The bacteriophage exclusion (BREX) system is a novel prokaryotic defense system against bacteriophages. To our knowledge, no study has systematically characterized the function of the BREX system in lactic acid bacteria. Lactobacillus casei Zhang is a probiotic bacterium originating from koumiss. By using single-molecule real-time sequencing, we previously identified N6-methyladenine (m6A) signatures in the genome of L. casei Zhang and a putative methyltransferase (MTase), namely, pglX This work further analyzed the genomic locus near the pglX gene and identified it as a component of the BREX system. To decipher the biological role of pglX, an L. casei Zhang pglX mutant…
The Gram-negative bacterium Aeromonas salmonicida subsp. salmonicida is an aquatic pathogen which causes furunculosis to salmonids, especially in fish farms. The emergence of strains of this bacterium exhibiting antibiotic resistance is increasing, limiting the effectiveness of antibiotherapy as a treatment against this worldwide disease. In the present study, we discovered an isolate of A. salmonicida subsp. salmonicida that harbors two novel plasmids variants carrying antibiotic resistance genes. The use of long-read sequencing (PacBio) allowed us to fully characterize those variants, named pAsa5-3432 and pRAS3-3432, which both differ from their classic counterpart through their content in mobile genetic elements. The plasmid…
Lactobacillus mucosae is currently of interest as putative probiotics due to their metabolic capabilities and ability to colonize host mucosal niches. L. mucosae LM1 has been studied in its functions in cell adhesion and pathogen inhibition, etc. It demonstrated unique abilities to use energy from carbohydrate and non-carbohydrate sources. Due to these functions, we report the first complete genome sequence of an L. mucosae strain, L. mucosae LM1. Analysis of the pan-genome in comparison with closely-related Lactobacillus species identified a complete glycogen metabolism pathway, as well as folate biosynthesis, complementing previous proteomic data on the LM1 strain. It also revealed…
Members of the marine genus Pseudoalteromonas have attracted great interest because of their ability to produce a large number of biologically active substances. Here, we report the complete genome sequence of Pseudoalteromonas agarivorans Hao 2018, a strain isolated from an abalone breeding environment, using second-generation Illumina and third-generation PacBio sequencing technologies. Illumina sequencing offers high quality and short reads, while PacBio technology generates long reads. The scaffolds of the two platforms were assembled to yield a complete genome sequence that included two circular chromosomes and one circular plasmid. Transcriptomic data for Pseudoalteromonas were not available. We therefore collected comprehensive RNA-seq…