Bioaugmentation of Exogenous Strain Rhodococcus sp. 2G Can Efficiently Mitigate Di(2-ethylhexyl) Phthalate...

Area of Science:

• Environmental microbiology
• Bioremediation
• Phytoremediation

Background:

• Soil contamination with di(2-ethylhexyl) phthalate (DEHP) poses risks to ecosystems and food safety.
• Bioaccumulation of DEHP in edible plants like Brassica parachinensis is a significant concern for human health.
• Existing remediation strategies often lack efficiency or specificity for complex soil environments.

Purpose of the Study:

• To develop a bioaugmentation strategy for simultaneous reduction of soil DEHP pollution and its bioaccumulation in Brassica parachinensis.
• To isolate and characterize a microbial strain capable of efficient DEHP degradation.
• To evaluate the efficacy of the developed strategy in a vegetable cultivation context.

Main Methods:

• Isolation and identification of a DEHP-degrading bacterial strain, Rhodococcus sp. 2G.
• Inoculation of Rhodococcus sp. 2G into DEHP-contaminated soil planted with Brassica parachinensis.
• Quantification of DEHP levels in soil and plant tissues.
• Analysis of microbial community interactions and rhizosphere enzyme activities.

Main Results:

• Rhodococcus sp. 2G efficiently degraded DEHP across a wide concentration range (50–1600 mg/L) via a unique pathway.
• Inoculation led to approximately 95% DEHP removal from soil and a 75% reduction in its bioaccumulation in the edible parts of Brassica parachinensis.
• The strain successfully colonized the rhizosphere without competing with indigenous microbes, enhancing DEHP mitigation.
• Increased rhizosphere enzyme activities and dissolved organic carbon (DOC) content contributed to the remediation efficiency.

Conclusions:

• Bioaugmentation with Rhodococcus sp. 2G is a highly effective strategy for mitigating DEHP contamination in soil and preventing its uptake by vegetables.
• This approach offers a promising solution for safe food production in DEHP-polluted agricultural lands.
• The unique degradation capabilities and rhizosphere compatibility of Rhodococcus sp. 2G highlight its potential for practical environmental applications.