Nitrogen Removal Performance and Metabolic Pathways Analysis of a Novel Aerobic Denitrifying Halotolerant Pseudomonas balearica Strain RAD-17

Abstract

An aerobic denitrification strain, Pseudomonas balearica RAD-17, was identified and showed efficient inorganic nitrogen removal ability. The average NO3−-N, NO2−-N, and total ammonium nitrogen (TAN) removal rate (>95% removal efficiency) in a batch test was 6.22 mg/(L∙h), 6.30 mg/(L∙h), and 1.56 mg/(L∙h), respectively. Meanwhile, optimal incubate conditions were obtained through single factor experiments. For nitrogen removal pathways, the transcriptional results proved that respiratory nitrate reductases encoded by napA, which was primarily performed in aerobic denitrification and cell assimilation, were conducted by gluS and gluD genes for ammonium metabolism. In addition, adding the strain RAD-17 into actual wastewater showed obvious higher denitrification performance than in the no inoculum group (84.22% vs. 22.54%), and the maximum cell abundance achieved 28.5 ± 4.5% in a ratio of total cell numbers. Overall, the efficient nitrogen removal performance plus strong environmental fitness makes the strain RAD-17 a potential alternative for RAS (recirculating aquaculture system) effluent treatment.

Multi-Strain Tropical Bacillus spp. as a Potential Probiotic Biocontrol Agent for Large-Scale Enhancement of Mariculture Water Quality

“…( Dawood et al, 2020 ; Zheng et al, 2020 ), and Pseudomonas spp. ( Ruan et al, 2020 ; Zhang et al, 2020 ), especially Bacillus spp. ( Barman et al, 2018 ; Gao et al, 2018 ), have advantages to the enhancement of aquaculture water quality.…”

Performance of Aerobic Denitrification by the Strain Pseudomonas balearica RAD-17 in the Presence of Antibiotics

“…The strain RAD-17, employed in the current research, was isolated from a PBS (poly-butylene succinate) based denitrification reactor for the treatment of aquaculture effluent. The operating conditions for the reactor can be found in [ 22 ], and information on the isolation and identification of this strain is available in our previous report [ 23 ]. The strain RAD-17 was identified as Pseudomonas balearica ( P. balearica ), based on 16S rRNA phylogenetic analysis with the Accession Number NCB: MK881511.…”

“…In addition, according to the complete genome sequence results (NCBI: PRJNA599547), gene annotation, and KEGG pathway results, the strain RAD-17 embodies a series of genes for denitrification under aerobic conditions. Under aerobic conditions, nitrate-nitrogen (NO 3 − –N) and nitrite nitrogen (NO 2 − –N) can be removed at rates of 6.22 mg L −1 h −1 and 6.30 mg L −1 h −1 , respectively [ 23 ]. Furthermore, the maximum nitrate reduction rate can be as high as 21.7 mg L −1 h −1 [ 25 ].…”

“…Research on the effect of TCs on denitrification is very limited and has mainly focused on the matrices of bioreactors [ 17 , 18 , 19 , 20 ], wastewater treatment plants (WWTPs) [ 21 ], and activated sludge [ 18 , 20 ]. However, contradictory conclusions were found for these research [ 22 , 23 ]. The effect of TCs on denitrification is usually dose-dependent, and most studies have demonstrated that denitrification is unaffected by TCs present at environmentally relevant concentrations [ 1 ].…”

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

“…To date, numerous bacteria with excellent capability of inorganic nitrogen removal have been reported, and research focused on separation, identi cation, culture, and application of single functional strain has been conducted (Chen et al, 2019;Yang et al, 2015).Such as, Xu (Xu et al, 2017) isolated a strain of Pseudomonas putida Y-9 with simultaneous nitri cation and denitri cation, and the average removal rates of ammonia, nitrate and nitrite were 2.85 mg/(L•h -1 ), 1.60 mg/(L•h -1 ), and 1.83mg/(L•h -1 ), respectively. Ruan (Ruan et al, 2020) isolated an aerobic denitrifying bacteria, the average NO 3 --N, NO 2 --N, and total ammonium nitrogen (TAN) removal rate (>95% removal e ciency) in a batch test was 6.22 mg/(L•h -1 ), 6.30 mg/(L•h -1 ) and 1.56 mg/(L•h -1 ), respectively. And revealed its metabolic pathway by qRT-PCR.…”