Biochar and Rhamnolipid Enhance Biodegradation of Phenanthrene in Agricultural Soil

Strategic Insights -

Scientists at Nanjing Forestry University have made a groundbreaking discovery in the field of agriculture. According to a new report, the combined effects of wheat straw biochar (BC) and biosurfactant rhamnolipid (RL) on the biodegradation kinetics of phenanthrene by indigenous microorganisms in agricultural soil have been investigated. The research has shown that the combined treatment significantly enhanced phenanthrene biodegradation compared to RL alone or the control.

Key Takeaways:

  • The combined treatment of BC and RL (60.63%) significantly enhanced phenanthrene biodegradation compared to RL alone (54.74%) and the control (45.98%).
  • BC amendment alone (42.55%) notably inhibited biodegradation by reducing phenanthrene bioavailability despite increasing bacterial abundance, enzyme activity, and community diversity.
  • Both RL and BC + RL treatments promoted bioavailability by transforming phenanthrene from tightly bound to readily bioavailable fractions.
  • RL-mediated increase in phenanthrene bioavailability to microbes by 11.93-17.90% via solubilization greatly enriched PAH-degrading bacterial genera and the *nit A* gene.
  • The BC + RL combination outperformed the single application of RL in improving phenanthrene biodegradation due to their synergy in stimulating microbial population and activity.
  • These findings demonstrate that BC and RL co-application enhances PAH removal through improved bioavailability and optimized microbial communities, offering a promising strategy for soil bioremediation to ensure agricultural product safety.

Statistics:

  • 60.63%: The combined treatment of BC and RL significantly enhanced phenanthrene biodegradation.
  • 54.74%: The biodegradation rate of phenanthrene when treated with RL alone.
  • 45.98%: The biodegradation rate of phenanthrene when treated with the control.
  • 42.55%: The biodegradation rate of phenanthrene when treated with BC amendment alone.
  • 11.93-17.90%: The RL-mediated increase in phenanthrene bioavailability to microbes via solubilization.

Sources:

  • Combined Effects of Biochar and Rhamnolipid on Phenanthrene Biodegradation in Agricultural Soil: Bioavailability and Microbial Community Dynamics (Agriculture, 2025,15(11):1116)
  • Journal URL: http://www.mdpi.com/journal/agriculture
  • Publisher: MDPI AG
  • DOI: https://doi.org/10.3390/agriculture15111116
  • NewsRx LLC. Nanjing Forestry University Researchers Report Recent Findings in Agriculture (Combined Effects of Biochar and Rhamnolipid on Phenanthrene Biodegradation in Agricultural Soil: Bioavailability and Microbial Community Dynamics). Agriculture Week. June 26, 2025; p 1563.