Nitrogen removal performance and metabolic pathways analysis of a novel aerobic denitrifying halotolerant Pseudomonas balearica strain RAD-17

• 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. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Industriell bioteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Industrial Biotechnology (hsv//eng)

Keyword

aerobic denitrification

Pseudomonas balearica RAD-17

nitrogen removal

metabolic pathways

bioaugmentation

Resursåtervinning

Resource Recovery

Publication and Content Type

ref (subject category)

art (subject category)