Bacterial endophyte-mediated naphthalene phytoprotection and phytoremediation

Area of Science:

• Environmental Science
• Microbiology
• Bioremediation

Background:

• Polyaromatic hydrocarbons (PAHs) are persistent environmental pollutants.
• Phytoremediation is a promising technique for PAH removal, but plant phytotoxicity can be a limiting factor.
• Naphthalene, a low-molecular-weight PAH, causes significant phytotoxic effects.

Purpose of the Study:

• To construct and evaluate an endophytic bacterium for enhanced phytoremediation of naphthalene.
• To assess the ability of the engineered strain to colonize plants and mitigate phytotoxicity.
• To determine the impact of bacterial inoculation on plant health and naphthalene degradation.

Main Methods:

• Construction of a naphthalene-degrading endophytic strain, Pseudomonas putida VM1441(pNAH7).
• Assessment of plant colonization in rhizosphere and root tissues.
• Evaluation of plant seed germination and transpiration rates under naphthalene exposure.
• Measurement of naphthalene degradation rates in contaminated soil.

Main Results:

• Pseudomonas putida VM1441(pNAH7) efficiently colonized plant roots both externally and internally.
• Inoculated plants showed increased seed germination and transpiration rates compared to controls when exposed to naphthalene.
• Bacterial inoculation led to a 40% higher naphthalene degradation rate in contaminated soil.

Conclusions:

• Engineered endophytic Pseudomonas putida VM1441(pNAH7) effectively protects plants from naphthalene phytotoxicity.
• This strain enhances plant performance and naphthalene degradation, improving phytoremediation efficacy.
• Endophytic bacteria offer a viable strategy for mitigating PAH contamination in soils.