Salt-tolerant phenol-degrading microorganisms isolated from Amazonian soil samples

Area of Science:

• Microbiology
• Environmental Science
• Biotechnology

Background:

• Phenolic compounds are common industrial pollutants.
• Bioremediation offers a sustainable solution for pollutant removal.
• Amazonian forest soils represent a largely untapped source of microbial diversity.

Purpose of the Study:

• To isolate and identify phenol-degrading microorganisms from Amazonian rainforest soil.
• To characterize the phenol and salt tolerance of isolated strains.
• To investigate the influence of different carbon sources on phenol degradation.

Main Methods:

• Enrichment culture with phenol and high salt concentration.
• Microorganism identification using microscopy, biochemical tests, fatty acid profiling, and 16S/18S rRNA sequencing.
• Phenol degradation assays comparing isolates with a reference strain and wastewater microbial populations.

Main Results:

• Candida tropicalis and Alcaligenes faecoalis were identified as effective phenol degraders.
• C. tropicalis exhibited higher tolerance to phenol (16 mM) and salt (15%) than A. faecalis (12 mM and 5.6%).
• C. tropicalis tolerated a broader pH range (3-9) compared to A. faecalis (7-9); degradation was repressed by glucose/acetate but stimulated by lactate in A. faecalis.

Conclusions:

• This study reports the first isolation of phenol-degrading microorganisms from Amazonian forest soils.
• Natural, uncontaminated environments harbor diverse microbial communities with significant bioremediation potential.
• The identified microorganisms, particularly C. tropicalis, show promise for developing novel bioremediation strategies.