Metatranscriptomic responses and microbial degradation of background polycyclic aromatic hydrocarbons in the coastal Mediterranean and Antarctica

• Published in: Environmental Science and Pollution Research
• Main Authors: Martinez-Varela, Alicia, Casas, Gemma, Berrojalbiz, Naiara, Lundin, Daniel, Piña, Benjamín, Dachs, Jordi, Vila-Costa, Maria
• Other Authors: orcid:
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2023
• Subjects: Polycyclic aromatic hydrocarbons (PAH); 16S amplicon sequencing; Antarctica; Mediterranean; Metatranscriptomics; PAH biodegradation rates; Take urgent action to combat climate change and its impacts; Conserve and sustainably use the oceans; seas and marine resources for sustainable development; Antarctic; Antarc*
• Online Access: http://hdl.handle.net/10261/340981; https://doi.org/10.1007/s11356-023-30650-1; https://api.elsevier.com/content/abstract/scopus_id/85178995648

Although microbial degradation is a key sink of polycyclic aromatic hydrocarbons (PAH) in surface seawaters, there is a dearth of field-based evidences of regional divergences in biodegradation and the effects of PAHs on site-specific microbial communities. We compared the magnitude of PAH degradation and its impacts in short-term incubations of coastal Mediterranean and the Maritime Antarctica microbiomes with environmentally relevant concentrations of PAHs. Mediterranean bacteria readily degraded the less hydrophobic PAHs, with rates averaging 4.72 ± 0.5 ng L h-1. Metatranscriptomic responses showed significant enrichments of genes associated to horizontal gene transfer, stress response, and PAH degradation, mainly harbored by Alphaproteobacteria. Community composition changed and increased relative abundances of Bacteroidota and Flavobacteriales. In Antarctic waters, there was no degradation of PAH, and minimal metatranscriptome responses were observed. These results provide evidence for factors such as geographic region, community composition, and pre-exposure history to predict PAH biodegradation in seawater. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by Spanish Ministry of Science and Innovation to GC and AMV through predoctoral fellowships, and through projects SENTINEL (CTM2015-70535-P) and ISOMICS (CTM2015-65691-R). The research group of Global Change and Genomic Biogeochemistry receives support from the Catalan Government (2017SGR800). IDAEA-CSIC is a Centre of Excellence Severo Ochoa (Spanish Ministry of Science and Innovation, Project CEX2018-000794-S). Peer reviewed