Complex bacterial diversity of Guaymas Basin hydrothermal sediments revealed by synthetic long-read sequencing (LoopSeq)

Hydrothermal sediments host phylogenetically diverse and physiologically complex microbial communities. Previous studies of microbial community structure in hydrothermal sediments have typically used short-read sequencing approaches. To improve on these approaches, we use LoopSeq, a high-throughput synthetic long-read sequencing method that has yielded promising results in analyses of microbial ecosystems, such as the human gut microbiome. In this study, LoopSeq is used to obtain near-full length (approximately 1400 - 1500 bp) bacterial 16S rRNA gene sequences from hydrothermal sediments in Guaymas Basin. Our analysis of sediments along well-documented thermal and geochemical gradients show how sulfur-cycling bacteria of different taxonomic groups persist as active catalysts of the sulfur cycle in varying combinations throughout surficial hydrothermal sediments in the Guaymas Basin.