this study, we investigated the microbiomes of municipal WWTPs in Bangkok, Wuhan, and Beijing that respectively represent tropical, subtropical, and temperate climate regions, and also explored how microbiomes assembled in these municipal WWTPs. Our results showed that the microbiomes from these municipal WWTPs were significantly different.

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Caves are typified by their permanent darkness and a shortage of nutrients. Consequently, bacteria play an important role in sustaining such subsurface ecosystems by dominating primary production and fueling biogeochemical cycles. China has one of the world's largest areas of karst topography in the Yunnan-Guizhou Plateau, yet the bacteriomes in these karst caves remain unexplored.

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Parabacteroides acidifaciens sp. nov., isolated from human faeces.

Int J Syst Evol Microbiol

March 2019

4​Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Key Laboratory of Rheumatology and Clinical Immunology, Ministry of Education, Beijing 100730, PR China.

A polyphasic taxonomic approach was applied to characterize an anaerobic bacterial strain, 426-9, that was isolated from human faeces. The strain was Gram-stain-negative, non-motile, non-spore-forming, non-pigmented and rod-shaped. Strain 426-9 grew anaerobically at 20-45 °C (optimally at 37-40 °C) and at pH 6.

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Previous studies have identified a putative mycothiol peroxidase (MPx) in Corynebacterium glutamicum that shared high sequence similarity to sulfur-containing Gpx (glutathione peroxidase; CysGPx). In the present study, we investigated the MPx function by examining its potential peroxidase activity using different proton donors. The MPx degrades hydrogen peroxide and alkyl hydroperoxides in the presence of either the thioredoxin/Trx reductase (Trx/TrxR) or the mycoredoxin 1/mycothione reductase/mycothiol (Mrx1/Mtr/MSH) regeneration system.

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Oxidation of methionine leads to the formation of the S and R diastereomers of methionine sulfoxide (MetO), which can be reversed by the actions of two structurally unrelated classes of methionine sulfoxide reductase (Msr), MsrA and MsrB, respectively. Although MsrAs have long been demonstrated in numerous bacteria, their physiological and biochemical functions remain largely unknown in Actinomycetes. Here, we report that a Corynebacterium glutamicum methionine sulfoxide reductase A (CgMsrA) that belongs to the 3-Cys family of MsrAs plays important roles in oxidative stress resistance.

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