Processes
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2019
·Vol. 7
·期 11
·827
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IF 1.963
Yong Li,Siyuan Zhao,Jiejie Zhang,Yang He,Jianqiang Zhang,Rong Ge
The aerobic denitrifying phosphate accumulating bacteria (ADPB) use NO3−as an electron acceptor and remove nitrate by denitrification and concomitant uptake of excessive phosphorus in aerobic conditions. Activated sludge was collected from the A2O aerobic biological pool of the sewage treatment plant at Hezuo Town, Chengdu City. The candidate ADPB strains were obtained by cultivation in the enriched denitrification media, followed by repeated isolation and purification on bromothymol blue (BTB) solid plates. The obtained candidates were further screened for ADPB strains by phosphorus uptake experiment, nitrate reduction test, metachromatic granules staining, and poly-β-hydroxybutyrate (PHB) staining. The 16 sedimentation ribosome deoxyribonucleic acid (16 S rDNA) molecular technique was used to determine their taxonomy. Further, the denitrification and dephosphorization capacities of ADPB strains were ascertained through their growth characteristics in nitrogen-phosphorus-rich liquid media. The results revealed a total of 25 ADPB strains screened from the activated sludge of the A2O aerobic biological pool of the sewage treatment plant at Hezuo Town. These strains belonged to two classes, four orders, and five genera. Among them, the strain SW18NP2 was a potentially new species in theAcinetobactergenus, while the strain SW18NP24 was a potential new species in thePseudomonasgenus at the time of their characterization. TheAcinetobacterwas the dominant genus. The obtained ADPB strains demonstrated a rich diversity. The ADPB strains had significant variations in denitrification and dephosphorization capacities. Twenty-three strains exhibited a total phosphorus removal rate of above 50%, and 19 strains exhibited a total nitrogen removal rate of above 50%. The strain SW18NP2 showed the best denitrifying phosphorus removal (DPR) capacity, with a dephosphorization rate of 82.32% and a denitrification rate of 73.73%. The ADPB in the A2O aerobic biological pool of the sewage treatment plant at Hezuo Town demonstrated a rich diversity and a strong DPR capacity.Keywords:aerobic denitrifying phosphate accumulating bacteria (ADPB);diversity;denitrifying phosphorus removal
研究领域:
环境微生物学
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污水处理
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DOI
高影响因子
JOURNAL OF BIOSCIENCE AND BIOENGINEERING
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2024
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IF 2.3
Mengyao Gui
Humic acid (HA), a common natural organic matter , could affect conventional anoxic denitrification. Aim of this study was to investigate effect of HA on the process of aerobic denitrification in Achromobacter sp. GAD-3, an aerobic denitrifying strain. The findings demonstrated that an increase in HA concentrations (≥5 mg L −1 ) promoted the aerobic denitrification process (excluding N 2 O reduction), manifesting as higher rates of nitrate removal (6.67–11.1 mg L −1 h −1 ) and lower levels of nitrite accumulation (30.2–20.7 mg L −1 ). This was attributed to the increased electron transfer activities and denitrifying reductase activities (including NAR, NIR and NOR) facilitated by HA. Accordingly, the expression of denitrification genes such as napA , cnorB , and nirS was enhanced by HA. Nonetheless, the nosZ gene and N 2 OR activity underwent suppression by HA, which was accountable for N 2 O emission. It is crucial to understand the HA mechanism towards aerobic denitrifiers for wastewater treatment plants to enhance nitrogen removal.
研究领域:
环境生物学
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废水处理
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DOI
PubMed
高影响因子
GLOBAL CHANGE BIOLOGY
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2021
·Vol. 27
·期 21
·5564-5579
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IF 10.863
Xiaoxuan Su,Teng Wen,Yingmu Wang,Junshi Xu,Li Cui,Jinbo Zhang,Ximei Xue,Kai Ding,Yijia Tang,Yong-guan Zhu
Ocean acidification in nitrogen-enriched estuaries has raised global concerns. For decades, biotic and abiotic denitrification in estuarine sediments has been regarded as the major ways to remove reactive nitrogen, but they occur at the expense of releasing greenhouse gas nitrous oxide (N 2 O). However, how these pathways respond to acidification remains poorly understood. Here we performed a N 2 O isotopocules analysis coupled with respiration inhibition and molecular approaches to investigate the impacts of acidification on bacterial, fungal, and chemo-denitrification, as well as N 2 O emission, in estuarine sediments through a series of anoxic incubations. Results showed that acidification stimulated N 2 O release from sediments, which was mainly mediated by the activity of bacterial denitrifiers, whereas in neutral environments, N 2 O production was dominated by fungi. We also found that the contribution of chemo-denitrification to N 2 O production cannot be ignored, but was not significantly affected by acidification. The mechanistic investigation further demonstrated that acidification changed the keystone taxa of sedimentary denitrifiers from N 2 O-reducing to N 2 O-producing ones and reduced microbial electron-transfer efficiency during denitrification. These findings provide novel insights into how acidification stimulates N 2 O emission and modulates its pathways in estuarine sediments, and how it may contribute to the acceleration of global climate change in the Anthropocene.
研究领域:
海洋生物学
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环境科学
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微生物学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
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IF 10.588
Jianxin Pan,Liangliang Liu,Hanping Pan,Lihui Yang,Meirong Su,Chaohai Wei
Metal sulfide-based biological process is considered as a promising biotechnology for next-generation wastewater treatment . However, it is not clear if simultaneous bio-reduction of nitrate and chromate was achievable in this process. This study aimed to evaluate the feasibility of metal sulfides (FeS and MnS) on simultaneous denitrification and chromate reduction in autotrophic denitrifying column bioreactors . Results showed that simultaneous reduction of nitrate and chromate was achieved using metal sulfides (FeS and MnS) as electron donors, in which sulfate was the sole soluble end-product. Apart from the sulfur element in the metal sulfides, Fe(II) and Mn(II) were also involved in nitrate and chromate reduction as indicative by the formation of their oxidative states compounds. In microbial communities , SHD-231 and Thiobacillus were the most predominant bacteria, which might have played important roles in simultaneous denitrification and chromate reduction. Compared to FeS, MnS showed a higher performance on nitrate and chromate removal, which could also reduce the toxic inhibition of chromate on nitrate reduction . According to results of XRD and XPS, as well as a lower sulfate production in the FeS system, FeS might have been covered easily to hydroxides due to its bio-oxidation, which limited mass transfer efficiency and bio-availability of FeS. The findings in this study offered insights in the development of promising approaches for the treatment of toxic and hazardous compounds using metal sulfide.
研究领域:
环境科学
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微生物学
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DOI
高影响因子
Journal of Water Process Engineering
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2025
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IF 6.7
Ze-Tong Feng,Yan Yu,Ying-Jun Sun,Jia-Min Zhou,Xin Ma,Fei Ding,Yi-Liu Zheng,Ren-Cun Jin,Chun-Qiang Shen,Qian-Qian Zhang
This study systematically evaluated the effects of intermittent versus continuous addition of zero-valent iron (ZVI) as exogenous enhancers on nitrogen removal performance in denitrification systems. Results shown that under carbon-to‑nitrogen ratios (C/N) was 3, 2, and 1, continuous addition of ZVI significantly improved total nitrogen removal efficiency (TNRE) by 8.57 %, 19.34 %, and 11.45 %, respectively, compared to the control system. Concurrently, extracellular polymeric substance (EPS) production increased by 32.43 %, 62.91 %, and 35.93 %, to that of intermittent ZVI addition system at the same phases. The continuous ZVI-added system enriched more mixotrophic denitrification bacteria and increased soluble iron ion concentrations through EPS-mediated electron shuttling and endogenous protection mechanisms. While, under C/N was 0, the TNRE in continuously ZVI-added system reduced to 8.3 ± 3.24 % due to iron mineral crust formation. Specifically, the TNRE of system with intermittent addition of ZVI stabilized at 17.03 ± 3.24 %, enriched more autotrophic denitrification bacteria and avoided excessive accumulation of iron oxides. Therefore, this experiment provided new insights into the stable operation of the ZVI-enhanced denitrification process for treating low C/N wastewater.
研究领域:
环境科学
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微生物学
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2018
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IF 4.61
Xuebin Hu,Yiyu Wang,Xiaoxuan Su,Yi Chen
The fungicide chlorothalonil (CHT) has been widely used in the tea orchard due to its high-efficiency and sterilization. It has been reported that repeated application of CHT inhibits soil nitrification process. However, the acute impact of CHT on soil denitrification and associated N 2 O emissions is unclear. This study evaluated nitrate (NO 3 − ) removal, denitrifying gene abundance and denitrifying enzyme activity of tea orchard soil after a 72-h-exposure to CHT. It was found that increasing CHT from 5 to 25 mg kg −1 suppressed the NO 3 − removal efficiency from 74.6% to 54.1%, but increased N 2 O emissions from 23.1% to 94.8%. Following treatment with 25 mg kg −1 of CHT, the abundances of the nir K, nir S and nos Z genes were reduced by 31.6%, 22.1%, and 50.7%, respectively. Alternatively, the declines of the electron transport system activity (ETSA) value and adenosine triphosphate (ATP) content suggested that CHT had an inhibitory effect on microbial metabolism. Enzyme activity studies further revealed that the decrease of nitrate reductase (NAR), nitrite reductase (NIR) and nitric oxide reductase (NOR) activities was the main reason for the suppression of denitrification by CHT. Furthermore, positive correlations were observed between denitrifying reductase activity and the intracellular metabolism, indicating that the decrease in microbial metabolism should also be responsible for the inhibitory effect of CHT on the denitrifying process. Overall, it was found that the acute exposure of soil to CHT could inhibit the denitrification process and significantly increase N 2 O emissions, which might result in destruction of the soil nitrogen cycle and exacerbation of global warming .
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2023
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IF 11.4
Xiaofei Li,Dengzhou Gao,Ye Li,Yanling Zheng,Hongpo Dong,Xia Liang,Min Liu,Lijun Hou
Estuarine and coastal environments are assumed to contribute to nitrous oxide (N2O) emissions under increasing nitrogen loading. However, isotopic and molecular mechanisms underlying N2O production pathways under elevated nitrogen concentration remain poorly understood. Here we used microbial inhibition, isotope mass balance, and molecular approaches to investigate N2O production mechanisms in estuarine and coastal sediments through a series of anoxic incubations. Site preference of the N2O molecule increased due to increasing nitrate concentration, suggesting the changes in N2O production pathways. Enhanced N2O production under high nitrate concentration was not mediated by bacterial denitrification, but instead was mainly regulated by fungal denitrification. Elevated nitrate concentration increased the contribution of fungal denitrification to N2O production by 11–25%, whereas it decreased bacterial N2O production by 16–33%. Chemodenitrification was also enhanced by high nitrate concentration, contributing to 13–28% of N2O production. Elevated nitrate concentration significantly mediated nirK-type denitrifiers structure and abundance, which are the keystone taxa driving N2O production. Collectively, these results suggest that increasing nitrate concentration can shift N2O production pathways from bacterial to fungal and chemodenitrification, which are mainly responsible for the enhanced N2O production and have widespread implications for N2O projections under ongoing nitrogen pollution in estuarine and coastal ecosystems.
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
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2025
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IF 7.7
Zi-Shang Ma,Han-Min Zhang,Wen-Jie Ma,Nuo-Yan Liu,Xue-Cheng Yu
Traditional heterotrophic denitrification encounters challenges in the treatment of wastewater with a low carbon to nitrogen ratio (C/N). This study successfully achieved complete nitrogen removal with energy efficiency through the anaerobic-anoxic-anoxic sulfur autotrophic (A 3 ) process in the treatment of low C/N wastewater. Notably, this process enabled simultaneous nitrification-heterotrophic denitrification (SND) coupled with sulfur-driven autotrophic denitrification (SAD) with a nitrogen removal rate of 0.15 kg N/m 3 /d (100 % of NH 4 + -N and 92 % of total nitrogen (TN) removal). More than 85 % of TN removal and 50 % of SND contribution were obtained under low-temperature conditions (about 10–14 °C). After cultivation in the A 3 system, the dominant bacterial genus changed from norank_f__Saprospiraceae (11.22 %–5.21 %) to Ferruginibacter (0.89 %–19.31 %). Additionally, Nitrospira (1.34 %) and Thiobacillus (2.14 %) exhibited a synergistic effect in the anoxic tank, collectively promoting the simultaneous nitrification and denitrification process. This study proposes a novel and energy-efficient approach for the treatment of low C/N wastewater.
研究领域:
环境工程
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废水处理
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微生物生态学
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生物脱氮
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Quanhao Dou,Li Zhang,Yongzhen Peng
Mitigating the intense competition for substrates and ecological niches between heterotrophic and autotrophic microorganisms is essential for sustaining nitrogen removal in partial denitrification/anammox (PD/A) systems. Herein, an innovative high-intensity PD/A process was designed, utilizing iron sulfide and minimal organic carbon input. The nitrogen loading rate (NLR) reached 0.96 ± 0.06 kg N/(m 3 ·d) at a C/N ratio of 0.5, considerably higher than all results reported to date. Elucidating microbial ecology in this lab-scale mixotrophic PD/A system is vital for large-scale application. Results showed that sulfur-oxidizing denitrifiers ( Thiobacillus and Pseudorhodoplanes ; 0 % ∼ 1.11 %), functioning as network hubs, redistributed nitrate burden from heterotrophic denitrifiers ( Denitratisoma ; 8.44 %) via inorganic electron uptake, while freeing niches for the anammox bacteria ( Ca. Brocadia; 143.67-fold enrichment). A synergistic microbial community integrating multiple metabolic pathways achieved 96.24 ± 0.11 % nitrogen removal. Furthermore, genetic evidence indicated that membrane-bound narG accelerated nitrate reduction, while hydroxylamine-dependent anammox ( via hao instead of nirS ) eliminated toxic NO intermediates. This enhanced bioreactor stability and reduced hydraulic retention time from 12 h to 2 h, maximizing NLR. Our findings propose a novel paradigm to advance PD/A systems toward low-carbon, high-rate operation, ensuring desirable effluent quality and microbial ecological balance.
研究领域:
环境生物技术
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微生物生态学
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污水处理
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反应器工程
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氮循环
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功能基因组学
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产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
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2021
·
IF 8.071
Rui Wan,Xiaoxiao Li,Yunyi Zha,Xiong Zheng,Haining Huang,Minghui Li
The widespread use of decabromodiphenyl ether (BDE-209) resulted in its deposition in environmental media and biological matrices. However, to date, few studies focused on the effect of BDE-209 on microorganisms , and those available were investigated via an enclosed system completely cutting off the communication between testing system and its native environment. Herein, 4.0 mg/g BDE-209 acute exposure induced a 20% decline of NO X -N (the sum of NO 3 − –N and NO 2 − –N) removal efficiency and a significant accumulation of NO 2 − –N and N 2 O. These inhibitory effects presented in a BDE-209 concentration-dependent manner. Using a semi-continuous microcosm, the inhibitory effects of BDE-209 on denitrification were observed to be significantly enhanced with the extending of exposure duration. Denitrifying genes assay illustrated that BDE-209 has an insignificant effect on the global abundance of denitrifying bacteria because of microbial exchange with its overlying water. But the utilization of electron donor (carbon substrate), the activity of electron transport system and denitrifying enzymes were significantly inhibited by BDE-209 exposure in a exposure-duration-dependent manner. Finally, insufficient electron donor and lower efficiency of electron transport and utilization on denitrifying enzymes deteriorated the denitrification performance. These results provided a new insight into BDE-209 influence on denitrification in the natural environment.
研究领域:
环境科学
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微生物学
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生态毒理学
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DOI
PubMed
高影响因子
AMB Express
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2018
·Vol. 8
·期 1
·1-8
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IF 1.719
Guo Yaping,Chang Hui,Wang Qiaoling,Shao Chenjia,Xu Jianmiao
Acrylonitrile (C3H3N) widely used in chemical raw materials has biological toxicity with –CN bond, so it is the key to removal of cyanide from acrylonitrile wastewater. In our previous research and investigation, a strain was identified as Arthrobacter nitroguajacolicus named ZJUTB06-99 and was proved to be capable of degrading acrylonitrile. In this paper, the strain ZJUTB06-99 was domesticated with acrylonitrile-containing medium and its decyanidation and denitrification in simulated acrylonitrile wastewater were studied. The intermediate product of acrylonitrile in degradation process was identified through gas chromatography–mass spectrometer, as well as the biodegradation pathway of acrylonitrile in wastewater was deduced tentatively. The kinetics equation of biodegradation of acrylonitrile was lnC = − 0.1784t + 5.3349, with the degradation half-life of acrylonitrile in wastewater by 3.885 h. The results of this study showed that the optimum levels of temperature, pH and bacteria concentration to attain the maximum biodegradation were obtained as 30 °C, 6 and 100 g/L, respectively. The disadvantages of the biodegradation with this strain and its possible enhanced method to degrade acrylonitrile in wastewater were also discussed.
研究领域:
环境科学
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微生物学
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DOI
高影响因子
DESALINATION
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2024
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IF 8.3
Xiaojing Zhang,Yujia Guo,Bingbing Ma,Ang Gao,Jiahui Nie,Chenyu Jia,Peng Zhou,Yongpeng Ma
Naproxen (NPX) has been frequently detected in various nitrogenous wastewaters and been proved have significant impact on nitrogen removal systems. Completely autotrophic nitrogen removal over nitrite (CANON) process was one of the most economical nitrogen removal technologies and has good application prospect. However, whether it was suitable for treating NPX containing wastewater was still unclear. This study investigated the migration of NPX in CANON process by adopting a membrane bioreactor (MBR), and analyzed its impact on the nitrogen removal and microbial characteristics by suppling incremental NPX. The results showed the NPX supplied in 0.001 to 1000 μg L −1 was mainly bio-adsorbed by the sludge, which then led to continuous suppression on anaerobic ammonium-oxidizing bacteria (AAOB) and decreased the TN removal from 79.1 % to 50.6 %. Additionally, the activity of hydroxylamine oxidoreductase and nitrite oxidoreductase enzymes both decreased. However, the abundance of AAOB and the functional gene hzsB initially increased as a stress response. Ammonia-oxidizing bacteria (AOB) were slightly impacted and then adapted, with the amoA gene amplifying 2.3 times and the abundance of Nitrosomonas increasing from 2.4 % to 4.0 %. Nitrite-oxidizing bacteria (NOB) were significantly enhanced, leading to an increase in effluent nitrate concentration from 34.7 to 101.6 mg L −1 , and in the abundance of Nitrospira from 2.2 % to 13.5 %. The enhancement in NOB significantly limited the AAOB activity in return via competing nitrite, and further limited the TN removal. Denitrifying bacteria experienced only slight impact, with the expression of narG , nirK , and nirS genes slightly fluctuated. It is essential to thoroughly washout NOB and introduce additional strategy for enhancing NPX biodegradation for stable operation of the CANON process when treating NPX containing wastewater.
研究领域:
环境工程
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微生物学
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污水处理
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DOI
高影响因子
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