From ecophysiology to cultivation methodology: filling the knowledge gap between uncultured and cultured microbes.

Earth is dominated by a myriad of microbial communities, but the majority fails to grow under in situ laboratory conditions. The basic cause of unculturability is that bacteria dominantly occur as biofilms in natural environments. Earlier improvements in the culture techniques are mostly done by optimizing media components. However, with technological advancement particularly in the field of genome sequencing and cell imagining techniques, new tools have become available to understand the ecophysiology of microbial communities. Hence, it becomes easier to mimic environmental conditions in the culture plate. Other methods include co-culturing, emendation of growth factors, and cultivation after physical cell sorting. Most recently, techniques have been proposed for bacterial cultivation by employing genomic data to understand either microbial interactions (network-directed targeted bacterial isolation) or ecosystem engineering (reverse genomics). Hopefully, these techniques may be applied to almost all environmental samples, and help fill the gaps between the cultured and uncultured microbial communities.

Nocardiopsis deserti sp. nov., isolated from a high altitude Atacama Desert soil.

The taxonomic status of a Nocardiopsis strain, designated H13T, isolated from a high altitude Atacama Desert soil, was established by using a polyphasic approach. The strain was found to have chemotaxonomic, cultural and morphological characteristics consistent with its classification within the genus Nocardiopsis and formed a well-supported clade in the Nocardiopsis phylogenomic tree together with the type strains of Nocardiopsis alborubida, Nocardiopsis dassonvillei and Nocardiopsis synnematoformans. Strain H13T was distinguished from its closest relatives by low average nucleotide identity (93.2-94.9 %) and in silico DNA-DNA hybridization (52.5-62.4 %) values calculated from draft genome assemblies and by a range of phenotypic properties. On the basis of these results, it is proposed that the isolate be assigned to the genus Nocardiopsis as Nocardiopsis deserti sp. nov. with isolate H13T (=CGMCC 4.7585T=KCTC 49249T) as the type strain.

Vitreimonas flagellata gen. nov., sp. nov., a novel member of the family Hyphomonadaceae isolated from an activated sludge sample.

A coccobacilli-shaped proteobacterium, designated strain SYSU XM001T, was isolated from an activated sludge sample collected from JiMei sewage treatment plant, Xiamen, PR China. Cells were Gram-stain-negative, catalase-positive and oxidase-negative. The 16S rRNA gene sequence of strain SYSU XM001T shared less than 92 % sequence identities with members of the class Alphaproteobacteria, with highest sequence similarity to Aquidulcibacter paucihalophilus TH1-2T (91.6 %; family Hyphomonadaceae, order Rhodobacterales). The strain exhibited growth at 25-37 °C, pH 7.0-9.0 and in the presence of up to 1 % (w/v) NaCl. Its chemotaxonomic features included ubiquinone-10 as the respiratory isoprenologue, iso-C16 : 0, 10-methyl C16 : 0 TSBA and anteiso-C17 : 0 as major cellular fatty acids and monoglycosyldiglyceride, glucuronopyranosyldiglyceride and two unidentified glycolipids as the main polar lipids. The DNA G+C content was determined to be 62.9 % (draft genome). Analyses of the phylogenetic data and differences in the chemotaxonomic and biochemical features from related genera in the family Hyphomonadaceae indicated that strain SYSU XM001T merits representation of a novel species of a novel genus, for which the name Vitreimonas flagellata gen. nov., sp. nov. is proposed. The type strain of Vitreimonas flagellata is SYSU XM001T (=CGMCC 1.16661T=KCTC 62915T).

Genome analysis reveals that Nocardiopsis baichengensis Li et al. 2006 is a later heterotypic synonym of Nocardiopsis halophila Al-Tai and Ruan 1994.

A genome-based phylogeny of the publicly available genomes of the genus Nocardiopsis reveals that Nocardiopsis baichengensis YIM 90130T is closely related to Nocardiopsis halophila DSM 44494T. Overall genome relatedness indices between the genomes of the two species were above the threshold values necessary for defining a new species (dDDH, 82.9 %; ANIb, 97.8 %; ANIm, 98.3 %; AAI, 97.7 %). Both species showed a similar G+C content of 73.6 mol% in their genomes. Considering the high similarity between the genomes of the two species, we propose that Nocardiopsisbaichengesis Li et al. 2006 should be reclassified as a later heterotypic synonym of Nocardiopsis halophila Al-Tai and Ruan 1994.

Nesterenkonia natronophila sp. nov., an alkaliphilic actinobacterium isolated from a soda lake, and emended description of the genus Nesterenkonia.

A Gram-stain-positive, alkaliphilic, moderately halophilic, cocci-shaped actinobacterium (strain M8T) was isolated from a sample of soda lake sediment (Lake Magadi, Tanzania). The isolate was heterotrophic, strictly aerobic, catalase-positive, oxidase-negative and formed orange-pigmented colonies in solid media. It utilized various sugars and organic acids as sole carbon sources. The organism grew at 10-38 °C, at pH 7.5-12.0 and in the presence of 1-12 % (w/v) NaCl, with optimal growth occurring at 30 °C, at pH 10 and in the presence of 5 % (w/v) NaCl. Comparative 16S rRNA gene sequence analysis showed that strain M8T belonged to the genus Nesterenkonia, sharing the closest similarities to Nesterenkoniahalobia DSM 20541T, Nesterenkoniahalophila YIM 70179T and Nesterenkoniaaethiopica DSM 17733T (97.5, 97.5 and 97.1 %, respectively). The characteristic diamino acid of strain M8T was found to be lysine and the polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two unidentified glycolipids and two unidentified phospholipids. The DNA G+C content was 61.8 mol% (genome). The strain contained MK-7, MK-9 and MK-10 as the respiratory quinones, and the major fatty acids (>10 %) comprised anteiso-C17 : 0 and anteiso-C15 : 0. On the basis of phylogenetic analyses and phenotypic data, strain M8T is considered to represent a novel species, for which the name Nesterenkonianatronophila sp. nov. is proposed. The type strain is M8T (=JCM 32100T=CGMCC 1.16706T=MCC 3367T).

Aestuariisphingobium litorale gen. nov., sp. nov., a novel proteobacterium isolated from a water sample of Pearl River estuary.

Strain SYSU M10002T was isolated from a water sample collected from the coastal region of Pearl River estuary, Guangdong Province, southern China. The taxonomic position of the isolate was investigated by polyphasic taxonomic approaches. The isolate was found to be Gram-negative, non-motile, short rods and aerobic. The strain was able to grow at 14-37 °C, pH 6.0-10.0 and in the presence of up to 0.5% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU M10002T is a member of the family Sphingomonadaceae, with high sequence similarity to Sphingorhabdus buctiana T5T (95.1%). Overall genomic related indices between the genome of strain SYSU M10002T and those of related strains were low to moderate (AAI values < 64.3%; POCP values < 58%), indicating that strain SYSU M10002T represents a novel lineage within the family Sphinogomonadaceae. Strain SYSU M10002T contained homospermidine as its polyamine. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, two unidentified phospholipids and an unidentified aminolipid. Ubiquinone Q-9 (44.9%) and Q-10 (43.2%) were the dominant respiratory quinones, along with a minor amount of Q-8 (11.9%). The predominant cellular fatty acids (> 10%) identified were summed feature 3 (C16:1ω7c and/or C16:1ω6c), summed feature 8 (C18:1ω7c) and C14:0 2-OH. The genomic DNA G+C content was 64.0%. Based on the analyses of the phenotypic, genotypic and phylogenetic characteristics, strain SYSU M10002T is determined to represent a novel species of a novel genus, for which the name Aestuariisphingobium litorale gen. nov., sp. nov. is proposed. The type strain of the species is SYSU M10002T (= KCTC 52944T = NBRC 112961T).

Flaviflagellibacter deserti gen. nov., sp. nov., a novel member of the order Rhizobiales isolated from a desert soil.

A motile, rod-shaped and yellow coloured proteobacterium, designated strain SYSU D60017T, was isolated from a desert soil sample. The bacterium was found to be an obligately aerobic, mesophilic and neutrophilic chemo-heterotroph. Cells were observed to be Gram-stain negative, catalase positive and oxidase positive. The major cellular fatty acids were identified as C19:0ω8c cyclo and Summed Feature 8 (C18:1ω7c and/or C18:1ω6c). The main respiratory quinone identified was ubiquinone-10. The DNA G + C content was determined to be 63.8% based on draft genome sequence data. The polar lipids detected were identified as diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and five unidentified polar lipids. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU D60017T is a member of the order Rhizobiales, but forms a distinct phylogenetic lineage. The differences in the phenotypic characteristics from members of related genera and its distinct phylogenetic position suggested that the isolate SYSU D60017T represents a novel species of a novel genus within the order Rhizobiales, for which the name Flaviflagellibacter deserti gen. nov., sp. nov. is proposed. The type strain of the new taxon is SYSU D60017T (= CGMCC 1.16444T = NBRC 112958T).

Botryobacter ruber gen. nov., sp. nov., a novel member of the family Hymenobacteraceae.

Strain SYSU D60016T, a rod-shaped bacterium that tends to form clusters, was isolated from a soil sample collected from the Gurbantunggut desert, China. Cells were Gram-stain-negative, catalase-negative and oxidase-positive. The 16S rRNA gene sequence of strain SYSU D60016T shared less than 94 % sequence identity with members of the family Hymenobacteraceae. The strain exhibited growth at 15-50 °C, pH 6-8 and in the presence of up to 3 % (w/v) NaCl. Its chemotaxonomic features included MK-7 as the respiratory menaquinone, iso-C15 : 0 and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B) as major cellular fatty acids and phosphatidylethanolamine as the main polar lipid. The DNA G+C content was determined to be 50.1 % (genome). Analyses of the phylogenetic data and differences in the chemotaxonomic and biochemical features from related genera in the family Hymenobacteraceae indicated that strain SYSU D60016T merits representation of a novel species of a novel genus in the family Hymenobacteraceae. The name Botryobacter ruber gen. nov., sp. nov. is, therefore, proposed to represent the phylogenetic position of strain SYSU D60016T in the family Hymenobacteraceae. The type strain of the proposed new taxon is SYSU D60016T (=KCTC 52794T=NBRC 112957T).

Georgenia alba sp. nov., a novel halotolerant actinobacterium isolated from a desert sand sample.

Strain SYSU D8008T was isolated from a desert sand sample collected from Saudi Arabia. The strain was observed to be Gram-stain positive, non-motile and aerobic. It can grow at 15-37 °C, pH 6.0-10.0 and can tolerant up to 7% (w/v) NaCl. Pairwise comparison of the 16S rRNA gene sequence indicated that strain SYSU D8008T shares high sequence similarities with Georgenia deserti SYSU D8004T (96.8%) and Georgenia halophila YIM 93316T (96.8%). Menaquinone MK-8(H4) was detected as the respiratory isoprenologue. The polar lipid profile of strain SYSU D8008T was found to consist of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two phosphatidylinositol mannosides, an unidentified glycolipid and an unidentified phospholipid. Strain SYSU D8008T was found to contain anteiso-C15:0 and iso-C15:0 as the predominant fatty acids. Galactose, glucose and rhamnose were detected as the whole cell sugars. Based on the phenotypic, genotypic and phylogenetic characteristics, strain SYSU D8008T can be differentiated from other closely related members of the genus Georgenia. The strain SYSU D8008T, therefore, is concluded to represent a novel species of the genus Georgenia, for which the name Georgenia alba sp. nov. is proposed. The type strain is SYSU D8008T (= CGMCC 1.15800T = KCTC 39988T).

Aquabacterium tepidiphilum sp. nov., a moderately thermophilic bacterium isolated from a hot spring.

A Gram-stain-negative, aerobic, non-spore-forming and rod-shaped bacterium, designated YIM 730274T, was isolated from a sediment sample collected from a hot spring located in Tibet, PR China, and was characterized by using a polyphasic taxonomy approach. Cells were motile by means of a polar flagellum. The strain was oxidase- and catalase-positive, and contained polyalkanoates and polyphosphate as storage polymers. Growth occurred at 25-50 °C, at pH 6.0-8.5 and with 0.5-1.0 % NaCl. The major fatty acids (>10 %) were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The known polar lipids comprised of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylserine. The isoprenoid quinone was Q-8. The G+C content of genomic DNA was 70.7 mol%. The results of phylogenetic analyses based on 16S rRNA gene sequences indicated that the strain forms a monophyletic branch at the periphery of the evolutionary radiation occupied by the genus Aquabacterium in the class Betaproteobacteria. The most closely related phylogenetic neighbours were Aquabacterium limnoticumABP-4T (97.8 % 16S rRNA gene sequence identity) and Aquabacterium communeB8T (97.2 % 16SrRNA gene sequence identity). DNA-DNA relatedness values between YIM 730274T and A. limnoticum KCTC 23306T (46.4±0.4 %) and A. commune DSM 11901T (42.2±1.2 %) were well below the 70 % limit for species identification. YIM 730274T was distinguishable from other members of the genus Aquabacterium by the differences in phenotypic, chemotaxonomic and genotypic characteristics. YIM 730274T merits recognition as a representative of a novel species of the genus Aquabacterium. It is proposed that the isolate should be classified in the genus Aquabacterium as representing a novel species, Aquabacteriumtepidiphilum sp. nov. The type strain is YIM 730274T (=KCTC 52716T=CCTCC AB 2016295T).

Blastococcus deserti sp. nov., isolated from a desert sample.

A Gram-positive and aerobic actinobacterium, strain SYSU D8006T, was isolated from a desert sand sample collected from Gurbantunggut desert, China. Phenotypically, the strain was found to grow at 14-50 °C, pH 6.0-9.0 and in the presence of up to 4% (w/v) NaCl. The chemotaxonomic features of strain SYSU D8006T included menaquinone MK-9(H4) as the respiratory quinone, diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside as known polar lipids, iso-C15:0, iso-C16:0, C17:1ω8c and C18:1ω9c as the predominant fatty acids, and arabinose, galactose and glucose as the whole cell sugars. Strain SYSU D8006T shared the highest 16S rRNA gene sequence identity with Blastococcus jejuensis DSM 19597T (98.2%). Based on the analyses of the phenotypic, genotypic and phylogenetic characteristics, strain SYSU D8006T is characterized to represent a novel species of the genus Blastococcus, for which the name Blastococcus deserti sp. nov. is proposed. The type strain is SYSU D8006T (= CGMCC 1.15935T = KCTC 49026T = CPCC 204618T).

Streptomyces desertarenae sp. nov., a novel actinobacterium isolated from a desert sample.

A Streptomyces isolate, designated strain SYSU D8023T, was isolated from a desert sand sample collected from Gurbantunggut desert, China. The characterisation of the isolate was achieved using a polyphasic taxonomic approach. The isolate was found to be Gram-positive and aerobic. The strain was found to be able to grow at 14-50 °C, pH 6.0-9.0 and in the presence of up to 7% (w/v) NaCl. Strain SYSU D8023T contains LL-diaminopimelic acid as a cell wall diamino acid. The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified glycolipid and an unidentified phospholipid. MK-9(H6) and MK-9(H8) were detected as the respiratory quinones, and anteiso-C15:0, iso-C16:0 and anteiso-C17:0 as the predominant fatty acids. Pairwise comparison of the 16S rRNA gene sequences indicated that strain SYSU D8023T has a sequence identity of 97.9% to Streptomyces barkulensis RC 1831T. The DNA G + C content of strain SYSU D8023T was determined to be 70.1 mol%. Based on the analyses of the phenotypic, genotypic and phylogenetic characteristics, strain SYSU D8023T was concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces desertarenae sp. nov. is proposed. The type strain of the species is SYSU D8023T (= CGMCC 4.7455T = KCTC 49023T).

Desertimonas flava gen. nov., sp. nov. isolated from a desert soil, and proposal of Ilumatobacteraceae fam. nov.

A non-motile, coccobacilli-shaped and yellow-coloured bacterium, designated strain SYSU D60003T, was isolated from a desert soil sample. Cells were Gram-stain-positive, catalase-negative and oxidase-positive. The whole cell hydrolysates contained ll-diaminopimelic acid as the diagnostic amino acid. The major fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C16 : 0. The respiratory menaquinones were MK-9(H8), MK-9(H4) and MK-9(H6). The DNA G+C content was determined to be 70.2 % (genome). The polar lipids detected were diphosphatidylglycerol, an unidentified glycolipid and seven unidentified polar lipids. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU D60003T belonged to the order Acidimicrobiales (class Acidimicrobiia), but formed a clade closely linked to members of the genus Ilumatobacter. Data from a polyphasic taxonomy study suggested that the isolate represents a novel species of a novel genus in the order Acidimicrobiales, for which the name Desertimonas flava gen. nov., sp. nov. is proposed. The type strain of the proposed new taxon is SYSU D60003T (=KCTC 39917T=NBRC 112924T). Additionally, the new taxon along with the genus Ilumatobater (family unassigned) were distinctly separated from the related families Acidimicrobiaceae, Iamiaceae and 'Microtrichaceae' in the phylogenetic trees, besides presenting a unique 16S rRNA gene signature nucleotides. Therefore, we propose a new family Ilumatobacteraceae fam. nov. within the order Acidimicrobiales to accommodate members of these two genera.

Nesterenkonia endophytica sp. nov., isolated from roots of Glycyrrhiza uralensis.

A Gram-positive and non-motile actinobacterium, designated strain EGI 60016T, was isolated from healthy roots of Glycyrrhiza uralensis F. collected from Xinyuan County, Xinjiang Province, China. The 16S rRNA gene sequence of strain EGI 60016T was found to show 97.5 and 97.3 % sequence similarities to Nesterenkonia rhizosphaerae EGI 80099T and Nesternkonia massiliensis NP1T, respectively. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain EGI 60016T formed a distinct clade with N. rhizosphaerae EGI 80099T and N. massiliensis NP1T. The polar lipids detected for strain EGI 60016T were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, an unidentified glycolipid, an unidentified lipid and an unidentified phospholipid. The DNA G+C content was determined to be 64.1 mol%. Other chemotaxonomic features of strain EGI 60016T included MK-7, MK-8 and MK-9 as the respiratory quinones, and anteiso-C15 : 0 and anteiso-C17 : 0 as the major fatty acids. Based on the results of the phylogenetic analysis supported by morphological, physiological, chemotaxonomic and other differentiating phenotypic characteristics, strain EGI 60016T is considered to represent a novel species of the genus Nesterenkonia, for which the name Nesterenkonia endophytica sp. nov. is proposed. The type strain is EGI 60016T (=CCTCC AB 2017176T=NBRC 112398T).

Aurantisolimonas haloimpatiens gen. nov., sp. nov., a bacterium isolated from soil.

A Gram-stain negative, strictly aerobic and non-motile bacterium, designated strain BN130233T, was isolated from a soil sample collected from Gyeongsangbuk-do, Republic of Korea. Colonies were orange in colour, with wet and smooth surfaces. Phylogenetic analyses based on the 16S rRNA gene sequences resulted in strain BN130233T forming a cluster with members of the family Chitinophagaceae Kämpfer et al. 2011, while sharing the highest sequence identity of 91.2 % with Chitinophaga niastensis JS16-4T. Good growth was observed at 20-28 °C, pH 7.0 and in the absence of NaCl. The major fatty acids were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH. The respiratory quinone was MK-7. Major polar lipids contained phosphatidylethanolamine, an unidentified phospholipid, three unidentified aminolipids and eight unidentified lipids. The genomic DNA G+C content was 40.6 mol%. Phenotypic and chemotaxonomic characteristics together with 16S rRNA gene sequence analyses showed that strain BN130233T was distinct from its close phylogenetic relatives in the family ChitinophagaceaeKämpfer et al. 2011. The strain is, therefore, proposed as a representative of a new genus and new species with the name Aurantisolimonas haloimpatiens. The type strain of Aurantisolimonas haloimpatiens is BN130233T (=CCTCC AB 2017051T=KCTC 42642T).

Stackebrandtia soli sp. nov., a novel actinobacterium isolated from a soil sample.

An aerobic actinobacterium, strain AN130378T, was isolated from a soil sample collected in Korea and subjected to taxonomic investigation using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence data showed that strain AN130378T is a member of the genus Stackebrandtia, with sequence similarities of 97.3 % to Stackebrandtia albiflava YIM 45751T and 97.1 % to Stackebrandtia endophytica YIM 64602T. The whole-cell hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid, and galactose, glucose and xylose. The major menaquinones were MK-11(H4), MK-10(H4) and MK-11(H6), while the major fatty acids were identified as iso-C15 : 0, anteiso-C17 : 0, anteiso-C15 : 0, iso-C17 : 0 and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, an unidentified aminophospholipid, four unidentified glycolipids, three unidentified phospholipids and two unidentified polar lipids. The G+C content of the genomic DNA was determined to be 67.7 mol%. All chemotaxonomic and genotypic data indicated that the strain belongs to the genus Stackebrandtia. On the basis of morphological, chemotaxonomic data and phylogenetic analysis, strain AN130378T is considered to represent a novel species within the genus Stackebrandtia, for which the name Stackebrandtia soli sp. nov. is proposed. The type strain is AN130378T (=DSM 103573T=KCTC 39809T).

Georgenia deserti sp. nov., a halotolerant actinobacterium isolated from a desert sample.

Strain SYSU D8004T was isolated from a sample collected from an arid area in Saudi Arabia. The isolate was Gram-stain-positive, non-motile, aerobic and non-spore-forming. It could grow at 4-45 °C, at pH 6.0-10.0 and in the presence of up to 17 % (w/v) NaCl. Pairwise comparison of the 16S rRNA gene sequences indicated that strain SYSU D8004T shared highest sequence similarity with Georgenia halophila YIM 93316T (96.5 %). Menaquinone MK-8(H4) was detected as the respiratory quinone. The polar lipid profile of strain SYSU D8004T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two phosphatidylinositol mannosides, two unidentified phospholipids and an unidentified glycolipid. Strain SYSU D8004T contained anteiso-C15 : 0, iso-C15 : 0 and C14 : 0 as the predominant fatty acids (>10 %). Galactose, glucose and rhamnose were detected as whole-cell sugars. Based on analyses of the phenotypic, genotypic and phylogenetic characteristics, it was determined that strain SYSU D8004T could be differentiated from other closely related members of the genus Georgenia. Strain SYSU D8004T is therefore considered to represent a novel species of the genus Georgenia, for which the name Georgenia deserti sp. nov. is proposed. The type strain is SYSU D8004T (=CGMCC 1.15793T=KCTC 39987T).

Saccharopolyspora deserti sp. nov., a novel halotolerant actinobacterium isolated from a desert.

Strain SYSU D8010T was isolated from a desert sand sample collected in Saudi Arabia. The taxonomic position of the isolate was investigated by the polyphasic taxonomic approach. The isolate was found to be Gram-positive and aerobic. The strain was able to grow at 14-40 °C, pH 5.0-9.0 and in the presence of up to 22 % (w/v) NaCl. Strain SYSU D8010T contained meso-diaminopimelic acid as cell-wall diamino acid, and arabinose, fucose, galactose, glucose and rhamnose as the whole-cell sugars. The primary polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositolmannosides. Menaquinone MK-9(H4) was detected as the respiratory quinone; and anteiso-C17 : 0, iso-C16 : 0, iso-C15 : 0 and iso-C17 : 0 as the predominant fatty acids. Pairwise comparison of the 16S rRNA gene sequences indicated that strain SYSU D8010T had a sequence similarity of 97.8 % to Saccharopolyspora halophila YIM 90500T. The genomic DNA G+C content of strain SYSU D8010T was determined to be 69.9 mol%. Based on the analyses of the phenotypic, genotypic and phylogenetic characteristics, strain SYSU D8010T was determined to represent a novel species of the genus Saccharopolyspora, for which the name Saccharopolyspora deserti sp. nov. is proposed. The type strain of the species is SYSU D8010T (=KCTC 39989T=CPCC 204620T).

Limoniibacter endophyticus gen. nov., sp. nov., an alphaproteobacterium isolated from the roots of Limonium otolepis.

A Gram-negative bacterium, designated as strain YIM 690229T, was isolated from the roots of Limonium otolepis. The strain was able to grow at 10-40 °C (optimum, 28-37 °C), pH 6.0-8.0 (optimum, 7.0) and in the presence of up to 7% NaCl (w/v) (optimum, up to 2.5%). Comparative 16S rRNA gene sequence analysis revealed that strain YIM 690229T shared less than 93.9% sequence similarities with members within the order Rhizobiales, and was remotely related to members of the family Hyphomicrobiaceae. Strain YIM 690229T was characterized by the presence of Q-10 as the predominant respiratory lipoquinone. The major fatty acids (> 10%) detected were C18:1 ω7c, C16:0, anteiso-C15:0 and summed feature 4 (iso-C17:1 I and/or anteiso-C17:1 B). The polar lipids consisted of diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanoamine and two unidentified lipids. The genomic DNA G + C content was 57.2 mol%. Data from this polyphasic taxonomy study suggested that strain YIM 690229T should be classified as a new species of a new genus within the family Hyphomicrobiaceae for which the name Limoniibacter endophyticus gen. nov., sp. nov., is proposed. The type species of the genus Limoniibacter gen. nov. is Limoniibacter endophyticus. The type strain of the species Limoniibacter endophyticus sp. nov. is YIM 690229T (= KCTC 42097T = JCM 30141T = CCTCC AB 2014130T = CGMCC 1.12906T).

Altererythrobacter lauratis sp. nov. and Altererythrobacter palmitatis sp. nov., isolated from a Tibetan hot spring.

Two Gram-negative, moderately thermophilic, yellow-pigmented, rod-shaped and motile bacterial strains, designated YIM 75003T and YIM 75004T, were isolated from sediment samples collected from the Tagejia hot spring in Tibet, western China. The taxonomic affiliation of the two strains was investigated by a polyphasic approach. Pairwise comparison of the 16S rRNA gene sequences showed that strains YIM 75003T and YIM 75004T are closely related to Altererythrobacter buctense M0322T (97.2 and 97.1% respectively), while sharing 99.9% sequence similarity against each other. Optimum growth of the two strains was observed at 37-45 °C, pH 8.0 and in the presence of 1-6% NaCl (w/v). Their predominant respiratory quinone was found to be ubiquinone 10. The major fatty acids in both the strains were identified as summed feature 8 (C18:1 ω6c and/or C18:1 ω7c) and summed feature 4 (C17:1 anteiso B and/or iso I). Their major polar lipid profiles were found to be diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid. The DNA G+C contents of strains YIM 75003T and YIM 75004T were determined to be 61.3 and 60.1 mol%, respectively. The DNA-DNA hybridization values between strains YIM 75003T and YIM 75004T, and between the two strains and their closely related phylogenetic neighbour A. buctense M0322T (=CGMCC 1.12871T) were less than 70%. Based on the morphological and physiological properties, phylogenetic analyses, chemotaxonomic characteristics and DNA-DNA relatedness values, the two strains can be distinguished from each other and from their phylogenetically closely related strain. Strains YIM 75003T and YIM 75004T are, therefore, considered to represent two novel species of the genus Altererythrobacter, for which the names Altererythrobacter lauratis sp. nov. (type strain YIM 75003T = KCTC 52606T = CCTCC AB2016268T) and Altererythrobacter palmitatis sp. nov. (type strain YIM 75004T = KCTC 52607T = CCTCC AB2016270T) are proposed.