Development of the first gene expression system for Salinicoccus strains with potential application in bioremediation of hypersaline wastewaters

Phylogenomic and molecular markers based studies on Staphylococcaceae and Gemella species. Proposals for an emended family Staphylococcaceae and three new families (Abyssicoccaceae fam. nov., Salinicoccaceae fam. nov. and Gemellaceae fam. nov.) harboring four new genera, Lacicoccus gen. nov., Macrococcoides gen. nov., Gemelliphila gen. nov., and Phocicoccus gen. nov

The family Staphylococcacae and genus Gemella contain several organisms of clinical or biotechnological importance. We report here comprehensive phylogenomic and comparative analyses on 112 available genomes from species in these taxa to clarify their evolutionary relationships and classification. In a phylogenomic tree based on 678 core proteins, Gemella species were separated from Staphylococcacae by a long branch indicating that they constitute a distinct family (Gemellaceae fam. nov.). In this tree, Staphylococcacae species formed two main clades, one encompassing the genera Aliicoccus, Jeotgalicoccus, Nosocomiicoccus and Salinicoccus (Family "Salinicoccaceae"), while the other clade consisted of the genera Macrococcus, Mammaliicoccus and Staphylococcus (Family Staphylococcaceae emend.). In this tree, species from the genera Gemella, Jeotgalicoccus, Macrococcus and Salinicoccus each formed two distinct clades. Two species clades for these genera are also observed in 16S rRNA gene trees and supported by average amino acid identity analysis. We also report here detailed analyses on protein sequences from Staphylococcaceae and Gemella genomes to identify conserved signature indels (CSIs) which are specific for different genus and family-level clades. These analyses have identified 120 novel CSIs robustly demarcating different proposed families and genera. The identified CSIs provide independent evidence that the genera Gemella, Jeotgalicoccus, Macrococcus and Salinicoccus consist of two distinct clades, which can be reliably distinguished based on multiple exclusively shared CSIs. We are proposing transfers of the species from the novel clades of the above four genera into the genera Gemelliphila gen. nov., Phocicoccus gen. nov., Macrococcoides gen. nov. and Lacicoccus gen. nov., respectively. The identified CSIs also provide strong evidence for division of Staphylococcaceae into an emended family Staphylococcaceae and two new families, Abyssicoccaceae fam. nov. and Salinicoccaceae fam. nov. All of these families can be reliably demarcated based on several exclusively shared CSIs.

Salt-contaminated water exposure induces gut microbial dysbiosis in chickens

Microbes play a crucial role in maintaining health by aiding in digestion, regulating the immune system, producing essential vitamins, and preventing the colonization of harmful bacteria. The stability of the microbiota is, therefore, necessary for overall well-being. However, several environmental factors can negatively affect the microbiota, including exposure to industrial waste, i.e., chemicals, heavy metals, and other pollutants. Over the past few decades, industries have grown significantly, but the wastewater from those industries has seriously harmed the environment and the health of living beings both locally and globally. The current study investigated the effects of salt-contaminated water exposure on gut microbiota in chickens. According to our findings, amplicon sequencing showed 453 OTUs across control and salt-contaminated water exposure groups. Proteobacteria, Firmicutes, and Actinobacteriota were the most dominant phyla in the chickens regardless of treatment. However, exposure to salt-contaminated water resulted in a remarkable decline in gut microbial diversity. While, the beta diversity revealed substantial differences in major gut microbiota components. Moroever, microbial taxonomic investigation indicated that the proportions of one bacterial phylum and nineteen bacterial genera significantly decreased. Also, the levels of one bacterial phylum and thirty three bacterial genera markedly increased under salt-contaminated water exposure, which indicates a disruption in gut microbial homeostasis. Hence the current study provides a basis to explore the effects of salt-contaminated water exposure on the health of vertebrate species.