To explore the microbial nitrogen metabolism of a two-stage anoxic/oxic (A/O)-moving bed biofilm reactor (MBBR), biofilms of the system's chambers were analyzed using metagenomic sequencing. Significant differences in microbial populations were found among the pre-anoxic, oxic and post-anoxic MBBRs (P < 0.01). Nitrospira and Nitrosomonas had positive correlations with ammonia nitrogen (NH-N) removal, and were also predominant in oxic MBBRs. These organisms were the hosts of functional genes for nitrification. The denitrifying genera were predominant in anoxic MBBRs, including Thiobacillus and Sulfurisoma in pre-anoxic MBBRs and Dechloromonas and Thauera in post-anoxic MBBRs. The four genera had positive correlations with total nitrate and nitrite nitrogen (NO-N) removal and were the hosts of functional genes for denitrification. Specific functional biofilms with different microbial nitrogen metabolisms were formed in each chamber of this system. This work provides a microbial theoretical support for the two-stage A/O-MBBR system.
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http://dx.doi.org/10.1016/j.biortech.2022.127729 | DOI Listing |
J Environ Manage
January 2025
Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan. Electronic address:
The toxicity of nitrite is an issue that cannot be overlooked in nitrogen pollution within aquaculture. A highly efficient bacterium capable of simultaneous nitrification and denitrification was screened from natto, and its 16S rRNA gene sequence was compared to existing records, confirming its identification as Bacillus subtilis sp. N4.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Federal Rural University of Pernambuco, Department of Agronomy, Dom Manoel de Medeiros Street, w/n, Recife, PE, 52171-900, Brazil. Electronic address:
Overgrazing is the primary human-induced cause of soil degradation in the Caatinga biome, intensely threatening lands vulnerable to desertification. Grazing exclusion, a simple and cost-effective practice, could restore soils' ecological functions. However, comprehensive insights into the effects of overgrazing and grazing exclusion on Caatinga soils' multifunctionality are lacking.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
College of Chemical and Environmental Engineering, Hanjiang Normal University, Shiyan 442000, China. Electronic address:
Environ Sci Technol
January 2025
College of Environment, Zhejiang University of Technology, Hangzhou 310032, P. R. of China.
Soil microbiota plays crucial roles in maintaining the health, productivity, and nutrient cycling of terrestrial ecosystems. The persistence and prevalence of heterocyclic compounds in soil pose significant risks to soil health. However, understanding the links between heterocyclic compounds and microbial responses remains challenging due to the complexity of microbial communities and their various chemical structures.
View Article and Find Full Text PDFFoods
January 2025
SKL of Marine Food Processing & Safety Control, National Engineering Research Center of Seafood, Collaborative Innovation Center of Seafood Deep Processing, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
Freshwater fish processing produces 30-70% nutrient-rich by-products, often discarded or undervalued. Grass carp by-products, rich in protein, offer potential as raw materials for fermented seasonings. This study explores the use of these by-products-specifically, minced fish and fish skin-in soybean fermentation to evaluate their effects on the quality of the resulting seasonings.
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