Exploring the Microbiome of Marmara Sea Mucilage: A Shotgun Metagenomics Study

Abstract

The intense emergence of mucilage in the Marmara Sea in 2021 has raised concerns due to its potential impact on the global marine system. Considering the potential of mucilage threatening the diverse ecosystems, it is important to define the mucilage microbiome. However, studies dedicated to exploring the biodiversity of mucilage are limited and de novo approaches are needed to understand unexplored biodiversity of mucilage microenvironment. This study aimed to investigate mucilage and water samples from certain stations in Marmara Sea. For this reason, 11 mucilage, 2 pre-mucilage water and 3 clean sea water were collected from 16 stations. DNA isolation, shotgun metagenome sequencing and bioinformatics analysis were performed. It was revealed that the mucilage microbiome and the clean water microbiome were different from each other, and the reads that could not be assigned to any taxon (dark matter) accounted for 58% (p=0.014) of the mucilage metagenome. The clean water had a higher presence of Euryarchaeota (p=0.014), Proteobacteria (p=0.019) and Rhodothermaeota (p=0.034), while Chlamydiae (p=0.014) and Fusobacteria (p=0.034) were found in excess in the mucilage. The study produced the first comparative data on clean sea water and the mucilage microbiome using shotgun metagenomics approaches.