Examinando por Autor "Johnson, D. Barrie"

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    Acidithiobacillus ferrianus sp. nov.: an ancestral extremely acidophilic and facultatively anaerobic chemolithoautotroph
    (Acidithiobacillus ferrianus sp. nov.: an ancestral extremely acidophilic and facultatively anaerobic chemolithoautotroph, 2020-03) Norris, Paul R.; Falagán, Carmen; Beltrán, Ana Moya; Castro, Matías; Quatrin, Raquel; Johnson, D. Barrie
    Strain MG, isolated from an acidic pond sediment on the island of Milos (Greece), is proposed as a novel species of ferrous iron- and sulfur-oxidizing Acidithiobacillus. Currently, four of the eight validated species of this genus oxidize ferrous iron, and strain MG shares many key characteristics with these four, including the capacities for catalyzing the oxidative dissolution of pyrite and for anaerobic growth via ferric iron respiration. Strain MG also grows aerobically on hydrogen and anaerobically on hydrogen coupled to ferric iron reduction. While the 16S rRNA genes of the iron-oxidizing Acidithiobacillus species (and strain MG) are located in a distinct phylogenetic clade and are closely related (98–99% 16S rRNA gene identity), genomic relatedness indexes (ANI/dDDH) revealed strong genomic divergence between strain MG and all sequenced type strains of the taxon, and placed MG as the first cultured representative of an ancestral phylotype of iron oxidizing acidithiobacilli. Strain MG is proposed as a novel species, Acidithiobacillus ferrianus sp. nov. The type strain is MGT(= DSM 107098T= JCM 33084T).Similar strains have been found as isolates or indicated by cloned 16S rRNA genes from several mineral sulfide mine sites.
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    Acidithiobacillus ferrianus sp. nov.: an ancestral extremely acidophilic and facultatively anaerobic chemolithoautotroph
    (Springer, 2020-03) Norris, Paul R.; Falagán, Carmen; Moya‑Beltrán, Ana; Castro, Matías; Quatrini, Raquel; Johnson, D. Barrie
    Strain MG, isolated from an acidic pond sediment on the island of Milos (Greece), is proposed as a novel species of ferrous iron- and sulfur-oxidizing Acidithiobacillus. Currently, four of the eight validated species of this genus oxidize ferrous iron, and strain MG shares many key characteristics with these four, including the capacities for catalyzing the oxidative dissolution of pyrite and for anaerobic growth via ferric iron respiration. Strain MG also grows aerobically on hydrogen and anaerobically on hydrogen coupled to ferric iron reduction. While the 16S rRNA genes of the iron-oxidizing Acidi-thiobacillus species (and strain MG) are located in a distinct phylogenetic clade and are closely related (98–99% 16S rRNA gene identity), genomic relatedness indexes (ANI/dDDH) revealed strong genomic divergence between strain MG and all sequenced type strains of the taxon, and placed MG as the first cultured representative of an ancestral phylotype of iron oxidizing acidithiobacilli. Strain MG is proposed as a novel species, Acidithiobacillus ferrianus sp. nov. The type strain is MGT (= DSM 107098T = JCM 33084T). Similar strains have been found as isolates or indicated by cloned 16S rRNA genes from several mineral sulfide mine sites. © 2020, The Author(s)
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    Acidithiobacillus sulfuriphilus sp. Nov.: An extremely acidophilic sulfur-oxidizing chemolithotroph isolated from a neutral pH environment
    (International Journal of Systematic and Evolutionary Microbiology, 2019) Falagan, Carmen; Moya-Beltran, Ana; Castro, Matías; Quatrini, Raquel; Johnson, D. Barrie
    The genus Acidithiobacillus currently includes seven species with validly published names, which fall into two major groups, those that can oxidize ferrous iron and those that do not. All seven species can use zero-valent sulfur and reduced sulfur oxy-anions as electron donors, are obligately chemolithotrophic and acidophilic bacteria with pH growth optima below 3.0. The 16S rRNA gene of a novel strain (CJ-2T) isolated from circum-neutral pH mine drainage showed 95–97 % relatedness to members of the genus Acidithiobacillus. Digital DNA–DNA hybridization (dDDH) values between strains and whole-genome pairwise comparisons between the CJ-2T strain and the reference genomes available for members of the genus Acidithiobacillus confirmed that CJ-2Trepresents a novel species of this genus. CJ-2T is a strict aerobe, oxidizes zero-valent sulfur and reduced inorganic sulfur compounds but does not use ferrous iron or hydrogen as electron donors. The isolate is mesophilic (optimum growth temperature 25–28C) and extremely acidophilic (optimum growth pH 3.0), though its pH optimum and maximum were significantly higher than those of non-iron-oxidising acidithiobacilli with validly published names. The major fatty acids of CJ-2T were C18: 1!7c, C:16: 1!7c/iso-C15: 0 2-OH, C16: 0 and C19: 0 cyclo !8c and the major respiratory quinone present was Q8. The name Acidithiobacillus sulfuriphilus sp. nov. is proposed, the type strain is CJ2T (=DSM 105150T=KCTC 4683T).
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    Acidithiobacillus sulfuriphilus sp. nov.: an extremely acidophilic sulfur-oxidizing chemolithotroph isolated from a neutral pH environment
    (International Journal of Systematic and Evolutionary Microbiology, 2019) Falagan, Carmen; Moya-Beltran, Ana; Castro, Matías; Quatrini, Raquel; Johnson, D. Barrie
    The genus Acidithiobacillus currently includes seven species with validly published names, which fall into two major groups, those that can oxidize ferrous iron and those that do not. All seven species can use zero-valent sulfur and reduced sulfur oxy-anions as electron donors, are obligately chemolithotrophic and acidophilic bacteria with pH growth optima below 3.0. The 16S rRNA gene of a novel strain (CJ-2T) isolated from circum-neutral pH mine drainage showed 95–97 % relatedness to members of the genus Acidithiobacillus. Digital DNA–DNA hybridization (dDDH) values between strains and whole-genome pairwise comparisons between the CJ-2T strain and the reference genomes available for members of the genus Acidithiobacillus confirmed that CJ-2Trepresents a novel species of this genus. CJ-2T is a strict aerobe, oxidizes zero-valent sulfur and reduced inorganic sulfur compounds but does not use ferrous iron or hydrogen as electron donors. The isolate is mesophilic (optimum growth temperature 25–28C) and extremely acidophilic (optimum growth pH 3.0), though its pH optimum and maximum were significantly higher than those of non-iron-oxidising acidithiobacilli with validly published names. The major fatty acids of CJ-2T were C18: 1!7c, C:16: 1!7c/iso-C15: 0 2-OH, C16: 0 and C19: 0 cyclo !8c and the major respiratory quinone present was Q8. The name Acidithiobacillus sulfuriphilus sp. nov. is proposed, the type strain is CJ2T (=DSM 105150T=KCTC 4683T).
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    Draft genome sequence of the nominated type strain of "Ferrovum myxofaciens," an acidophilic, iron-oxidizing betaproteobacterium
    (American Society for Microbiology, 2014) Moya-Beltrán, Ana; Cárdenas, Juan Pablo; Covarrubias, Paulo C.; Issotta, Francisco; Ossandon, Francisco J.; Grail, Barry M.; Holmes, David S.; Quatrini, Raquel; Johnson, D. Barrie
    Ferrovum myxofaciens” is an iron-oxidizing betaproteobacterium with widespread distribution in acidic low-temperature en vironments, such as acid mine drainage streams. Here, we describe the genomic features of this novel acidophile and investigate the relevant metabolic pathways that enable its survival in these environments.
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    Molecular systematics of the Genus Acidithiobacillus: Insights into the phylogenetic structure and diversification of the taxon
    (Frontiers Media S.A., 2017-01) Nuñez, Harold; Moya-Beltrán; Ana; Covarrubias, Paulo C.; Issotta, Francisco; Cárdenas, Juan Pablo; González, Mónica; Atavales, Joaquín; Acuña, Lillian G.; Johnson, D. Barrie; Quatrini, Raquel
    The acidithiobacilli are sulfur-oxidizing acidophilic bacteria that thrive in both natural and anthropogenic low pH environments. They contribute to processes that lead to the generation of acid rock drainage in several different geoclimatic contexts, and their properties have long been harnessed for the biotechnological processing of minerals. Presently, the genus is composed of seven validated species, described between 1922 and 2015: Acidithiobacillus thiooxidans, A. ferrooxidans, A. albertensis, A. caldus, A. ferrivorans, A. ferridurans, and A. ferriphilus. However, a large number of Acidithiobacillus strains and sequence clones have been obtained from a variety of ecological niches over the years, and many isolates are thought to vary in phenotypic properties and cognate genetic traits. Moreover, many isolates remain unclassified and several conflicting specific assignments muddle the picture from an evolutionary standpoint. Here we revise the phylogenetic relationships within this species complex and determine the phylogenetic species boundaries using three different typing approaches with varying degrees of resolution: 16S rRNA gene-based ribotyping, oligotyping, and multi-locus sequencing analysis (MLSA). To this end, the 580 16S rRNA gene sequences affiliated to the Acidithiobacillus spp. were collected from public and private databases and subjected to a comprehensive phylogenetic analysis. Oligotyping was used to profile high-entropy nucleotide positions and resolve meaningful differences between closely related strains at the 16S rRNA gene level. Due to its greater discriminatory power, MLSA was used as a proxy for genome-wide divergence in a smaller but representative set of strains. Results obtained indicate that there is still considerable unexplored diversity within this genus. At least six new lineages or phylotypes, supported by the different methods used herein, are evident within the Acidithiobacillus species complex. Although the diagnostic characteristics of these subgroups of strains are as yet unresolved, correlations to specific metadata hint to the mechanisms behind econiche-driven divergence of some of the species/phylotypes identified. The emerging phylogenetic structure for the genus outlined in this study can be used to guide isolate selection for future population genomics and evolutionary studies in this important acidophile model. © 2017 Nuñez, Moya-Beltrán, Covarrubias, Issotta, Cárdenas, González, Atavales, Acuña, Johnson and Quatrini.
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    Multi Locus Sequence Typing scheme for Acidithiobacillus caldus strain evaluation and differentiation
    (Elsevier Masson s.r.l., 2014) Nuñez, Harold; Loyola, David; Cárdenas, Juan Pablo; Holmes, David S.; Johnson, D. Barrie; Quatrini, Raquel
    Phenotypic, metabolic and genetic properties of several Acidithiobacillus caldus strains indicate the existence of as yet undefined levels of variation within the species. Inspite of this, intraspecies genetic diversity has not yet been explored in detail. In this study, the design and implementation of a Multi Locus Sequence Typing (MLST) scheme for At. caldus is described. This represents the first MLST-based study applied to industrial isolates of the species. Seven informative and discriminant MLST markers were selected using a sequence-driven approach and a custom-designed bioinformatic pipeline. The allelic profiles of thirteen At. caldus strains from diverse geographical origins and industrial settings were derived using this scheme. MLST-based population structure analysis indicated only moderate amounts of genetic diversity within the set of strains, further supporting their current assignment to a single species. Also, no clear evidence for geographical isolation could be derived from this study. However, the prevalence of sequence type 1 in heap leaching industrial settings support the view that bioprocess conditions and dynamics may have a strong influence on At. caldus (microbial) microdiversity patterns. The MLST scheme presented herein is a valuable tool for the identification and classification of strains of At. caldus for either ecological or evolutionary studies and possibly also for industrial monitoring purposes. © 2014 The Authors.