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Abstract: A Gram-negative, arsenite-oxidizing bacterial strain, designated VC-1, was isolated from sediment samples from the Camarones Valley in the Atacama Desert, Chile. Strain VC-1 was strictly aerobic, oxidase and catalase positive, rod shaped, of about 5.5μm in length and 0.5–1.0μm in diameter. It was motile by means of multiple polar flagella. The phylogenetic reconstruction of the 16S rRNA gene sequence, an MLSA study by concatenating six genes, and DDH studies indicated that the strain differed genotypically from its closest relatives and was therefore recognized as a new species within the genus Pseudomonas. Phenotypic analysis combining metabolic tests, fatty acid profiles and MALDI-TOF profiles of total cell extracts supported the classification of the new species for which we propose the designation Pseudomonas arsenicoxydans sp. nov. The type strain is accessible under the culture collection numbers CCUG 58201T and CECT 7543T. [Copyright &y& Elsevier]

A Gram-staining-negative non endospore-forming strain, T13(2019) T was isolated from water samples from Atlantic salmon ( Salmo salar ) fry culture in Chile and studied in detail for its taxonomic position. The isolate shared highest 16S rRNA gene sequence similarities with the type strains of Flavobacterium chungangense (98.44 %) followed by Flavobacterium tructae and Flavobacterium spartansii (both 98.22 %). Menaquinone MK-6 was the predominant respiratory quinone in T13(2019) T . Major polar lipids were phosphatidylethanolamine, an ornithine lipid and the unidentified polar lipids L1, L3 and L4 lacking a functional group. The major polyamine was sym -homospermidine. The fatty acid profile contained major amounts of iso-C 15 : 0 , iso-C 15 : 0 3-OH, iso-C 17 : 0 3-OH, C 15 : 0 , summed feature 3 (C 16 : 1  ω7 c and/or iso-C 15 : 0 2-OH) and various hydroxylated fatty acids in smaller amounts, among them iso-C 16 : 0 3-OH, and C 15 : 0 3-OH, which supported the grouping of the isolate into the genus Flavobacterium . Physiological/biochemical characterisation and ANI calculations with the type strains of the most closely related species allowed a clear phenotypic and genotypic differentiation. In addition it became obvious, that the type strains of F. tructae and F. spartansii showed 100 % 16S rRNA gene sequence similarities and ANI values of 97.21%/ 97.59 % and DDH values of 80.40 % [77.5 and 83%]. These data indicate that F. tructae and F. spartansii belong to the same species and it is proposed that F. spartansii is a later heterotypic synonym of F. tructae . For strain T13(2019) T (=CIP 111411 T =LMG 30298 T =CCM 8798 T ) a new species with the name Flavobacterium salmonis sp. nov. is proposed.

A Gram-stain positive, pleomorphic, oxidase-negative, non-motile isolate from the ulcer of a farmed Atlantic salmon ( Salmo salar ), designated strain T11b T , was subjected to a comprehensive taxonomic investigation. A comparative analysis of the 16S rRNA gene sequence showed highest similarities to the type strains of Pseudarthrobacter siccitolerans (98.1 %) and Arthrobacter methylotrophus and Pseudarthrobacter phenanthrenivorans (both 98.0 %). The highest ANI value observed between the assembled genome of T11b T and the publicly available Pseudarthrobacter and Arthrobacter type strain genomes were 81.15 and 80.99 %, respectively. The major respiratory quinone was menaquinone MK-9(H 2 ). The polyamine pattern contained predominantly spermidine. The polar lipid profile consisted of the major lipids diphosphatidylglycerol, phosphatidylglycerol, monogalactosyl-diacylglycerol and dimannosylglyceride. Minor amouts of trimannosyldiacylglycerol and phosphatidylinositol were also detected. The peptidoglycan was of the type A3α l-Lys-l-Ser-l-Thr-l-Ala (A11.23). In the fatty acid profile, anteiso and iso branched fatty acids predominated (anteiso C 15 : 0 , iso C 16 : 0 , anteiso C 17 : 0 ). Moderate to low DNA-DNA similarities, physiological traits as well as unique traits in the fatty acid pattern distinguished strain T11b T from the next related species. All these data point to the fact that strain T11b T represents a novel species of the genus Arthrobacter for which we propose the name Arthrobacter ulcerisalmonis sp. nov. The type strain is T11b T (=CIP 111621 T =CCM 8854 T =LMG 30632 T =DSM 107127 T ).

One slightly beige-white pigmented, Gram-stain-negative, rod-shaped bacterium, strain I-STPP5b T , was isolated from the trachea of a Gentoo penguin chick individual ( Pygoscelin papua ) investigated in Fildes Bay, Chilean Antarctic (62° 12' S, 58° 57' W). I-STPP5b T consists of a 3.4 Mb chromosome with a DNA G+C content of 44.4 mol%. Of the 3056 predicted genes, 1206 were annotated as hypothetical proteins and 51 were tRNAs. Phylogenetic analysis based on nearly full-length 16S rRNA gene sequences showed that the isolate shared a 16S rRNA gene sequence identity to the type strains of Psychrobacter phenylpyruvicus (98.8 %), Psychrobacter arenosus and Psychrobacter pasteurii (both 98.3 %), Psychrobacter piechaudii (98.2 %) and Psychrobacter sanguinis (98.1 %), but 16S rRNA gene sequence similarities to all other Psychrobacter species were ≤98.0 %. Partial gyrB nucleotide and amino acid sequence similarities among strain STPP5b T and the next related type strains were all below 81.8 and 92.9%, respectively. DNA-DNA hybridisation (DDH) with P. phenylpyruvicus LMG 5372 T , P. arenosus DSM 15389 T and P. sanguinis DSM 23635 T also showed low values (all below 30 %). The main cellular fatty acids of the strain were C 18 : 1 ω9c and C 16 : 1 ω7c and/or C 16 : 1 ω6c. Based on phylogenetic, chemotaxonomic, genomic and phenotypic analyses we propose a new species of the genus Psychrobacter, with the name Psychrobacter pygoscelis sp. nov. and strain I-STPP5b T (=CIP 111410 T = CCM 8799 T =LMG 30301 T ) as type strain.

A pink pigmented, Gram-negative, rod-shaped, non-spore-forming bacterium (strain 36B243 T ), was isolated from the spleen of a black rock cod (Notothenia coriiceps, Richardson 1844) in the Chilean Antarctica. Strain 36B243 T has a 5.26 Mb chromosome with a DNA G + C content of 35.4 mol%. The draft genome includes the prediction and annotation of 4585 coding genes, and 46 tRNA, 1 tmRNA, and 2735 hypothetical proteins. Phylogenetic analysis based on the 16S rRNA gene sequence placed strain 36B243 T into the genus Pedobacter with high sequence similarity to the type strains of Pedobacter sandarakinus (97.5%) and Pedobacter petrophilus (97.1%). Sequence similarities to type strains of all other current Pedobacter species were below 97.1%. Predominant fatty acids are summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c) and iso-C 15:0 followed by iso-C 17:0 3-OH and C 16:0 . The major respiratory quinone was menaquinone MK-7. The polar lipid profile contained the major lipids phosphatidylethanolamine, five unidentified aminolipids, two lipids lacking a functional group and two minor glycolipids and one lipid lacking a functional group. An alkali-stable lipid was present. The polyamine pattern contained the predominant compound sym-homospermidine. Characterization by 16S rRNA gene sequence analysis, physiological parameters, pigment analysis, ubiquinone, polar lipid, and fatty acid composition revealed that strain 36B243 T represents a new species of the genus Pedobacter. For this reason, we propose the name Pedobacter nototheniae sp. nov. with the type strain 36B243 T (= LMG 30634 T  = CCM 8855 T  = CIP 111622 T ).

An orange-pigmented, oxidase-positive bacterial strain (I-41R45 T ), isolated from the kidney of a black rock cod fish sampled in the Chilean Antarctic was studied in a polyphasic taxonomic investigation. Cells of the isolate were coccoid and stained Gram-negative. A comparison of the 16S rRNA gene sequence of strain I-41R45 T with sequences of type strains of most closely related Paracoccus species showed highest sequence similarities to Paracoccus hibiscisoli (98.4 %), Paracoccus marcusii (98.3 %), Paracoccus haeundaensis and Paracoccus carotinifaciens (both 98.2 %). 16S rRNA gene sequence similarities to all other Paracoccus species were below 97 %. The draft genome of strain I-41R45 T had a size of 4.59 Mb with a DNA G+C content of 65.26 mol% and included the prediction and annotation of 4426 coding genes, 1973 protein-coding genes and 46 tRNAs. The fatty acid profile of strain I-41R45 T consisted mainly of the major fatty acids C 18 : 1 ω 7 c/ω 9t /ω 12t and C 18:0 , typical of the genus Paracoccus . DNA-DNA hybridizations between I-41R45 T and type strains of P. hibiscisoli, P. marcusii and P. haeundaensis resulted in similarity values of 45 % (reciprocal 26 %), 66 % (reciprocal 61 %), and 29 % (reciprocal 36 %), respectively. DNA-DNA hybridization results, together with the differentiating biochemical and chemotaxonomic properties, showed that strain I-41R45 T represents a novel Paracoccus species, for which the name Paracoccus nototheniae sp. nov. (type strain I-41R45 T =CCM 8875 T =CIP 111632 T ), is proposed.

Two bacterial strains, designated Sa 1147-06(T) and Sa 1143-06, were isolated from Atlantic salmon (Salmo salar) farmed in Lake Chapo, Chile, and were studied using a polyphasic approach. Both isolates were very similar; cells were rod-shaped, formed yellow-pigmented colonies and were Gram-reaction-negative. Based on 16S rRNA gene sequence analysis, strains Sa 1147-06(T) and Sa 1143-06 shared 100  % sequence similarity and showed 98.9 and 97.5 % sequence similarity to Chryseobacterium jeonii AT1047(T) and Chryseobacterium antarcticum AT1013(T), respectively. Sequence similarities to all other members of the genus Chryseobacterium were below 97.3  %. The major fatty acids of strain Sa 1147-06(T) were iso-C₁₃:₀, iso-C₁₅:₀, anteiso-C₁₅:₀ and iso-C₁₇:₁ω9c, with iso-C₁₅:₀ 3-OH, iso-C₁₆:₀ 3-OH and iso-C₁₇:₀ 3-OH constituting the major hydroxylated fatty acids. DNA-DNA hybridizations with C. jeonii JMSNU 14049(T) and C. antarcticum JMNSU 14040(T) gave relatedness values of 20.7  % (reciprocal 15.1  %) and 15.7 % (reciprocal 25.7  %), respectively. Together, the DNA-DNA hybridization results and differentiating biochemical properties showed that strains Sa 1147-06(T) and Sa 1143-06 represent a novel species, for which the name Chryseobacterium chaponense sp. nov. is proposed. The type strain is Sa 1147-06(T) (=DSM 23145(T) =CCM 7737(T)).