Mzabimyces algeriensis gen. nov., sp. nov., a halophilic filamentous actinobacterium isolated from a Saharan soil,and proposal of Mzabimycetaceae fam. nov.

Three halophilic mycelium-forming actinobacteria, strains H195^T, H150 and H151, were isolated from a Saharan soil sample collected from Béni-isguen in the Mzab region (Ghardaïa, South of Algeria) and subjected to a polyphasic taxonomic characterisation. These strains were observed to show an aerial mycelium differentiated into coccoid spore chains and fragmented substrate mycelium. Comparative analysis of the 16S rRNA gene sequences revealed that the highest sequence similarities were to Saccharopolyspora qijiaojingensis YIM 91168^T (92.02 % to H195^T). Phylogenetic analyses showed that the strains H195^T, H150 and H151 represent a distinct phylogenetic lineage. The cell-wall hydrolysate was found to contain meso-diaminopimelic acid, and the diagnostic whole-cell sugars were identified as arabinose and galactose. The major cellular fatty acids were identified as iso-C_15:0, iso-C_16:0, iso-C_17:0 and anteiso-C_17:0. The diagnostic phospholipid detected was phosphatidylcholine and MK-9 (H₄) was found to be the predominant menaquinone. The genomic DNA G+C content of strain H195^T was 68.2 mol%. On the basis of its phenotypic features and phylogenetic position, we propose that strain H195^T represents a novel genus and species, Mzabimyces algeriensis gen. nov., sp. nov., within a new family, Mzabimycetaceae fam. nov. The type strain of M. algeriensis is strain H195^T (=DSM 46680^T = MTCC 12101^T).     

Actinopolyspora algeriensis sp. nov., a novel halophilic actinomycete isolated from a Saharan soil

A halophilic actinomycete strain designated H19(T), was isolated from a Saharan soil in the Bamendil region (Ouargla province, South Algeria) and was characterized taxonomically by using a polyphasic approach. The morphological and chemotaxonomic characteristics of the strain were consistent with those of members of the genus Actinopolyspora, and 16S rRNA gene sequence analysis confirmed that strain H19(T) was a novel species of the genus Actinopolyspora. DNA-DNA hybridization value between strain H19(T) and the nearest Actinopolyspora species, A. halophila, was clearly below the 70?% threshold. The genotypic and phenotypic data showed that the organism represents a novel species of the genus Actinopolyspora for which the name Actinopolyspora algeriensis sp. nov. is proposed, with the type strain H19(T) (=?DSM 45476(T)?=?CCUG 62415(T)).     

Actinomadura fibrosa sp. nov. isolated from soil

A new species of the genus Actinomadura which belongs to the Actinomadura madurae group of Goodfellow et al. was isolated from soil collected in Togo, West Africa. Traditional taxonomic methods plus contemporary fatty acid analysis techniques were used to establish the position of this species. Both physiological characteristics and fatty acid composition differentiate this strain from previously described species. This culture produces a new polyether antibiotic. It is characterized by the production of white to pink aerial hyphae on a limited number of media. The aerial hyphae appear asporogenous, forming thick fibers and projections instead of true spores. The reverse side is a distinctive reddish orange. This organism is resistant to 5% NaCl and grows at temperatures between 20 and 45 degrees C. Whole cells contain meso-diaminopimelic acid, galactose, glucose, mannose, madurose, phosphatidylinositol, and diphosphatidylglycerol. The menaquinones detected were MK-9(H6) and minor amounts of MK-9(H8). The name proposed for this new species is Actinomadura fibrosa; the type strain is strain NRRL 18348.     

Isoptericola rhizophila sp. nov., a novel actinobacterium isolated from rhizosphere soil

A Gram-positive, yellow pigmented strain, BKS 3-46^T was isolated from a soil sample collected from the rhizosphere of Ficus benghalensis (banyan tree) in Bhitarkanika mangrove forest, in the Indian state of Odisha, and subjected to polyphasic taxonomic study. The 16S rRNA gene sequence of the strain was determined and the sequence analysis showed that strain BKS 3-46^T should be assigned to the genus Isoptericola. The chemotaxonomic data supported this taxonomic placement i.e. presence of menaquinone MK-9(H₄); major fatty acids anteiso C_15:0 and iso-C_15:0; and phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol (PI) as major polar lipids. Further phylogenetic analysis of the 16S rRNA gene sequence confirmed that the strain BKS 3-46^T belongs to the genus Isoptericola and is closely related to Isoptericola halotolerans MTCC 11265^T (98.6 %) followed by Isoptericola nanjingensis MTCC 11633^T (98.4 %) and Isoptericola chiayiensis MTCC 11634^T (98.1 %). However, the DNA–DNA hybridization values obtained between strain BKS 3-46^T and other related strains were well below the threshold that is required for the proposal of a novel species. The G+C content of the genomic DNA was determined to be 70.4 mol%. The phenotypic and genotypic data showed that the strain BKS 3-46^T merits the recognition as a representative of a novel species of the genus Isoptericola. It is proposed that the isolate should be classified in the genus Isoptericola as a novel species, Isoptericola rhizophila sp. nov. The type strain is BKS 3-46^T (=MTCC 11080^T=JCM 19252^T).     

Actinoplanes aureus sp. nov., a novel protease-producing actinobacterium isolated from soil

Antonie van Leeuwenhoek - A novel protease-producing actinobacterium, designated strain NEAU-A11T, was isolated from soil collected from Aohan banner, Chifeng, Inner Mongolia Autonomous Region,...     

Streptomonospora algeriensis sp. nov., a halophilic actinomycete isolated from soil in Algeria

A halophilic actinomycete strain, designated H27^T, was isolated from a soil sample collected from a hypersaline habitat in Djelfa Province (North-Central Algeria), and then investigated using a polyphasic taxonomic approach. The strain was observed to produce poor aerial mycelium, which formed short chains of oval to cylindrical-shaped spores at maturity, and non fragmented substrate mycelium. The optimum NaCl concentration for growth was found to be 10–15 % (w/v) and the optimum growth temperature and pH were found to be 28–37 °C and 6–7, respectively. The diagnostic diamino acid in the cell-wall peptidoglycan was identified as meso-diaminopimelic acid. The predominant menaquinones of strain H27^T were identified as MK-11 (H₄) and MK-10 (H₆). The major fatty acids were found to be iso-C_16:0, anteiso-C_17:0, 10 methyl C_17:0 and 10 methyl C_16:0. The diagnostic phospholipids detected were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol. The chemotaxonomic properties of strain H27^T are consistent with those shared by members of the genus Streptomonospora. 16S rRNA gene sequence analysis indicated that strain H27^T is most closely related to Streptomonospora alba DSM 44588^T (98.8 %) and Streptomonospora flavalba DSM 45155^T (98.7 %) whereas the DNA–DNA relatedness values between strain H27^T and the two type strains were 17.1 and 57.9 %, respectively. Based on the combined genotypic and phenotypic evidence, it is proposed that strain H27^T should be classified as representative of a novel species, for which the name Streptomonospora algeriensis sp. nov. is proposed. The type strain is H27^T (=DSM 45604^T =CCUG 63369^T =MTCC 11563^T).     

Herbidospora solisilvae sp. nov., a novel cellulose-degrading actinobacterium isolated from forest soil

An aerobic, non-motile, Gram-stain positive, cellulose-degrading actinobacterium, designated strain NEAU-GS84^T, was isolated from a forest soil sample collected from Linchun Ridge Forest Park in Sanya, Hainan Province, China, and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics indicated that strain NEAU-GS84^T could belong to the genus Herbidospora. The 16S rRNA gene sequence analysis indeed confirmed that strain NEAU-GS84^T belonged to the genus Herbidospora and was most closely related to Herbidospora yilanensis JCM 18062^T (99.2% 16S rRNA gene sequence similarity) and Herbidospora galbida NEAU-GS14^T (99.0%). The cell wall of strain NEAU-GS84^T contained meso-diaminopimelic acid as the major diamino acid and the whole-cell hydrolysates mainly contained glucose, madurose and ribose. The major polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxyphosphatidylethanolamin, phosphoglycolipids, two phosphatidylinositol mannosides and one unidentified phospholipid. The predominant menaquinone was MK-10(H₄). Major fatty acids were 10-methly C_17:0, C_17:0 and iso-C_16:0. These chemotaxonomic data substantiated the affiliation of strain NEAU-GS84^T to the genus Herbidospora. The DNA G+C content was 70.7 mol%. The genome size of strain NEAU-GS84^T is about 8.37 Mb and contained 41 cellulose-binding domain synthesis genes, 13 β-glucosidase synthesis genes, 6 endoglucanase synthesis genes and 9 xylanase synthesis genes. Based on digital DNA–DNA hybridization and average nucleotide identity values, the new strain NEAU-GS84^T could be differentiated from its closest relatives. Therefore, the strain represents a novel species of the genus Herbidospora, for which the name Herbidospora solisilvae sp. nov. is proposed. The type strain is NEAU-GS84^T (=?CCTCC AA 2018041^T?=?JCM 33460^T).

     

Actinomadura mexicana sp. nov. and Actinomadura meyerii sp. nov., two novel soil sporoactinomycetes

The taxonomic position of two soil isolates, strains A288(T) and A290(T) [provisionally assigned to the genus Actinomadura] was clarified in a polyphasic study. The organisms showed a combination of chemotaxonomic and morphological properties typical of actinomadurae. They also formed distinct phyletic lines in the 16S rRNA Actinomadura gene tree; strain A288(T) was associated with A. nitritigenes whereas strain A290(T) was closely related to a group that consisted of A. citrea, A. coerulea, A. glauciflava, A. luteofluorescens and A. verrucosospora. Strains A288(T) and A290(T) showed key phenotypic features which readily distinguish them from one another and from representatives of related validly described species of Actinomadura. It is proposed that the two organisms be classified as new species of the genus Actinomadura. The names proposed for the new taxa are Actinomadura mexicana (A290(T) = DSM 44485(T) = NRRL B-24203(T)), and Actinomadura meyerii (A288(T) = DSM 44485(T) = NRRL B-24203(T)).     

<Emphasis Type="Italic">Saccharothrix ghardaiensis</Emphasis> sp. nov., an actinobacterium isolated from Saharan soil

The taxonomic position of a new Saccharothrix strain, designated MB46^T, isolated from a Saharan soil sample collected in Mzab region (Ghardaïa province, South Algeria) was established following a polyphasic approach. The novel microorganism has morphological and chemical characteristics typical of the members of the genus Saccharothrix and formed a phyletic line at the periphery of the Saccharothrix espanaensis subcluster in the 16S rRNA gene dendrograms. Results of the 16S rRNA gene sequence comparisons revealed that strain MB46^T shares high degrees of similarity with S. espanaensis DSM 44229^T (99.2%), Saccharothrix variisporea DSM 43911^T (98.7%) and Saccharothrix texasensis NRRL B-16134^T (98.6%). However, the new strain exhibited only 12.5–17.5% DNA relatedness to the neighbouring Saccharothrix spp. On the basis of phenotypic characteristics, 16S rRNA gene sequence comparisons and DNA-DNA hybridizations, strain MB46^T is concluded to represent a novel species of the genus Saccharothrix, for which the name Saccharothrix ghardaiensis sp. nov. (type strain MB46^T = DSM 46886^T = CECT 9046^T) is proposed.