Promicromonospora iranensis sp. nov., an actinobacterium isolated from rhizospheric soil

Puerhibacterium puerhi gen. nov., sp. nov., a novel member of the family Promicromonosporaceae, isolated from Pu-erh tea pile-fermentation

A Gram-staining positive aerobic bacterium, designated TLY-12^T, was isolated from the Pu-erh tea pile-fermentation process in Pu'er city, Yunnan, China. Strain TLY-12^T grew at 15-37 °C (optimum, 30 °C), pH 6.0-11.0 (optimum, pH 9.0) and 0-9.0% (w/v) NaCl (optimum, 3.0%). The major cellular fatty acids were anteiso-C_15:0, C_16:0 and iso-C_16:0. The respiratory quinone were menaquinones MK-9 (H₂) and MK-9 (H₄). The polar lipids were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylinositol (PI), phosphoglycolipid (PGL), glycolipid (GL) and an unidentified phospholipid (PL). The peptidoglycan contained glutamic acid, aspartic acid, alanine and lysine, with the last named being the diagnostic diamino acid. Whole-cell sugars of the isolate were ribose, galactose and glucose. Phylogenetic analyses of 16S rRNA gene showed that this strain belonged to the family Promicromonosporaceae, and was most closely related to Isoptericola cucumis DSM 101603 ^T, which gave sequence similarity of 97.9%. Genome sequencing revealed a genome size of 3.91 Mbp and a G + C content of 75.0%. Average nucleotide identity and digital DNA-DNA hybridization values were all below the species threshold of described Promicromonosporaceae species. Genome phylogenetic analysis showed that strain TLY-12^T formed a separate evolutionary branch, and was parallel to other related genera of Promicromonosporaceae. Based on the phylogenetic, phenotypic, chemotaxonomic and genome pairwise data, strain TLY-12^T is considered to represent a novel species in a new genus in the family Promicromonosporaceae, for which the name Puerhibacterium puerhi gen. nov, sp. nov. is proposed. The type strain is TLY-12^T (= CGMCC 1.17157^T = KCTC 49467^T).

Draft genome sequence of Promicromonospora panici sp. nov., a novel ionizing-radiation-resistant actinobacterium isolated from roots of the desert plant Panicum turgidum

A novel strain of the genus Promicromonospora, designated PT9^T, was recovered from irradiated roots of the xerophyte Panicum turgidum collected from the Ksar Ghilane oasis in southern Tunisia. Strain PT9^T is aerobic, non-spore-forming, Gram- positive actinomycete that produces branched hyphae and forms white to yellowish-white colonies. Chemotaxonomic features, including fatty acids, whole cell sugars and polar lipid profiles, support the assignment of PT9^T to the genus Promicromonospora. The genomic relatedness indexes based on DNA-DNA hybridization and average nucleotide identity values revealed a significant genomic divergence between strain PT9^T and all sequenced type strains of the taxon. Phylogenomic analysis showed that isolate PT9^T was most closely related to Promicromonospora soli CGMCC 4.7398^T. Phenotypic and phylogenomic analyses suggest that isolate PT9^T represents a novel species of the genus Promicromonospora, for which the name Promicromonospora panici sp. nov. is proposed. The type strain is PT9^T (LMG 31103^T = DSM 108613^T).The isolate PT9^T is an ionizing-radiation-resistant actinobacterium (D₁₀ value = 2.6 kGy), with resistance to desiccation and hydrogen peroxide. The complete genome sequence of PT9^T consists of 6,582,650 bps with 71.2% G+C content and 6291 protein-coding sequences. This genome will help to decipher the microbial genetic bases for ionizing-radiation resistance mechanisms including the response to oxidative stress.

Promicromonospora soli sp. nov., a novel actinomycete isolated from soil

A novel actinobacterium, designated strain NEAU-GS50^T, was isolated from soil collected from Mount Song and characterized by using a polyphasic approach. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the organism should be assigned to the genus Promicromonospora and that it forms a monophyletic clade with its closest relatives Promicromonospora umidemergens JCM 17975^T (98.94 % 16S rRNA gene sequence similarity), Promicromonospora alba 1C-HV12^T (98.82 %) and Promicromonospora kermanensis DSM45485^T (98.68 %). Similarly, chemotaxonomic data including major menaquinones, fatty acid compositions and polar lipid profiles, also supported the placement of strain NEAU-GS50^T in the genus Promicromonospora. However, DNA-DNA relatedness, physiological and biochemical data showed that strain NEAU-GS50^T could be distinguished from its closest relatives. Therefore, strain NEAU-GS50^T represents a novel species of the genus Promicromonospora, for which the name Promicromonospora soli sp. nov. is proposed, with strain NEAU-GS50^T (CGMCC4.7398^T=DSM 104515^T) as the type strain.

Promicromonospora callitridis sp. nov., an endophytic actinobacterium isolated from the surface-sterilized root of an Australian native pine tree

A new strain of the genus Promicromonospora, CAP94T, was isolated from the surface sterilized root of Callitrispreissii (Australian native pine tree). This strain was a Gram-stain-positive, aerobic actinobacterium with hyphae breaking up into fragments which were non-motile, rod-like, coccoid elements. Phylogenetic evaluation based on 16S rRNA gene sequence analysis placed this isolate as a member of the family Promicromonospora ceae, and most closely to Promicromonospora sukumoe NBRC 14650T (99.4 %), Promicromonospora kroppenstedtii DSM 19349T (99.2 %) and Promicromonosporaaerolata V54AT (99.1 %). Chemotaxonomic data including cell-wall components, major menaquinone and major fatty acids confirmed the affiliation of strain CAP94T to the genus Promicromonospora. The results of the phylogenetic analysis, including physiological and biochemical studies in combination with DNA-DNA hybridization, allowed the genotypic and phenotypic differentiation of strain CAP94T and the closest species with validly published names. The name proposed for the new species is Promicromonospora callitridis sp. nov. The type strain is CAP94T (=DSM 103339T=TBRC 6025T).

Promicromonospora kermanensis sp. nov., an actinobacterium isolated from soil

A novel strain belonging to the genus Promicromonospora, designated HM 533T, was isolated from soil in Kerman Province, Iran. It produced long and branched hyphae on ISP 2 medium that developed into a large number of irregular-shaped spores. It showed optimal growth at 25-30 °C and pH 5.0-8.0 with 0-4 % (w/v) NaCl. The peptidoglycan type of strain HM 533T was A4α l-Lys-l-Ala-d-Glu. Whole-cell hydrolysates of strain HM 533T contained the sugars ribose, glucose and galactose. The main phospholipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, two unknown glycolipids and an unknown phospholipid. MK-9(H4) and MK-9(H2) were the predominant menaquinones. The fatty acids pattern was mainly composed of the saturated branched-chain acids anteiso-C15 : 0 and iso-C15 : 0. The 16S rRNA gene sequence analysis showed the highest pairwise sequence identity (99.5-97.1 %) with the members of the genus Promicromonospora. Based on phenotypic and genotypic features, strain HM 533T is considered to represent a novel species of the genus Promicromonospora, for which the name Promicromonospora kermanensis is proposed with strain HM 533T (=DSM 45485T=UTMC 00533T=CECT 8709T) as the type strain.

Krasilnikoviella muralis gen. nov., sp. nov., a member of the family Promicromonosporaceae, isolated from the Takamatsuzuka Tumulus stone chamber interior and reclassification of Promicromonospora flava as Krasilnikoviella flava comb. nov

A Gram-stain-positive, facultatively anaerobic actinomycete, designated strain T6220-5-2bT, was isolated from a sample taken from a mouldy spot on the surface of a mural painting (the white tiger, Byakko) inside the stone chamber of Takamatsuzuka Tumulus in Asuka village, Nara Prefecture, Japan. Based on 16S rRNA gene sequence analysis of the isolate, it was closely related to the genus Promicromonospora, but formed of a novel lineage within the family Promicromonosporaceae. The closest related species to strain T6220-5-2bT was Promicromonospora flava, with which it shared 99.1 % 16S rRNA gene sequence similarity. The isoprenoid quinone systems were menaquinones MK-9(H2), MK-9(H0) and MK-9(H4). The predominant cellular fatty acids for the isolate were anteiso-C15 : 0 and iso-C15 : 0. The peptidoglycan contained glutamic acid, aspartic acid, alanine and lysine, with the last named being the diagnostic diamino acid. The cell-wall acyl type was acetyl. The major polar lipids of the isolate were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannoside, two unknown phospholipids and an unknown phosphoglycolipid. Whole-cell sugars of the isolate were galactose, glucose and ribose. The DNA G+C content of the genomic DNA was 75.2 mol%. Based on the results of phylogenetic, physiological and biochemical analyses and DNA-DNA hybridization experiments, the isolate was considered to represent a novel species of a new genus in the family Promicromonosporaceae, for which the name Krasilnikoviella muralis gen. nov., sp. nov. is proposed. The type strain of Krasilnikoviella muralis is T6220-5-2bT (=JCM 28789T=NCIMB 15040T). The reclassification of Promicromonospora flava as Krasilnikoviella flava comb. nov. is also proposed with the emended description of this species.

Actinobacteria from Arid and Desert Habitats: Diversity and Biological Activity

The lack of new antibiotics in the pharmaceutical pipeline guides more and more researchers to leave the classical isolation procedures and to look in special niches and ecosystems. Bioprospecting of extremophilic Actinobacteria through mining untapped strains and avoiding resiolation of known biomolecules is among the most promising strategies for this purpose. With this approach, members of acidtolerant, alkalitolerant, psychrotolerant, thermotolerant, halotolerant and xerotolerant Actinobacteria have been obtained from respective habitats. Among these, little survey exists on the diversity of Actinobacteria in arid areas, which are often adapted to relatively high temperatures, salt concentrations, and radiation. Therefore, arid and desert habitats are special ecosystems which can be recruited for the isolation of uncommon Actinobacteria with new metabolic capability. At the time of this writing, members of Streptomyces, Micromonospora, Saccharothrix, Streptosporangium, Cellulomonas, Amycolatopsis, Geodermatophilus, Lechevalieria, Nocardia, and Actinomadura are reported from arid habitats. However, metagenomic data present dominant members of the communities in desiccating condition of areas with limited water availability that are not yet isolated. Furthermore, significant diverse types of polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) genes are detected in xerophilic and xerotolerant Actinobacteria and some bioactive compounds are reported from them. Rather than pharmaceutically active metabolites, molecules with protection activity against drying such as Ectoin and Hydroxyectoin with potential application in industry and agriculture have also been identified from xerophilic Actinobacteria. In addition, numerous biologically active small molecules are expected to be discovered from arid adapted Actinobacteria in the future. In the current survey, the diversity and biotechnological potential of Actinobacteria obtained from arid ecosystems, along with the recent work trend on Iranian arid soils, are reported.

Promicromonospora alba sp. nov., an actinomycete isolated from the cuticle of Camponotus japonicas Mayr

A novel actinomycete, designated strain 1C-HV12^T, was isolated from the cuticle of Camponotus japonicas Mayr and characterized using a polyphasic approach. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the organism should be assigned to the genus Promicromonospora and that it forms a monophyletic clade with the closest relatives Promicromonospora umidemergens JCM 17975^T(99.17 % 16S rRNA gene sequence similarity), Promicromonospora vindobonensis V45^T (98.88 %) and Promicromonospora iranensis HM 792^T (98.85 %). Moreover, morphological and chemotaxonomic properties of strain 1C-HV12^T also confirmed the affiliation of the isolate to the genus Promicromonospora. The peptidoglycan hydrolysates contained alanine, glutamic acid and lysine, and whole-cell sugars were galactose, glucose, rhamnose and ribose. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified phosphoglycolipid, an unidentified phospholipid and an unidentified glycolipid. The major menaquinones were MK-9(H₄) and MK-9(H₂). The predominant cellular fatty acids were anteiso-C_15 : 0, iso-C_15 : 0 and anteiso-C_17 : 0. The DNA G+C content was 71.6 mol%. However, the low level of DNA-DNA relatedness and some phenotypic characteristics allowed the isolate to be differentiated from closely related species. Therefore, it is concluded that strain 1C-HV12^T represents a novel species of the genus Promicromonospora, for which the name Promicromonospora alba sp. nov. is proposed. The type strain is 1C-HV12^T ( = CGMCC 4.7283^T = DSM 100490^T).