Spatial Pattern and Genetic Diversity of Marine Bacterial Communities of Coastal Seawater and Sediments from Qatar

Abstract

Abstract Severe environmental conditions can have a diverse impact on marine microorganisms, including bacteria. This can have an inevitable impact on the biofouling of membrane-based desalination plants. In this work, we have utilized the indicator bacteria such as total coliform, fecal coliform, and Pseudomonas aeruginosa and 16S rRNA sequencing to investigate the impact of environmental conditions and spatial variations on the diversity of bacterial communities in the coastal waters and sediments from selected sites of Qatar over different seasons. The concentration levels of indicator bacteria were affected by increasing temperature and pH and decreasing salinity of seawater samples. Diversity indices and the molecular phylogeny demonstrated that Proteobacteria, Bacteroidetes, and Cyanobacteria were the dominant phyla in all locations. The most abundant operational taxonomic units (OTUs) at the family level were from Flavobacteriaceae (27.07%, 4.31%) and Rhodobacteraceae (22.51%, 9.86%) in seawater and sediments, respectively. Alphaproteobacteria (33.87%, 16.82%), Flavobacteria (30.68%, 5.84%), Gammaproteobacteria (20.35%, 12.45%) were abundant at the species level in both seawater and sediment, respectively, while Clostridia (13.72%) was abundant in sediment only. Results suggest that the sediments can act as a reservoir for indicators of bacteria with higher diversity and lower abundance as compared to seawater. This study helps to understand the impact of environmental conditions on the diversity and structural behavior of microbial communities specific to the marine environment of the Arabian Gulf.