Enhanced nitrogen removal from low-temperature wastewater by an iterative screening of cold-tolerant denitrifying bacteria

2021 ◽  
Author(s):  
Jin Qu ◽  
Ruojin Zhao ◽  
Yinyan Chen ◽  
Yiyi Li ◽  
Peng Jin ◽  
...  
Keyword(s):  
Low Temperature ◽  
Nitrogen Removal ◽  
Denitrifying Bacteria ◽  
Cold Tolerant

scholarly journals Enhanced Nitrogen Removal of Wastewater at Low Temperature by Iterative Screening of Cold-Tolerant Denitrifying Bacteria

2021 ◽  
Author(s):  
Jin Qu ◽  
Zhanwang zheng ◽  
Ruojin Zhao ◽  
Yinyan Chen ◽  
Yiyi Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Nitrogen Removal ◽  
Domestic Wastewater ◽  
Specific Pcr ◽  
Moraxella Osloensis ◽  
Cold Tolerant ◽  
Nitrite Removal ◽  
Balance Analysis ◽  
Nitrification And Denitrification ◽  
Nitrate And Nitrite

Abstract The biological denitrification for wastewater treatment in winter is often seriously compromised due to the effects of low-temperature (<13 °C) on metabolic activity of microorganism. In this study, an excellent cold-tolerant denitrifying bacterium, Moraxella osloensis LT-01 was isolated by iterative domestication. The strain LT-01 retained about 60% maximal growth activity at 10 °C. Under initial concentrations of 100 mg/L, average ammonium, nitrate and nitrite removal efficiencies for domestic wastewater (C/N 4:1) at 10 °C were 70.35%, 65.39% and 61.74% in 24 h, respectively. Nitrogen balance analysis showed that about 46% of TN was directed toward in the dissimilation form of gas, and 16% of TN was assimilated for cell growth. Key genes hydroxylamine reductase gene (HAO) and nitrite reductase (NirS) involved in nitrification and denitrification processes were identified by gene-specific PCR, indicating that strain LT-01 perform nitrogen removal efficiently via unique simultaneous nitrification and denitrification. These results suggest the bacterium LT-01 has great potential as an effective performer for treating domestic wastewater in winter.

scholarly journals Start-up Strategies for Anaerobic Ammonia Oxidation (Anammox) in In-Situ Nitrogen Removal from Polluted Groundwater in Rare Earth Mining Areas

2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Ex Situ ◽  
High Concentration ◽  
Low Concentration ◽  
Start Up ◽  
Anammox Activity

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.

Screening and Influencing Factors of Halophilic Denitrifying Bacteria

2012 ◽  
Vol 550-553 ◽  
pp. 1455-1459
Author(s):  
Jing Tang ◽  
Hong Ming E ◽  
Jin Xiang Fu ◽  
Jin Nan Chen ◽  
Ming Fan
Keyword(s):  
Nitrogen Removal ◽  
Morphological Characteristics ◽  
Development Trend ◽  
Denitrifying Bacteria ◽  
High Salt ◽  
Research Progress ◽  
Saline Wastewater ◽  
Carbon And Nitrogen ◽  
Petroleum Chemical ◽  
Seafood Processing

With nitrite or nitrate nitrogen as electron acceptor in the high salt conditons, halophilic denitrifying bacteria can transfer nitrite or nitrate to nitrogen, thereby purifying the high-salt wastewater. Halophilic denitrifying bacteria play an important role in the carbon and nitrogen removal of saline wastewater, such as petroleum, chemical industry, seafood processing and seafood farming. This article dissussed halophilic denitrifying bacteria screening, the main types and the corresponding morphological characteristics, then we focused on the research progress of main factors of halophilic denitrifying bacteria’s growth and nitrogen removal. Finally put forward the current problems of the research and development trend of halophilic denitrifying bacteria.

scholarly journals Identification of cold stress responsive microRNAs in cold tolerant and susceptible Hemerocallis fulva by high throughput sequencing

2020 ◽  
Author(s):  
Changbing Huang ◽  
Chun Jiang ◽  
limin Jin ◽  
Huanchao Zhang
Keyword(s):  
Low Temperature ◽  
Cold Stress ◽  
Cold Tolerance ◽  
Temperature Stress ◽  
Stress Responses ◽  
Target Genes ◽  
Low Temperature Stress ◽  
Differentially Expressed ◽  
Differentially Expressed Mirnas ◽  
Cold Tolerant

Abstract Background:Hemerocallis fulva is a perennial herb belonging to Hemerocallis of Hemerocallis. Because of the large and bright colors, it is often used as a garden ornamental plant. But most varieties of H. fulva on the market will wither in winter, which will affect their beauty. It is very important to study the effect of low temperature stress on the physiological indexes of H. fulva and understand the cold tolerance of different H. fulva. MiRNA is a kind of endogenous non coding small molecular RNA with length of 21-24nt. It mainly inhibits protein translation by cutting target genes, and plays an important role in the development of organisms, gene expression and biological stress. Low temperature is the main abiotic stress affecting the production of H. fulva in China, which hinders the growth and development of plants. A comprehensive understanding of the expression pattern of microRNA in H. fulva under low temperature stress can improve our understanding of microRNA mediated stress response. Although there are many studies on miRNAs of various plants under cold stress at home and abroad, there are few studies on miRNAs related to cold stress of H. fulva. It is of great significance to explore the cold stress resistant gene resources of H. fulva, especially the identification and functional research of miRNA closely related to cold stress, for the breeding of excellent H. fulva.Results A total of 5619 cold-responsive miRNAs, 315 putative novel and 5 304 conserved miRNAs, were identified from the leaves and roots of two different varieties ‘Jinyan’ (cold-tolerant) and ‘Lucretius ’ (cold-sensitive), which were stressed under -4 oC for 24 h. Twelve conserved and three novel miRNAs (novel-miR10, novel-miR19 and novel-miR48) were differentially expressed in leaves of ‘Jinyan’ under cold stress. Novel-miR19, novel-miR29 and novel-miR30 were up-regulated in roots of ‘Jinyan’ under cold stress. Thirteen and two conserved miRNAs were deferentially expressed in leaves and roots of ‘Lucretius’ after cold stress. The deferentially expressed miRNAs between two cultivars under cold stress include novel miRNAs and the members of the miR156, miR166 and miR319 families. A total of 6 598 target genes for 6 516 known miRNAs and 82 novel miRNAs were predicted by bioinformatic analysis, mainly involved in metabolic processes and stress responses. Ten differentially expressed miRNAs and predicted target genes were confirmed by quantitative reverse transcription PCR(q-PCR), and the expressional changes of target genes were negatively correlated to differentially expressed miRNAs. Our data indicated that some candidate miRNAs (e.g., miR156a-3-p, miR319a, and novel-miR19) may play important roles in plant response to cold stress.Conclusions Our study indicates that some putative target genes and miRNA mediated metabolic processes and stress responses are significant to cold tolerance in H. fulva.

scholarly journals Comparative transcriptome analysis of the cold resistance of the sterile rice line 33S

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0261822
Author(s):  
Hongjun Xie ◽  
Mingdong Zhu ◽  
Yaying Yu ◽  
Xiaoshan Zeng ◽  
Guohua Tang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cold Resistance ◽  
Temperature Response ◽  
Enrichment Analysis ◽  
Abiotic Factor ◽  
Comparative Transcriptome ◽  
Important Species ◽  
Expression Of Genes ◽  
Nutrient Reserve ◽  
Cold Tolerant

Rice (Oryza sativa L.) is one of the most important species for food production worldwide. Low temperature is a major abiotic factor that affects rice germination and reproduction. Here, the underlying regulatory mechanism in seedlings of a TGMS variety (33S) and a cold-sensitive variety (Nipponbare) was investigated by comparative transcriptome. There were 795 differentially expressed genes (DEGs) identified only in cold-treated 33S, suggesting that 33S had a unique cold-resistance system. Functional and enrichment analysis of these DEGs revealed that, in 33S, several metabolic pathways, such as photosynthesis, amino acid metabolism, secondary metabolite biosynthesis, were significantly repressed. Moreover, pathways related to growth and development, including starch and sucrose metabolism, and DNA biosynthesis and damage response/repair, were significantly enhanced. The expression of genes related to nutrient reserve activity were significantly up-regulated in 33S. Finally, three NAC and several ERF transcription factors were predicted to be important in this transcriptional reprogramming. This present work provides valuable information for future investigations of low-temperature response mechanisms and genetic improvement of cold-tolerant rice seedlings.

scholarly journals Evaluation of a novel low-carbon to nitrogen- and temperature-tolerant simultaneously nitrifying–denitrifying bacterium and its use in the treatment of river water

RSC Advances ◽  
2018 ◽  
Vol 8 (48) ◽  
pp. 27417-27422 ◽  
Author(s):  
Peng Jin ◽  
Yinyan Chen ◽  
Zhanwang Zheng ◽  
Qizhen Du
Keyword(s):  
Low Temperature ◽  
River Water ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Simultaneous Nitrification And Denitrification ◽  
Low Carbon ◽  
High Nitrogen ◽  
Denitrifying Bacterium ◽  
Nitrification And Denitrification

A novel simultaneous nitrification and denitrification Klebsiella sp. exhibits high nitrogen removal efficiency under low-temperature and low C/N wastewater.

scholarly journals Genetic Dissection of Germinability under Low Temperature by Building a Resequencing Linkage Map in japonica Rice

2020 ◽  
Vol 21 (4) ◽  
pp. 1284 ◽  
Author(s):  
Shukun Jiang ◽  
Chao Yang ◽  
Quan Xu ◽  
Lizhi Wang ◽  
Xianli Yang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Genetic Distance ◽  
Recombinant Inbred Lines ◽  
Seed Vigor ◽  
Japonica Rice ◽  
Rice Breeding ◽  
Positive Effects ◽  
Comparison Results ◽  
Cold Tolerant ◽  
Bin Map

Among all cereals, rice is highly sensitive to cold stress, especially at the germination stage, which adversely impacts its germination ability, seed vigor, crop stand establishment, and, ultimately, grain yield. The dissection of novel quantitative trait loci (QTLs) or genes conferring a low-temperature germination (LTG) ability can significantly accelerate cold-tolerant rice breeding to ensure the wide application of rice cultivation through the direct seeding method. In this study, we identified 11 QTLs for LTG using 144 recombinant inbred lines (RILs) derived from a cross between a cold-tolerant variety, Lijiangxintuanheigu (LTH), and a cold-sensitive variety, Shennong265 (SN265). By resequencing two parents and RIL lines, a high-density bin map, including 2,828 bin markers, was constructed using 123,859 single-nucleotide polymorphisms (SNPs) between two parents. The total genetic distance corresponding to all 12 chromosome linkage maps was 2,840.12 cm. Adjacent markers were marked by an average genetic distance of 1.01 cm, corresponding to a 128.80 kb physical distance. Eight and three QTL alleles had positive effects inherited from LTH and SN265, respectively. Moreover, a pleiotropic QTL was identified for a higher number of erected panicles and a higher grain number on Chr-9 near the previously cloned DEP1 gene. Among the LTG QTLs, qLTG3 and qLTG7b were also located at relatively small genetic intervals that define two known LTG genes, qLTG3-1 and OsSAP16. Sequencing comparisons between the two parents demonstrated that LTH possesses qLTG3-1 and OsSAP16 genes, and SN-265 owns the DEP1 gene. These comparison results strengthen the accuracy and mapping resolution power of the bin map and population. Later, fine mapping was done for qLTG6 at 45.80 kb through four key homozygous recombinant lines derived from a population with 1569 segregating plants. Finally, LOC_Os06g01320 was identified as the most possible candidate gene for qLTG6, which contains a missense mutation and a 32-bp deletion/insertion at the promoter between the two parents. LTH was observed to have lower expression levels in comparison with SN265 and was commonly detected at low temperatures. In conclusion, these results strengthen our understanding of the impacts of cold temperature stress on seed vigor and germination abilities and help improve the mechanisms of rice breeding programs to breed cold-tolerant varieties.

Biological Nitrogen Removal under Low Temperature in a Membrane Separation Bioreactor

1993 ◽  
Vol 28 (10) ◽  
pp. 325-333 ◽  
Author(s):  
C. Chiemchaisri ◽  
K. Yamamoto
Keyword(s):  
Low Temperature ◽  
Nitrogen Removal ◽  
Oxygen Transfer ◽  
Membrane Separation ◽  
Nitrifying Bacteria ◽  
Biological Nitrogen Removal ◽  
Nitrification Rate ◽  
Temperature Decrease ◽  
Operational Cycle ◽  
Biological Nitrogen

Biological nitrogen removal under low temperature in a membrane separation bioreactor for on-site domestic wastewater treatment was studied. The bioreactor was operated under intermittent aeration of a 180-minute operational cycle to achieve simultaneous nitrification and denitrification for nitrogen removal. During stepwise temperature decrease from 25°C to 5°C at every two weeks duration, nitrogen removal started to deteriorate as temperature dropped to 10°C. It decreased from more than 90% at 25°C to 20% at 5°C as a result of inhibition of nitrification at low temperature. However, increasing oxygen supply, i.e. increasing aeration time in operational cycle, could completely recover nitrification at 10°C. Nitrogen removal could be achieved by introducing non-aeration period after complete nitrification was obtained. Average nitrogen removal was 90 and 85% under 10 and 5°C respectively. The results indicated that sufficient oxygen transfer could be maintained in the membrane separation bioreactor even if the temperature was as low as 5°C. Analysis of respiratory quinone component of sludge suggested the decrease of strict aerobic bacteria percentage in mixed liquor during temperature decrease and increase of their percentage during the recovery of nitrification at 10°C. These changes could be related to the nitrification through the changes of oxygen transfer condition in the system. Insignificant difference of maximum volumetric nitrification rate obtained at 25 and 5°C probably suggests that there was not much difference in oxygen availability for nitrifying bacteria between both the temperatures once high and stable nitrogen removal was achieved.

Photosynthesis, photoinhibition and low temperature acclimation in cold tolerant plants

1993 ◽  
Vol 37 (1) ◽  
pp. 19-39 ◽  
Author(s):  
Norman P. A. Huner ◽  
Gunnar Öquist ◽  
Vaughan M. Hurry ◽  
Marianna Krol ◽  
Stefan Falk ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Acclimation ◽  
Tolerant Plants ◽  
Cold Tolerant

scholarly journals Chromatin-Level Differences Elucidate Potential Determinants of Contrasting Levels of Cold Sensitivity in Maize Lines

2020 ◽  
Author(s):  
Maciej Jończyk ◽  
Alicja Sobkowiak ◽  
Joanna Trzcinska-Danielewicz ◽  
Paweł Sowiński
Keyword(s):  
Low Temperature ◽  
Cold Stress ◽  
Photosynthetic Apparatus ◽  
Regulatory Elements ◽  
Cold Sensitivity ◽  
Regulatory Sequences ◽  
Physiological Level ◽  
Cold Tolerant ◽  
Tolerant Line ◽  
Cold Sensitive

Abstract Maize is a subtropical, cold-sensitive species. However, some varieties of this species have the potential to withstand long-term low temperatures, even at the seedling stage. The molecular basis of this phenomenon has not been determined. In a chromatin-level study, we compared the cold-stress reaction of seedlings of two maize inbred lines showing contrasting levels of cold sensitivity. The cold-tolerant line was selected based on field data and previous physiological and transcriptomic level studies. The first condition of gene expression—chromatin accessibility—was assessed by formaldehyde-aided isolation of regulatory elements method and DNA sequencing. Potentially expressed genes and cis-regulatory sequences open for interaction with transcription factors have been defined. The results of this study suggest that during cold stress, the tolerant maize line shifted resources from growth to defense. This shift was shown by potential hormone-level events—degradation of growth-promoting gibberellins and synthesis of jasmonic and abscisic acids. This finding is congruent with the xeromorphic morphology of seedlings of the cold-tolerant line and their ability to regrow when stress ceases. It is a common reaction of cold-tolerant maize lines. Moreover, in the cold-tolerant line, several genes from the low-temperature signaling pathways were potentially expressed. Additionally, numerous stress-response AP2/EREBP-binding cis-motifs were accessible in the cold-tolerant line. Differently in the cold-sensitive B73 line, MADS-binding cis-motifs were the most abundant. Development of the photosynthetic apparatus is crucial for the survival of maize seedlings at low temperature. Our results suggest efficient photosynthesis in seedlings of the cold-tolerant line, as was described earlier in physiological-level analyses.

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