Naumannella huperziae sp. nov., an endophytic actinobacterium isolated from Huperzia serrata (Thunb.).

An endophytic, short rod-shaped, non-motile and non-spore-forming actinobacterium, designated strain CPCC 204135T, was isolated from a surface-sterilized medicinal plant, Huperzia serrata (Thunb.), collected from Sichuan Province, south-west China. Strain CPCC 204135T was observed to grow at temperatures between 20 and 37 °C (optimum, 28-32 °C), at pH 6.0-9.0 (optimum, pH 7.0-8.0) and in the presence of 0-9.0 % (w/v) NaCl (optimum, 0-3 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CPCC 204135T belonged to the genus Naumannella, showing the highest level of 16S rRNA gene sequence similarity with Naumannella halotolerans DSM 24323T (97.2 %), the only species of the genus Naumannella in the family Propionibacteriaceaewith avalidly published name. The DNA-DNA hybridization value between strain CPCC 204135T and N. halotolerans DSM 24323T was 20.1±1.8 %, which is far below the accepted 70 % threshold for species delineation. The cell-wall hydrolysates contained ll-diaminopimelic acid, alanine, glycine and glutamic acid, with the peptidoglycan type of A3γ. Diphosphatidylglycerol, phosphatidylglycerol, an unidentified phospholipid, one unidentified aminolipid, one unidentified polar lipid and several kinds of glycolipids were detected in the polar lipids profile. MK-9(H4) was identified as the predominant menaquinone. The major cellular fatty acids (>10 %) were anteiso-C15 : 0 and iso-C16 : 0. The G+C content of the genomic DNA of strain CPCC 204135T was determined to be 71.8 mol%. On the basis of phylogenetic analysis, and phenotypic and chemotaxonomic characteristics, we concluded that strain CPCC 204135T represents a novel species of the genus Naumannella, for which the name Naumannella huperziae sp. nov. is proposed, with strain CPCC 204135T (=DSM 101717T=NBRC 111773T) as the type strain.

Abundant and diverse endophytic actinobacteria associated with medicinal plant Maytenus austroyunnanensis in Xishuangbanna tropical rainforest revealed by culture-dependent and culture-independent methods.

Endophytes are now considered as an important component of biodiversity. However, the diversity of endophytic actinobacteria associated with tropical rainforest native medicinal plants is essentially unknown. In this study, the diversity of endophytic actinobacteria residing in root, stem and leaf tissues of medicinal plant Maytenus austroyunnanensis collected from tropical rainforest in Xishuangbanna, China was investigated with a combination of cultivation and culture-independent analysis on the basis of 16S rRNA gene sequencing. By using different selective isolation media and methods, a total of 312 actinobacteria were obtained, and they were affiliated with the order Actinomycetales (distributed into 21 genera). Based on a protocol for endophytes enrichment, three 16S rRNA gene clone libraries were constructed and 84 distinct operational taxonomic units were identified and they distributed among the orders Actinomycetales and Acidimicrobiales, including eight suborders and at least 38 genera with a number of rare actinobacteria genera. Phylogenetic analysis showed that 32% of the clones in the libraries had lower than 97% similarities with related type strains. Interestingly, six genera from the order Actinomycetales and uncultured clones from Acidimicrobiales have not, to our knowledge, been previously reported as endophytes. Our study confirms abundant endophytic actinobacterial consortium in tropical rainforest native plant and suggests that this special habitat represents an underexplored reservoir of diverse and novel actinobacteria of potential interest for bioactive compounds discovery.

Isolation, diversity, and antimicrobial activity of rare actinobacteria from medicinal plants of tropical rain forests in Xishuangbanna, China.

Endophytic actinobacteria are relatively unexplored as potential sources of novel species and novel natural products for medical and commercial exploitation. Xishuangbanna is recognized throughout the world for its diverse flora, especially the rain forest plants, many of which have indigenous pharmaceutical histories. However, little is known about the endophytic actinobacteria of this tropical area. In this work, we studied the diversity of actinobacteria isolated from medicinal plants collected from tropical rain forests in Xishuangbanna. By the use of different selective isolation media and methods, a total of 2,174 actinobacteria were isolated. Forty-six isolates were selected on the basis of their morphologies on different media and were further characterized by 16S rRNA gene sequencing. The results showed an unexpected level of diversity, with 32 different genera. To our knowledge, this is the first report describing the isolation of Saccharopolyspora, Dietzia, Blastococcus, Dactylosporangium, Promicromonospora, Oerskovia, Actinocorallia, and Jiangella species from endophytic environments. At least 19 isolates are considered novel taxa by our current research. In addition, all 46 isolates were tested for antimicrobial activity and were screened for the presence of genes encoding polyketide synthetases and nonribosomal peptide synthetases. The results confirm that the medicinal plants of Xishuangbanna represent an extremely rich reservoir for the isolation of a significant diversity of actinobacteria, including novel species, that are potential sources for the discovery of biologically active compounds.

Glycomyces scopariae sp. nov. and Glycomyces mayteni sp. nov., isolated from medicinal plants in China.

Two actinomycete strains, designated YIM 56256(T) and YIM 61331(T), were isolated from the roots of Scoparia dulcis and Maytenus austroyunnanensis, two Chinese medicinal plants, and their taxonomic status was established based on a polyphasic investigation. The organisms were found to have chemical and morphological markers typical of members of the genus Glycomyces. 16S rRNA gene sequence analysis showed that they were closely related to each other and to Glycomyces sambucus E71(T). A battery of physiological characteristics and levels of DNA-DNA relatedness indicated that strains YIM 56256(T) and YIM 61331(T) represent two novel species, clearly different from the related known Glycomyces species. On the basis of the data presented, it is evident that each of these strains represents a novel species of the genus Glycomyces, for which the names Glycomyces scopariae sp. nov. (type strain YIM 56256(T) =KCTC 19158(T) =DSM 44968(T)) and Glycomyces mayteni sp. nov. (type strain YIM 61331(T) =KCTC 19527(T) =CCTCC AA 208004(T)) are proposed.

Pseudonocardia endophytica sp. nov., isolated from the pharmaceutical plant Lobelia clavata.

An endophytic actinomycete strain, designated YIM 56035(T), was isolated from the inner tissue of the traditional Chinese medicinal plant Lobelia clavata. The strain stained Gram-positive, was aerobic and exhibited branching, white aerial mycelium and yellowish-brown substrate mycelium. The strain formed spore chains on aerial hyphae. The G+C content of the genomic DNA was 70.3 mol%. On the basis of morphological, physiological, chemotaxonomic and phylogenetic characteristics, strain YIM 56035(T) was assigned to the genus Pseudonocardia. Analysis of 16S rRNA gene sequences showed 98.5, 97.3, 97.3 and 97.1 % similarity to the closely related type strains Pseudonocardia kongjuensis LM 157(T), Pseudonocardia autotrophica IMSNU 20050(T), Pseudonocardia ammonioxydans H9(T) and Pseudonocardia compacta IMSNU 20111(T), respectively. The results of DNA-DNA hybridizations and comparison of some phenotypic characteristics revealed that the strain represents a novel species of the genus Pseudonocardia. The name Pseudonocardia endophytica sp. nov. is proposed, with the type strain YIM 56035(T) (=DSM 44969(T) =CCTCC AA 206026(T) =KCTC 19150(T)).

Streptomyces mayteni sp. nov., a novel actinomycete isolated from a Chinese medicinal plant.

An actinomycete strain, designated YIM 60475(T), was isolated from the roots of Maytenus austroyunnanensis and was characterized by using a polyphasic approach. The strain was determined to belong to the genus Streptomyces, based on its phenotypic and phylogenetic characteristics. The strain produced spiral spore chains on aerial mycelium. The cell wall contained LL-diaminopimelic acid. Whole-cell hydrolysates contained galactose, glucose, and xylose. The phospholipid was type II. The DNA G+C content of the type strain was 73.3 mol%. DNA-DNA hybridization and comparison of physiological and chemical characteristics suggested that strain YIM 60475(T) is a new Streptomyces species, for which the name Streptomyces mayteni sp. nov. is proposed. The type strain is YIM 60475(T) (=CCTCC AA 207005(T) = KCTC 19383(T)).

Glycomyces endophyticus sp. nov., an endophytic actinomycete isolated from the root of Carex baccans Nees.

An actinomycete, designated strain YIM 56134(T), was isolated from the root of a Chinese medicinal plant, Carex baccans Nees, collected from Yunnan, south-west China, and subjected to a polyphasic taxonomic study. An analysis of 16S rRNA gene sequence similarities showed that strain YIM 56134(T) was a member of the genus Glycomyces, being most closely related to Glycomyces algeriensis NRRL B-16327(T) (99.0 % similarity), Glycomyces lechevalierae DSM 44724(T) (99.0 %), Glycomyces rutgersensis IFO 14488(T) (98.9 %) and Glycomyces harbinensis IFO 14487(T) (98.7 %). Strain YIM 56134(T) could be distinguished from other established Glycomyces species on the basis of relatively low sequence similarity (<97 %). Phenotypic and chemotaxonomic data supported the affiliation of this strain to the genus Glycomyces. The results of DNA-DNA hybridization and some physiological and biochemical tests allowed differentiation of the strain from related Glycomyces species. Therefore, strain YIM 56134(T) represents a novel species of the genus Glycomyces, for which the name Glycomyces endophyticus sp. nov. is proposed. The type strain is YIM 56134(T) (=KCTC 19152(T) =DSM 45002(T)).

Saccharopolyspora endophytica sp. nov., an endophytic actinomycete isolated from the root of Maytenus austroyunnanensis.

A Gram-positive, aerobic, non-motile, non-acid-alcohol-fast strain, designated YIM 61095(T), was isolated from the root of Maytenus austroyunnanensis collected from a tropical rainforest of Xishuangbanna in Yunnan Province, south-west China. Strain YIM 61095(T) exhibited chemotaxonomic and morphological characteristics that were consistent with members of the genus Saccharopolyspora. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 61095(T) was a member of the genus Saccharopolyspora and was most closely related to Saccharopolyspora flava AS 4.1520(T) (97.7% sequence similarity). The major fatty acids were iso-C(15:0), iso-C(16:0), iso-C(17:0) and anteiso-C(17:0). The predominant quinone detected was MK-9(H(4)). The DNA G+C content was 66.2 mol%. The phenotypic characteristics and DNA-DNA hybridization relatedness data indicated that strain YIM 61095(T) should be distinguished from Saccharopolyspora flava AS 4.1520(T). On the basis of the evidence presented in this study, strain YIM 61095(T) represents a novel species of the genus Saccharopolyspora, for which the name Saccharopolyspora endophytica sp. nov. is proposed. The type strain is YIM 61095(T) (=KCTC 19397(T)=CCTCC AA 208003(T)).