Evolution of Protein Molecules

Manual for the Identification of Medical Bacteria.

The purpose of this announcement is to effect the valid publication of the following effectively published new names and new combinations under the procedure described in the Bacteriological Code (1990 Revision). Authors and other individuals wishing to have new names and/or combinations included in future lists should send three copies of the pertinent reprint or photocopies thereof, or an electronic copy of the published paper to the IJSEM Editorial Office for confirmation that all of the other requirements for valid publication have been met. It is also a requirement of IJSEM and the ICSP that authors of new species, new subspecies and new combinations provide evidence that types are deposited in two recognized culture collections in two different countries. It should be noted that the date of valid publication of these new names and combinations is the date of publication of this list, not the date of the original publication of the names and combinations. The authors of the new names and combinations are as given below. Inclusion of a name on these lists validates the publication of the name and thereby makes it available in the nomenclature of prokaryotes. The inclusion of a name on this list is not to be construed as taxonomic acceptance of the taxon to which the name is applied. Indeed, some of these names may, in time, be shown to be synonyms, or the organisms may be transferred to another genus, thus necessitating the creation of a new combination.

List of new names and new combinations previously effectively, but not validly, published.

The application of phylogenetic taxonomic procedures led to improvements in the classification of bacteria assigned to the phylum Actinobacteria but even so there remains a need to further clarify relationships within a taxon that encompasses organisms of agricultural, biotechnological, clinical, and ecological importance. Classification of the morphologically diverse bacteria belonging to this large phylum based on a limited number of features has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees. Here, draft genome sequences of a large collection of actinobacterial type strains were used to infer phylogenetic trees from genome-scale data using principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families, and genera, as well as many species and a few subspecies were shown to be in need of revision leading to proposals for the recognition of 2 orders, 10 families, and 17 genera, as well as the transfer of over 100 species to other genera. In addition, emended descriptions are given for many species mainly involving the addition of data on genome size and DNA G+C content, the former can be considered to be a valuable taxonomic marker in actinobacterial systematics. Many of the incongruities detected when the results of the present study were compared with existing classifications had been recognized from 16S rRNA gene trees though whole-genome phylogenies proved to be much better resolved. The few significant incongruities found between 16S/23S rRNA and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences. Similarly good congruence was found between the discontinuous distribution of phenotypic properties and taxa delineated in the phylogenetic trees though diverse non-monophyletic taxa appeared to be based on the use of plesiomorphic character states as diagnostic features.

/pdf/genome-based-taxonomic-classification-of-the-phylum-4uc1zrzg88.pdf

Genome-Based Taxonomic Classification of the Phylum Actinobacteria

DNA base composition was determined by reversed-phase high-performance liquid chromatography (HPLC). DNA was hydrolysed into nucleosides with nuclease P1 and bacterial alkaline phosphatase. The mixture of nucleosides was applied to HPLC without any further purification. One determination by chromatography needed 2 μg of hydrolysed nucleosides and took only 8 min. The relative standard error of nucleoside analysis was less than 1%. The system described here gives a direct and precise method for determining DNA base composition.

Research letterDetermination of DNA base composition by reversed-phase high-performance liquid chromatography

Archaeal abundance and diversity within different sections of summer sea-ice and sea water in prydz bay, antarctica: archaeal abundance and diversity within different sections of summer sea-ice and sea water in prydz bay, antarctica

Our model offers insight into the ecological properties of SRB and identifies a previously undocumented dimension of OM degradation. This targeted inhibition approach could provide a novel framework for illustrating how functional microbial taxa associate the composition and structure of the microbial community, molecular ecological network, and community assembly processes. ABSTRACT Sulfate-reducing bacteria (SRB) are essential functional microbial taxa for degrading organic matter (OM) in anoxic marine environments. However, there are little experimental data regarding how SRB regulates microbial communities. Here, we applied a top-down microbial community management approach by inhibiting SRB to elucidate their contributions to the microbial community during OM degradation. Based on the highly replicated microcosms (n = 20) of five different incubation stages, we found that many microbial community properties were influenced after inhibiting SRB, including the composition, structure, network, and community assembly processes. We also found a strong coexistence pattern between SRB and other abundant phylogenetic lineages via positive frequency-dependent selection. The relative abundances of the families Synergistaceae, Peptostreptococcaceae, Dethiosulfatibacteraceae, Prolixibacteraceae, Marinilabiliaceae, and Marinifilaceae were simultaneously suppressed after inhibiting SRB during OM degradation. A close association between SRB and the order Marinilabiliales among coexisting taxa was most prominent. They contributed to preserved modules during network successions, were keystone nodes mediating the networked community, and contributed to homogeneous ecological selection. The molybdate tolerance test of the isolated strains of Marinilabiliales showed that inhibited SRB (not the inhibitor of SRB itself) triggered a decrease in the relative abundance of Marinilabiliales. We also found that inhibiting SRB resulted in reduced pH, which is unsuitable for the growth of most Marinilabiliales strains, while the addition of pH buffer (HEPES) in SRB-inhibited treatment microcosms restored the pH and the relative abundances of these bacteria. These data supported that SRB could modify niches to affect species coexistence. IMPORTANCE Our model offers insight into the ecological properties of SRB and identifies a previously undocumented dimension of OM degradation. This targeted inhibition approach could provide a novel framework for illustrating how functional microbial taxa associate the composition and structure of the microbial community, molecular ecological network, and community assembly processes. These findings emphasize the importance of SRB during OM degradation. Our results proved the feasibility of the proposed study framework, inhibiting functional taxa at the community level, for illustrating when and to what extent functional taxa can contribute to ecosystem services.

Niche Modification by Sulfate-Reducing Bacteria Drives Microbial Community Assembly in Anoxic Marine Sediments

A Gram-stain-negative, non-motile, fine rod or short filament shaped, jacinth pigmented bacterium, designated strain WDS2C27T, was isolated from a marine solar saltern in Wendeng, Weihai, PR China (37°31′5″ N, 122°1′47″ E). Growth of WDS2C27T occurred at 20–42 °C (optimum 37 °C) and pH 6.5–8.5 (optimal pH 7.0–8.0). Optimal growth occurred in modified marine broth containing 6 % (w/v) NaCl. The major polar lipids in WDS2C27T were phosphatidylethanolamine, two unidentified aminolipids and one unidentified lipid. The major respiratory quinone of WDS2C27T was MK-6. The dominant fatty acids were iso-C15 : 0 and anteiso-C15 : 0. The DNA G+C content was 35.0 mol%. The nucleotide sequence of the 16S rRNA gene indicated that the most closely related strain was Psychroflexus planctonicus X15M-8T (92.0 % over 1452 bp). WDS2C27T showed 60.7 % average amino acid identity, 55.6 % percentage of conserved proteins, 75.0 % average nucleotide identity and 13.1 % digital DNA–DNA hybridization identity with the type species of the genus Psychroflexus , Psychroflexus torquis ATCC 700755T. The phenotypic and genotypic properties and phylogenetic inference indicated that WDS2C27T could be assigned to a novel species within a novel genus, for which the name Mesohalobacter halotolerans gen. nov., sp. nov. is proposed. Strain WDS2C27T (=MCCC 1H00133T=KCTC 52044T) is the type strain.

Mesohalobacter halotolerans gen. nov., sp. nov., isolated from a marine solar saltern.

A Gram-stain-negative, non-spore-forming, non-motile, short-rod-shaped, and aerobic bacterial strain (designated L72T) was isolated from propylene oxide saponification wastewater activated sludge obtained from a wastewater treatment facility in Binzhou (Shandong Province, PR China). Strain L72T grew between 25 and 40 °C (optimum growth at 30 °C). The pH range for growth was between 6.0 and 8.0 (optimum growth at pH 7.0). The range of NaCl concentrations for the growth of strain L72T was 0–3.0 % (w/v), with optimum growth at 1.0–2.0 % (w/v). The major cellular fatty acids of strain L72T were C19:0cyclo ω8c, C18:1ω7c, iso-C15:0, and anteiso-C15:0. Strain L72T contained Q–10 as the predominant respiratory quinone. The polar lipid profile was composed of Phosphatidylcholine, Glycolipid, Aminophospholipid, Phosphatidylethanolamine, Phosphatidylserine, Phosphatidyldimethylethanolamine, one unknown lipid (L) and two unidentified Phospholipids (PL). Genome sequencing revealed a genome size of 4,703,686 bp and a G + C content of 69.0 mol%. The 16S rRNA gene sequence similarities of strain L72T with other species were less than 94%. Phylogenetic analyses based on 16S rRNA gene sequences and genome data, revealed that strain L72T formed a distinct phylogenetic lineage within the order Hyphomicrobiales, separating them from members of all families. Strain L72T showed 70.7% average nucleotide identity and 18.6% digital DNA-DNA hybridization identity with the closely related species Rhodoligotrophos defluvii. Based on the phenotypic, phylogenetic and chemotaxonomic data, a new family Propylenellaceae fam. nov. comprising the genus Propylenella gen. nov. and species Propylenella binzhouense sp. nov. is proposed. The type strain is L72T (=  CCTCC AB 2019081T  =  KCTC 72254T).

Propylenella binzhouense gen. nov., sp. nov. isolated from activated sludge, and proposal of Propylenellaceae fam. nov

A Gram-stain-negative, facultatively aerobic, beige and slender bacterium, designed N1Y132T, was isolated from a sediment sample taken from coastal zone of Weihai, China (37°34'31.44" N, 122°9'15" E). Growth occurred at 15-33 °C (optimal 25-28 °C), at pH 6.5-8.5 (optimal pH 7.5), in 0-9% (w/v) NaCl (optimal 2.0-2.5%). According to the phylogenetic analysis based on the 16S rRNA gene sequences, strain N1Y132T showed the highest sequence similarity (97.9%) with Carboxylicivirga taeanensis JCM 19490T, followed by C. sediminis JR1T (97.4%), C. mesophila JCM 18290T (96.4%) and C. linearis FB218T (95.1%). Thus, strain N1Y132T was a member of the genus Carboxylicivirga. The average nucleotide identity (ANI) values between strain N1Y132T and C. sediminis JR1T, C. linearis FB218T and C. mesophila JCM 18290T were 74.8%, 71.1% and 74.9%, respectively. Chemotaxonomic analysis showed that the sole respiratory quinone was MK-7 and the major fatty acids (>5.0%) included iso-C15:0, anteiso-C15:0, iso-C13:0, iso-C14:0, iso-C15:0 3-OH, and C15:1ω6c. The polar lipids were consisted of a phosphatidylethanolamine, two phosphoaminolipids and six unidentified lipids. The DNA G+C content was 38.1 mol%. Based on the evidence presented in this study, strain N1Y132T represents a novel species of the genus Carboxylicivirga, for which the name Carboxylicivirga marinus sp. nov. is proposed. The type strain is N1Y132T (=KCTC 72934T=MCCC 1H00431T).

/pdf/carboxylicivirga-marinus-sp-nov-isolated-from-marine-570obahnbi.pdf

Zong-Jun Du

Papers

Archaeal abundance and diversity within different sections of summer sea-ice and sea water in prydz bay, antarctica: archaeal abundance and diversity within different sections of summer sea-ice and sea water in prydz bay, antarctica

Niche Modification by Sulfate-Reducing Bacteria Drives Microbial Community Assembly in Anoxic Marine Sediments

Mesohalobacter halotolerans gen. nov., sp. nov., isolated from a marine solar saltern.

Propylenella binzhouense gen. nov., sp. nov. isolated from activated sludge, and proposal of Propylenellaceae fam. nov

Carboxylicivirga marinus sp. nov., Isolated From Marine Sediment, and Genome Insight of the Genus Carboxylicivirga