Bacteriology studies multiple aspects of bacteria including morphology, metabolism, function, and ecology. The approaches generally involve identification, classification, and characterization. The development of next-generation sequencing (NGS) technologies allows researchers to investigate microorganisms from a broader and deeper perspective, enabling better characterization of the bacterial genome as well as deeper taxonomic identification of complex microbiomes in specific environments such as soil, ocean, and even human body. NGS is capable of processing multiple DNA sequences in parallel and dramatically reduces sequencing cost and time. The technical developments, applications, and research of NGS are moving forward rapidly over the years. Many studies have highlighted the use of NGS strategies in bacterial classification, microbiome, comparative genomics, and evolutionary genomics, etc.
16S rRNA amplicon sequencing, metagenomics, and metatranscriptomics are widely used NGS strategies in bacterial identification and characterization. The key features of NGS include in vitro library construction and clonal amplification, array-based sequencing enables DNA fragments to be multiplexed, and DNA solid-phase fixation. Compared with Sanger sequencing based on selective binding chain-terminating dideoxynucleotides during in vitro replication by DNA polymerase, NGS has high sequencing depth, which allows for high sensitivity and comprehensive genomic coverage. More significantly, NGS allows for higher sample throughput and can produce massive sequencing data in a single run.
Figure 1. An overview of the different applications of next-generation sequencing analysis. (Simner 2017)
