Antioxidative Enzyme Responses to Antimony Stress of Serratia marcescens – an Endophytic Bacteria of Hedysarum pallidum Roots
Mounia Kassa Laouar 1  
,   Aicha Mechakra 1  
,   Agnès Rodrigue 2  
,   Ouissem Meghnous 1  
,   Alima Bentellis 3  
,   Oualida Rached 3  
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Biology and Environment Laboratory, Faculty of Nature and Life Sciences, Mentouri University Constantine 1, Constantine, Algeria
Laboratory of Microbiology, Adaptation and Pathogeny, University Lyon 1, France
Biotechnology High National School Taoufik Khaznadar, Ali Mendjeli University City, Constantine, Algeria
Oualida Rached   

Biotechnology High National School Taoufik Khaznadar
Submission date: 2018-10-01
Final revision date: 2018-11-28
Acceptance date: 2018-12-04
Online publication date: 2019-09-02
Publication date: 2019-10-23
Pol. J. Environ. Stud. 2020;29(1):141–152
Studies on bacterial endophytes resistant to antimony (Sb), a pollutant deemed alarming, are virtually non-existent. An endophytic bacterial strain showing resistance to high antimony concentrations was isolated for the first time from the roots of Hedysarum pallidum Desf., a Sb accumulator Fabacea growing on mining spoils. With the combined use of morphological, biochemical and molecular methods, the isolated strain was identified as Serratia marcescens species. It showed a minimum inhibitory concentration (MIC) to its growth at 450 mM of Sb. In the presence of excessive concentrations of Sb, corresponding to 30 mM of Sb, i.e., 3652.8 mg/L of Sb, the strain maintained important growth compared to the control. The Sb toxicity caused a significant increase (p<0.05) in the hydrogen peroxide (H2O2) amount and malondialdehyde (MDA) content. The oxidative stress induced significant increases (p<0.05) in the strain antioxidant biomarkers such as proline, catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD). Significant and positive correlations (p<0.05) were found between oxidative and antioxidant biomarkers and between antioxidant biomarkers, highlighting the interrelationships between them in oxidative stress fighting. Results show an important adaptation of the strain to high Sb levels that can be used in the Sb-contaminated soils bioremediation.