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. 2018 May 17:18:e00257.
doi: 10.1016/j.btre.2018.e00257. eCollection 2018 Jun.

NAP enzyme recruitment in simultaneous bioremediation and nanoparticles synthesis

Marwa Eltarahony  1 , Sahar Zaki  1 , Zeinab Kheiralla  2 , Desouky Abd-El-Haleem  1
Affiliations

NAP enzyme recruitment in simultaneous bioremediation and nanoparticles synthesis

Marwa Eltarahony et al. Biotechnol Rep (Amst). .

Erratum in

Abstract

The periplasmic nitrate reductase enzyme (NAP) has become attractive catalyst, whose exploitation has emerged as one of the indispensable strategies toward environmentally benign applications. To achieve them efficiently and overcome the sensitivity of NAP in harsh environmental circumstances, the immobilization for denitrifying bacteria and NAP enzyme for simultaneous bioremediation and bionanoparticles synthesis was studied. NAP catalyzed NO3- reduction at Vmax of 0.811 μM/min and Km of 14.02 mM. Concurrently, the immobilized MMT cells completely removed NO3- upon 192 h with AgNPs synthesis ranging from 23.26 to 58.14 nm as indicated by SEM. Wherase, immobilized NAP exhibited lower efficiency with 28.6% of NO3- elimination within 288 h and large aggregated AgNPs ranging from 94.44 nm to 172.22 nm. To the best of author knowledge, the immobilization for denitrifying bacteria and NAP enzyme for simultaneous bioremediation and bionanoparticles synthesis was not studied before.

Keywords: Bioremediation; Denitrification; Immobilization; Nanoparticles; Nitrate reductase.

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Figures

None
Graphical abstract
Fig. 1
Fig. 1
The activity profile of NAP enzyme of strain MMT under different ranges of temperature (A) and pH (B).
Fig. 2
Fig. 2
Relative activity (%) at 4 °C and 30 °C for 240 h.
Fig. 3
Fig. 3
Preservation of NAP at −20 °C in the presence/absence of preservation buffer.
Fig. 4
Fig. 4
Lineweaver-Burk plot of velocity versus substrate concentration.
Fig. 5
Fig. 5
Application of immobilized MMT cells in A) removal of NO3− and NO3− from artificial wastewater, B) Biosynthesized AgNPs. Arrows pointing to tiny AgNPs.
Fig. 6
Fig. 6
Application of immobilized NAP-enzyme in: A) removal of NO3− from artificial wastewater, B) Biosynthesized AgNPs, Arrows pointing to AgNPs aggregates.
Fig. 7
Fig. 7
EDX pattern of immobilized MMT-cells (A) and immobilized NAP-enzyme (B) beads at the end of incubation period.
Fig. 8
Fig. 8
XRD crystallographic pattern of immobilized MMT-cells (A) and immobilized NAP-enzyme (B) beads at the end of incubation period.
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