Journal Article

Anaerobic Degradation of Naphthalene and Pyrene by Sulfate-Reducing Cultures Enriched from Former Manufactured Gas Plant Soil

Panneerselvan, Logeshwaran, Dhar, Kartik, Megharaj, Mallavarapu, Subashchandrabose, Suresh R., Venkateswarlu, Kadiyala

2023

Overview

Biodegradation of polycyclic aromatic hydrocarbons (PAHs) under completely anaerobic sulfate-reducing conditions is an energetically challenging process. To date, anaerobic degradations of only two-ringed naphthalene and three-ringed phenanthrene by sediment-free and enriched sulfate-reducing bacteria have been reported. In this study, sulfate-reducing enrichment cultures capable of degrading naphthalene and four-ringed PAH, pyrene, were enriched from a contaminated former gas plant site soil. Bacterial community composition analysis revealed that a naphthalene-degrading enrichment culture, MMNap, was dominated (84.90%) by a Gram-positive endospore-forming member of the genus Desulfotomaculum with minor contribution (8.60%) from a member of Clostridium . The pyrene-degrading enrichment, MMPyr, was dominated (97.40%) by a species of Desulfotomaculum . The sequences representing the Desulfotomaculum phylotypes shared 98.80% similarity to each other. After 150 days of incubation, MMNap degraded 195 µM naphthalene with simultaneous reduction of sulfate and accumulation of sulfide. Similarly, MMPyr degraded 114 µM pyrene during 180 days of incubation with nearly stochiometric sulfate consumption and sulfide accumulation. In both cases, the addition of sulfate reduction inhibitor, molybdate (20 mM), resulted in complete cessation of the substrate utilization and sulfate reduction that clearly indicated the major role of the sulfate-reducing Desulfotomaculum in biodegradation of the two PAHs. This study is the first report on anaerobic pyrene degradation by a matrix-free, strictly anaerobic, and sulfate-reducing enrichment culture.

• Publisher: Springer US,Springer Nature B.V
• Subject: Accumulation / Anaerobic conditions / Anaerobic processes / Anaerobiosis / Aromatic compounds / Aromatic hydrocarbons / Bacteria / bacterial communities / Biodegradation / Biodegradation, Environmental / Biomedical and Life Sciences / Clostridium / Community composition / community structure / Desulfotomaculum / Ecology / Enrichment / enrichment culture / Enrichment media / Environmental Microbiology / Geoecology/Natural Processes / Life Sciences / Manufactured gas / Microbial Ecology / Microbiology / Molybdate / molybdates / Naphthalene / Naphthalenes - metabolism / Nature Conservation / Phenanthrene / phenanthrenes / phylotype / Polycyclic aromatic hydrocarbons / Polycyclic Aromatic Hydrocarbons - metabolism / Pyrene / Pyrenes / soil / Soil contamination / Soil microorganisms / Soils / Substrates / Sulfate reduction / Sulfate-reducing bacteria / Sulfates / Sulfates - metabolism / Sulfides / Sulphate reduction / Sulphides / Water Quality/Water Pollution