Pseudomonas mendocina LYX: A novel aerobic bacterium with advantage of removing nitrate high effectively by assimilation and dissimilation simultaneously

Abstract

• Pseudomonas mendocina was first reported for aerobic nitrate removal.

• It removed 90% of NO₃⁻-N in 24 h under aerobic conditions.

• This strain converted NO₃⁻-N to bio-nitrogen (37.9%) and gaseous nitrogen (49.7%).

• Inoculation of this strain increased sludge denitrification rate by 4.3 times.

The problem of nitrate accumulation in aerobic tank and total nitrogen excessive discharge in effluent was very common in traditional livestock and poultry farming wastewater treatment systems owing to the lengthy process flow and low process control level. A strain LYX of aerobic bacterium was isolated from the activated sludge of a wastewater treatment system in a pig farm, which could remove nitrate effectively in aerobic tank and was identified Pseudomonas mendocina by 16S rRNA sequencing. Under the condition of nitrate as the sole nitrogen source, this strain removed over 90% of NO₃⁻-N with an initial concentration of 110 mg/L under aerobic conditions within 48 hours. Among them, 37.9% of NO₃⁻-N was assimilated into Bio-N, about 51.9% was reduced to gaseous nitrogen and less than 0.5% of nitrogen was replaced by NO₂⁻-N and NH₄⁺-N, 9.7% NO₃⁻-N remained in the effluent at the end. At the same time, four key genes (napA, nirK, norB and nosZ) related to nitrate nitrogen removal were expressed during the denitrification process of P. mendocina LYX, in which the transcription level of the indicator genes of this aerobic denitrifying bacterium (napA) was the highest. In addition, it was found with the ¹⁵N tracer technique that inoculation of this strain on sludge increased the amount of nitrogen loss from 9.26 nmol N/(g·h) to 23.835 nmol N/(g·h). Therefore, P. medocina LYX is a potential bioagent for advanced nitrogen removal by assimilating and reducing nitrate simultaneously in aerobic tanks.

Graphical abstract

Keywords

Pseudomonas mendocina / Aerobic nitrate removal / ¹⁵N tracing technique / Denitrification assimilatively and disimilatively / Aerobic denitrifying genes

References

[1] APAH (2005). Standard Methods for the Examination of Water and Wastewater. Washington, DC: American Public Health Administration

[2] Bai H, Liao S, Wang A, Huang J, Shu W, Ye J (2019). High-efficiency inorganic nitrogen removal by newly isolated Pannonibacter phragmitetus B1. Bioresource Technology, 271: 91–99

[3] Berks B C, Richardson D J, Robinson C, Reilly A, Aplin R T, Ferguson S J (1994). Purification and characterization of the periplasmic nitrate reductase from Thiosphaera pantotropha. European Journal of Biochemistry, 220(1): 117–124

[4] Bi Z, Wanyan D Q, Li X, Huang Y (2020). Biological conversion pathways of sulfate reduction ammonium oxidation in anammox consortia. Frontiers of Environmental Science & Engineering, 14(3): 38

[5] Bouchez T, Patureau D, Delgenès J P, Moletta R (2009). Successful bacterial incorporation into activated sludge flocs using alginate. Bioresource Technology, 100(2): 1031–1032

[6] Bousselhaj K, Fars D, Laghmari A, Nejmeddine A, Ouazzani N, Ciavatta C (2004). Nitrogen fertilizer value of sewage sludge co-composts. Agronomie, 24(8): 487–492

[7] CEPB(China Environmental Protection Bureau) (2002). Standard Methods for Examination of Water and Wastewater. Beijing: Chinese Environmental Science Press

[8] Henderson S L, Dandie C E, Patten C L, Zebarth B J, Burton D L, Trevors J T, Goyer C (2010). Changes in denitrifier abundance, denitrification gene mRNA levels, nitrous oxide emissions, and denitrification in anoxic soil microcosms amended with glucose and plant residues. Applied and Environmental Microbiology, 76(7): 2155–2164

[9] Hu Z, Zhang J, Li S, Xie H (2013). Impact of carbon source on nitrous oxide emission from anoxic/oxic biological nitrogen removal process and identification of its emission sources. Environmental Science and Pollution Research International, 20(2): 1059–1069

[10] Khardenavis A A, Kapley A, Purohit H J (2007). Simultaneous nitrification and denitrification by diverse Diaphorobacter sp. Applied Microbiology and Biotechnology, 77(2): 403–409

[11] Knapp C W, Dodds W K, Wilson K C, O’brien J M, Graham D W (2009). Spatial heterogeneity of denitrification genes in a highly homogenous urban stream. Environmental Science & Technology, 43(12): 4273–4279

[12] Lei X, Jia Y, Chen Y, Hu Y (2019). Simultaneous nitrification and denitrification without nitrite accumulation by a novel isolated Ochrobactrum anthropic LJ81. Bioresource Technology, 272: 442–450

[13] Li B, Wang Y, Li J, Yang L, Li X, Zhou Z, Li Y, Chen X, Wu L (2019 ). The symbiosis of anaerobic ammonium oxidation bacteria and heterotrophic denitrification bacteria in a size-fractioned single-stage partial nitrification/anammox reactor. Biochemical Engineering Journal, 151: 107353

[14] Massara . TM, Malamis . S, Guisasola. A, Baeza J A, Noutsopoulos C,Katsou E (2017).A review on nitrous oxide (N₂O) emissions during biological nutrient removal from municipal wastewater and sludge reject water. Science of The Total Environment, 596 :106–123

[15] Miyahara M, Kim S W, Fushinobu S, Takaki K, Yamada T, Watanabe A, Miyauchi K, Endo G, Wakagi T, Shoun H (2010). Potential of aerobic denitrification by Pseudomonas stutzeri TR2 to reduce nitrous oxide emissions from wastewater treatment plants. Applied and Environmental Microbiology, 76(14): 4619–4625

[16] Pan Y, Ni B J, Bond P L, Ye L, Yuan Z (2013). Electron competition among nitrogen oxides reduction during methanol-utilizing denitrification in wastewater treatment. Water Research, 47(10): 3273–3281

[17] Philippot L (2002). Denitrifying genes in bacterial and Archaeal genomes. Biochimica et Biophysica Acta- Gene Structure and Expression, 1577(3): 355–376

[18] Rajta A, Bhatia R, Setia H, Pathania P (2020). Role of heterotrophic aerobic denitrifying bacteria in nitrate removal from wastewater. Journal of Applied Microbiology, 128(5):1261–1278

[19] Takaya N, Catalan-Sakairi M, Sakaguchi Y, Kato I, Zhou Z, Shoun H(2003). Aerobic denitrifying bacteria that produce low levels of nitrous oxide. Applied and Environmental Microbiology, 69(6): 3152–3157

[20] Su J F, Yang S, Huang T L, Li M, Liu J R, Yao Y X (2020). Enhancement of the denitrification in low C/N condition and its mechanism by a novel isolated Comamonas sp. YSF15. Environmental Pollution, 256: 113294

[21] Sun S, Cheng X, Sun D (2013). Emission of N₂O from a full-scale sequencing batch reactor wastewater treatment plant: Characteristics and influencing factors. International Biodeterioration & Biodegradation, 85(7): 545–549

[22] Van Doan T, Lee T K, Shukla S K, Tiedje J M, Park J (2013). Increased nitrous oxide accumulation by bioelectrochemical denitrification under autotrophic conditions: Kinetics and expression of denitrification pathway genes. Water Research, 47(19): 7087–7097

[23] Wood D W, Setubal J C, Kaul R, Monks D E, Kitajima J P, Okura V K, Zhou Y, Chen L S, Wood G E, Almeida N F, Woo L, Chen Y C, Paulsen I T, Eisen J A, Karp P D, Bovee D, Chapman P, Clendenning J, Deatherage G, Gillet W, Grant C, Kutyavin T, Levy R, Li M J, McClelland E, Palmieri A, Raymond C, Rouse G, Saenphimmachak C, Wu Z, Romero P, Gordon D, Zhang S P, Yoo H, Tao Y M, Biddle P, Jung M, Krespan W, Perry M, Gordon-Kamm B, Liao L, Kim S, Hendrick C, Zhao Z Y, Dolan M, Chumley F, Tingey S V, Tomb J F, Gordon M P, Olson M V, Nester E W (2001). The genome of the natural genetic engineer Agrobacterium tumefaciens C58. Science, 294(5550): 2317–2323

[24] Wang X J, Wang W Q, Zhang Y, Sun Z T, Zhang J, Chen G H, Li J (2019) Simultaneous nitrification and denitrification by a novel isolated Pseudomonas sp. JQ-H3 using polycaprolactone as carbon source. Bioresource Technology, 288:121506

[25] Wu J, Hong Y, Ye J, Li Y, Liu X, Jiao L, Li T, Li Y, Bin L, Wang Y (2019). Diversity of anammox bacteria and contribution to the nitrogen loss in surface sediment. International Biodeterioration & Biodegradation, 142: 227–234

[26] Xu Z, Dai X, Chai X (2018). Effect of different carbon sources on denitrification performance, microbial community structure and denitrification genes. Science of the Total Environment, 634: 195–204

[27] Yao S, Ni J, Chen Q, Borthwick A G L (2013). Enrichment and characterization of a bacteria consortium capable of heterotrophic nitrification and aerobic denitrification at low temperature. Bioresource Technology, 127: 151–157

[28] Zhang J, Jia W, Wang R, Ngo H H, Guo W, Xie H, Liang S (2016). Microbial community characteristics during simultaneous nitrification-denitrification process: Effect of COD/TP ratio. Environmental Science and Pollution Research International, 23(3): 2557–2565

[29] Zhang M Y, Pan L Q, Liu L P, Su C, Dou L, Su Z P, He Z Y (2020). Phosphorus and nitrogen removal by a novel phosphate-accumulating organism, Arthrobacter sp. CEPF HHEP5 capable of heterotrophic nitrificationaerobic denitrification: Safety assessment, removal characterization, mechanism exploration and wastewater treatment. Bioresource Technology, 312:123633

[30] Zhang Q L, Liu Y, Ai G M, Miao L L, Zheng H Y, Liu Z P (2012). The characteristics of a novel heterotrophic nitrification–aerobic denitrification bacterium, Bacillus methylotrophicus strain L7. Bioresource Technology, 108(3): 35–44

[31] Zhang Y, Wang Y Y, Yan Y, Han H C, Wu M (2019). Characterization of CANON reactor performance and microbial community shifts with elevated COD/N ratios under a continuous aeration mode. Frontiers of Environmental Science & Engineering, 13(1): 7

[32] Zhao B, He Y L, Hughes J, Zhang X F (2010). Heterotrophic nitrogen removal by a newly isolated Acinetobacter calcoaceticus HNR. Bioresource Technology, 101(14): 5194–5200

RIGHTS & PERMISSIONS

Higher Education Press