Establishment of Genome Based Criteria for Classification of the Family Desulfovibrionaceae and Proposal of Two Novel Genera, Alkalidesulfovibrio gen. nov. and Salidesulfovibrio gen. nov

Bacteria in the Desulfovibrionaceae family, which contribute to S element turnover as sulfate-reducing bacteria (SRB) and disproportionation of partially oxidized sulfoxy anions, have been extensively investigated since the importance of the sulfur cycle emerged. Novel species belonging to this taxon are frequently reported, because they exist in various environments and are easy to culture using established methods. Due to the rapid expansion of the taxon, correction and reclassification have been conducted. The development of high-throughput sequencing facilitated rapid expansion of genome sequence database. Genome-based criteria, based on these databases, proved to be potential classification standard by overcoming the limitations of 16S rRNA-based phylogeny. Although standards methods for taxogenomics are being established, the addition of a novel genus requires extensive calculations with taxa, including many species, such as Desulfovibrionaceae. Thus, the genome-based criteria for classification of Desulfovibrionaceae were established and validated in this study. The average amino-acid identity (AAI) cut-off value, 63.43 ± 0.01, was calculated to be an appropriate criterion for genus delineation of the family Desulfovibrionaceae. By applying the AAI cut-off value, 88 genomes of the Desulfovibrionaceae were divided into 27 genera, which follows the core gene phylogeny results. In this process, two novel genera (Alkalidesulfovibrio and Salidesulfovibrio) and one former invalid genus (“Psychrodesulfovibrio”) were officially proposed. Further, by applying the 95–96% average nucleotide identity (ANI) standard and the 70% digital DNA–DNA hybridization standard values for species delineation of strains that were classified as the same species, five strains have the potential to be newly classified. After verifying that the classification was appropriately performed through relative synonymous codon usage analysis, common characteristics were listed by group. In addition, by detecting metal resistance related genes via in silico analysis, it was confirmed that most strains display metal tolerance.

The Role of Thermal Water in Chronic Skin Diseases Management: A Review of the Literature

The benefits of thermal water in different diseases have been known since ancient times. Over the past decades, a re-assessment of the use of mineral water for the treatment of several pathologic conditions has taken place around the world. Today, water therapy is being practiced in many countries that have a variety of mineral springs considerably different in their hydrogeologic origin, temperature, and chemical composition. Thermal water and balneotherapy offer several advantages: this approach needs no chemicals or potentially harmful drugs; there are almost no side effects during and after treatment, and there is a low risk to the patient’s general health and well-being. However, it is difficult to evaluate the efficacy of this therapeutic approach in clinical practice due to the complexity of molecular mechanisms underlying its efficacy. Here we review the current knowledge of the chemical, immunological, and microbiological basis for therapeutic effects of thermal water with a specific focus on chronic inflammatory skin diseases. We also describe recent evidence of the major dermatologic diseases that are frequently treated by balneotherapy with a remarkable rate of success. Moreover, we discuss the potential role of balneotherapy either alone or as a complement to conventional medical treatments.

Relationship between true digestibility of dietary phosphorus and gastrointestinal bacteria of goats

The present research was conducted to evaluate the connection between the true digestibility of Phosphorus (TDP) in diet and bacterial community structure in the gastrointestinal tract (GIT) of goats. Twenty-eight Nubian goats were chosen and metabolic experiment was conducted to analyze TDP of research animals. Eight goats were grouped into the high digestibility of phosphorus (HP) phenotype, and another 8 were grouped into the low digestibility of phosphorus (LP) phenotype. And from the rumen, abomasum, jejunim, cecum and colon content of the goats, bacterial 16S rRNA gene amplicons were sequenced. In the rumen 239 genera belonging to 23 phyla, in abomasum 319 genera belonging to 30 phyla, in jejunum 248 genera belonging to 36 phyla, in colon 248 genera belonging to 25 phyla and in cecum 246 genera belonging to 23 phyla were noticed. In addition, there was a significant correlation between the TDP and the abundance of Ruminococcaceae_UCG-010, Ruminococcus_2, Ruminococcaceae_UCG-014, Selenomonas_1 and Prevotella in the rumen, Lachnospiraceae_ND3007_group, Saccharofermentans, Ruminococcus_1, Ruminococcaceae_UCG-014, Lachnospiraceae_XPB1014_group and Desulfovibrio in the abomasum, Prevotella, Clostridium_sensu_stricto_1, Fibrobacter, Desulfovibrio and Ruminococcus_2 in the jejunum, Ruminococcaceae_UCG-014 in the colon, and Desulfovibrio in the cecum. Present research trial recommended that the community of gastrointestinal microbiota is a factor affecting TDP in goats.

Recent advances in dissimilatory sulfate reduction: From metabolic study to application

Sulfate-reducing bacteria (SRB) are a group of diverse anaerobic microorganisms omnipresent in natural habitats and engineered environments that use sulfur compounds as the electron acceptor for energy metabolism. Dissimilatory sulfate reduction (DSR)-based techniques mediated by SRB have been utilized in many sulfate-containing wastewater treatment systems worldwide, particularly for acid mine drainage, groundwater, sewage and industrial wastewater remediation. However, DSR processes are often operated suboptimally and disturbances are common in practical application. To improve the efficiency and robustness of SRB-based processes, it is necessary to study SRB metabolism and operational conditions. In this review, the mechanisms of DSR processes are reviewed and discussed focusing on intracellular and extracellular electron transfer with different electron donors (hydrogen, organics, methane and electrodes). Based on the understanding of the metabolism of SRB, responses of SRB to environmental stress (pH-, temperature-, and salinity-related stress) are summarized at the species and community levels. Application in these stressed conditions is discussed and future research is proposed. The feasibility of recovering energy and resources such as biohydrogen, hydrocarbons, polyhydroxyalkanoates, magnetite and metal sulfides through the use of SRB were investigated but some long-standing questions remain unanswered. Linking the existing scientific understanding and observations to practical application is the challenge as always for promotion of SRB-based techniques.

Halodesulfovibrio spirochaetisodalis gen. nov. sp. nov. and reclassification of four Desulfovibrio spp

An antibiotic-producing, obligate anaerobic, Gram-stain-negative, catalase- and oxidase-negative strain (JC271T) was isolated from a marine habitat and identified, based on 16S rRNA gene sequence analysis, as a novel member of the family Desulfovibrionaceae. The closest phylogenetic relatives of strain JC271T were found to be Desulfovibrio marinisediminis C/L2T (99.2 %), Desulfovibrio acrylicus W218T (98.7 %), Desulfovibrio desulfuricans subsp. aestuarii (98.6 %), Desulfovibrio oceani subsp. oceani (98.0 %), Desulfovibrio oceani subsp. galatae (98.0 %) and other members of the genus Desulfovibrio (≤91.9 %). To resolve its full taxonomic position, the genomic sequence of strain JC271T was compared to available genomes of the most closely related phylogenetic members. Average Nucleotide Identity scores and DNA-DNA hybridization values confirmed that strain JC271T represents a novel genomic species. Iso-C17 : 0, iso-C17 : 1ω9c, and iso-C15 : 0 were found to be the major (comprising >10 % of the total present) fatty acids of strain JC271T. Phosphatidylglycerol, phosphatidylethanolamine and unidentified lipids (L1-8) were the polar lipids identified. The G+C content of strain JC271T was 46.2 mol%. Integrated genomic and phenotypic data supported the classification of strain JC271T as a representative of a novel genus, for which the name Halodesulfovibrio spirochaetisodalis gen. nov., sp. nov. is proposed. The type strain is JC271T (=KCTC 15474T=DSM 100016T). It is also proposed that Desulfovibrio acrylicus W218T is the latter heterotypic synonym of Desulfovibrio desulfuricans subsp. aestuarii Sylt 3T. Desulfovibrio desulfuricans subsp. aestuarii Sylt 3T should also be elevated as Halodesulfovibrio aestuarii comb. nov. and Desulfovibrio marinisediminisreclassified as Halodesulfovibrio marinisediminis comb. nov. Desulfovibrio oceani subsp. oceanishould be reclassified as Halodesulfovibrio oceani subsp. oceani comb. nov. and Desulfovibrio oceani subsp. galateae as Halodesulfovibrio oceani subsp. galateae comb. nov.