Screening of efficient Antimony-oxidizing bacterium Lysinibacillus HC02 and its effect on preventing the absorption and accumulation of Sb in Brassica napus
摘要
The oxidation of antimony (Sb) by rhizosphere microorganisms is regarded as a strategy to mitigate the phytotoxicity of Sb(III). This study aims to isolate a highly efficient Sb-oxidizing bacterium (named HC02) from Sb-contaminated soil and to investigate the bacterium's impact on the growth of Brassica napus under practical soil conditions.
MethodsThe oxidative properties of HC02 were assessed in LB liquid medium at a concentration of 0.05 mM. The Brassica napus pot experiment involved inoculating HC02 using two methods: root irrigation treatment (IR02) and root dipping treatment (DR02). The growth of Brassica napus, its Sb content, the chemical properties of the rhizosphere soil, and the chemical forms of Sb present were analyzed.
ResultsThe oxidation rate of 0.05 mM Sb(III) by HC02 exceeds 90% within 48 h. HC02 possesses the ability to secrete 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase and indole acetic acid (IAA). The addition of HC02 significantly promoted the growth of Brassica napus. Furthermore, both IR02 and DR02 treatments resulted in a significant reduction of total Sb content in roots, with decreases of 38.7% and 41.6%, respectively. Additionally, these treatments also led to a reduction in Sb(III) content in leaves, with reductions of 7.9% and 20.2%.
ConclusionsHC02 exhibits a strong oxidizing ability towards Sb(III). The incorporation of HC02 promotes the growth of Brassica napus while effectively preventing the absorption and accumulation of Sb. This research offers a theoretical foundation for the safe utilization of Sb-contaminated soil and the secure production of vegetables.
Graphical Abstract• Lysinibacillus HC02 is a new highly efficient antimony-oxidizing bacterium.
• Antimony toxicity of Brassica napus can be mitigate by Lysinibacillus HC02.
• The mechanisms of HC02 regulating absorption and accumulation of Sb in Brassica napus was revealed.