Biodegradation of Polycyclic Aromatic Hydrocarbons in Mangrove Sediments Under Different Strategies: Natural Attenuation, Biostimulation, and Bioaugmentation with Rhodococcus erythropolis T902.1

Polycyclic aromatic hydrocarbons (PAHs)
are pollutants that occur in mangrove sediments. Their
removal by bacteria often depends on specific characteristics
as the number of benzene rings they possess and
their solubility. Their removal also depends on environmental
factors, such as pH, temperature, oxygen, and the
ability of the endogenous or exogenous microflora to
metabolize hydrocarbons.With the aim of treating mangrove
sediments polluted by hydrocarbons in a biological
way, a biodegradation experiment was conducted
using mangrove sediments artificially contaminated
with a mixture of four PAHs. The study used
Rhodococcus erythropolis as an exogenous bacterial
strain in order to assess the biodegradation of the PAH
mixture by natural attenuation, biostimulation, bioaugmentation,
and a combination of biostimulation and
bioaugmentation. The results showed that the last three
treatments were more efficient than natural attenuation.
The biostimulation/bioaugmentation combination
proved to be the most effective PAH degradation
treatment.