A stress-tolerant strain Rhodococcus sp. WH103 was isolated and co-immobilized to more efficiently degrade phenazine-1-carboxylic acid

Hui Wang ¹, Xiang Wang ², Yao Zu ³

⁰The Province Key Laboratory of the Aqueous Environment Protection and Pollution Control of Yangtze River, Anhui, College of Resources and Environment, Anqing Normal University, Anqing, 246003, China.

Scientific Reports +

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April 16, 2025

View abstract on PubMed

Summary

Phenazine-1-carboxylic acid (PCA) degradation was achieved using Rhodococcus sp. WH103 immobilized on biochar beads. This method efficiently removes PCA and reduces its phytotoxicity, offering a sustainable environmental remediation solution.

Area Of Science

Environmental microbiology
Bioremediation technologies
Agricultural science

Background

Phenazine-1-carboxylic acid (PCA) is a key component of the bio-fungicide shenqinmycin, valued for its antimicrobial properties in agriculture.
PCA poses risks to non-target organisms and can cause phytotoxicity, creating a need for effective degradation methods.

Purpose Of The Study

To isolate and identify efficient PCA-degrading bacteria from the rice rhizosphere.
To develop and optimize a co-immobilization strategy using sodium alginate (SA) and biochar for enhanced PCA degradation and reduced phytotoxicity.

Main Methods

Enrichment culture was used to isolate PCA-degrading bacteria from rice rhizosphere samples.
Rhodococcus sp. WH103, exhibiting high PCA degradation efficiency and tolerance to heat and salt stress, was selected for further study.
Co-immobilization of WH103 cells with SA and biochar was optimized for bead formation and degradation efficiency.

Main Results

Six PCA-degrading bacterial strains were isolated, with Rhodococcus sp. WH103 showing superior performance.
Optimized SA-biochar-bacterial beads degraded PCA to <0.001 mM within 21 hours and were reusable for 12 cycles.
The SA-biochar-bacterial beads significantly reduced PCA's phytotoxicity during seed germination.

Conclusions

Rhodococcus sp. WH103 is a robust strain for PCA degradation, effective even under stress conditions.
SA-biochar co-immobilization provides an efficient, reusable, and eco-friendly method for PCA bioremediation.
This study offers a promising approach for applying pollutant-degrading microorganisms in environmental remediation and mitigating agricultural chemical risks.

Keywords:

Degradation Immobilization Microbial inoculant Phenazine-1-carboxylic acid