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Several spore-forming strains of Bacillus are marketed as probiotics due to their ability to survive harsh gastrointestinal conditions and confer health benefits to the host. We report the complete genomes of two commercially available probiotics, Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, and compare them with the genomes of other Bacillus and Lactobacillus. The taxonomic position of both organisms was established with a maximum-likelihood tree based on twenty six housekeeping proteins. Analysis of all probiotic strains of Bacillus and Lactobacillus reveal that the essential sporulation proteins are conserved in all Bacillus probiotic strains while they are absent in Lactobacillus spp. We identified various antibiotic resistance, stress-related, and adhesion-related domains in these organisms, which likely provide support in exerting probiotic action by enabling adhesion to host epithelial cells and survival during antibiotic treatment and harsh conditions.

F-type lectins are fucolectins with characteristic fucose and calcium-binding sequence motifs and a unique lectin fold (the "F-type" fold). F-type lectins are phylogenetically widespread with selective distribution. Several eukaryotic F-type lectins have been biochemically and structurally characterized, and the F-type lectin domain (FLD) has also been studied in the bacterial proteins, Streptococcus mitis lectinolysin and Streptococcus pneumoniae SP2159. However, there is little knowledge about the extent of occurrence of FLDs and their domain organization, especially, in bacteria. We have now mined the extensive genomic sequence information available in the public databases with sensitive sequence search techniques in order to exhaustively survey prokaryotic and eukaryotic FLDs. We report 437 FLD sequence clusters (clustered at 80% sequence identity) from eukaryotic, eubacterial and viral proteins. Domain architectures are diverse but mostly conserved in closely related organisms, and domain organizations of bacterial FLD-containing proteins are very different from their eukaryotic counterparts, suggesting unique specialization of FLDs to suit different requirements. Several atypical phylogenetic associations hint at lateral transfer. Among eukaryotes, we observe an expansion of FLDs in terms of occurrence and domain organization diversity in the taxa Mollusca, Hemichordata and Branchiostomi, perhaps coinciding with greater emphasis on innate immune strategies in these organisms. The naturally occurring FLDs with diverse domain organizations that we have identified here will be useful for future studies aimed at creating designer molecular platforms for directing desired biological activities to fucosylated glycoconjugates in target niches., (© The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)