Modulation of microbial consortia enriched from different polluted environments during petroleum biodegradation

Area of Science:

• Environmental microbiology
• Bioremediation
• Petroleum science

Background:

• Environmental microbial communities are crucial for hydrocarbon pollutant bioremediation.
• Understanding bacterial community dynamics is essential for effective oil spill cleanup.

Purpose of the Study:

• To assess bacterial abundance and diversity changes during Tunisian Zarzatine oil degradation.
• To identify key bacterial genera and species involved in petroleum biodegradation.
• To correlate the presence of degrading genes with biodegradation rates.

Main Methods:

• Enrichment of four indigenous bacterial consortia from diverse environmental sources (soil, sediment, seawater).
• Quantification of total petroleum hydrocarbon degradation.
• Illumina 16S rRNA gene sequencing for bacterial community profiling.
• Polymerase Chain Reaction (PCR) and PICRUSt analysis for functional gene assessment.

Main Results:

• All four consortia achieved high degradation rates, up to 92.0% of total petroleum hydrocarbons within two months.
• Distinct bacterial community compositions were observed: Pseudomonas and Acinetobacter dominated soil/sediment consortia, while Dietzia, Fusobacterium, and Mycoplana were prevalent in seawater consortia.
• Specific species like Dietzia daqingensis and Acinetobacter venetianus showed increased abundance.
• Functional gene analysis (alkB, ndoB, cat23, xylA, nidA1) showed partial agreement with 16S rRNA data, suggesting a link between catabolic genes and biodegradation efficiency.

Conclusions:

• Bacterial communities exhibit significant modulation during petroleum biodegradation.
• Specific genera and species play distinct roles depending on the environmental origin of the consortia.
• The study provides valuable insights for optimizing in situ bioremediation strategies for oil pollution.