Nitrogen removal by a metal‐resistant bacterium, Pseudomonas putida ZN1, capable of heterotrophic nitrification–aerobic denitrification

Abstract

BACKGROUND Bacteria capable of heterotrophic nitrification–aerobic denitrification have received increasing attention, and can achieve simultaneous nitrification and denitrification processes to accelerate nitrogen removal rate. However, heavy metals in industrial wastewater seriously affect the nitrogen removal by these bacteria. Thus, this work focused on the nitrogen removal ability of a metal‐resistant bacterium Pseudomonas putida ZN1. RESULTS ZN1 effectively removed ammonium, nitrate and nitrite with maximum removal efficiencies of 97.47%, 86.08% and 71.57%, and it also preferred to utilize ammonium during the simultaneous nitrification and denitrification process. The inhibitory effect of heavy metals on ammonium removal decreased in the order Ni2+ > Cr6+ > Zn2+ > Cu2+, and copB‐I was responsible for the higher copper tolerance of ZN1. The nitrogen removal pathway of ZN1 was proposed to be heterotrophic nitrification combined with aerobic denitrification through the nitrogen source utilization, gas detection, enzyme assay and gene amplification. CONCLUSION ZN1 exhibited excellent heterotrophic nitrification and aerobic denitrification capacity, and it effectively removed ammonium from wastewater containing the heavy metals Cu2+, Zn2+, Cr6+ and Ni2+. All results make strain ZN1 a promising candidate for future application in treating actual wastewater. © 2018 Society of Chemical Industry

Denitrification performance of Pseudomonas fluorescens Z03 immobilized by graphene oxide-modified polyvinyl-alcohol and sodium alginate gel beads at low temperature

“…As is shown in figure 4, the amount of GO added has no effect on the intermediates of heterotrophic nitrification. Almost no accumulation of nitrite, nitrate or other intermediates occurs throughout the whole heterotrophic nitrification process, which is consistent with results found for Pseudomonas putida ZN1 [27] and Klebsiella sp. TN-10 [28].…”

Role of heterotrophic aerobic denitrifying bacteria in nitrate removal from wastewater

“…and Pseudomonas taiwanensis using glucose. Zhang et al () studied the effect of different C/N ratios and concluded that the C/N ratio of 16 with citrate as the carbon source was most conducive for nitrogen removal, which is much higher than other heterotrophs. This suggests that these species can be used in wastewater treatment plant with high organic loads.…”

“…Metal‐resistant Pseudomonas putida with nitrogen removal ability was isolated from the coking industry (Zhang et al ). It showed high capacity for nitrogen removal and high tolerance to metal ions.…”

Enhanced nitrogen removal of low C/N wastewater using a novel microbial fuel cell (MFC) with Cupriavidus sp. S1 as a biocathode catalyst (BCS1)

“…To date, bacteria with this capability has been found extensively, namely Pseudomonas putida ZN1, Vibrio diabolicus SF16, Pseudomonas stutzeri YG‐24, Zobellella taiwanensis DN‐7 and Cupriavidus sp. S1 . The high total nitrogen (TN) removal efficiency of above 90% was usually obtained under aerobic condition.…”

“…S1. [4][5][6][7][8] The high total nitrogen (TN) removal efficiency of above 90% was usually obtained under aerobic condition. Given these positive characteristics, they serve as a promising alternative for other traditional wastewater nitrogen removal processes.…”