Effect of endophytic bacteria on the phytoremediation potential of halophyte Tamarix smyrnensis for Sb-contaminated soils

Abstract

Phytoremediation, including bacteria-assisted phytoremediation, presents a promising technology for treating shooting range soils contaminated with toxic metalloids. In this study, a pot experiment was performed using the halophyte Tamarix smyrnensis and soil collected from a shooting range and artificially spiked at two different antimonite (Sb(III)) concentrations (50 mg/kg and 250 mg/kg) with the aim to explore the Sb phytoremediation of the halophyte. The effect of salt (0.3%) and Mn addition (300 ppm) on its remediation capacity was also investigated. Moreover, the root endophytic community of the halophyte was found able to remove Sb(III) and was periodically inoculated to the plants. The consortium application increased the Sb bioavailable fraction in the soil and enhanced the Sb accumulation in root and aerial parts (up to 50% and 55% respectively at high Sb(III) concentration) compared to the uninoculated plants. Moreover, the presence of Mn increased the translocation factor (21% increase for inoculated and 46% increase for uninoculated plants) while lower TF was observed at high Sb concentrations (0,2 and 0,07 was the lowest value at low and high Sb treatments respectively). The addition of salt, Mn and root endophytic bacteria aided the halophyte to cope with elevated Sb concentrations. The total chlorophyll concentration was higher in inoculated plants compared to the uninoculated ones in all treatments, implying the positive effects of endophytic inoculation. The halophyte T. smyrnensis with the aid of endophytic community presents a promising alternative for remediating shooting range soils especially in areas impacted by salinity.

NOVELTY STATEMENT

• The halophyte T. smyrnensis presents a promising alternative for remediating shooting range soils

• The application of endophytic bacteria improved the Sb phytoremediation capacity of T. smyrnensis

• The halophyte T. smyrnensis can be used for Sb phytoextraction in soils impacted by salinity

Keywords:

• Antimony
• halophytes
• phytoremediation
• salinity
• Sb resistant endophytic bacteria

Authors’ contributions

Conceptualization: Nicolas Kalogerakis, Evdokia Syranidou; Methodology and experimental work: Konstantinos Fyntrilakis, Sofia Kyritsi, Petroula Seridou; Formal analysis: Petroula Seridou and Evdokia Syranidou; Writing - original draft preparation: Evdokia Syranidou; Writing - review and editing: Petroula Seridou, Nicolas Kalogerakis; Funding acquisition: Nicolas Kalogerakis; Supervision: Nicolas Kalogerakis, Evdokia Syranidou. All authors have approved the final manuscript.

Consent to participate

This research does not involve human participants and/or animals.

Consent for publication

All authors agreed with the content and all gave explicit consent to submit.

Disclosure statement

The authors have no relevant financial or non-financial interests to disclose.

Data availability statement

Available upon reasonable request.

Additional information

Funding

Financial support by the European Union’s Horizon 2020 project “ELECTRA” under Grant Agreement No. 826244 is highly appreciated.