Ochrobactrum endophyticum sp. nov., isolated from roots of Glycyrrhiza uralensis.

A novel Gram-staining negative, motile, rod-shaped and aerobic bacterial strain, designated EGI 60010(T), was isolated from healthy roots of Glycyrrhiza uralensis F. collected from Yili County, Xinjiang Province, North-West China. The 16S rRNA gene sequence of strain EGI 60010(T) showed 97.2 % sequence similarities with Ochrobactrum anthropi ATCC 49188(T) and Ochrobactrum cytisi ESC1(T), and 97.1 % with Ochrobactrum lupini LUP21(T). The phylogenetic analysis based on 16S rRNA gene sequences showed that the new isolate clustered with members of the genera Ochrobactrum, and formed a distinct clade in the neighbour-joining tree. Q-10 was identified as the respiratory quinone for strain EGI 60010(T). The major fatty acids were summed feature 8 (C18:1 ω6c and/or C18:1 ω7c), C19:0 cyclo ω8c, summed feature 4 (C17:1 iso I/anteiso B) and C16:0. The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylglycerol and phosphatidylcholine. The DNA G+C content of strain EGI 60010(T) was determined to be 60.4 mol%. The genomic DNA relatedness values determined between strain EGI 60010(T) and the closely related strains O. anthropi JCM 21032(T), O. cytisi CCTCC AB2014258(T) and O. lupini NBRC 102587(T) were 50.3, 50.0 and 41.6 %, respectively. Based on the results of the molecular studies supported by its differentiating phenotypic characteristics, strain EGI 60010(T) was considered to represent a novel species within the genus Ochrobactrum, for which the name Ochrobactrum endophyticum sp. nov., is proposed. The type strain is EGI 60010(T) (=CGMCC 1.15082(T) = KCTC 42485(T) = DSM 29930(T)).

Novosphingobium endophyticum sp. nov. isolated from roots of Glycyrrhiza uralensis.

A novel Gram-staining-negative, non-motile, rod-shaped and aerobic bacterial strain, designated EGI 60015(T), was isolated from healthy roots of Glycyrrhiza uralensis F. collected from Yili County, Xinjiang Province, Northwest China. The 16S rRNA gene sequence of strain EGI 60015(T) was found to show 97.6% sequence similarity with Novosphingobium pentaromativorans US6-1(T). The phylogenetic analysis based on 16S rRNA gene sequences showed that the strain formed a clade with N. pentaromativorans US6-1(T) in the neighbor-joining tree. Q-10 was identified as the respiratory quinone of strain EGI 60015(T). The major fatty acids were summed feature 8 (C18:1 ω6c and/or C18:1 ω7c; 55.04%), summed feature 4 (C17:1 anteiso B and/or iso I; 18.34%) and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c; 8.53%). The polar lipids detected were phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and sphingoglycolipids. The DNA G+C content of strain EGI 60015(T) was determined to be 66.6 mol%. The genomic DNA relatedness value between EGI 60015(T) and N. pentaromativorans US6-1(T) (54%) was below the 70% limit for species identification. Based on the result of the molecular studies supported by its morphological, physiological, chemotaxonomic and other differentiating phenotypic characteristics, strain EGI 60015(T) was considered to represent a novel species within the genus Novosphingobium, for which the name Novosphingobium endophyticum sp. nov. is proposed. The type strain is EGI 60015(T) (=CGMCC 1.15095(T) = KCTC 42486(T) = DSM 29948(T)).

Enterobacter tabaci sp. nov., a novel member of the genus Enterobacter isolated from a tobacco stem.

A Gram-stain negative, motile, rod-shaped bacterium, designated strain YIM Hb-3(T), was isolated from the stem of a tobacco plant. The strain was observed to form convex, circular and yellow-colored colonies. The predominant respiratory quinone was identified as Q-8. The major fatty acids (>5%) detected were C(16:1)ω7c and/or C(16:1)ω6c (summed feature 3), C(16:0), C(17:0)cyclo, C(18:1)ω7c and/or C(18:1)ω6c (summed feature 8), C(14:0)3-OH and/or iso-C(16:1)I (summed feature 2), C(14:0) and C(12:0). The genomic DNA G+C content was determined to be 54.8 mol%. Phylogenetic trees based on 16S rRNA gene sequences and multilocus sequence analysis showed that strain YIM Hb-3(T) had the closest phylogenetic relationship with Enterobacter mori LMG 25706(T). DNA-DNA relatedness value between strain YIM Hb-3(T) and E. mori LMG 25706(T) was 46.9 ± 3.8%. On the basis of phenotypic and chemotaxonomic data, phylogenetic analysis, and DNA-DNA relatedness value, strain YIM Hb-3(T) is considered to represent a novel species of the genus Enterobacter, for which the name Enterobacter tabaci sp. nov. is proposed. The type strain is YIM Hb-3(T) (=KACC 17832(T) =KCTC 42694(T)).

Umezawaea endophytica sp. nov., isolated from tobacco root samples.

Two Gram-staining positive, aerobic and non-motile actinomycete strains, designated YIM 2047X(T) and YIM 2047D, were isolated from tobacco root samples collected from Shiling county, Yunnan province, South-West China. The isolates grew at 15-40 °C, pH 6.0-8.0 and 0-4.5 % NaCl (w/v). The whole-cell hydrolysates contained meso-diaminopimelic acid, galactose, mannose, ribose and rhamnose. The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major cellar fatty acids identified were iso-C14:0, iso-C15:0, anteiso-C15:0, iso-C16:0, C16:0, C17:1 ω8c and C17:0. MK-9 (H4) was the predominant menaquinone. The genomic DNA G+C contents were 73.4 and 74.2 mol%, respectively. These chemotaxonomic data, together with their morphological properties, were consistent with the assignment of the two strains to the genus Umezawaea. They showed highest similarities to Umezawaea tangerina JCM 10302(T) on phylogenetic analysis of their 16S rRNA gene sequences and were found to form a coherent cluster. However, the DNA-DNA hybridization values of YIM 2047X(T) and YIM 2047D with U. tangerina JCM 10302(T) were 46.5 ± 3.1 and 57.5 ± 1.6 %, respectively; while the reassociation value between themselves was 80.4 ± 2.3 %. The results of physiological and biochemical tests allowed the two new isolates to be differentiated phenotypically from the recognized strain U. tangerina JCM 10302(T). On the basis of results from this polyphasic study, the strains were characterized as a novel species of the genus Umezawaea, for which the name Umezawaea endophytica sp. nov. is proposed. The type strain is YIM 2047X(T) (=KCTC 39538(T) = CPCC 204132(T)).

Marinactinospora endophytica sp. nov., isolated from a medicinal plant.

A novel endophytic actinobacterium, designated strain YIM 690053(T), was isolated from healthy stems of Salsola ferganica Drob, and was characterized using a polyphasic taxonomic approach. The strain formed well-branched substrate mycelia with no fragmentation, and abundant aerial mycelia that differentiated into long spores. The strain was found to grow at 10-55 °C, pH 6.0-10.0 and in the presence of 0-7 % (w/v) NaCl. The genomic DNA G+C content was determined to be 70.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 690053(T) belongs to the genus Marinactinospora, and it shared the highest 16S rRNA gene sequence similarity with Marinactinospora thermotolerans SCSIO 00652(T) (98.96 %). However, the DNA-DNA relatedness values between the two strains was 37.85 ± 2.77 %. Based on the differences in the molecular and biochemical characteristics from its closest relative, strain YIM 690053(T) is concluded to represent a novel species of the genus Marinactinospora, for which the name Marinactinospora endophytica sp. nov. is proposed. The type strain is YIM 690053(T)(=KCTC 29664(T) = DSM 46799(T)).

Flavobacterium notoginsengisoli sp. nov., isolated from the rhizosphere of Panax notoginseng.

Two novel bacterial strains, designated SYP-B540(T) and SYP-B556, were isolated from rhizospheric soil of Panax notoginseng located at Yunnan Province, China. Both strains were Gram-staining negative, aerobic, non-motile, elongated rod shaped and yellow coloured. They grew optimally at 28 °C and pH 7.0. Analysis of 16S rRNA gene sequences showed that the two strains shared 99.8 % sequence similarity to each other, but lower than 97.6 % to the other known species of the genus Flavobacterium. The predominant respiratory quinone for the two strains was MK-6, and the major fatty acids were iso-C15:0 and summed Feature 3 (comprising 16:1 ω7c and/or 16:1 ω6c). The polar lipids consisted of phosphatidylethanolamine, two unidentified polar lipids and three unidentified amino-phospholipids. The DNA G+C contents of strains SYP-B540(T) and SYP-B556 were 33.3 and 32.7 mol%, respectively. In addition, the DNA-DNA hybridization values of strains SYP-B540(T) and SYP-B556 to their closest phylogenetic neighbors were significantly lower than 70 %. On the basis of the polyphasic taxonomy studies, strains SYP-B540(T) and SYP-B556 represent a novel species of the genus Flavobacterium, for which the name Flavobacterium notoginsengisoli sp. nov. is proposed. The type strain is SYP-B540(T) (=KCTC 32505(T) = NBRC 110012(T) = BCRC 80724(T)).

Streptomyces canchipurensis sp. nov., isolated from a limestone habitat.

Hundung Limestone habitat, Manipur, India is an unexplored site for microbial diversity studies. Using polyphasic taxonomy, a Streptomyces strain, MBRL 172(T), has been characterized. The strain was found to show highest 16S rRNA gene sequence similarity with Streptomyces coeruleofuscus NBRC 12757(T) (99.2 %). The DNA relatedness between MBRL 172(T) and S. coeruleofuscus NBRC 12757(T), and between MBRL 172(T) and Streptomyces nogalater NBRC 13445(T), were 36.8 ± 4.4 and 52.5 ± 2.7 %, respectively. Strain MBRL 172(T) was found to contain LL-diaminopimelic acid as the diagnostic diamino acid and glucose, mannose and xylose as the major sugars in whole cell hydrolysates. The polar lipids in the cell membrane were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositolmannoside. The predominant menaquinones detected were MK-9(H6) and MK-9(H8). The cellular fatty acids identified were mainly saturated fatty acids: anteiso-C15:0, iso-C16:0 and iso-C15:0. Based on differences in the biochemical and molecular characteristics from its closest relatives, the strain can be proposed to represent a novel taxon in the genus Streptomyces, for which the name Streptomyces canchipurensis is proposed, with the type strain MBRL 172(T) (=JCM 17575(T) = KCTC 29105(T)).

Rhodococcus canchipurensis sp. nov., an actinomycete isolated from a limestone deposit site.

A novel actinobacterial strain, MBRL 353(T), was isolated from a sample collected from a limestone quarry at Hundung, Manipur, India. Comparison of 16S rRNA gene sequences of strain MBRL 353(T) and other members of the genus Rhodococcus showed sequence similarities ranging from 95.5 to 98.2 %, with strain MBRL 353(T) showing closest sequence similarity to Rhodococcus triatomae IMMIB RIV-085(T) (98.2 %) and Rhodococcus equi DSM 20307(T) (97.2 %). DNA-DNA hybridization results, however, revealed that DNA-DNA relatedness values between strain MBRL 353(T) and R. triatomae DSM 44892(T) (43.4 %) and R. equi DSM 20307(T) (33.4 %) were well below the 70 % limit for species identification. Strain MBRL 353(T) contained meso-diaminopimelic acid as the diagnostic diamino acid and galactose and arabinose in the cell wall. Mycolic acids were present. The major fatty acids were C(16 : 0) (45.7 %), C(18 : 1)ω9c (18.2 %) and 10-methyl C(18 : 0) (11.3 %). The only menaquinone detected was MK-8(H(2)), while the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and one unknown phospholipid. The G+C content of the genomic DNA was 69.2 mol%. The phenotypic and genotypic data showed that strain MBRL 353(T) merits recognition as a representative of a novel species of the genus Rhodococcus for which the name Rhodococcus canchipurensis sp. nov. is proposed; the type strain is MBRL 353(T) (= KCTC 19851(T) = JCM 17578(T)).

Micromonospora kangleipakensis sp. nov., isolated from a sample of limestone quarry.

Strain MBRL 34(T), isolated from a sample of limestone quarry located at Hundung, Manipur, India, was characterized by polyphasic taxonomy. The strain showed the highest 16S rRNA gene sequence similarity with Micromonospora echinaurantica DSM 43904(T) (98.4 %), but formed a monophyletic clade with Micromonospora coerulea DSM 43143(T) (98.3 %) in the neighbour-joining tree. DNA-DNA hybridization experiments gave a DNA-DNA relatedness value of 53.1 % between MBRL 34(T) and M. coerulea DSM 43143(T). Strain MBRL 34(T) contained meso-diaminopimelic acid, galactose and glucose in the whole-cell hydrolysates along with small amounts of mannose, xylose, rhamnose and ribose. The major polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositolmannoside, along with an unknown lipid. MK-10(H6), MK-10(H2) MK-11(H4) and MK-10(H4) were the predominant menaquinones detected. The major fatty acids were iso-C16 : 0 and iso-C15 : 0. The G+C content of the genomic DNA was 73.5 %. Based on the taxonomic characteristics from a polyphasic study, strain MBRL 34(T) merits recognition as a representative of a novel species of the genus Micromonospora for which the name Micromonospora kangleipakensis sp. nov. is proposed; the type strain is MBRL 34(T) ( = DSM 45612(T) = JCM 17696(T)).

Streptomyces muensis sp. nov.

A strain of Streptomyces, MBRL 179(T), isolated from a sample from a Limestone quarry located at Hundung, Manipur, India, was characterized by polyphasic taxonomy. The strain formed a monophyletic clade with Streptomyces spinoverrucosus NBRC 14228(T) (16S rRNA gene sequence similarity of 99.3 %) in the Neighbour-joining tree. DNA-DNA hybridization experiment gave a DNA-DNA relatedness value of 34.7 % between MBRL 179(T) and S. spinoverrucosus NBRC 14228(T). Strain MBRL 179(T) contained LL-diaminopimelic acid, xylose, glucose, and mannose in the whole cell-wall hydrolysates along with small amount of ribose. The major polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositolmannoside, with other unknown phospholipids and aminophospholipid. MK-9(H6), MK-9(H8) and MK-9(H4) were the predominant menaquinones detected. The major fatty acids were anteiso-C16:0 (28.1 %), iso-C16:0 (20.3 %), C16:0 (9.4 %) and anteiso-C17:0 (8.3 %). The G+C content of the genomic DNA was 71.1 %. Based on the polyphasic experiment results, the strain MBRL 179(T) merits recognition as a representative of a novel species of the genus Streptomyces for which the name Streptomyces muensis sp. nov. is proposed; the type strain is MBRL 179(T) (=JCM 17576(T) = KCTC 29124(T)).

Microlunatus cavernae sp. nov., a novel actinobacterium isolated from Alu ancient cave, Yunnan, South-West China.

A Gram-positive, coccoid, non-endospore-forming actinobacterium, designated YIM C01117(T), was isolated from a soil sample collected from Alu ancient cave, Yunnan province, south-west China. Based on the 16S rRNA gene sequence analysis, strain YIM C01117(T) was shown to belong to the genus Microlunatus, with highest sequence similarity of 97.4 % to Microlunatus soli DSM 21800(T). The whole genomic DNA relatedness as shown by the DNA-DNA hybridization study between YIM C01117(T) and M. soli DSM 21800(T) had a low value (47 ± 2 %). Strain YIM C01117(T) was determined to contain LL-diaminopimelic acid with Gly, Glu and Ala amino acids (A3γ' type) in the cell wall. Whole-cell hydrolysates were found to contain glucose, galactose, mannose and ribose. The major polar lipids were determined to be phosphatidylglycerol and diphosphatidylglycerol. The predominant menaquinone system present is MK-9(H4), while the major fatty acids were identified to be anteiso-C15:0 (24.1 %), iso-C16:0 (22.3 %) and iso-C15:0 (11.4 %). The G+C content of the genomic DNA was determined to be 65.9 mol%. The chemotaxonomic and genotypic data support the affiliation of the strain YIM C01117(T) to the genus Microlunatus. The results of physiological and biochemical tests allow strain YIM C01117(T) to be differentiated phenotypically from recognized Microlunatus species. Strain YIM C01117(T) is therefore considered to represent a novel species of the genus Microlunatus, for which the name Microlunatus cavernae sp. nov. is proposed. The type strain is YIM C01117(T) (= DSM 26248(T) = JCM 18536(T)).

Streptomyces manipurensis sp. nov., a novel actinomycete isolated from a limestone deposit site in Manipur, India.

A novel actinobacterium, designated MBRL 201(T), was isolated from a sample collected from a limestone quarry at Hundung, Manipur, India. The strain was characterized using polyphasic taxonomy. Comparison of the 16S rRNA gene sequence of strain MBRL 201(T) and other Streptomyces species showed sequence similarities ranging from 93.0 to 99.6 % and strain MBRL 201(T) showed closest similarities to Streptomyces virginiae NBRC 12827(T) (99.6 %) and Streptomyces cinnamonensis NBRC 15873(T) (99.6 %). The DNA relatedness between MBRL 201(T) and the type strains of S. virginiae NBRC 12827(T) and S. cinnamonensis NBRC 15873(T) were 44.5 and 35.6 % respectively. Strain MBRL 201(T) contained LL: -diaminopimelic acid (A(2)pm) as the diagnostic diamino acid, with glucose as the main sugar, while small amounts of galactose, glucose, mannose, rhamnose, ribose and xylose were also present in cell-wall hydrolysates. The major fatty acids identified were anteiso-C(15:0) (38.9 %), iso-C(15:0) (19.9 %) and anteiso-C(17:1) (14.7 %). The predominant menaquinones detected were MK-9(H(6)) and MK-9(H(8)), while the polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositolmannosides, with other unknown phospholipids and lipids. The G+C content of the genomic DNA was 72.9 %. The phenotypic and genotypic data showed that strain MBRL 201(T) merits recognition as a representative of a novel species of the genus Streptomyces. It is proposed that the isolate should be classified in the genus Streptomyces as a novel species, Streptomyces manipurensis sp. nov. The type strain is MBRL 201(T) (=DSM 42029(T) = JCM 17351(T)).

Physiological and genomic properties of Thermus tenuipuniceus sp. nov., a novel slight reddish color member isolated from a terrestrial geothermal spring.

Two closely related, thermophilic bacteria, designated strains YIM 76954T and YIM 76947, were isolated from the Rehai Geothermal Field, Tengchong, Yunnan province, south-west China. Polyphasic approach and whole genome sequencing were used to determine the taxonomy status and genomic profiles of the novel strains. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates were closely related to Thermus scotoductus SE-1T (97.1% sequence similarity), and T. amyloliquefaciens YIM 77409T (96.6%). The strains could be differentiated from most recognized Thermus species by their whitish to slight reddish colony color, distinct DNA fingerprinting profiles and low ANI values. Cells stained Gram-negative, rod-shaped of diameter 0.2-0.5µm and length 1.5-5.0µm. Growth occurred at 50-75°C, pH 6.0-9.0 and in the presence of up to 1.0% (w/v) NaCl concentration. Thiosulfate was found to enhance cell growth, besides improving the intensity of its colony color. Oxygen, nitrate, sulfur, and Fe(III) could be used as terminal electron acceptors for growth. MK-8 was the major respiratory menaquinone. Major fatty acids were iso-C17:0, iso-C15:0, anteiso-C17:0, and anteiso-C15:0. The genome size was 2.26Mbp with 65.5% average GC content. A total of 2374 genes was predicted, comprising 2322 protein-coding and 52 RNA genes. On the basis of the polyphasic evidence presented, it is proposed that strain YIM 76954T represents a novel species of the genus Thermus, for which the name Thermus tenuipuniceus sp. nov. is proposed. The type strain is YIM 76954T (=JCM 30350T=KCTC 4677T).

Biocontrol and plant growth promoting activities of a Streptomyces corchorusii strain UCR3-16 and preparation of powder formulation for application as biofertilizer agents for rice plant.

Streptomyces corchorusii strain UCR3-16, obtained from rice rhizospheric soils showed antifungal activities against 6 major rice fungal pathogens by diffusible and volatile compounds production. The strain was found positive for production of fungal cell wall degrading enzymes such as chitinase, ß-1,3-glucanase, ß-1,4-glucanase, lipase and protease. The strain was also positive for plant growth promoting traits. It produced up to 30.5µg/ml of IAA and solubilized a significant amount of inorganic phosphate (up to 102µg/ml). It also produced 69% siderophore units. The strain also produced ammonia and gave positive result for ACC deaminase activity. Highest vigor index of inoculated seedlings was observed when rice seeds were treated with cell suspension of UCR3-16 corresponding to 4.5×10(8)cfu/ml. Bioinoculant-treated seeds also showed similar results under pathogen challenged conditions. In pot trial experiments, UCR3-16-treated rice plants showed significantly increased growth and grain yield production. Powder formulation of the strain was developed using talcum and corn starch as carriers and the shelf-lives were monitored. Talcum formulation showed higher cell-count than corn starch even after 6 months of storage, and optimum condition for storage of the powder formulation were found to be at 4°C. Pot trial experiments using talcum powder formulation also showed significant positive effects on growth of rice plants. Field trial using talcum powder formulation also exhibited significant enhancement in shoot length and weight of shoot and root, and total grain yield and weight of grains in rice plants. Talcum formulation also significantly reduced the sheath blight disease in rice leaves.

Actinobacterial diversity in limestone deposit sites in Hundung, Manipur (India) and their antimicrobial activities.

Studies on actinobacterial diversity in limestone habitats are scarce. This paper reports profiling of actinobacteria isolated from Hundung limestone samples in Manipur, India using ARDRA as the molecular tool for preliminary classification. A total of 137 actinobacteria were clustered into 31 phylotypic groups based on the ARDRA pattern generated and representative of each group was subjected to 16S rRNA gene sequencing. Generic diversity of the limestone isolates consisted of Streptomyces (15 phylotypic groups), Micromonospora (4), Amycolatopsis (3), Arthrobacter (3), Kitasatospora (2), Janibacter (1), Nocardia (1), Pseudonocardia (1) and Rhodococcus (1). Considering the antimicrobial potential of these actinobacteria, 19 showed antimicrobial activities against at least one of the bacterial and candidal test pathogens, while 45 exhibit biocontrol activities against at least one of the rice fungal pathogens. Out of the 137 actinobacterial isolates, 118 were found to have at least one of the three biosynthetic gene clusters (PKS-I, PKS-II, NRPS). The results indicate that 86% of the strains isolated from Hundung limestone deposit sites possessed biosynthetic gene clusters of which 40% exhibited antimicrobial activities. It can, therefore, be concluded that limestone habitat is a promising source for search of novel secondary metabolites.

Characterization and evaluation of antimicrobial and cytotoxic effects of Streptomyces sp. HUST012 isolated from medicinal plant Dracaena cochinchinensis Lour.

A highly potent secondary metabolite producing endophytic strain, Streptomyces sp. HUST012 was isolated from the stems of the medicinal plant Dracaena cochinchinensis Lour. Strain HUST012 showed antimicrobial and antitumor activities which were significantly much higher than those of dragon's blood extracted from D. cochinchinensis Lour. On further analysis, the strain was found to produce two metabolites, SPE-B11.8 (elucidated to be a novel metabolite (Z)-tridec-7-ene-1,2,13-tricarboxylic acid) and SPE-B5.4 (elucidated as Actinomycin-D). The Minimum Inhibitory Concentration values of SPE-B11.8 against a set of test bacterial organisms (Methicillin-resistant Staphylococcus epidermis ATCC 35984, Methicillin-resistant Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Klebsiella pneumoniae ATCC 13883) ranged between 15.63 and 62.5 µg/ml while that for SPE-B5.4 ranged between 0.04 and 2.24 µg/ml. The compound SPE-B11.8 showed cytotoxic effect at 41.63 and 29.54 µg/ml IC 50-values against Hep G2 and MCF-7, respectively, while the compound SPE-B5.4 exhibited stronger activities against them at 0.23 and 0.18 µg/ml IC 50-values.

Streptomyces hundungensis sp. nov., a novel actinomycete with antifungal activity and plant growth promoting traits.

A novel actinobacterium MBRL 251(T), isolated from a sample collected from a limestone quarry at Hundung, Manipur, India, was characterized using a polyphasic approach. The 16S ribosomal RNA gene sequence of strain MBRL 251(T) showed closest similarities with Streptomyces xanthochromogenes NRRL B-5410(T) (99.6%) and Streptomyces michiganensis NBRC 12797(T) (99.6%). The DNA relatedness between MBRL 251(T) and S. xanthochromogenes NBRC 12828(T), and S. michiganensis NBRC 12797(T) was 46.6% and 40.7%, respectively. Strain MBRL 251(T) contained LL-diaminopimelic acid as the diagnostic diamino acid, with glucose and xylose as the main cell wall sugars, whereas small amounts of galactose, mannose, rhamnose and ribose were also detected in the whole-cell wall hydrolysates. The major fatty acids identified were anteiso-C15:0 (35.1%), iso-C16:0 (21.1%) and anteiso-C17:1 (13.2%). The predominant menaquinones detected were MK-9(H6) and MK-9(H8), whereas the polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositolmannosides. The G+C content of the genomic DNA was 72.3%. The phenotypic and genotypic data showed that strain MBRL 251(T) merits the recognition as a representative of a novel species of the genus Streptomyces. It is proposed that the isolate should be classified in the genus Streptomyces as a novel species, Streptomyces hundungensis sp. nov. The type strain is MBRL 251(T) (=JCM 17577(T)=KCTC 29124(T)).