Enhancement of rhizocompetence in pathogenic bacteria removal of a constructed wetland system

Abstract

The main goal of the present study was to enhance the rhizobacterium potential in a horizontal subsurface flow constructed wetland system planted with Phragmites australis, through environmentally friendly biological approaches. The bioinoculation of antagonist bacteria has been used to promote higher rhizosphere competence and improve pathogenic bacteria removal from wastewater. The experiment was performed both with single and sequential bioinoculation. The results showed that strain PFH1 played an active role in pathogenic bacteria removal, remarkably improving inactivation kinetics of the pathogenic tested bacterium Salmonella typhi in the plant rhizosphere. The single bioinoculation of selected bacteria into the rhizosphere of P. australis improved the kinetics of S. typhi inactivation by approximately 1 U-Log10 (N/N0) (N is the number of viable cultured bacteria at time t, N0 is the number of viable and cultivable bacteria at time t0) compared to the control. By a series of multi-bioinoculations, the enhancement of pathogenic bacteria reduction compared to the inhibition rate in the pilot-scale control was of 2 U-Log10(N/N0). These findings suggested that this strain represents a promising candidate to enhance water purification in constructed wetlands.

Wetlands for environmental protection

“…Bioinoculation of selected bacteria strain (PFH1) played an active role in the removal of pathogens. The kinetics of inactivation of pathogenic bacteria S. typhi was improved by single bioinoculation of PFH1 into the rhizosphere by approximately 1U-Log 10 (N/No) compared to the control in HSF-CW system (Saad et al, 2019). A HSF-CW was combined with a UV treatment system reduced the microbiological indicators, eliminating E. coli (log 10 reduction) (Russo, Pino, et al, 2019).…”