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Sample records for ws5995b producer streptomyces

  1. Four new anthraquinones from a soil actinomycete Streptomyces sp. WS-13394 and their bioactivities.

    Science.gov (United States)

    Wu, Zhaoyuan; Zhang, Yani; Fang, Wei; Shi, Liqiao; Wan, Zhongyi

    2018-02-01

    Further chemical study of secondary metabolites from the soil actinomycete Streptomyces sp. WS-13394 resulted in the isolation of four new alkylated anthraquinone analogues (5-8). Their structures were elucidated on the basis of extensive spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR. The new compounds, together with analogues obtained before (1-4), were tested for their in vitro cytotoxicity against Huh-7 and SGC-7901.

  2. 21 CFR 868.5995 - Tee drain (water trap).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

  3. Antibiotics produced by Streptomyces.

    Science.gov (United States)

    Procópio, Rudi Emerson de Lima; Silva, Ingrid Reis da; Martins, Mayra Kassawara; Azevedo, João Lúcio de; Araújo, Janete Magali de

    2012-01-01

    Streptomyces is a genus of Gram-positive bacteria that grows in various environments, and its shape resembles filamentous fungi. The morphological differentiation of Streptomyces involves the formation of a layer of hyphae that can differentiate into a chain of spores. The most interesting property of Streptomyces is the ability to produce bioactive secondary metabolites, such as antifungals, antivirals, antitumorals, anti-hypertensives, immunosuppressants, and especially antibiotics. The production of most antibiotics is species specific, and these secondary metabolites are important for Streptomyces species in order to compete with other microorganisms that come in contact, even within the same genre. Despite the success of the discovery of antibiotics, and advances in the techniques of their production, infectious diseases still remain the second leading cause of death worldwide, and bacterial infections cause approximately 17 million deaths annually, affecting mainly children and the elderly. Self-medication and overuse of antibiotics is another important factor that contributes to resistance, reducing the lifetime of the antibiotic, thus causing the constant need for research and development of new antibiotics. Copyright © 2012 Elsevier Editora Ltda. All rights reserved.

  4. Integrative Gene Cloning and Expression System for Streptomyces sp. US 24 and Streptomyces sp. TN 58 Bioactive Molecule Producing Strains

    Directory of Open Access Journals (Sweden)

    Samiha Sioud

    2009-01-01

    Full Text Available Streptomyces sp. US 24 and Streptomyces sp. TN 58, two strains producing interesting bioactive molecules, were successfully transformed using E. coli ET12567 (pUZ8002, as a conjugal donor, carrying the integrative plasmid pSET152. For the Streptomyces sp. US 24 strain, two copies of this plasmid were tandemly integrated in the chromosome, whereas for Streptomyces sp. TN 58, the integration was in single copy at the attB site. Plasmid pSET152 was inherited every time for all analysed Streptomyces sp. US 24 and Streptomyces sp. TN 58 exconjugants under nonselective conditions. The growth, morphological differentiation, and active molecules production of all studied pSET152 integrated exconjugants were identical to those of wild type strains. Consequently, conjugal transfer using pSET152 integration system is a suitable means of genes transfer and expression for both studied strains. To validate the above gene transfer system, the glucose isomerase gene (xylA from Streptomyces sp. SK was expressed in strain Streptomyces sp. TN 58. Obtained results indicated that heterologous glucose isomerase could be expressed and folded effectively. Glucose isomerase activity of the constructed TN 58 recombinant strain is of about eighteenfold higher than that of the Streptomyces sp. SK strain. Such results are certainly of importance due to the potential use of improved strains in biotechnological process for the production of high-fructose syrup from starch.

  5. Uptake of nourseothricin by the producing microorganism, Streptomyces noursei

    International Nuclear Information System (INIS)

    Roeder, B.; Graefe, U.

    1985-01-01

    The uptake of 14 C-(U)-nourseothricin by stationary phase mycelium of Streptomyces noursei JA 3890b-NG 13/14 was demonstrated. An energy-dependent transport system appears to be involved in the transport of the antibiotic. Relatively large quantities of the antibiotic were adsorbed to the surface of mycelium. Degradation of nourseothricin by the producing microorganism was not detectable. (author)

  6. Characterization of Ethanolic Extract of Streptomyces sp. as a Pancreatic Lipase Inhibitors Produced by Endophytic Streptomyces sp. AEBg12

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    Lenni Fitri

    2017-07-01

    Full Text Available Endophytic Streptomyces sp. AEBg12 isolated from Zingiber cassumunar (Bangle is known to produce pancreatic lipase inhibitory compound. However, the characteristics of this active compound has not been reported yet. This study aimed to determine the characteristics of pancreatics inhibitory compound produced by Streptomyces sp. AEBg12 and to assess the role of endophytic actinobacteria in producing pancreatic lipase inhibitor using endophytic-free bangle tissue culture, wild bangle and compared with the activity of Streptomyces sp. AEBg12 endophytes. Supernatant of Streptomyces sp. AEBg12 was extracted using ethanol, ethyl acetate, and n-hexane solvents. Toxicity test was performed using larvae of shrimp Artemia salina. The results showed that the best solvent to obtain pancreatic lipase inhibitor compounds was ethanol. Phytochemical analysis showed that ethanolic extract of endophytic Streptomyces sp. AEBg12 contained flavonoids. IC50 value of ethanol extract was 180.83 µg/ml. The result of TLC showed that ethanolic extract of Streptomyces AEBg12 had a blue luminescence band indicated that there were either flavone, flavanones, flavonols or isoflavones. Inhibitory activity of Streptomyces sp. AEBg12 was higher than wild bangle and bangle tissue culture. The information from this study can be be used as a basic data for further characterization of the active compound, which might be developed as an antiobesity agent through its pancreatic lipase inhibitory activity.

  7. ISOLATION AND PURIFICATION OF STREPTOMYCES SPP. PRODUCING VANCOMYCIN

    International Nuclear Information System (INIS)

    EL-KABBANY, H.M.I.

    2008-01-01

    Soil samples obtained from different governments in Egypt were analyzed to determine the presence of types of antibiotic producing actinomycetes using starch-nitrite agar, starch-casein nitrate agar and Czapek's Dox agar as culture media. Different Streptomyces spp. were isolated. The Streptomyces (S.) isolates encountered were S. violochromogens, S. violaceus-nigar and S. orientalis and known as standard Vancomycin producers. The optimum conditions of S. orientalis; incubation period, initial pH and incubation temperature, were determined. In addition, physical properties; appearance, melting point, solubility, mass spectrophotometer of ultra violet (UV) and the effect of gamma rays, were also determined

  8. Construction of ivermectin producer by domain swaps of avermectin polyketide synthase in Streptomyces avermitilis.

    Science.gov (United States)

    Zhang, Xiaolin; Chen, Zhi; Li, Meng; Wen, Ying; Song, Yuan; Li, Jilun

    2006-10-01

    Ivermectin, 22, 23-dihydroavermectin B1, is commercially important in human, veterinary medicine, and pesticides. It is currently synthesized by chemical reduction of the double bond between C22 and C23 of avermectins B1, which are a mixture of B1a (>80%) and B1b (produced by fermentation of Streptomyces avermitilis. The cost of ivermectin is much higher than that of avermectins B1 owing to the necessity of region-specific hydrogenation at C22-C23 of avermectins B1 with rhodium chloride as the catalyst for producing ivermectin. Here we report that ivermectin can be produced directly by fermentation of recombinant strains constructed through targeted genetic engineering of the avermectin polyketide synthase (PKS) in S. avermitilis Olm73-12, which produces only avermectins B and not avermectins A and oligomycin. The DNA region encoding the dehydratase (DH) and ketoreductase (KR) domains of module 2 from the avermectin PKS in S. avermitilis Olm73-12 was replaced by the DNA fragment encoding the DH, enoylreductase, and KR domains from module 4 of the pikromycin PKS of Streptomyces venezuelae ATCC 15439 using a gene replacement vector pXL211. Twenty-seven of mutants were found to produce a small amount of 22, 23-dihydroavermectin B1a and avermectin B1a and B2a by high performance liquid chromatography and liquid chromatography mass spectrometry analysis. This study might provide a route to the low-cost production of ivermectin by fermentation.

  9. 32 CFR Appendix B to Part 45 - DD Form 214ws

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false DD Form 214ws B Appendix B to Part 45 National... CERTIFICATE OF RELEASE OR DISCHARGE FROM ACTIVE DUTY (DD FORM 214/5 SERIES) Pt. 45, App. B Appendix B to Part 45—DD Form 214ws EC23OC91.007 ...

  10. Production and characterization of biosurfactant from marine Streptomyces species B3.

    Science.gov (United States)

    Khopade, Abhijit; Ren, Biao; Liu, Xiang-Yang; Mahadik, Kakasaheb; Zhang, Lixin; Kokare, Chandrakant

    2012-02-01

    The present study demonstrates the production and properties of a biosurfactant isolated from marine Streptomyces species B3. The production of the biosurfactant was found to be higher in medium containing sucrose and lower in the medium containing glycerol. Yeast extract was the best nitrogen source for the production of the biosurfactant. The isolated biosurfactant reduced the surface tension of water to 29 mN/m. The purified biosurfactant was shown critical micelle concentrations of 110 mg/l. The emulsifying activity and stability of the biosurfactant was investigated at different salinities, pH, and temperature. The biosurfactant was effective at very low concentrations over a wide range of temperature, pH, and salt concentration. The purified biosurfactant was shown strong antimicrobial activity. The biosurfactant was produced from the marine Streptomyces sp. using non-hydrocarbon substrates such as sucrose that was readily available and not required extensive purification procedure. Streptomyces species B3 can be used for microbially enhanced oil recovery process. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. 'Streptomyces caelicus', an antibiotic-producing species of the genus Streptomyces, and Streptomyces canchipurensis Li et al. 2015 are later heterotypic synonyms of Streptomyces muensis Ningthoujam et al. 2014.

    Science.gov (United States)

    Wink, Joachim; Schumann, Peter; Atasayar, Ewelina; Klenk, Hans-Peter; Zaburannyi, Nestor; Westermann, Martin; Martin, Karin; Glaeser, Stefanie P; Kämpfer, Peter

    2017-04-01

    'Streptomyces caelicus' DSM 40835 was first reported as the producer of the antibiotic griselimycin by some coworkers of Rhone Poulenc in 1971. The project on isolation of the antibiotic compound was stopped because of the bad solubility and selectivity of the compound towards Mycobacteria. At Sanofi-Aventis, Germany, the project was re-evaluated in 2007 and the gene cluster of griselimycin could be identified, characterized and was patented in 2013. At this time, 'S. caelicus' was an invalid name. During the strain characterization work, it was found that 'S. caelicus' belongs to the group of species of the genus Streptomyces which show an unusual heterogeneity of the 16S rRNA gene sequences. However, high 16S rRNA gene sequence similarities to Streptomyces muensis JCM 17576T and Streptomyces canchipurensis JCM 17575T were obvious. Here, we present a comparative description of 'Streptomyces caelicus' DS 9461 (=DSM 40835=NCCB 100592) with S. muensis and S. canchipurensis by use of a polyphasic taxonomy approach and additional comparison of some housekeeping genes by multilocus sequence analysis (MLSA). An emended description of Streptomyces muensis is provided as a result of this work.

  12. Discovering potential Streptomyces hormone producers by using disruptants of essential biosynthetic genes as indicator strains.

    Science.gov (United States)

    Thao, Nguyen B; Kitani, Shigeru; Nitta, Hiroko; Tomioka, Toshiya; Nihira, Takuya

    2017-10-01

    Autoregulators are low-molecular-weight signaling compounds that control the production of many secondary metabolites in actinomycetes and have been referred to as 'Streptomyces hormones'. Here, potential producers of Streptomyces hormones were investigated in 40 Streptomyces and 11 endophytic actinomycetes. Production of γ-butyrolactone-type (IM-2, VB) and butenolide-type (avenolide) Streptomyces hormones was screened using Streptomyces lavendulae FRI-5 (ΔfarX), Streptomyces virginiae (ΔbarX) and Streptomyces avermitilis (Δaco), respectively. In these strains, essential biosynthetic genes for Streptomyces hormones were disrupted, enabling them to respond solely to the externally added hormones. The results showed that 20% of each of the investigated strains produced IM-2 and VB, confirming that γ-butyrolactone-type Streptomyces hormones are the most common in actinomycetes. Unlike the γ-butyrolactone type, butenolide-type Streptomyces hormones have been discovered in recent years, but their distribution has been unclear. Our finding that 24% of actinomycetes (12 of 51 strains) showed avenolide activity revealed for the first time that the butenolide-type Streptomyces hormone is also common in actinomycetes.

  13. Streptomyces lasiicapitis sp. nov., an actinomycete that produces kanchanamycin, isolated from the head of an ant (Lasius fuliginosus L.).

    Science.gov (United States)

    Ye, Lan; Zhao, Shanshan; Li, Yao; Jiang, Shanwen; Zhao, Yue; Li, Jinmeng; Yan, Kai; Wang, Xiangjing; Xiang, Wensheng; Liu, Chongxi

    2017-05-01

    During a screening for novel and biotechnologically useful actinobacteria in insects, a kanchanamycin-producing actinomycete with antifungal activity, designated strain 3H-HV17(2)T, was isolated from the head of an ant (Lasius fuliginosus L.) and characterized using a polyphasic approach. 16S rRNA gene sequence similarity studies showed that strain 3H-HV17(2)T belongs to the genus Streptomyces with the highest sequence similarities to Streptomyces spectabilis NBRC 13424T (98.90 %, with which it phylogenetically clustered, Streptomyces alboflavus NRRL B-2373T (98.65 %) and Streptomyces flavofungini NBRC 13371T (98.36 %). Phylogenetic analysis based on the gyrB gene also supported the close relationship of these strains. The morphological and chemotaxonomic properties of the strain are also consistent with those members of the genus Streptomyces. A combination of DNA-DNA hybridization experiments and phenotypic tests were carried out between strain 3H-HV17(2)T and its phylogenetically closely related strains, which further clarified their relatedness and demonstrated that strain 3H-HV17(2)T could be distinguished from these strains. Therefore, strain 3H-HV17(2)T is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces lasiicapitis sp. nov. is proposed. The type strain is 3H-HV17(2)T (=CGMCC 4.7349T=DSM 103124T).

  14. Streptomyces amphotericinicus sp. nov., an amphotericin-producing actinomycete isolated from the head of an ant (Camponotus japonicus Mayr).

    Science.gov (United States)

    Cao, Tingting; Mu, Shan; Lu, Chang; Zhao, Shanshan; Li, Dongmei; Yan, Kai; Xiang, Wensheng; Liu, Chongxi

    2017-12-01

    A novel actinomycete, designated strain 1H-SSA8 T , was isolated from the head of an ant (Camponotus japonicus Mayr) and was found to produce amphotericin. A polyphasic approach was employed to determine the status of strain 1H-SSA8 T . Morphological and chemotaxonomic characteristics were consistent with those of members of the genus Streptomyces. The menaquinones detected were MK-9(H6), MK-9(H8) and MK-9(H4). The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine and phosphatidylinositol mannoside. The major fatty acids were identified as iso-C16 : 0, C16 : 0, C15 : 0 and anteiso-C15 : 0. Analysis of the 16S rRNA gene sequence showed that strain 1H-SSA8 T belongs to the genus Streptomyces with high sequence similarity to Streptomyces ramulosus NRRL B-2714 T (99.2 %). Two tree-making algorithms based on 16S rRNA gene sequences showed that the isolate formed a phyletic line with Streptomyces himastatinicus ATCC 53653 T (98.7 %). The MLSA utilizing partial sequences of the housekeeping genes (atpD, gyrB, recA, rpoB and trpB) also supported the position. However, evolutionary distances were higher than the 0.007 MLSA evolutionary distance threshold proposed for species-level relatedness. Moreover, the low level of DNA-DNA relatedness and phenotypic differences allowed the novel isolate to be differentiated from its most closely related strain S. ramulosus NRRL B-2714 T and strain S. himastatinicus ATCC 53653 T . It is concluded that the organism can be classified as representing a novel species of the genus Streptomyces, for which the name Streptomyces amphotericinicus sp. nov. is proposed. The type strain is 1H-SSA8 T (=CGMCC 4.7350 T =DSM 103128 T ).

  15. Taxonomic analyses of members of the Streptomyces cinnabarinus cluster, description of Streptomyces cinnabarigriseus sp. nov. and Streptomyces davaonensis sp. nov.

    Science.gov (United States)

    Landwehr, Wiebke; Kämpfer, Peter; Glaeser, Stefanie P; Rückert, Christian; Kalinowski, Jörn; Blom, Jochen; Goesmann, Alexander; Mack, Matthias; Schumann, Peter; Atasayar, Ewelina; Hahnke, Richard L; Rohde, Manfred; Martin, Karin; Stadler, Marc; Wink, Joachim

    2018-01-01

    Roseoflavin is the only known riboflavin (vitamin B2) analog with antibiotic properties. It is actively taken up by many micro-organisms and targets flavinmononucleotide riboswitches and flavoproteins. It is described as the product of the tentatively named 'Streptomyces davawensis' JCM 4913. Taxonomic analysis of this strain with a polyphasic approach showed that it is very closely related to Streptomyces cinnabarinus (DSM 40467). The two Streptomyces isolates were obtained from different geographical locations (the Philippines and the Kamchatka Peninsula, respectively), their genomes have been sequenced and the question was whether or not the two isolates were representatives of the same species. As we also worked with another isolate of Streptomyces cinnabarinus JS 360, the producer of the cinnabaramides, we wanted to clarify the taxonomic position of the three isolates by using a polyphasic approach. After analysis of the 16S rRNA gene sequence, we found in total 23 species of the genus Streptomyces that showed a similarity higher than 98.5 % to the three strains. We showed that 'S. davawensis' JCM 4913 and S. cinnabarinus DSM 40467 were very closely related but belong to two different species. Hence, we validate 'S. davawensis' as Streptomyces davaonensis sp. nov. with the type strain JCM 4913 T (=DSM 101723 T ). In addition, the cinnabaramide producer can be clearly differentiated from S. davaonensis and this isolate is described as Streptomyces cinnabarigriseus sp. nov. with strain JS360 T (=NCCB 100590 T =DSM 101724 T ) as the type strain.

  16. Determination of ionophore antibiotics nactins produced by fecal Streptomyces from sheep.

    Science.gov (United States)

    Wang, Jun; Tan, Hongming; Lu, Yu; Cao, Lixiang

    2014-04-01

    To investigate the correlation between fecal actinobacteria and host animals, Streptomyces was isolated from fresh faeces of healthy sheep and secondary metabolites were analyzed. The most frequently isolated strain S161 with antibiotic activity against bacteria and fungi were analyzed. The S161 showed the highest 99 % similarity to Streptomyces canus DSB17 based on the 16S rRNA gene sequence analysis. Metabolite analysis based on MS and NMR spectra showed that S161 produces nactins, cyclotetralactones derived from nonactic acid and homononactic acid as building units of ionophoretic character. Due to ionophores are antimicrobial compounds that are commonly fed to ruminant animals to improve feed efficiency, stable beneficial interactions between Streptomyces bacteria and vertebrates have been demonstrated.

  17. Lignocellulose-Adapted Endo-Cellulase Producing Streptomyces Strains for Bioconversion of Cellulose-Based Materials.

    Science.gov (United States)

    Ventorino, Valeria; Ionata, Elena; Birolo, Leila; Montella, Salvatore; Marcolongo, Loredana; de Chiaro, Addolorata; Espresso, Francesco; Faraco, Vincenza; Pepe, Olimpia

    2016-01-01

    Twenty-four Actinobacteria strains, isolated from Arundo donax, Eucalyptus camaldulensis and Populus nigra biomass during natural biodegradation and with potential enzymatic activities specific for the degradation of lignocellulosic materials, were identified by a polyphasic approach. All strains belonged to the genus Streptomyces ( S .) and in particular, the most highly represented species was Streptomyces argenteolus representing 50% of strains, while 8 strains were identified as Streptomyces flavogriseus (synonym S. flavovirens ) and Streptomyces fimicarius (synonyms Streptomyces acrimycini, Streptomyces baarnensis, Streptomyces caviscabies , and Streptomyces flavofuscus ), and the other four strains belonged to the species Streptomyces drozdowiczii, Streptomyces rubrogriseus, Streptomyces albolongus , and Streptomyces ambofaciens . Moreover, all Streptomyces strains, tested for endo and exo-cellulase, cellobiase, xylanase, pectinase, ligninase, peroxidase, and laccase activities using qualitative and semi-quantitative methods on solid growth medium, exhibited multiple enzymatic activities (from three to six). The 24 strains were further screened for endo-cellulase activity in liquid growth medium and the four best endo-cellulase producers ( S. argenteolus AE58P, S. argenteolus AE710A, S. argenteolus AE82P, and S. argenteolus AP51A) were subjected to partial characterization and their enzymatic crude extracts adopted to perform saccharification experiments on A. donax pretreated biomass. The degree of cellulose and xylan hydrolysis was evaluated by determining the kinetics of glucose and xylose release during 72 h incubation at 50°C from the pretreated biomass in the presence of cellulose degrading enzymes (cellulase and β-glucosidase) and xylan related activities (xylanase and β-xylosidase). The experiments were carried out utilizing the endo-cellulase activities from the selected S. argenteolus strains supplemented with commercial β-gucosidase and

  18. Streptomyces cameroonensis sp. nov., a Geldanamycin Producer That Promotes Theobroma cacao Growth.

    Science.gov (United States)

    Boudjeko, Thaddée; Tchinda, Romaric Armel Mouafo; Zitouni, Mina; Nana, Joëlle Aimée Vera Tchatchou; Lerat, Sylvain; Beaulieu, Carole

    2017-03-31

    The taxonomy of an actinobacterial strain, designated JJY4 T , was established using a polyphasic approach. JJY4 T was isolated from the rhizosphere of Chromolaena odorata in Yaoundé (Cameroon) during a project for the selection of biological control agents. Strain JJY4 T exhibited antimicrobial activities against bacteria, fungi, and oomycetes. Strain JJY4 T also exhibited the traits of plant growth-promoting rhizobacteria such as the solubilization of inorganic phosphate, production of siderophores and indole-3-acetic acid, and 1-aminocyclopropane-1-carboxylate deaminase activity. In planta assays performed on cocoa plantlets confirmed that strain JJY4 T exhibited strong abilities to promote plant growth and protect against Phytophthora megakarya, the main causal agent of cocoa pod rot. The formation of rugose-ornamented spores in spiral spore chains by strain JJY4 T is a typical feature of members found in the Streptomyces violaceusniger clade and, similar to some members of the clade, strain JJY4 T produces geldanamycin. A phylogenetic analysis based on 16S rRNA gene sequences confirmed this classification and suggests that strain JJY4 T be added to the subclade constituted of the type strains Streptomyces malaysiensis DSM 41697 T and Streptomyces samsunensis DSM 42010 T . However, DNA-DNA relatedness and physiological characteristics allowed for the differentiation of strain JJY4 T from its closest phylogenetic relatives. Based on these results, strain JJY4 T (=NRRL B-65369, =NBRC 112705) appears to represent a novel species in the S. violaceusniger clade for which the proposed name is Streptomyces cameroonensis sp. nov.

  19. Expression by Streptomyces lividans of the Rat α Integrin CD11b A-Domain as a Secreted and Soluble Recombinant Protein

    Directory of Open Access Journals (Sweden)

    Dorra Zouari Ayadi

    2007-01-01

    Full Text Available We already reported the use of a long synthetic signal peptide (LSSP to secrete the Streptomyces sp. TO1 amylase by Streptomyces lividans strain. We herein report the expression and secretion of the rat CD11b A-domain using the same LSSP and S. lividans as host strain. We have used the Escherichia coli/Streptomyces shuttle vector pIJ699 for the cloning of the A-domain DNA sequence downstream of LSSP and under the control of the constitutive ermE-up promoter of Streptomyces erythraeus. Using this construct and S. lividans as a host strain, we achieved the expression of 8 mg/L of soluble secreted recombinant form of the A-domain of the rat leukocyte β2 integrin CD11/CD18 alpha M subunit (CD11b. This secreted recombinant CD11b A-domain reacted with a function blocking antibody showing that this protein is properly folded and probably functional. These data support the capability of Streptomyces to produce heterologous recombinant proteins as soluble secreted form using the “LSSP” synthetic signal peptide.

  20. Potent antifouling compounds produced by marine Streptomyces

    KAUST Repository

    Xu, Ying; He, Hongping; Schulz, Stefan; Liu, Xin; Fusetani, Nobushino; Xiong, Hairong; Xiao, Xiang; Qian, Peiyuan

    2010-01-01

    of a marine Streptomyces strain obtained from deep-sea sediments. Antifouling activities of these five compounds and four other structurally-related compounds isolated from a North Sea Streptomyces strain against major fouling organisms were compared

  1. Characterization of the Antibiotic Compound No. 70 Produced by Streptomyces sp. IMV-70

    Science.gov (United States)

    Trenozhnikova, Lyudmila P.; Khasenova, Almagul K.; Balgimbaeva, Assya S.; Fedorova, Galina B.; Katrukha, Genrikh S.; Tokareva, Nina L.; Kwa, Boo H.; Azizan, Azliyati

    2012-01-01

    We describe the actinomycete strain IMV-70 isolated from the soils of Kazakhstan, which produces potent antibiotics with high levels of antibacterial activity. After the research of its morphological, chemotaxonomic, and cultural characteristics, the strain with potential to be developed further as a novel class of antibiotics with chemotherapeutics potential was identified as Streptomyces sp. IMV-70. In the process of fermentation, the strain Streptomyces spp. IMV-70 produces the antibiotic no. 70, which was isolated from the culture broth by extraction with organic solvents. Antibiotic compound no. 70 was purified and separated into individual components by HPLC, TLC, and column chromatography methods. The main component of the compound is the antibiotic 70-A, which was found to be identical to the peptolide etamycin A. Two other antibiotics 70-B and 70-C have never been described and therefore are new antibiotics. The physical-chemical and biological characteristics of these preparations were described and further researched. Determination of the optimal growth conditions to cultivate actinomycete-producer strain IMV-70 and development of methods to isolate, purify, and accumulate preparations of the new antibiotic no. 70 enable us to research further the potential of this new class of antibiotics. PMID:22536145

  2. Characterization of the Antibiotic Compound No. 70 Produced by Streptomyces sp. IMV-70

    Directory of Open Access Journals (Sweden)

    Lyudmila P. Trenozhnikova

    2012-01-01

    Full Text Available We describe the actinomycete strain IMV-70 isolated from the soils of Kazakhstan, which produces potent antibiotics with high levels of antibacterial activity. After the research of its morphological, chemotaxonomic, and cultural characteristics, the strain with potential to be developed further as a novel class of antibiotics with chemotherapeutics potential was identified as Streptomyces sp. IMV-70. In the process of fermentation, the strain Streptomyces spp. IMV-70 produces the antibiotic no. 70, which was isolated from the culture broth by extraction with organic solvents. Antibiotic compound no. 70 was purified and separated into individual components by HPLC, TLC, and column chromatography methods. The main component of the compound is the antibiotic 70-A, which was found to be identical to the peptolide etamycin A. Two other antibiotics 70-B and 70-C have never been described and therefore are new antibiotics. The physical-chemical and biological characteristics of these preparations were described and further researched. Determination of the optimal growth conditions to cultivate actinomycete-producer strain IMV-70 and development of methods to isolate, purify, and accumulate preparations of the new antibiotic no. 70 enable us to research further the potential of this new class of antibiotics.

  3. Molecular Identification of Streptomyces producing antibiotics and their antimicrobial activities

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    Latifa A. Al_husnan

    2016-12-01

    Full Text Available Five strains of Streptomyces, namely S, N, W, E and C (designations should be mentioned in detail here isolated from the rhizosphere soil cultivated with palm Alajua (date, pressed dates, AlMedina city, Saudi Arabia, were induced to produce antibiotics. Antimicrobial activities were determined on solid medium supplemented with starch. The detection was based on the formation of transparent zones around colonies. The results indicated that isolates had antibacterial activities against Staphylococcus aureus, Bacillus cereus, B. subtilis, Pseudomonas aeruginosa and also showed antifungal activity against Candida albicans and Aspergillus niger. DNA extracted from five isolates was used as template for 16s rDNA gene amplification. The expected PCR size was 1.5 kbp;1.6 kbp; 1.25 kbp; 1.25kbp and 1.0 k bp for S, N, W, E and C isolates respectively using universal 16s rDNA gene primers using direct PCR. The isolates varied morphologically on the basis of spore color, aerial and substrate mycelium formation, and production of diffusible pigment. Isolates were tested under a microscope by using slide culture technique. The results indicate that the soil of this region is source of Streptomyces having antibacterial and antifungal activity and thus better utilization of these microorganisms as biological control agents.

  4. The tylosin resistance gene tlrB of Streptomyces fradiae encodes a methyltransferase that targets G748 in 23S rRNA

    DEFF Research Database (Denmark)

    Liu, M; Kirpekar, F; Van Wezel, G P

    2000-01-01

    tlrB is one of four resistance genes encoded in the operon for biosynthesis of the macrolide tylosin in antibiotic-producing strains of Streptomyces fradiae. Introduction of tlrB into Streptomyces lividans similarly confers tylosin resistance. Biochemical analysis of the rRNA from the two...... is dependent on the presence of the methyl group donor, S-adenosyl methionine. Analysis of the 74-mer RNA substrate by biochemical and mass spectrometric methods shows that TlrB adds a single methyl group to the base of G748. Homologues of TlrB in other bacteria have been revealed through database searches...

  5. Production of Manooligomannan from Palm Kernel Cake by Mannanase Produced from Streptomyces Cyaenus

    Directory of Open Access Journals (Sweden)

    Awan Purnawan

    2017-04-01

    Full Text Available The increase of public attention to health has prompted researchers to look for new sources of functional food. Palm Cake Kernel (PKC waste was abundant in Indonesia, Oligosaccharide has an important benefit for human health. Recently oligosaccharide is not only important as an artificial sweetener, but also as a functional food component. This study was aimed to produce oligo-mannan enzymatically from PKC waste using mannanase derived from of Streptomyces cyaenus isolates of indigenous Indonesia. The enzyme concentration was determined by enzyme activity assay while oligo-mannan content in the PKC was analyzed using TLC and HPLC. Mannanase enzyme activity of 1706 U/ml on the second day of agitation 200 rpm at a temperature of 30°C Hydrolysis of mannooligomannan by using mannanase produced by streptomyces cyaenus. The optimum mannanase enzyme activity obtained on day 2 with the value of the activity as much of 0.702 U/mL. The protein content of the 2nd day at an agitation speed of 150 rpm, 200 rpm, and 250 rpm, respectively, were 1783, 1950 and 2283 ppm. Streptomyces cyaenus is Indonesian original isolates potentially producing mannanase that can produce mannooligomannan.

  6. Self-resistance in Streptomyces, with Special Reference to β-Lactam Antibiotics.

    Science.gov (United States)

    Ogawara, Hiroshi

    2016-05-10

    Antibiotic resistance is one of the most serious public health problems. Among bacterial resistance, β-lactam antibiotic resistance is the most prevailing and threatening area. Antibiotic resistance is thought to originate in antibiotic-producing bacteria such as Streptomyces. In this review, β-lactamases and penicillin-binding proteins (PBPs) in Streptomyces are explored mainly by phylogenetic analyses from the viewpoint of self-resistance. Although PBPs are more important than β-lactamases in self-resistance, phylogenetically diverse β-lactamases exist in Streptomyces. While class A β-lactamases are mostly detected in their enzyme activity, over two to five times more classes B and C β-lactamase genes are identified at the whole genomic level. These genes can subsequently be transferred to pathogenic bacteria. As for PBPs, two pairs of low affinity PBPs protect Streptomyces from the attack of self-producing and other environmental β-lactam antibiotics. PBPs with PASTA domains are detectable only in class A PBPs in Actinobacteria with the exception of Streptomyces. None of the Streptomyces has PBPs with PASTA domains. However, one of class B PBPs without PASTA domain and a serine/threonine protein kinase with four PASTA domains are located in adjacent positions in most Streptomyces. These class B type PBPs are involved in the spore wall synthesizing complex and probably in self-resistance. Lastly, this paper emphasizes that the resistance mechanisms in Streptomyces are very hard to deal with, despite great efforts in finding new antibiotics.

  7. Three-dimensional WS2 nanosheet networks for H2O2 produced for cell signaling

    Science.gov (United States)

    Tang, Jing; Quan, Yingzhou; Zhang, Yueyu; Jiang, Min; Al-Enizi, Abdullah M.; Kong, Biao; An, Tiance; Wang, Wenshuo; Xia, Limin; Gong, Xingao; Zheng, Gengfeng

    2016-03-01

    Hydrogen peroxide (H2O2) is an important molecular messenger for cellular signal transduction. The capability of direct probing of H2O2 in complex biological systems can offer potential for elucidating its manifold roles in living systems. Here we report the fabrication of three-dimensional (3D) WS2 nanosheet networks with flower-like morphologies on a variety of conducting substrates. The semiconducting WS2 nanosheets with largely exposed edge sites on flexible carbon fibers enable abundant catalytically active sites, excellent charge transfer, and high permeability to chemicals and biomaterials. Thus, the 3D WS2-based nano-bio-interface exhibits a wide detection range, high sensitivity and rapid response time for H2O2, and is capable of visualizing endogenous H2O2 produced in living RAW 264.7 macrophage cells and neurons. First-principles calculations further demonstrate that the enhanced sensitivity of probing H2O2 is attributed to the efficient and spontaneous H2O2 adsorption on WS2 nanosheet edge sites. The combined features of 3D WS2 nanosheet networks suggest attractive new opportunities for exploring the physiological roles of reactive oxygen species like H2O2 in living systems.Hydrogen peroxide (H2O2) is an important molecular messenger for cellular signal transduction. The capability of direct probing of H2O2 in complex biological systems can offer potential for elucidating its manifold roles in living systems. Here we report the fabrication of three-dimensional (3D) WS2 nanosheet networks with flower-like morphologies on a variety of conducting substrates. The semiconducting WS2 nanosheets with largely exposed edge sites on flexible carbon fibers enable abundant catalytically active sites, excellent charge transfer, and high permeability to chemicals and biomaterials. Thus, the 3D WS2-based nano-bio-interface exhibits a wide detection range, high sensitivity and rapid response time for H2O2, and is capable of visualizing endogenous H2O2 produced in

  8. Pulsed cathodoluminescence and Raman spectra of MoS{sub 2} and WS{sub 2} nanocrystals and their combination MoS{sub 2}/WS{sub 2} produced by self-propagating high-temperature synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Bozheyev, Farabi, E-mail: farabi.bozheyev@gmail.com [Institute of High Technology Physics, National Research Tomsk Polytechnic University, 30 Lenin Ave., 634050 Tomsk (Russian Federation); National Nanolaboratory, al-Farabi Kazakh National University, 71 al-Farabi Ave., 050000 Almaty (Kazakhstan); Nazarbayev University Research and Innovation System, 53 Kabanbay Batyr St., 010000 Astana (Kazakhstan); Valiev, Damir [Institute of High Technology Physics, National Research Tomsk Polytechnic University, 30 Lenin Ave., 634050 Tomsk (Russian Federation); Nemkayeva, Renata [National Nanolaboratory, al-Farabi Kazakh National University, 71 al-Farabi Ave., 050000 Almaty (Kazakhstan)

    2016-02-29

    Molybdenum and tungsten disulfide nanoplates were produced by self-propagating high-temperature synthesis in argon atmosphere. This method provides an easy way to produce MoS{sub 2} and WS{sub 2} from nanoplates up to single- and several layers. The Raman peak intensities corresponding to in-plane E{sup 1}{sub 2g} and out-of-plane A{sub 1g} vibration modes and their shifts strongly depend on the thicknesses of the MoS{sub 2} and WS{sub 2} platelets indicating size-dependent scaling laws and properties. An electron beam irradiation of MoS{sub 2} and WS{sub 2} powders leads to an occurrence of pulsed cathodoluminescence (PCL) spectra at 575 nm (2.15 eV) and 550 nm (2.25 eV) characteristic to their intrinsic band gaps. For the combination of MoS{sub 2} and WS{sub 2} nanopowders, a PCL shoulder at 430 nm (2.88 eV) was observed, which is explained by the radiative electron-hole recombination at the MoS{sub 2}/WS{sub 2} grain boundaries. The luminescence decay kinetics of the MoS{sub 2}/WS{sub 2} nanoplates appears to be slower than for individual MoS{sub 2} and WS{sub 2} platelets due to a spatial separation of electrons and holes at MoS{sub 2}/WS{sub 2} junction resulting in extension of recombination time.

  9. Diversity and functions of volatile organic compounds produced by Streptomyces from a disease-suppressive soil.

    Science.gov (United States)

    Cordovez, Viviane; Carrion, Victor J; Etalo, Desalegn W; Mumm, Roland; Zhu, Hua; van Wezel, Gilles P; Raaijmakers, Jos M

    2015-01-01

    In disease-suppressive soils, plants are protected from infections by specific root pathogens due to the antagonistic activities of soil and rhizosphere microorganisms. For most disease-suppressive soils, however, the microorganisms and mechanisms involved in pathogen control are largely unknown. Our recent studies identified Actinobacteria as the most dynamic phylum in a soil suppressive to the fungal root pathogen Rhizoctonia solani. Here we isolated and characterized 300 isolates of rhizospheric Actinobacteria from the Rhizoctonia-suppressive soil. Streptomyces species were the most abundant, representing approximately 70% of the isolates. Streptomyces are renowned for the production of an exceptionally large number of secondary metabolites, including volatile organic compounds (VOCs). VOC profiling of 12 representative Streptomyces isolates by SPME-GC-MS allowed a more refined phylogenetic delineation of the Streptomyces isolates than the sequencing of 16S rRNA and the house-keeping genes atpD and recA only. VOCs of several Streptomyces isolates inhibited hyphal growth of R. solani and significantly enhanced plant shoot and root biomass. Coupling of Streptomyces VOC profiles with their effects on fungal growth, pointed to VOCs potentially involved in antifungal activity. Subsequent assays with five synthetic analogs of the identified VOCs showed that methyl 2-methylpentanoate, 1,3,5-trichloro-2-methoxy benzene and the VOCs mixture have antifungal activity. In conclusion, our results point to a potential role of VOC-producing Streptomyces in disease suppressive soils and show that VOC profiling of rhizospheric Streptomyces can be used as a complementary identification tool to construct strain-specific metabolic signatures.

  10. Diversity and functions of volatile organic compounds produced by Streptomyces from a disease-suppressive soil

    Directory of Open Access Journals (Sweden)

    Viviane eCordovez

    2015-10-01

    Full Text Available In disease-suppressive soils, plants are protected from infections by specific root pathogens due to the antagonistic activities of soil and rhizosphere microorganisms. For most disease-suppressive soils, however, the microorganisms and mechanisms involved in pathogen control are largely unknown. Our recent studies identified Actinobacteria as the most dynamic phylum in a soil suppressive to the fungal root pathogen Rhizoctonia solani. Here we isolated and characterized 300 isolates of rhizospheric Actinobacteria from the Rhizoctonia-suppressive soil. Streptomyces species were the most abundant, representing approximately 70% of the isolates. Streptomyces are renowned for the production of an exceptionally large number of secondary metabolites, including volatile organic compounds (VOCs. VOC profiling of 12 representative Streptomyces isolates by SPME-GC-MS allowed a more refined phylogenetic delineation of the Streptomyces isolates than the sequencing of 16S rRNA and the house-keeping genes atpD and recA only. VOCs of several Streptomyces isolates inhibited hyphal growth of R. solani and significantly enhanced plant shoot and root biomass. Coupling of Streptomyces VOC profiles with their effects on fungal growth, pointed to VOCs potentially involved in antifungal activity. Subsequent assays with five synthetic analogues of the identified VOCs showed that methyl 2-methylpentanoate, 1,3,5-trichloro-2-methoxy benzene and the VOCs mixture have antifungal activity. In conclusion, our results point to a potential role of VOC-producing Streptomyces in disease suppressive soils and show that VOC profiling of rhizospheric Streptomyces can be used as a complementary identification tool to construct strain-specific metabolic signatures.

  11. Production of gold nanoparticles by Streptomyces djakartensis isolate B-5

    Directory of Open Access Journals (Sweden)

    Sara Biglari

    2014-09-01

    Full Text Available  Objective(s: Biosynthesis of gold nanoparticles (NGPs is environmentally safer than chemical and physical procedures. This method requires no use of toxic solvents and synthesis of dangerous products and is environmentally safe. In this study, we report the biosynthesis of NGPs using Streptomyces djakartensis isolate B-5. Materials and Methods: NGPs were biosynthesized by reducing aqueous gold chloride solution via a Streptomyces isolate without the need for any additive for protecting nanoparticles from aggregation. We characterized the responsible Streptomycete; its genome DNA was isolated, purified and 16S rRNA was amplified by PCR. The amplified isolate was sequenced; using the BLAST search tool from NCBI, the microorganism was identified to species level. Results: Treating chloroauric acid solutions with this bacterium resulted in reduction of gold ions and formation of stable NGPs. TEM and SEM electro micrographs of NGPs indicated size range from 2- 25 nm with average of 9.09 nm produced intracellular by the bacterium. SEM electro micrographs revealed morphology of spores and mycelia. The amplified PCR fragment of 16S rRNA gene was cloned and sequenced from both sides; it consisted of 741 nucleotides. According to NCBI GenBank, the bacterium had 97.1% homology with Streptomyces djakartensis strain RT-49. The GenBank accession number for partial 16S rRNA gene was recorded as JX162550. Conclusion: Optimized application of such findings may create applications of Streptomycetes for use as bio-factories in eco-friendly production of NGPs to serve in demanding industries and related biomedical areas. Research in this area should also focus on the unlocking the full mechanism of NGPs biosynthesis by Streptomycetes.

  12. Caryolan-1-ol, an antifungal volatile produced by Streptomyces spp., inhibits the endomembrane system of fungi.

    Science.gov (United States)

    Cho, Gyeongjun; Kim, Junheon; Park, Chung Gyoo; Nislow, Corey; Weller, David M; Kwak, Youn-Sig

    2017-07-01

    Streptomyces spp. have the ability to produce a wide variety of secondary metabolites that interact with the environment. This study aimed to discover antifungal volatiles from the genus Streptomyces and to determine the mechanisms of inhibition. Volatiles identified from Streptomyces spp. included three major terpenes, geosmin, caryolan-1-ol and an unknown sesquiterpene. antiSMASH and KEGG predicted that the volatile terpene synthase gene clusters occur in the Streptomyces genome. Growth inhibition was observed when fungi were exposed to the volatiles. Biological activity of caryolan-1-ol has previously not been investigated. Fungal growth was inhibited in a dose-dependent manner by a mixture of the main volatiles, caryolan-1-ol and the unknown sesquiterpene, from Streptomyces sp. S4-7. Furthermore, synthesized caryolan-1-ol showed similar antifungal activity. Results of chemical-genomics profiling assays showed that caryolan-1-ol affected the endomembrane system by disrupting sphingolipid synthesis and normal vesicle trafficking in the fungi. © 2017 The Authors.

  13. CobB1 deacetylase activity in Streptomyces coelicolor

    Czech Academy of Sciences Publication Activity Database

    Mikulík, Karel; Felsberg, Jürgen; Kudrnáčová, E.; Bezoušková, Silvia; Šetinová, Dita; Stodůlková, Eva; Zídková, J.; Zídek, Václav

    2012-01-01

    Roč. 90, č. 2 (2012), s. 179-187 ISSN 0829-8211 R&D Projects: GA AV ČR(CZ) IAA500110805; GA ČR GA303/09/0475 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z50200510 Keywords : sirtuin * NAD(+)dependent deacetylation activity CobB1 * Streptomyces coeliocolor Subject RIV: EE - Microbiology, Virology Impact factor: 2.915, year: 2012

  14. Atmospheric Precipitations, Hailstone and Rainwater, as a Novel Source of Streptomyces Producing Bioactive Natural Products

    Science.gov (United States)

    Sarmiento-Vizcaíno, Aida; Espadas, Julia; Martín, Jesús; Braña, Alfredo F.; Reyes, Fernando; García, Luis A.; Blanco, Gloria

    2018-01-01

    A cultivation-dependent approach revealed that highly diverse populations of Streptomyces were present in atmospheric precipitations from a hailstorm event sampled in February 2016 in the Cantabrian Sea coast, North of Spain. A total of 29 bioactive Streptomyces strains isolated from small samples of hailstone and rainwater, collected from this hailstorm event, were studied here. Taxonomic identification by 16S rRNA sequencing revealed more than 20 different Streptomyces species, with their closest homologs displaying mainly oceanic but also terrestrial origins. Backward trajectory analysis revealed that the air-mass sources of the hailstorm event, with North Western winds, were originated in the Arctic Ocean (West Greenland and North Iceland) and Canada (Labrador), depending on the altitude. After traveling across the North Atlantic Ocean during 4 days the air mass reached Europe and precipitated as hailstone and rain water at the sampling place in Spain. The finding of Streptomyces species able to survive and disperse through the atmosphere increases our knowledge of the biogeography of genus Streptomyces on Earth, and reinforces our previous dispersion model, suggesting a generalized feature for the genus which could have been essential in his evolution. This unique atmospheric-derived Streptomyces collection was screened for production of bioactive secondary metabolites. Analyses of isolates ethyl acetate extracts by LC-UV-MS and further database comparison revealed an extraordinary diversity of bioactive natural products. One hundred molecules were identified, mostly displaying contrasted antibiotic and antitumor/cytotoxic activities, but also antiparasitic, antiviral, anti-inflammatory, neuroprotector, and insecticide properties. More interestingly, 38 molecules not identified in natural products databases might represent new natural products. Our results revealed for the first time an extraordinary diversity of Streptomyces species in the atmosphere able to

  15. Isolation, Characterization and Bioactivities of an Extracellular Polysaccharide Produced from Streptomyces sp. MOE6

    Directory of Open Access Journals (Sweden)

    Marwa O. Elnahas

    2017-08-01

    Full Text Available A Streptomyces strain was isolated from soil and the sequence of 1471 nucleotides of its 16S rDNA showed 99% identity to Streptomyces sp. HV10. This newly isolated Streptomyces strain produced an extracellular polysaccharide (EPS composed mainly of glucose and mannose in a ratio of 1:4.1, as was characterized by Fourier transform infrared spectroscopy (FTIR, HPLC and 1H-NMR. The antioxidant activities of the partially purified MOE6-EPS were determined by measuring the hydroxyl free radical scavenging activity and the scavenging of 2,2-diphenyl-2-picryl-hydrazyl (DPPH radicals. In addition, the partially purified MOE6-EPS showed high ferrous ion (Fe2+ chelation activity which is another antioxidant activity. Interestingly, 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assays that were colorimetric assays for NAD(PH-dependent cellular oxidoreductases and a proxy of the number of viable cells, showed that the partially purified MOE6-EPS inhibited the proliferation of the human breast cancer cells (MDA-MB-231. The scratch wound assay showed that MOE6-EPS reduced the migration of mouse breast cancer cells (4T1. This study reports the production of EPS from Streptomyces species with promising antioxidant, metal chelating and mammalian cell inhibitory activities.

  16. Isolation, Characterization and Bioactivities of an Extracellular Polysaccharide Produced from Streptomyces sp. MOE6.

    Science.gov (United States)

    Elnahas, Marwa O; Amin, Magdy A; Hussein, Mohamed M D; Shanbhag, Vinit C; Ali, Amal E; Wall, Judy D

    2017-08-24

    A Streptomyces strain was isolated from soil and the sequence of 1471 nucleotides of its 16S rDNA showed 99% identity to Streptomyces sp. HV10. This newly isolated Streptomyces strain produced an extracellular polysaccharide (EPS) composed mainly of glucose and mannose in a ratio of 1:4.1, as was characterized by Fourier transform infrared spectroscopy (FTIR), HPLC and ¹H-NMR. The antioxidant activities of the partially purified MOE6-EPS were determined by measuring the hydroxyl free radical scavenging activity and the scavenging of 2,2-diphenyl-2-picryl-hydrazyl (DPPH) radicals. In addition, the partially purified MOE6-EPS showed high ferrous ion (Fe 2+ ) chelation activity which is another antioxidant activity. Interestingly, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays that were colorimetric assays for NAD(P)H-dependent cellular oxidoreductases and a proxy of the number of viable cells, showed that the partially purified MOE6-EPS inhibited the proliferation of the human breast cancer cells (MDA-MB-231). The scratch wound assay showed that MOE6-EPS reduced the migration of mouse breast cancer cells (4T1). This study reports the production of EPS from Streptomyces species with promising antioxidant, metal chelating and mammalian cell inhibitory activities.

  17. Streptomyces capitiformicae sp. nov., a novel actinomycete producing angucyclinone antibiotics isolated from the head of Camponotus japonicus Mayr.

    Science.gov (United States)

    Jiang, Shanwen; Piao, Chenyu; Yu, Yang; Cao, Peng; Li, Chenxu; Yang, Fan; Li, Mutong; Xiang, Wensheng; Liu, Chongxi

    2018-01-01

    A novel actinomycete, designated strain 1H-SSA4 T , was isolated from the head of an ant (Camponotus japonicus Mayr) and was found to produce angucyclinone antibiotics. A polyphasic approach was used to determine the taxonomic status of strain 1H-SSA4 T . The DNA G+C content of the draft genome sequence, consisting of 11.4 Mbp, was 70.0 mol%. 16S rRNA gene sequence similarity studies showed that strain 1H-SSA4 T belongs to the genus Streptomyces with the highest sequence similarity to Streptomyces hygroscopicus subsp. ossamyceticus NBRC 13983 T (98.9 %), and phylogenetically clustered with this species, Streptomyces torulosus LMG 20305 T (98.8 %), Streptomyces ipomoeae NBRC 13050 T (98.5 %) and Streptomyces decoyicus NRRL 2666 T (98.4 %). The morphological and chemotaxonomic properties of the strain were also consistent with those members of the genus Streptomyces. A combination of DNA-DNA hybridization experiments and phenotypic tests were carried out between strain 1H-SSA4 T and the above-mentioned strains, which further clarified their relatedness and demonstrated that strain 1H-SSA4 T could be distinguished from these strains. Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces capitiformicae sp. nov. is proposed. The type strain is 1H-SSA4 T (=CGMCC 4.7403 T =DSM 104537 T ).

  18. Streptomyces kronopolitis sp. nov., an actinomycete that produces phoslactomycins isolated from a millipede (Kronopolites svenhedind Verhoeff).

    Science.gov (United States)

    Liu, Chongxi; Ye, Lan; Li, Yao; Jiang, Shanwen; Liu, Hui; Yan, Kai; Xiang, Wensheng; Wang, Xiangjing

    2016-12-01

    A phoslactomycin-producing actinomycete, designated strain NEAU-ML8T, was isolated from a millipede (Kronopolites svenhedind Verhoeff) and characterized using a polyphasic approach. 16S rRNA gene sequence analysis showed that strain NEAU-ML8T belongs to the genus Streptomyces with the highest sequence similarities to Streptomyces lydicus NBRC 13058T (99.39 %) and Streptomyces chattanoogensis DSM 40002T (99.25 %). The maximum-likelihood phylogenetic tree based on 16S rRNA gene sequences showed that the isolate formed a distinct phyletic line with NBRC 13058T and S. chattanoogensis DSM 40002T. This branching pattern was also supported by the tree rconstructed with the neighbour-joining method. A combination of DNA-DNA hybridization experiments and phenotypic tests were carried out between strain NEAU-ML8T and its phylogenetically closely related strains, which further clarified their relatedness and demonstrated that NEAU-ML8T could be distinguished from NBRC 13058T and S. chattanoogensis DSM 40002T. Therefore, it is concluded that strain NEAU-ML8T can be classified as representing a novel species of the genus Streptomyces, for which the name Streptomyces kronopolitis sp. nov. is proposed. The type strain is NEAU-ML8T (=DSM 101986T=CGMCC 4.7323T).

  19. Microtermolides A and B from termite-associated Streptomyces sp. and structural revision of vinylamycin

    DEFF Research Database (Denmark)

    Carr, Gavin; Poulsen, Michael; Klassen, Jonathan L.

    2012-01-01

    Microtermolides A (1) and B (2) were isolated from a Streptomyces sp. strain associated with fungus-growing termites. The structures of 1 and 2 were determined by 1D- and 2D-NMR spectroscopy and high-resolution mass spectrometry. Structural elucidation of 1 led to the re-examination of the struct......Microtermolides A (1) and B (2) were isolated from a Streptomyces sp. strain associated with fungus-growing termites. The structures of 1 and 2 were determined by 1D- and 2D-NMR spectroscopy and high-resolution mass spectrometry. Structural elucidation of 1 led to the re...

  20. Identification and activation of novel biosynthetic gene clusters by genome mining in the kirromycin producer Streptomyces collinus Tü 365

    DEFF Research Database (Denmark)

    Iftime, Dumitrita; Kulik, Andreas; Härtner, Thomas

    2016-01-01

    Streptomycetes are prolific sources of novel biologically active secondary metabolites with pharmaceutical potential. S. collinus Tü 365 is a Streptomyces strain, isolated 1972 from Kouroussa (Guinea). It is best known as producer of the antibiotic kirromycin, an inhibitor of the protein biosynth......Streptomycetes are prolific sources of novel biologically active secondary metabolites with pharmaceutical potential. S. collinus Tü 365 is a Streptomyces strain, isolated 1972 from Kouroussa (Guinea). It is best known as producer of the antibiotic kirromycin, an inhibitor of the protein...

  1. Disease control effect of strevertenes produced by Streptomyces psammoticus against tomato fusarium wilt.

    Science.gov (United States)

    Kim, Jeong Do; Han, Jae Woo; Lee, Sung Chul; Lee, Dongho; Hwang, In Cheon; Kim, Beom Seok

    2011-03-09

    During screening of microorganisms producing antifungal metabolites, Streptomyces psammoticus strain KP1404 was isolated. The culture extract of this strain showed potent disease control efficacy against Fusarium wilt on tomato plants. The antifungal metabolites ST-1 and ST-2 were isolated from the culture extract using a variety of chromatographic procedures. On the basis of MS and NMR spectrometric analysis, the structures of the antifungal active compounds ST-1 and ST-2 were determined to be the polyene antibiotics strevertene A and strevertene B, respectively. In vitro, strevertenes A and B showed inhibitory effects against the mycelial growth of Alternaria mali , Aspergillus oryzae , Cylindrocarpon destructans , Colletotrichum orbiculare , Fusarium oxysporum f.sp. lycopersici, and Sclerotinia sclerotiorum , even at concentrations of 4-16 μg/mL. Fusarium wilt development on tomato plants was strongly retarded by treatment with 1 μg/mL of these strevertenes. The disease control efficacies of strevertenes on Fusarium wilt were as remarkable as that of benomyl.

  2. The Prevalence and Distribution of Neurodegenerative Compound-Producing Soil Streptomyces spp.

    Science.gov (United States)

    Watkins, Anna L.; Ray, Arpita; R. Roberts, Lindsay; Caldwell, Kim A.; Olson, Julie B.

    2016-01-01

    Recent work from our labs demonstrated that a metabolite(s) from the soil bacterium Streptomyces venezuelae caused dopaminergic neurodegeneration in Caenorhabditis elegans and human neuroblastoma cells. To evaluate the capacity for metabolite production by naturally occurring streptomycetes in Alabama soils, Streptomyces were isolated from soils under different land uses (agriculture, undeveloped, and urban). More isolates were obtained from agricultural than undeveloped soils; there was no significant difference in the number of isolates from urban soils. The genomic diversity of the isolates was extremely high, with only 112 of the 1509 isolates considered clones. A subset was examined for dopaminergic neurodegeneration in the previously established C. elegans model; 28.3% of the tested Streptomyces spp. caused dopaminergic neurons to degenerate. Notably, the Streptomyces spp. isolates from agricultural soils showed more individual neuron damage than isolates from undeveloped or urban soils. These results suggest a common environmental toxicant(s) within the Streptomyces genus that causes dopaminergic neurodegeneration. It could also provide a possible explanation for diseases such as Parkinson’s disease (PD), which is widely accepted to have both genetic and environmental factors. PMID:26936423

  3. Ammonia Released by Streptomyces aburaviensis Induces Droplet Formation in Streptomyces violaceoruber.

    Science.gov (United States)

    Schmidt, Kathrin; Spiteller, Dieter

    2017-08-01

    Streptomyces violaceoruber grown in co-culture with Streptomyces aburaviensis produces an about 17-fold higher volume of droplets on its aerial mycelium than in single-culture. Physical separation of the Streptomyces strains by either a plastic barrier or by a dialysis membrane, which allowed communication only by the exchange of volatile compounds or diffusible compounds in the medium, respectively, still resulted in enhanced droplet formation. The application of molecular sieves to bioassays resulted in the attenuation of the droplet-inducing effect of S. aburaviensis indicating the absorption of the compound. 1 H-NMR analysis of molecular-sieve extracts and the selective indophenol-blue reaction revealed that the volatile droplet-inducing compound is ammonia. The external supply of ammonia in biologically relevant concentrations of ≥8 mM enhanced droplet formation in S. violaceoruber in a similar way to S. aburaviensis. Ammonia appears to trigger droplet production in many Streptomyces strains because four out of six Streptomyces strains exposed to ammonia exhibited induced droplet production.

  4. Establishment of a real-time PCR method for quantification of geosmin-producing Streptomyces spp. in recirculating aquaculture systems.

    Science.gov (United States)

    Auffret, Marc; Pilote, Alexandre; Proulx, Emilie; Proulx, Daniel; Vandenberg, Grant; Villemur, Richard

    2011-12-15

    Geosmin and 2-methylisoborneol (MIB) have been associated with off-flavour problems in fish and seafood products, generating a strong negative impact for aquaculture industries. Although most of the producers of geosmin and MIB have been identified as Streptomyces species or cyanobacteria, Streptomyces spp. are thought to be responsible for the synthesis of these compounds in indoor recirculating aquaculture systems (RAS). The detection of genes involved in the synthesis of geosmin and MIB can be a relevant indicator of the beginning of off-flavour events in RAS. Here, we report a real-time polymerase chain reaction (qPCR) protocol targeting geoA sequences that encode a germacradienol synthase involved in geosmin synthesis. New geoA-related sequences were retrieved from eleven geosmin-producing Actinomycete strains, among them two Streptomyces strains isolated from two RAS. Combined with geoA-related sequences available in gene databases, we designed primers and standards suitable for qPCR assays targeting mainly Streptomyces geoA. Using our qPCR protocol, we succeeded in measuring the level of geoA copies in sand filter and biofilters in two RAS. This study is the first to apply qPCR assays to detect and quantify the geosmin synthesis gene (geoA) in RAS. Quantification of geoA in RAS could permit the monitoring of the level of geosmin producers prior to the occurrence of geosmin production. This information will be most valuable for fish producers to manage further development of off-flavour events. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. New and bioactive compounds from Streptomyces strains residing in the wood of Celastraceae.

    Science.gov (United States)

    Pullen, Christian; Schmitz, Petra; Meurer, Kristina; Bamberg, Daniel D v; Lohmann, Stephanie; De Castro França, Suzelei; Groth, Ingrid; Schlegel, Brigitte; Möllmann, Ute; Gollmick, Friedrich; Gräfe, Udo; Leistner, Eckhard

    2002-11-01

    Wood from three different plants of the Celastraceae growing in their natural habitats in Brazil (Maytenus aquifolia Mart.) and South Africa [Putterlickia retrospinosa van Wyk and Mostert, P. verrucosa (E. Meyer ex Sonder) Szyszyl.] was established as a source of endophytic bacteria using a medium selective for actinomycetes. Two isolates were identified as Streptomyces setonii and S. sampsonii whereas two others were not assignable to any of the known Streptomyces species. They were preliminarily named Streptomyces Q21 and Streptomyces MaB-QuH-8. The latter strain produces a new chloropyrrol and chlorinated anthracyclinone. The chloropyrrol showed high activity against a series of multiresistent bacteria and mycobacteria.

  6. Isolation and molecular identification chitinase-producing Streptomyces strains and examination of their in-vitro antagonistic effects

    Directory of Open Access Journals (Sweden)

    Alireza Dehnad

    2015-12-01

    Full Text Available Introduction: The chemical fungicides are used widely in the world. To reduce the application of synthetic fungicides in treating plant diseases, biological methods are considered as an alternative way to control plant diseases. Many actinomycetes, particularly Streptomyces species are biological agents against a broad spectrum of fungal plant pathogens. The purpose of this study was using the kitinolitik actinomycetes isolated from soil of Eastern Azerbaijan province In order to produce biological pesticides. Materials and methods: Soil samples were taken from different areas of Eastern Azerbaijan province. According to Streptomyces morphological features, single colonies were isolated. To identify the bacteria by molecular characteristic, the genomic DNA was extracted and then the sequences of 16S rDNA were replicated. By using specific primers the bacterial isolates containing chitinase gene were screened. The isolates consisted Chitinase enzyme and were antagonistically cultured with Alternaria genus which is a fungal plant pathogen. Results: Out of 60 soil collected samples, 31 Streptomyces bacterial isolates were separated. Four isolates showed positive results to selectivity action of the chitinase enzyme. Treatment of 3 bacterial isolates with 2 pathogenic fungi showed that AE09 is the most effective anti-fungal isolates. Discussion and conclusion: Soils in Eastern Azerbaijan province are rich of Streptomyces bacteria which generate antifungal compounds. Obtaining the Streptomyces bacteria which have chitinase gene, can lead to identification of very effective strains as anti-fungal.

  7. Butenolides from Streptomyces albus J1074 Act as External Signals To Stimulate Avermectin Production in Streptomyces avermitilis.

    Science.gov (United States)

    Nguyen, Thao Bich; Kitani, Shigeru; Shimma, Shuichi; Nihira, Takuya

    2018-05-01

    In streptomycetes, autoregulators are important signaling compounds that trigger secondary metabolism, and they are regarded as Streptomyces hormones based on their extremely low effective concentrations (nM) and the involvement of specific receptor proteins. Our previous distribution study revealed that butenolide-type Streptomyces hormones, including avenolide, are a general class of signaling molecules in streptomycetes and that Streptomyces albus strain J1074 may produce butenolide-type Streptomyces hormones. Here, we describe metabolite profiling of a disruptant of the S. albus aco gene, which encodes a key biosynthetic enzyme for butenolide-type Streptomyces hormones, and identify four butenolide compounds from S. albus J1074 that show avenolide activity. The compounds structurally resemble avenolide and show different levels of avenolide activity. A dual-culture assay with imaging mass spectrometry (IMS) analysis for in vivo metabolic profiling demonstrated that the butenolide compounds of S. albus J1074 stimulate avermectin production in another Streptomyces species, Streptomyces avermitilis , illustrating the complex chemical interactions through interspecies signals in streptomycetes. IMPORTANCE Microorganisms produce external and internal signaling molecules to control their complex physiological traits. In actinomycetes, Streptomyces hormones are low-molecular-weight signals that are key to our understanding of the regulatory mechanisms of Streptomyces secondary metabolism. This study reveals that acyl coenzyme A (acyl-CoA) oxidase is a common and essential biosynthetic enzyme for butenolide-type Streptomyces hormones. Moreover, the diffusible butenolide compounds from a donor Streptomyces strain were recognized by the recipient Streptomyces strain of a different species, resulting in the initiation of secondary metabolism in the recipient. This is an interesting report on the chemical interaction between two different streptomycetes via Streptomyces

  8. Potent antifouling compounds produced by marine Streptomyces

    KAUST Repository

    Xu, Ying

    2010-02-01

    Biofouling causes huge economic loss and a recent global ban on organotin compounds as antifouling agents has increased the need for safe and effective antifouling compounds. Five structurally similar compounds were isolated from the crude extract of a marine Streptomyces strain obtained from deep-sea sediments. Antifouling activities of these five compounds and four other structurally-related compounds isolated from a North Sea Streptomyces strain against major fouling organisms were compared to probe structure-activity relationships of compounds. The functional moiety responsible for antifouling activity lies in the 2-furanone ring and that the lipophilicity of compounds substantially affects their antifouling activities. Based on these findings, a compound with a straight alkyl side-chain was synthesized and proved itself as a very effective non-toxic, anti-larval settlement agent against three major fouling organisms. The strong antifouling activity, relatively low toxicity, and simple structures of these compounds make them promising candidates for new antifouling additives. © 2009 Elsevier Ltd. All rights reserved.

  9. Secondary Metabolites Produced during the Germination of Streptomyces coelicolor

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    Matouš Čihák

    2017-12-01

    Full Text Available Spore awakening is a series of actions that starts with purely physical processes and continues via the launching of gene expression and metabolic activities, eventually achieving a vegetative phase of growth. In spore-forming microorganisms, the germination process is controlled by intra- and inter-species communication. However, in the Streptomyces clade, which is capable of developing a plethora of valuable compounds, the chemical signals produced during germination have not been systematically studied before. Our previously published data revealed that several secondary metabolite biosynthetic genes are expressed during germination. Therefore, we focus here on the secondary metabolite production during this developmental stage. Using high-performance liquid chromatography-mass spectrometry, we found that the sesquiterpenoid antibiotic albaflavenone, the polyketide germicidin A, and chalcone are produced during germination of the model streptomycete, S. coelicolor. Interestingly, the last two compounds revealed an inhibitory effect on the germination process. The secondary metabolites originating from the early stage of microbial growth may coordinate the development of the producer (quorum sensing and/or play a role in competitive microflora repression (quorum quenching in their nature environments.

  10. Comparative genomics of Streptomyces avermitilis, Streptomyces cattleya, Streptomyces maritimus and Kitasatospora aureofaciens using a Streptomyces coelicolor microarray system

    NARCIS (Netherlands)

    Hsiao, Nai-hua; Kirby, Ralph

    DNA/DNA microarray hybridization was used to compare the genome content of Streptomyces avermitilis, Streptomyces cattleya, Streptomyces maritimus and Kitasatospora aureofaciens with that of Streptomyces coelicolor A3(2). The array data showed an about 93% agreement with the genome sequence data

  11. The Conserved Actinobacterial Two-Component System MtrAB Coordinates Chloramphenicol Production with Sporulation in Streptomyces venezuelae NRRL B-65442

    Directory of Open Access Journals (Sweden)

    Nicolle F. Som

    2017-06-01

    Full Text Available Streptomyces bacteria make numerous secondary metabolites, including half of all known antibiotics. Production of antibiotics is usually coordinated with the onset of sporulation but the cross regulation of these processes is not fully understood. This is important because most Streptomyces antibiotics are produced at low levels or not at all under laboratory conditions and this makes large scale production of these compounds very challenging. Here, we characterize the highly conserved actinobacterial two-component system MtrAB in the model organism Streptomyces venezuelae and provide evidence that it coordinates production of the antibiotic chloramphenicol with sporulation. MtrAB are known to coordinate DNA replication and cell division in Mycobacterium tuberculosis where TB-MtrA is essential for viability but MtrB is dispensable. We deleted mtrB in S. venezuelae and this resulted in a global shift in the metabolome, including constitutive, higher-level production of chloramphenicol. We found that chloramphenicol is detectable in the wild-type strain, but only at very low levels and only after it has sporulated. ChIP-seq showed that MtrA binds upstream of DNA replication and cell division genes and genes required for chloramphenicol production. dnaA, dnaN, oriC, and wblE (whiB1 are DNA binding targets for MtrA in both M. tuberculosis and S. venezuelae. Intriguingly, over-expression of TB-MtrA and gain of function TB- and Sv-MtrA proteins in S. venezuelae also switched on higher-level production of chloramphenicol. Given the conservation of MtrAB, these constructs might be useful tools for manipulating antibiotic production in other filamentous actinomycetes.

  12. Antifungal performance of extracellular chitinases and culture supernatants of Streptomyces galilaeus CFFSUR-B12 against Mycosphaerella fijiensis Morelet.

    Science.gov (United States)

    Castillo, Benjamín Moreno; Dunn, Michael F; Navarro, Karina Guillén; Meléndez, Francisco Holguín; Ortiz, Magdalena Hernández; Guevara, Sergio Encarnación; Palacios, Graciela Huerta

    2016-03-01

    The tropical and mycoparasite strain Streptomyces galilaeus CFFSUR-B12 was evaluated as an antagonist of Mycosphaerella fijiensis Morelet, causal agent of the Black Sigatoka Disease (BSD) of banana. On zymograms of CFFSUR-B12 culture supernatants, we detected four chitinases of approximately 32 kDa (Chi32), 20 kDa (Chi20), and two with masses well over 170 kDa (ChiU) that showed little migration during denaturing electrophoresis at different concentrations of polyacrylamide. The thymol-sulphuric acid assay showed that the ChiU were glycosylated chitinases. Moreover, matrix assisted laser desorption ionization time-of-flight MS analysis revealed that the ChiU are the same protein and identical to a family 18 chitinase from Streptomyces sp. S4 (gi|498328075). Chi32 was similar to an extracellular protein from Streptomyces albus J1074 (gi|478687481) and Chi20 was non-significantly similar to chitinases from five different strains of Streptomyces (P > 0.05). Subsequently, Chi32 and Chi20 were partially purified by anion exchange and hydrophobic interaction chromatography and tested against M. fijiensis. Chitinases failed to inhibit ascospore germination, but inhibited up to 35 and 62% of germ tube elongation and mycelial growth, respectively. We found that crude culture supernatant and living cells of S. galilaeus CFFSUR-B12 were the most effective in inhibiting M. fijiensis and are potential biocontrol agents of BSD.

  13. Martinomycin, a new polyether antibiotic produced by Streptomyces salvialis. I. Taxonomy, fermentation and biological activity.

    Science.gov (United States)

    Bernan, V S; Montenegro, D A; Goodman, J J; Alluri, M R; Carter, G T; Abbanat, D R; Pearce, C J; Maiese, W M; Greenstein, M

    1994-12-01

    Actinomycete culture LL-D37187 has been found to produce the new polyether antibiotic martinomycin. Taxonomic studies, including morphological, physiological, and cell wall chemistry analyses, revealed that culture LL-D37187 is a novel streptomycete species, and the proposed name is Streptomyces salvialis. Martinomycin exhibits activity against the Southern Army Worm (Spodoptera eridania) and Gram-positive bacteria.

  14. Streptomyces lacrimifluminis sp. nov., a novel actinobacterium that produces antibacterial compounds, isolated from soil.

    Science.gov (United States)

    Zhang, Binglin; Tang, Shukun; Chen, Ximing; Zhang, Ling; Zhang, Gaoseng; Zhang, Wei; Liu, Guangxiu; Chen, Tuo; Li, Shiweng; Dyson, Paul

    2016-12-01

    A novel actinobacterial strain, designated Z1027T, was isolated from a soil sample collected near the Tuotuo River, Qinghai-Tibet Plateau (China). The strain exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. The taxonomic position of strain Z1027T was determined using a polyphasic approach. The organism had chemotaxonomic and morphological properties consistent with its classification in the genus Streptomyces and formed a distinct phyletic line in the 16S rRNA gene tree, together with Streptomyces turgidiscabies ATCC 700248T (99.19 % similarity), Streptomyces graminilatus JL-6T (98.84 %) and Streptomyces reticuliscabiei CFBP 4531T (98.36 %). The genomic DNA G+C content of strain Z1027T was 74±1 mol%. The DNA-DNA relatedness values between strain Z1027T and Streptomyces turgidiscabies ATCC 700248T and Streptomyces reticuliscabiei CFBP 4531T were 38.5±0.4 and 26.2±1.2 %, respectively, both of them significantly lower than 70 %. Chemotaxonomic data revealed that strain Z1027T possessed MK-9(H6) and MK-9(H8) as the major menaquinones, ll-diaminopimelic acid as the diagnostic diamino acid and galactose as a whole-cell sugar. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatydilinositol and seven other unknown polar lipids were detected; iso-C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 were the major fatty acids. On the basis of these genotypic and phenotypic data, it is proposed that isolate Z1027T (=CGMCC 4.7272T=JCM 31054T) should be classified as the type strain of a novel species of the genus Streptomyces,Streptomyces lacrimifluminis sp. nov.

  15. Taxonomic evaluation of Streptomyces albus and related species using multilocus sequence analysis and proposals to emend the description of Streptomyces albus and describe Streptomyces pathocidini sp. nov

    Science.gov (United States)

    In phylogenetic analyses of the genus Streptomyces using 16S rRNA gene sequences, Streptomyces albus subsp. albus NRRL B-1811T forms a cluster with 5 other species having identical or nearly identical 16S rRNA gene sequences. Moreover, the morphological and physiological characteristics of these oth...

  16. Development of Streptomyces sp. FR-008 as an emerging chassis

    Directory of Open Access Journals (Sweden)

    Qian Liu

    2016-09-01

    Full Text Available Microbial-derived natural products are important in both the pharmaceutical industry and academic research. As the metabolic potential of original producer especially Streptomyces is often limited by slow growth rate, complicated cultivation profile, and unfeasible genetic manipulation, so exploring a Streptomyces as a super industrial chassis is valuable and urgent. Streptomyces sp. FR-008 is a fast-growing microorganism and can also produce a considerable amount of macrolide candicidin via modular polyketide synthase. In this study, we evaluated Streptomyces sp. FR-008 as a potential industrial-production chassis. First, PacBio sequencing and transcriptome analyses indicated that the Streptomyces sp. FR-008 genome size is 7.26 Mb, which represents one of the smallest of currently sequenced Streptomyces genomes. In addition, we simplified the conjugation procedure without heat-shock and pre-germination treatments but with high conjugation efficiency, suggesting it is inherently capable of accepting heterologous DNA. In addition, a series of promoters selected from literatures was assessed based on GusA activity in Streptomyces sp. FR-008. Compared with the common used promoter ermE*-p, the strength of these promoters comprise a library with a constitutive range of 60–860%, thus providing the useful regulatory elements for future genetic engineering purpose. In order to minimum the genome, we also target deleted three endogenous polyketide synthase (PKS gene clusters to generate a mutant LQ3. LQ3 is thus an “updated” version of Streptomyces sp. FR-008, producing fewer secondary metabolites profiles than Streptomyces sp. FR-008. We believe this work could facilitate further development of Streptomyces sp. FR-008 for use in biotechnological applications.

  17. Isolation and characterization of fatty acid methyl ester (FAME)-producing Streptomyces sp. S161 from sheep (Ovis aries) faeces.

    Science.gov (United States)

    Lu, Y; Wang, J; Deng, Z; Wu, H; Deng, Q; Tan, H; Cao, L

    2013-09-01

    An actinomycete producing oil-like mixtures was isolated and characterized. The strain was isolated from sheep faeces and identified as Streptomyces sp. S161 based on 16S rRNA gene sequence analysis. The strain showed cellulase and xylanase activities. The (1) H nuclear magnetic resonance (NMR) spectra of the mixtures showed that the mixtures were composed of fatty acid methyl esters (52·5), triglycerides (13·7) and monoglycerides (9·1) (mol.%). Based on the gas chromatography-mass spectrometry (GC-MS) analysis, the fatty acid methyl esters were mainly composed of C14-C16 long-chain fatty acids. The results indicated that Streptomyces sp. S161 could produce fatty acid methyl esters (FAME) directly from starch. To our knowledge, this is the first isolated strain that can produce biodiesel (FAME) directly from starch. © 2013 The Society for Applied Microbiology.

  18. Munumbicins, wide-spectrum antibiotics produced by Streptomyces NRRL 30562, endophytic on Kennedia nigriscans

    OpenAIRE

    Castillo, UF; Strobel, GA; Ford, EJ; Hess, WM; Porter, H; Jensen, JB; Albert, H; Robison, R; Condron, MAM; Teplow, DB; Stevens, D; Yaver, D

    2002-01-01

    Munumbicins A, B, C and D are newly described antibiotics with a wide spectrum of activity against many human as well as plant pathogenic fungi and bacteria, and a Plasmodium sp. These compounds were obtained from Streptomyces NRRL 3052, which is endophytic in the medicinal plant snakevine (Kennedia nigriscans), native to the Northern Territory of Australia. This endophyte was cultured, the broth was extracted with an organic solvent and the contents of the residue were purified by bioassay-g...

  19. Streptomyces aridus sp. nov., isolated from a high altitude Atacama Desert soil and emended description of Streptomyces noboritoensis Isono et al. 1957.

    Science.gov (United States)

    Idris, Hamidah; Labeda, David P; Nouioui, Imen; Castro, Jean Franco; Del Carmen Montero-Calasanz, Maria; Bull, Alan T; Asenjo, Juan A; Goodfellow, Michael

    2017-05-01

    A polyphasic study was undertaken to determine the taxonomic status of a Streptomyces strain which had been isolated from a high altitude Atacama Desert soil and shown to have bioactive properties. The strain, isolate H9 T , was found to have chemotaxonomic, cultural and morphological properties that place it in the genus Streptomyces. 16S rRNA gene sequence analyses showed that the isolate forms a distinct branch at the periphery of a well-delineated subclade in the Streptomyces 16S rRNA gene tree together with the type strains of Streptomyces crystallinus, Streptomyces melanogenes and Streptomyces noboritoensis. Multi-locus sequence analysis (MLSA) based on five house-keeping gene alleles showed that isolate H9 T is closely related to the latter two type strains and to Streptomyces polyantibioticus NRRL B-24448 T . The isolate was distinguished readily from the type strains of S. melanogenes, S. noboritoensis and S. polyantibioticus using a combination of phenotypic properties. Consequently, the isolate is considered to represent a new species of Streptomyces for which the name Streptomyces aridus sp. nov. is proposed; the type strain is H9 T (=NCIMB 14965 T =NRRL B65268 T ). In addition, the MLSA and phenotypic data show that the S. melanogenes and S. noboritoensis type strains belong to a single species, it is proposed that S. melanogenes be recognised as a heterotypic synonym of S. noboritoensis for which an emended description is given.

  20. Role of Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase in Oleaginous Streptomyces sp. Strain G25

    Science.gov (United States)

    Röttig, Annika; Strittmatter, Carl Simon; Schauer, Jennifer; Hiessl, Sebastian; Daniel, Rolf

    2016-01-01

    ABSTRACT Recently, we isolated a novel Streptomyces strain which can accumulate extraordinarily large amounts of triacylglycerol (TAG) and consists of 64% fatty acids (dry weight) when cultivated with glucose and 50% fatty acids (dry weight) when cultivated with cellobiose. To identify putative gene products responsible for lipid storage and cellobiose utilization, we analyzed its draft genome sequence. A single gene encoding a wax ester synthase/acyl coenzyme A (CoA):diacylglycerol acyltransferase (WS/DGAT) was identified and heterologously expressed in Escherichia coli. The purified enzyme AtfG25 showed acyltransferase activity with C12- or C16-acyl-CoA, C12 to C18 alcohols, or dipalmitoyl glycerol. This acyltransferase exhibits 24% amino acid identity to the model enzyme AtfA from Acinetobacter baylyi but has high sequence similarities to WS/DGATs from other Streptomyces species. To investigate the impact of AtfG25 on lipid accumulation, the respective gene, atfG25, was inactivated in Streptomyces sp. strain G25. However, cells of the insertion mutant still exhibited DGAT activity and were able to store TAG, albeit in lower quantities and at lower rates than the wild-type strain. These findings clearly indicate that AtfG25 has an important, but not exclusive, role in TAG biosynthesis in the novel Streptomyces isolate and suggest the presence of alternative metabolic pathways for lipid accumulation which are discussed in the present study. IMPORTANCE A novel Streptomyces strain was isolated from desert soil, which represents an extreme environment with high temperatures, frequent drought, and nutrient scarcity. We believe that these harsh conditions promoted the development of the capacity for this strain to accumulate extraordinarily large amounts of lipids. In this study, we present the analysis of its draft genome sequence with a special focus on enzymes potentially involved in its lipid storage. Furthermore, the activity and importance of the detected

  1. Two new species of the genus Streptomyces: Streptomyces camponoti sp. nov. and Streptomyces cuticulae sp. nov. isolated from the cuticle of Camponotus japonicus Mayr.

    Science.gov (United States)

    Piao, Chenyu; Zheng, Weiwei; Li, Yao; Liu, Chongxi; Jin, Liying; Song, Wei; Yan, Kai; Wang, Xiangjing; Xiang, Wensheng

    2017-09-01

    Two novel actinomycetes, designated strains 2C-SSA16(2) T and 1C-GS8 T , were isolated from the cuticle of Camponotus japonicus Mayr, collected from Northeast Agricultural University, Heilongjiang Province, north China. Both of them contained genes (involved in antibiotics biosynthesis) of the ketosynthase (KS) and methyl malonyl transferase domains (PKS-I) and the adenylation domain (NRPS). A polyphasic study was carried out to establish the taxonomic positions of these strains. The 16S rRNA gene sequence analysis showed that the two novel isolates 2C-SSA16(2) T and 1C-GS8 T exhibited 98.8% similarity with each other and that they are most closely related to Streptomyces umbrinus JCM 4521 T (99.0, 98.6%), Streptomyces ederensis JCM 4958 T (98.9, 98.7%), Streptomyces aurantiacus JCM 4453 T (98.6, 98.2%), Streptomyces glomeroaurantiacus JCM 4677 T (98.6, 98.1%), Streptomyces tauricus JCM4837 T (98.2, 98.0%) and Streptomyces phaeochromogenes JCM 4070 T (98.2, 99.2%). The corresponding phylogenetic analysis based on partial gyrB gene sequences showed that strains 2C-SSA16(2) T and 1C-GS8 T formed a cluster with the above-mentioned strains. The DNA-DNA hybridization data and phenotypic characteristics indicated that strains 2C-SSA16(2) T and 1C-GS8 T could be readily distinguished from each other and their closest phylogenetic relatives. Therefore, these two strains are suggested to represent two novel species of the genus Streptomyces, for which the names Streptomyces camponoti sp. nov. and Streptomyces cuticulae sp. nov. are proposed. The type strains are 2C-SSA16(2) T (=CGMCC 4.7276 T  = DSM 100522 T ) and 1C-GS8 T (=CGMCC 4.7348 = DSM 103127 T ), respectively.

  2. Screening of wild type Streptomyces isolates able to overproduce clavulanic acid

    Directory of Open Access Journals (Sweden)

    Daniela A. Viana Marques

    2014-09-01

    Full Text Available The selection of new microorganisms able to produce antimicrobial compounds is hoped for to reduce their production costs and the side effects caused by synthetic drugs. Clavulanic acid is a β-lactam antibiotic produced by submerged culture, which is widely used in medicine as a powerful inhibitor of β-lactamases, enzymes produced by bacteria resistant to antibiotics such penicillin and cephalosporin. The purpose of this work was to select the best clavulanic acid producer among strains of Streptomyces belonging to the Microorganism Collection of the Department of Antibiotics of the Federal University of Pernambuco (DAUFPE. Initially, the strains were studied for their capacity to inhibit the action of β-lactamases produced by Klebsiella aerogenes ATCC 15380. From these results, five strains were selected to investigate the batch kinetics of growth and clavulanic acid production in submerged culture carried out in flasks. The results were compared with the ones obtained by Streptomyces clavuligerus ATCC 27064 selected as a control strain. The best clavulanic acid producer was Streptomyces DAUFPE 3060, molecularly identified as Streptomyces variabilis, which increased the clavulanic acid production by 28% compared to the control strain. This work contributes to the enlargement of knowledge on new Streptomyces wild strains able to produce clavulanic acid by submerged culture.

  3. WS2

    KAUST Repository

    Sattar, Shahid; Singh, Nirpendra; Schwingenschlö gl, Udo

    2016-01-01

    by first-principles calculations. Broken inversion symmetry due to the presence of WS2 opens a substantial band gap in silicene or germanene. F doping of WS2 results in spin polarization, which, in conjunction with proximity-enhanced spin-orbit coupling

  4. Genetic interrelations in the actinomycin biosynthetic gene clusters of Streptomyces antibioticus IMRU 3720 and Streptomyces chrysomallus ATCC11523, producers of actinomycin X and actinomycin C

    Directory of Open Access Journals (Sweden)

    Crnovčić I

    2017-04-01

    Full Text Available Ivana Crnovčić,1 Christian Rückert,2 Siamak Semsary,1 Manuel Lang,1 Jörn Kalinowski,2 Ullrich Keller1 1Institut für Chemie, Technische Universität Berlin, Berlin-Charlottenburg, 2Technology Platform Genomics, Center for Biotechnology, Bielefeld University, Bielefeld, Germany Abstract: Sequencing the actinomycin (acm biosynthetic gene cluster of Streptomyces antibioticus IMRU 3720, which produces actinomycin X (Acm X, revealed 20 genes organized into a highly similar framework as in the bi-armed acm C biosynthetic gene cluster of Streptomyces chrysomallus but without an attached additional extra arm of orthologues as in the latter. Curiously, the extra arm of the S. chrysomallus gene cluster turned out to perfectly match the single arm of the S. antibioticus gene cluster in the same order of orthologues including the the presence of two pseudogenes, scacmM and scacmN, encoding a cytochrome P450 and its ferredoxin, respectively. Orthologues of the latter genes were both missing in the principal arm of the S. chrysomallus acm C gene cluster. All orthologues of the extra arm showed a G +C-contents different from that of their counterparts in the principal arm. Moreover, the similarities of translation products from the extra arm were all higher to the corresponding translation products of orthologue genes from the S. antibioticus acm X gene cluster than to those encoded by the principal arm of their own gene cluster. This suggests that the duplicated structure of the S. chrysomallus acm C biosynthetic gene cluster evolved from previous fusion between two one-armed acm gene clusters each from a different genetic background. However, while scacmM and scacmN in the extra arm of the S. chrysomallus acm C gene cluster are mutated and therefore are non-functional, their orthologues saacmM and saacmN in the S. antibioticus acm C gene cluster show no defects seemingly encoding active enzymes with functions specific for Acm X biosynthesis. Both acm

  5. Recent advances in understanding Streptomyces

    Science.gov (United States)

    Chater, Keith F.

    2016-01-01

    About 2,500 papers dated 2014–2016 were recovered by searching the PubMed database for Streptomyces, which are the richest known source of antibiotics. This review integrates around 100 of these papers in sections dealing with evolution, ecology, pathogenicity, growth and development, stress responses and secondary metabolism, gene expression, and technical advances. Genomic approaches have greatly accelerated progress. For example, it has been definitively shown that interspecies recombination of conserved genes has occurred during evolution, in addition to exchanges of some of the tens of thousands of non-conserved accessory genes. The closeness of the association of Streptomyces with plants, fungi, and insects has become clear and is reflected in the importance of regulators of cellulose and chitin utilisation in overall Streptomyces biology. Interestingly, endogenous cellulose-like glycans are also proving important in hyphal growth and in the clumping that affects industrial fermentations. Nucleotide secondary messengers, including cyclic di-GMP, have been shown to provide key input into developmental processes such as germination and reproductive growth, while late morphological changes during sporulation involve control by phosphorylation. The discovery that nitric oxide is produced endogenously puts a new face on speculative models in which regulatory Wbl proteins (peculiar to actinobacteria) respond to nitric oxide produced in stressful physiological transitions. Some dramatic insights have come from a new model system for Streptomyces developmental biology, Streptomyces venezuelae, including molecular evidence of very close interplay in each of two pairs of regulatory proteins. An extra dimension has been added to the many complexities of the regulation of secondary metabolism by findings of regulatory crosstalk within and between pathways, and even between species, mediated by end products. Among many outcomes from the application of chromosome

  6. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation

    Science.gov (United States)

    Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta

    2016-01-01

    In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces. To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins. PMID:27248800

  7. An indigoidine biosynthetic gene cluster from Streptomyces chromofuscus ATCC 49982 contains an unusual IndB homologue.

    Science.gov (United States)

    Yu, Dayu; Xu, Fuchao; Valiente, Jonathan; Wang, Siyuan; Zhan, Jixun

    2013-01-01

    A putative indigoidine biosynthetic gene cluster was located in the genome of Streptomyces chromofuscus ATCC 49982. The silent 9.4-kb gene cluster consists of five open reading frames, named orf1, Sc-indC, Sc-indA, Sc-indB, and orf2, respectively. Sc-IndC was functionally characterized as an indigoidine synthase through heterologous expression of the enzyme in both Streptomyces coelicolor CH999 and Escherichia coli BAP1. The yield of indigoidine in E. coli BAP1 reached 2.78 g/l under the optimized conditions. The predicted protein product of Sc-indB is unusual and much larger than any other reported IndB-like protein. The N-terminal portion of this enzyme resembles IdgB and the C-terminal portion is a hypothetical protein. Sc-IndA and/or Sc-IndB were co-expressed with Sc-IndC in E. coli BAP1, which demonstrated the involvement of Sc-IndB, but not Sc-IndA, in the biosynthetic pathway of indigoidine. The yield of indigoidine was dramatically increased by 41.4 % (3.93 g/l) when Sc-IndB was co-expressed with Sc-IndC in E. coli BAP1. Indigoidine is more stable at low temperatures.

  8. Optimization of biosynthesis conditions and catalitic behavior evaluation of cellulase-free xylanase produced by a new Streptomyces sp. strain

    Directory of Open Access Journals (Sweden)

    GABRIELA BAHRIM

    2011-07-01

    Full Text Available Cellulase-free xylanase by Streptomyces sp.P12-137 was obtained bycultivation on the wheat bran as the sole carbon source. The effect of carbon and nitrogen sources and a ratio of them on the cellulase-free xylanase production was investigated. The new isolate Streptomyces sp. strain was able to grow in submerged system and to produce an increased level of xylanase. Wheat bran induced xylanase biosynthesis yield at a high level (9.27 UA/ml. For economical reasons cultivation was achieved on a cheap fermentative medium represented by agro-industrial wastes. The optima of the pH and temperature of the crude xylanase activity were 5.5 and 70°C,respectively.

  9. Microwave Assisted Rapid and Green Synthesis of Silver Nanoparticles Using a Pigment Produced by Streptomyces coelicolor klmp33

    OpenAIRE

    Manikprabhu, Deene; Lingappa, K.

    2013-01-01

    Traditional synthesis of silver nanoparticles using chemical methods produces toxic substances. In contrast biological synthesis is regarded as a safe and nontoxic process but the major drawback of biological synthesis is, this process is slow. In the present investigation, we developed a rapid and green synthesis of silver nanoparticles employing a pigment produced by Streptomyces coelicolor klmp33 in just 90?s. The silver nanoparticles were characterized by UV-visible spectroscopy, transmis...

  10. Secondary Metabolites Produced during the Germination of Streptomyces coelicolor

    Czech Academy of Sciences Publication Activity Database

    Čihák, M.; Kameník, Zdeněk; Šmídová, Klára; Bergman, N.; Benada, Oldřich; Kofroňová, Olga; Petříčková, Kateřina; Bobek, Jan

    2017-01-01

    Roč. 8, DEC 13 (2017), č. článku 2495. ISSN 1664-302X R&D Projects: GA MŠk(CZ) LO1509; GA MŠk(CZ) LM2015055 Institutional support: RVO:61388971 Keywords : spore germination * Streptomyces * cell signaling Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.076, year: 2016

  11. Streptopyridines, volatile pyridine alkaloids produced by Streptomyces sp. FORM5

    Directory of Open Access Journals (Sweden)

    Ulrike Groenhagen

    2014-06-01

    Full Text Available Streptomyces sp. FORM5 is a bacterium that is known to produce the antibiotic streptazolin and related compounds. We investigated the strain for the production of volatiles using the CLSA (closed-loop stripping analysis method. Liquid and agar plate cultures revealed the formation of new 2-alkylpyridines (streptopyridines, structurally closely related to the already known 2-pentadienylpiperidines. The structures of the streptopyridines A to E were confirmed by total synthesis. The analysis of the liquid phase by solvent extraction or extraction with an Oasis adsorbent showed that streptazolin and 2-pentadienylpiperidine are the major compounds, while the streptopyridines are only minor components. In the gas phase, only the streptopyridines could be detected. Therefore, an orthogonal set of analysis is needed to assess the metabolic profile of bacteria, because volatile compounds are obviously overlooked by traditional analytical methods. The streptopyridines are strain specific volatiles that are accompanied by a broad range of headspace constituents that occur in many actinomycetes. Volatiles might be of ecological importance for the producing organism, and, as biosynthetic intermediates or shunt products, they can be useful as indicators of antibiotic production in a bacterium.

  12. A standard-driven implementaion of WS-BPEL 2.0

    DEFF Research Database (Denmark)

    Hallwyl, Tim; Henglein, Fritz; Hildebrandt, Thomas

    2010-01-01

    We present a systematic study of the WS-BPEL 2.0 standard based on two complementary methods: the process of constructing a new high-level WS-BPEL implementation driven by the structure of the standard, and an empirical evaluation of existing interpretations of the standard reflected in five widely...... differing results produced by existing implementations on test cases constructed to exercise their interpretation. The core concepts in WS-BPEL have been formalized and analyzed successfully previously. Our choice to study the standard by constructing a high-level, standard-driven implementation rather than...... an abstract, mathematical formalization has made it feasible to cover the complete standard, notably the integration with XPath. Given WS-BPEL's design goal of being platform-independent the inconsistencies are arguably a serious concern since they cannot be attributed to the quality of any particular...

  13. Antagonistic activity of antibiotic producing Streptomyces sp. against fish and human pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Nazmul Hossain

    2014-04-01

    Full Text Available In this study, attempts were made to isolate Streptomyces sp. from soil samples of two different regions of Bangladesh and evaluate their antagonistic activity against fish and human pathogenic bacteria. A total of 10 isolates were identified as Streptomyces sp. based on several morphological, physiological and biochemical tests. Cross streak method was used to observe the antagonistic activity of the Streptomyces sp. isolates against different fish pathogens belonging to the genus Aeromonas, Pseudomonas and Edwardsiella and human clinical isolates belonging to the genus Klebsiella, Salmonella and Streptococcus. Seven Streptomyces sp. isolates showed antagonism against both fish and human pathogenic bacteria. Four isolates viz., N24, N26, N28 and N47 showed broad spectrum of antagonistic activity (80-100% against all genera of fish and human pathogenic bacteria. The isolate N49 exhibited highest spectrum of antagonism against all fish pathogens (90-100% but comparatively lower degree of antagonism against human pathogens (50-60%. Rest of the two isolates (N21 and N23 showed variability in their antagonism. Results showed that broad spectrum antibiotic(s could be developed from the isolates N24, N26, N28 and N47against several human and fish pathogens. The isolate N49 could be a potential source of antibiotic, especially for fish pathogenic bacteria.

  14. Pacemaker activity and inhibitory neurotransmission in the colon of Ws/Ws mutant rats

    DEFF Research Database (Denmark)

    Albertí, Elena; Mikkelsen, Hanne Birte; Wang, Xuanyu

    2007-01-01

    The aim of this study was to characterize the pacemaker activity and inhibitory neurotransmission in the colon of Ws/Ws mutant rats, which harbor a mutation in the c-kit gene that affects development of interstitial cells of Cajal (ICC). In Ws/Ws rats, the density of KIT-positive cells was markedly...... as indirect innervation via ICC. In summary, loss of ICC markedly affects pacemaker and motor activities of the rat colon. Inhibitory innervation is largely maintained but nitrergic innervation is reduced possibly related to the loss of ICC-mediated relaxation....

  15. Exciton broadening in WS2 /graphene heterostructures

    International Nuclear Information System (INIS)

    Hill, Heather M.; Rigosi, Albert F.; Raja, Archana

    2017-01-01

    Here, we have used optical spectroscopy to observe spectral broadening of WS 2 exciton reflectance peaks in heterostructures of monolayer WS 2 capped with mono- to few-layer graphene. The broadening is found to be similar for the A and B excitons and on the order of 5–10 meV. No strong dependence on the number of graphene layers was observed within experimental uncertainty. The broadening can be attributed to charge- and energy-transfer processes between the two materials, providing an observed lower bound for the corresponding time scales of 65 fs.

  16. Streptomyces leeuwenhoekii sp. nov., the producer of chaxalactins and chaxamycins, forms a distinct branch in Streptomyces gene trees

    Science.gov (United States)

    A polyphasic study was carried out to establish the taxonomic status of an Atacama Desert isolate, Streptomyces strain C34T, which synthesises novel antibiotics, the chaxalactins and chaxamycins. The organism was shown to have chemotaxonomic, cultural, and morphological properties consistent with it...

  17. Occurrence of Streptomyces aurantiacus in Mangroves of Bhitarkanika

    Directory of Open Access Journals (Sweden)

    Gupta, N.

    2007-01-01

    Full Text Available Thirteen strains of Streptomyces were isolated from phyllosphere of nine mangrove tree species found in Bhitarkanika mangrove ecosystem of Orissa. According to physiological, biochemical data, all 13 of the isolates were taxonomically identified to the genus Streptomyces as aurantiacus species. All strains are grayish, spirals and forming amorphous colony. Almost all utilized araginose, produced H2S, resistant towards rifampicin and penicillin, urea except few strains. However, they exhibited different extracellular activity like phosphate solubilization, lipase and L asparaginase production. This is a unique report from this mangrove ecosystem as far as Streptomyces occurrence is concerned.

  18. Improvement of oxytetracycline production mediated via cooperation of resistance genes in Streptomyces rimosus.

    Science.gov (United States)

    Yin, Shouliang; Wang, Xuefeng; Shi, Mingxin; Yuan, Fang; Wang, Huizhuan; Jia, Xiaole; Yuan, Fang; Sun, Jinliang; Liu, Tiejun; Yang, Keqian; Zhang, Yuxiu; Fan, Keqiang; Li, Zilong

    2017-09-01

    Increasing the self-resistance levels of Streptomyces is an effective strategy to improve the production of antibiotics. To increase the oxytetracycline (OTC) production in Streptomyces rimosus, we investigated the cooperative effect of three co-overexpressing OTC resistance genes: one gene encodes a ribosomal protection protein (otrA) and the other two express efflux proteins (otrB and otrC). Results indicated that combinational overexpression of otrA, otrB, and otrC (MKABC) exerted a synergetic effect. OTC production increased by 179% in the recombinant strain compared with that of the wild-type strain M4018. The resistance level to OTC was increased by approximately two-fold relative to the parental strain, thereby indicating that applying the cooperative effect of self-resistance genes is useful to improve OTC production. Furthermore, the previously identified cluster-situated activator OtcR was overexpressed in MKABC in constructing the recombinant strain MKRABC; such strain can produce OTC of approximately 7.49 g L -1 , which represents an increase of 19% in comparison with that of the OtcR-overexpressing strain alone. Our work showed that the cooperative overexpression of self-resistance genes is a promising strategy to enhance the antibiotics production in Streptomyces.

  19. Photovoltaic heterojunctions of fullerenes with MoS2 and WS2 monolayers

    KAUST Repository

    Gan, Liyong

    2014-04-17

    First-principles calculations are performed to explore the geometry, bonding, and electronic structures of six ultrathin photovoltaic heterostructures consisting of pristine and B- or N-doped fullerenes and MoS2 or WS2 monolayers. The fullerenes prefer to be attached with a hexagon parallel to the monolayer, where B and N favor proximity to the monolayer. The main electronic properties of the subsystems stay intact, suggesting weak interfacial interaction. Both the C60/MoS 2 and C60/WS2 systems show type-II band alignments. However, the built-in potential in the former case is too small to effectively drive electron-hole separation across the interface, whereas the latter system is predicted to show good photovoltaic performance. Unfortunately, B and N doping destroys the type-II band alignment on MoS2 and preserves it only in one spin channel on WS2, which is unsuitable for excitonic solar cells. Our results suggest that the C60/WS 2 system is highly promising for excitonic solar cells. © 2014 American Chemical Society.

  20. Streptocollin, a type IV lanthipeptide produced by Streptomyces collinus Tü 365

    DEFF Research Database (Denmark)

    Iftime, Dumitrita; Jasyk, Martin; Kulik, Andreas

    2015-01-01

    Lanthipeptides are ribosomally synthesized and posttranslationally modified microbial secondary metabolites. Here, we report the identification and isolation of streptocollin from Streptomyces collinus Tü 365, a new member of the class IV lanthipeptides. Insertion of the constitutive ermE* promoter...

  1. Streptomyces odonnellii sp. nov., a proteolytic streptomycete isolated from soil under cerrado (savanna) vegetation cover.

    Science.gov (United States)

    Pereira, Pedro Henrique Freitas; Macrae, Andrew; Reinert, Fernanda; de Souza, Rodrigo Fonseca; Coelho, Rosalie Reed Rodrigues; Pötter, Gabrielle; Klenk, Hans-Peter; Labeda, David P

    2017-12-01

    A novel streptomycete, strain 594 T , isolated from Brazilian soil collected under cerrado (savanna) vegetation cover is described. Strain 594 T produced thermophilic chitinolytic proteases in assays containing feather meal and corn steep liquor as sole sources of carbon and nitrogen. The strain produced white to grey aerial mycelium and spiral chains of spiny-surfaced spores on the aerial mycelium and did not produce diffusible pigments. The ll-isomer of diaminopimelic acid was present in the cell wall and menaquinones were predominantly MK-9(H6) (52 %) and MK-9(H8) (30 %) with 6 % MK-9(H4) and slightly less than 1 % MK-9(H2). Polar lipids present were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and an unknown phospholipid. The major fatty acids were anteiso-C15 : 0, anteiso-C16 : 0, anteiso-C14 : 0 and anteiso-C17 : 0. The G+C content of the genomic DNA was 70.4 mol%. Phylogenetic analysis of the nearly complete 16S rRNA gene sequence indicated that it differed from described Streptomyces species. Multilocus sequence analysis (MLSA) using five housekeeping genes (atpD, gyrB, rpoB, recA and trpB) comparing Streptomyces type strains showed that the MLSA distance of strain 594 T to the most closely related species was greater than the 0.007 threshold. The in silico DNA-DNA relatedness between the genome sequence of strain 594 T and that of the phylogenetically nearest species was well below the species level recommendation. There was thus multiple evidence justifying the description of this strain as representing a novel species, for which the name Streptomyces odonnellii sp. nov. is proposed. The type strain is 594 T (=IMPPG 594 T =DSM 41949 T =NRRL B-24891 T ).

  2. Secondary metabolites produced by marine streptomyces as antibiofilm and quorum-sensing inhibitor of uropathogen Proteus mirabilis.

    Science.gov (United States)

    Younis, Khansa Mohammed; Usup, Gires; Ahmad, Asmat

    2016-03-01

    Quorum-sensing regulates bacterial biofilm formation and virulence factors, thereby making it an interesting target for attenuating pathogens. In this study, we investigated anti-biofilm and anti-quorum-sensing compounds from secondary metabolites of halophiles marine streptomyces against urinary catheter biofilm forming Proteus mirabilis without effect on growth viability. A total of 40 actinomycetes were isolated from samples collected from different places in Iraq including marine sediments and soil samples. Fifteen isolates identified as streptomyces and their supernatant screened as anti-quorum-sensing by inhibiting quorum-sensing regulated prodigiosin biosynthesis of Serratia marcescens strain Smj-11 as a reporter strain. Isolate Sediment Lake Iraq (sdLi) showed potential anti-quorum-sensing activity. Out of 35 clinical isolates obtained from Urinary catheter used by patient at the Universiti Kebangsaan Malaysia Medical Center, 22 isolates were characterized and identified as Proteus mirabilis. Isolate Urinary Catheter B4 (UCB4) showed the highest biofilm formation with highest resistance to used antibiotic and was chosen for further studies. Ethyl acetate secondary metabolites extract was produced from sdLi isolate. First, we determined the Minimum Inhibitory Concentration (MIC) of sdLi crude extract against UCB4 isolate, and all further experiments used concentrations below the MIC. Tests of subinhibitory concentrations of sdLi crude extract showed good inhibition against UCB4 isolate biofilm formation on urinary catheter and cover glass using Scanning electron microscopy and light microscopy respectively. The influence of sub-MIC of sdLi crude extract was also found to attenuate the quorum sensing (QS)-dependent factors such as hemolysin activity, urease activity, pH value, and motility of UCB4 isolate. Evidence is presented that these nontoxic secondary metabolites may act as antagonists of bacterial quorum sensing by competing with quorum-sensing signals

  3. Streptomyces rhizosphaerihabitans sp. nov. and Streptomyces adustus sp. nov., isolated from bamboo forest soil.

    Science.gov (United States)

    Lee, Hyo-Jin; Whang, Kyung-Sook

    2016-09-01

    Three novel isolates belonging to the genus Streptomyces, designated JR-35T, JR-46 and WH-9T, were isolated from bamboo forest soil in Damyang, Korea. The 16S rRNA gene sequences of strains JR-35T and JR-46 showed highest similarities with Streptomyces olivochromogenes NBRC 3178T (99.1 %), Streptomyces siamensis KC-038T (98.9 %), Streptomyces chartreusis NBRC 12753T (98.9 %), Streptomyces resistomycificus NRRL ISP-5133T (98.9 %) and Streptomyces bobili JCM 4627T (98.8 %), and strain WH-9Tshowed highest sequence similarities with Streptomyces. bobili JCM 4627T (99.2 %), Streptomyces phaeoluteigriseus NRRL ISP-5182T (99.2 %), Streptomyces alboniger NBRC 12738T (99.2 %), Streptomyces galilaeus JCM 4757T (99.1 %) and Streptomyces pseudovenezuelae NBRC 12904T (99.1 %). The predominant menaquinones were MK-9 (H6) and MK-9 (H8). The major fatty acids were anteiso-C15 : 0, iso-C16 : 0, iso-C14 : 0 and iso-C15 : 0 for strains JR-35T and JR-46 and anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0 for strain WH-9T. The G+C content of the genomic DNA of strains JR-35T, JR-46 and WH-9T were 69.4, 74.4 and 74.1 mol%, respectively. Based on the phenotypic and genotypic data, the three strains are assigned to two novel species of the genus Streptomyces, for which the names Streptomyces rhizosphaerihabitans sp. nov. (type stain JR-35T=KACC 17181T=NBRC 109807T) and Streptomyces adustus sp. nov. (type strain WH-9T=KACC 17197T=NBRC 109810T) are proposed.

  4. Streptomyces Exploration: Competition, Volatile Communication and New Bacterial Behaviours.

    Science.gov (United States)

    Jones, Stephanie E; Elliot, Marie A

    2017-07-01

    Streptomyces bacteria are prolific producers of specialized metabolites, and have a well studied, complex life cycle. Recent work has revealed a new type of Streptomyces growth termed 'exploration' - so named for the ability of explorer cells to rapidly traverse solid surfaces. Streptomyces exploration is stimulated by fungal interactions, and is associated with the production of an alkaline volatile organic compound (VOC) capable of inducing exploration by other streptomycetes. Here, we examine Streptomyces exploration from the perspectives of interkingdom interactions, pH-induced morphological switches, and VOC-mediated communication. The phenotypic diversity that can be revealed through microbial interactions and VOC exposure is providing us with insight into novel modes of microbial development, and an opportunity to exploit VOCs to stimulate desired microbial behaviours. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Streptomyces verrucosisporus sp. nov., isolated from marine sediments.

    Science.gov (United States)

    Phongsopitanun, Wongsakorn; Kudo, Takuji; Ohkuma, Moriya; Pittayakhajonwut, Pattama; Suwanborirux, Khanit; Tanasupawat, Somboon

    2016-09-01

    Five actinomycete isolates, CPB1-1T, CPB2-10, BM1-4, CPB3-1 and CPB1-18, belonging to the genus Streptomyces were isolated from marine sediments collected from Chumphon Province, Thailand. They produced open loops of warty spore chains on aerial mycelia. ll-Diaminopimelic acid, glucose and ribose were found in their whole-cell hydrolysates. Polar lipids found were diphosphatidylglycerol, phosphatidylethanolamine, lysophosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. Menaquinones were MK-9(H6), MK-9(H8), MK-10(H6) and MK-10(H8). Major cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The taxonomic position of the strains was described using a polyphasic approach. blastn analysis of the 16S rRNA gene sequence revealed that these five strains exhibited the highest similarities with 'Streptomyces mangrovicola' GY1 (99.0 %), Streptomyces fenghuangensisGIMN4.003T (98.6 %), Streptomyces barkulensisRC 1831T (98.5 %) and Streptomyces radiopugnans R97T (98.3 %). However, their phenotypic characteristics and 16S rRNA gene sequences as well as DNA-DNA relatedness differentiated these five strains from the other species of the genus Streptomyces. Here, we propose the novel actinomycetes all being representatives of the same novel species, Streptomyces verrucosisporus, with type strain CPB1-1T (=JCM 18519T=PCU 343T=TISTR 2344T).

  6. Biochemical studies on antibiotic production from Streptomyces sp.: Taxonomy, fermentation, isolation and biological properties

    Directory of Open Access Journals (Sweden)

    Houssam M. Atta

    2015-01-01

    Full Text Available Tunicamycin is a nucleotide antibiotic which was isolated from the fermentation broth of a Streptomyces strain No. T-4. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain T-4 was identified as Streptomyces torulosus. It is active in vitro against some microbial pathogenic viz: Staphylococcus aureus, NCTC 7447; Micrococcus lutea, ATCC 9341; Bacillus subtilis, NCTC 10400; B. pumilus, NCTC; Klebsiella pneumonia, NCIMB 9111; Escherichia coli, NCTC 10416; Pseudomonas aeruginosa, ATCC 10145; Saccharomyces cerevisiae ATCC 9763; Candida albicans, IMRU 3669; Aspergillus flavus, IMI 111023; Aspergillus niger IMI 31276; Aspergillus fumigatus ATCC 16424; Fusarium oxysporum; Rhizoctonia solani; Alternaria alternata; Botrytis fabae and Penicillium chrysogenium. The production media were optimized for maximum yield of secondary metabolites. The metabolites were extracted using n-butanol (1:1, v/v at pH 7.0. The chemical structural analysis with UV, IR, and MS spectral analyses confirmed that the compound produced by Streptomyces torulosus, T-4 is tunicamycin antibiotic.

  7. Synthetic Biology in Streptomyces Bacteria

    NARCIS (Netherlands)

    Medema, Marnix H.; Breitling, Rainer; Takano, Eriko

    2011-01-01

    Actinomycete bacteria of the genus Streptomyces are major producers of bioactive compounds for the biotechnology industry. They are the source of most clinically used antibiotics, as well as of several widely used drugs against common diseases, including cancer . Genome sequencing has revealed that

  8. (melanin) production in Streptomyces

    African Journals Online (AJOL)

    GRACE

    Nine strains among 180 Streptomyces isolates produce a diffusible dark brown pigment on both peptone-yeast extract agar and synthetic tyrosine-agar. They also show the positive reaction to L- tyrosine or L-dopa substrates. The pigment has been referred to be as merely as dark brown water- soluble pigment, as melanoid ...

  9. Asteroids - NeoWs API

    Data.gov (United States)

    National Aeronautics and Space Administration — NeoWs (Near Earth Object Web Service) is a RESTful web service for near earth Asteroid information. With NeoWs a user can: search for Asteroids based on their...

  10. Obtaining mutants of Streptomyces griseoflavus strain 1339, producers of glucose isomerase, following gamma irradiation

    International Nuclear Information System (INIS)

    Dzhedzheva, G.; Stoeva, N.; Stojchev, M.

    1990-01-01

    A water suspension of Streptomyces griseoflavus strain 1339 spores of a density of 8.7.10 6 spores/cm 3 is gamma irradiated ( 60 Co, RHM-γ-20, 30.3 Gy/min). The survival of Streptomyces griseoflavus strain 1339 spores was determined depending on radiation doses, exposure times and incubation temperature. Five major morphological types of colonies were isolated, characterized by different levels of glucose isomerase activity. Maximum specific glucose isomerase activity (GIU/g) was attained after the third gamma irradiation step using a dose of 3000 Gy. 2 tabs., 3 figs., 7 refs

  11. Preliminary X-ray crystallographic analysis of the glycosyltransferase from a marine Streptomyces species

    International Nuclear Information System (INIS)

    Gong, Liping; Xiao, Yi; Liu, Qiang; Li, Sumei; Zhang, Changsheng; Liu, Jinsong

    2010-01-01

    The recombinant glycosyltransferase ElaGT from the elaiophylin-producing marine Streptomyces sp. SCSIO 01934 has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 2.9 Å resolution. ElaGT is a glycosyltransferase from a marine Streptomyces species that is involved in the biosynthesis of elaiophylin. Here, the molecular cloning, protein expression and purification, preliminary crystallization and crystallographic characterization of ElaGT are reported. The rod-shaped crystals belonged to space group P2 1 22, with unit-cell parameters a = 66.7, b = 131.7, c = 224.6 Å, α = 90, β = 90, γ = 90°. Data were collected to 2.9 Å resolution. A preliminary molecular-replacement solution implied the presence of two ElaGT molecules in the asymmetric unit

  12. Streptomyces phaeopurpureus Shinobu 1957 (Approved Lists 1980) and Streptomyces griseorubiginosus (Ryabova and Preobrazhenskaya 1957) Pridham et al. 1958 (Approved Lists 1980) are heterotypic subjective synonyms.

    Science.gov (United States)

    Kämpfer, Peter; Rückert, Christian; Blom, Jochen; Goesmann, Alexander; Wink, Joachim; Kalinowski, Jörn; Glaeser, Stefanie P

    2017-08-01

    On the basis of whole genome comparisons of Streptomyces griseorubiginosus and Streptomyces phaeopurpureus it could by shown that these two species are subjective synonyms. The names of both species have been published in the Approved Lists of Bacterial Names and, in such a case, normally Rule 24b (1) of the Prokaryotic Code applies, which reads: 'If two names compete for priority and if both names date from 1 January 1980 on an Approved List, the priority shall be determined by the date of the original publication of the name before 1 January 1980'. Streptomyces griseorubiginosus and Streptomyces phaeopurpureus were both effectively published in 1957, and for both publications, the exact date cannot be obtained. In this case a further statement of Rule 24 applies, which reads: 'If the names or epithets are of the same date, the author who first unites the taxa has the right to choose one of them, and his choice must be followed.' Hence we propose that Streptomyces phaeopurpureus is a later heterotypic subjective synonym of Streptomyces griseorubiginosus.

  13. ISOLASI STREPTOMYCES SPP. PADA KAWASAN HUTAN PROVINSI BALI SERTA UJI DAYA HAMBATNYA TERHADAP LIMA STRAIN DIARRHEAGENIC ESCHERICHIA COLI

    Directory of Open Access Journals (Sweden)

    I WAYAN EKA DHARMAWAN

    2014-04-01

    Full Text Available An exploration study of natural resources soil bacteria antibiotic-producer, Streptomyces spp. was done in two steps. The first step was isolation of Streptomyces and the second involved testing their inhibition activities against five strains diarrheagenic Escherichia coli. Soil samples were collected from ten forest areas in Bali. As many as 55 isolates were collected with various macroscopic dan microscopic characters. Most isolates (eight Streptomyces isolates were collected from forest area in Penulisan, Kintamani (RTK. 20. The diversities of isolates are influenced by environment condition. All Streptomyces isolated were tested against five strains diarrheagenic Escherichia coli to check antibiotic activity for inhibit growth of E. coli. Streptomycine was used as a control. The result showed that the largest inhibition zones of Streptomyces against E. coli strains EHEC, ETEC, EIEC, EPEC and DAEC were produced by Streptomyces PK5 (48,67 ± 0,58 mm, Streptomyces GAA4 (29,00 ± 2,00 mm, Streptomyces GBK3 (42,67 ± 2,08 mm, Streptomyces SkBB5 (29,00 ± 2,65 mm and Streptomyces GM3 (33,67 ± 3,21 mm respectively.

  14. Development of Next Generation Synthetic Biology Tools for Use in Streptomyces venezuelae

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, Ryan M. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States). QB3 Inst.; Sachs, Daniel [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Petkiewicz, Shayne J. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Barajas, Jesus F. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Blake-Hedges, Jacquelyn M. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Thompson, Mitchell G. [Univ. of California, Berkeley, CA (United States). Dept. of Plant & Microbial Biology; Reider Apel, Amanda [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Rasor, Blake J. [Miami Univ., Oxford, Ohio (United States). Dept. of Biology; Katz, Leonard [Univ. of California, Berkeley, CA (United States). QB3 Inst.; Keasling, Jay D. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States). QB3 Inst.; Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engineering and Department of Bioengineering; Technical Univ. of Denmark, Kogle Alle (Denmark). Novo Nordisk Foundation Center for Biosustainability

    2016-09-07

    Streptomyces have a rich history as producers of important natural products and this genus of bacteria has recently garnered attention for its potential applications in the broader context of synthetic biology. However, the dearth of genetic tools available to control and monitor protein production precludes rapid and predictable metabolic engineering that is possible in hosts such as Escherichia coli or Saccharomyces cerevisiae. In an effort to improve genetic tools for Streptomyces venezuelae, we developed a suite of standardized, orthogonal integration vectors and an improved method to monitor protein production in this host. These tools were applied to characterize heterologous promoters and various attB chromosomal integration sites. A final study leveraged the characterized toolset to demonstrate its use in producing the biofuel precursor bisabolene using a chromosomally integrated expression system. In conclusion, these tools advance S. venezuelae to be a practical host for future metabolic engineering efforts.

  15. Genome Sequence of the Bacterium Streptomyces davawensis JCM 4913 and Heterologous Production of the Unique Antibiotic Roseoflavin

    Science.gov (United States)

    Jankowitsch, Frank; Schwarz, Julia; Rückert, Christian; Gust, Bertolt; Szczepanowski, Rafael; Blom, Jochen; Pelzer, Stefan; Kalinowski, Jörn

    2012-01-01

    Streptomyces davawensis JCM 4913 synthesizes the antibiotic roseoflavin, a structural riboflavin (vitamin B2) analog. Here, we report the 9,466,619-bp linear chromosome of S. davawensis JCM 4913 and a 89,331-bp linear plasmid. The sequence has an average G+C content of 70.58% and contains six rRNA operons (16S-23S-5S) and 69 tRNA genes. The 8,616 predicted protein-coding sequences include 32 clusters coding for secondary metabolites, several of which are unique to S. davawensis. The chromosome contains long terminal inverted repeats of 33,255 bp each and atypical telomeres. Sequence analysis with regard to riboflavin biosynthesis revealed three different patterns of gene organization in Streptomyces species. Heterologous expression of a set of genes present on a subgenomic fragment of S. davawensis resulted in the production of roseoflavin by the host Streptomyces coelicolor M1152. Phylogenetic analysis revealed that S. davawensis is a close relative of Streptomyces cinnabarinus, and much to our surprise, we found that the latter bacterium is a roseoflavin producer as well. PMID:23043000

  16. Resonant enhancement of band-to-band tunneling in in-plane MoS2/WS2 heterojunctions

    Science.gov (United States)

    Kuroda, Tatsuya; Mori, Nobuya

    2018-04-01

    The band-to-band (BTB) tunneling current J through in-plane MoS2/WS2 heterojunctions is calculated by the nonequilibrium Green function method combined with tight-binding approximation. Types A and B of band configurations are considered. For type-A (type-B) heterojunctions, a potential notch exists (or is absent) at the heterointerface. Both type-A and type-B MoS2/WS2 heterojunctions can support a higher BTB current than MoS2 and WS2 homojunctions. For type-A heterojunctions, the resonant enhancement of J occurs resulting in a significantly higher BTB tunneling current.

  17. Microstructural Study of IF-WS2 Failure Modes

    Directory of Open Access Journals (Sweden)

    Jamie Cook

    2014-07-01

    Full Text Available This manuscript summarizes the failure mechanisms found in inorganic fullerene-type tungsten disulfide (IF-WS2 nanoparticles treated with diverse pressure loading methods. The approaches utilized to induce failure included: the use of an ultrasonic horn, the buildup of high pressures inside a shock tube which created a shock wave that propagated and impinged in the sample, and impact with military rounds. After treatment, samples were characterized using electron microscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, and surface area analysis. The microstructural changes observed in the IF-WS2 particulates as a consequence of the treatments could be categorized in two distinct fracture modes. The most commonly observed was the formation of a crack at the particles surface followed by a phase transformation from the 3D cage-like structures into the 2D layered polymorphs, with subsequent agglomeration of the plate-like sheets to produce larger particle sizes. The secondary mechanism identified was the incipient delamination of IF-WS2. We encountered evidence that the IF-WS2 structure collapse initiated in all cases at the edges and vertices of the polyhedral particles, which acted as stress concentrators, independent of the load application mode or its duration.

  18. Genetic segregation in a high-yielding streptomycin-producing strain of Streptomyces griseus.

    Science.gov (United States)

    Roth, M; Schwalenberg, B; Reiche, R; Noack, D; Geuther, R; Eritt, I

    1982-01-01

    The streptomycin-producing Streptomyces griseus HP spontaneously segregated non-reverting derivatives with altered phenotypes. Clones characterized by increased spore formation and decreased streptomycin production were found. Two other types of derivatives were defective in aerial mycelium and streptomycin formation as well, but differed in the capacity to synthesize a yellow pigment. These derivatives were examined with respect to further properties. The stability of S. griseus HP was investigated in relation to conditions of continuous culture. Both at 26 and 30 degrees C, under glycerol and NH4Cl limitation a rapid segregation and enrichment of streptomycin-non-producing derivatives occurred. At 34 degrees C and glycerol limitation segregation began only after about 35 generations of continuous culture. In NH4Cl-limited chemostats the original strain was stable during 80 generations. In the course of the continuous culture experiments it was shown that the onset of genetic segregation within mycelia can be detected before it becomes obvious in colonies grown from the mycelia. This was achieved by fractionation of the mycelia by protoplast formation and subsequent plating on regeneration medium allowing colony growth and differentiation.

  19. [Progress in developing and applying Streptomyces chassis - A review].

    Science.gov (United States)

    Xiao, Liping; Deng, Zixin; Liu, Tiangang

    2016-03-04

    Natural products and their derivatives play an important role in modern healthcare. Their diversity in bioactivity and chemical structure inspires scientists to discover new drug entities for clinical use. However, chemical synthesis of natural compounds has insurmountable difficulties in technology and cost. Also, many original-producing bacteria have disadvantages of needing harsh cultivation conditions, having low productivity and other shortcomings. In addition, some gene clusters responsible for secondary metabolite biosynthesis are silence in the original strains. Therefore, it is of great significance to exploit strategy for the heterologous expression of natural products guided by synthetic biology. Recently, researchers pay more attention on using actinomycetes that are the main source of many secondary metabolites, such as antibiotics, anticancer agents, and immunosuppressive drugs. Especially, with huge development of genome sequencing, abundant resources of natural product biosynthesis in Streptomyces have been discovered, which highlight the special advantages on developing Streptomyces as the heterologous expression chassis cells. This review begins with the significance of the development of Streptomyces chassis, focusing on the strategies and the status in developing Streptomyces chassis cells, followed by examples to illustrate the practical applications of a variety of Streptomyces chassis.

  20. Streptomyces bacteria as potential probiotics in aquaculture

    Directory of Open Access Journals (Sweden)

    Tan Loh eTeng Hern

    2016-02-01

    Full Text Available In response to the increased seafood demand from the ever-going human population, aquaculture has become the fastest growing animal food-producing sector. However, the indiscriminate use of antibiotics as a biological control agents for fish pathogens has led to the emergence of antibiotic resistance bacteria. Probiotics are defined as living microbial supplement that exert beneficial effects on hosts as well as improvement of environmental parameters. Probiotics have been proven to be effective in improving the growth, survival and health status of the aquatic livestock. This review aims to highlight the genus Streptomyces can be a good candidate for probiotics in aquaculture. Studies showed that the feed supplemented with Streptomyces could protect fish and shrimp from pathogens as well as increase the growth of the aquatic organisms. Furthermore, the limitations of Streptomyces as probiotics in aquaculture is also highlighted and solutions are discussed to these limitations.

  1. Central Carbon Metabolic Pathways in Streptomyces

    NARCIS (Netherlands)

    van Keulen, Geertje; Siebring, Jeroen; Dijkhuizen, Lubbert; Dyson, Paul

    Streptomyces and other actinomycetes are fascinating soil bacteria of major economic importance. They produce 70% of antibiotics known to man and numerous other pharmaceuticals for treatment of, e.g. cancer, a range of infections, high cholesterol, or have immunosuppressive activity. It is not

  2. Strain-Level Diversity of Secondary Metabolism in Streptomyces albus

    Science.gov (United States)

    Seipke, Ryan F.

    2015-01-01

    Streptomyces spp. are robust producers of medicinally-, industrially- and agriculturally-important small molecules. Increased resistance to antibacterial agents and the lack of new antibiotics in the pipeline have led to a renaissance in natural product discovery. This endeavor has benefited from inexpensive high quality DNA sequencing technology, which has generated more than 140 genome sequences for taxonomic type strains and environmental Streptomyces spp. isolates. Many of the sequenced streptomycetes belong to the same species. For instance, Streptomyces albus has been isolated from diverse environmental niches and seven strains have been sequenced, consequently this species has been sequenced more than any other streptomycete, allowing valuable analyses of strain-level diversity in secondary metabolism. Bioinformatics analyses identified a total of 48 unique biosynthetic gene clusters harboured by Streptomyces albus strains. Eighteen of these gene clusters specify the core secondary metabolome of the species. Fourteen of the gene clusters are contained by one or more strain and are considered auxiliary, while 16 of the gene clusters encode the production of putative strain-specific secondary metabolites. Analysis of Streptomyces albus strains suggests that each strain of a Streptomyces species likely harbours at least one strain-specific biosynthetic gene cluster. Importantly, this implies that deep sequencing of a species will not exhaust gene cluster diversity and will continue to yield novelty. PMID:25635820

  3. Identification and statistical optimization of fermentation conditions for a newly isolated extracellular cholesterol oxidase-producing Streptomyces cavourensis strain NEAE-42

    OpenAIRE

    El-Naggar, Noura El-Ahmady; El-Shweihy, Nancy M.; El-Ewasy, Sara M.

    2016-01-01

    Background Due to broad range of clinical and industrial applications of cholesterol oxidase, isolation and screening of bacterial strains producing extracellular form of cholesterol oxidase is of great importance. Results One hundred and thirty actinomycete isolates were screened for their cholesterol oxidase activity. Among them, a potential culture, strain NEAE-42 is displayed the highest extracellular cholesterol oxidase activity. It was selected and identified as Streptomyces cavourensis...

  4. WS1: one more new Galactic bona fide luminous blue variable★

    Science.gov (United States)

    Kniazev, A. Y.; Gvaramadze, V. V.; Berdnikov, L. N.

    2015-04-01

    In this Letter, we report the results of spectroscopic and photometric monitoring of the candidate luminous blue variable (LBV) WS1, which was discovered in 2011 through the detection of a mid-infrared circular shell and follow-up optical spectroscopy of its central star. Our monitoring showed that WS1 brightened in the B, V and I bands by more than 1 mag during the last three years, while its spectrum revealed dramatic changes during the same time period, indicating that the star became much cooler. The light curve of WS1 demonstrates that the brightness of this star has reached maximum in 2013 December and then starts to decline. These findings unambiguously proved the LBV nature of WS1 and added one more member to the class of Galactic bona fide LBVs, bringing their number to sixteen (an updated census of these objects is provided).

  5. Variability of Streptomyces narbonesis producing ν-1,3/1,4 glucanglucan hydrolasi induced by UV and mitomycin C

    International Nuclear Information System (INIS)

    Elinov, N.P.; Pronina, M.I.; Zaikina, N.A.; Azizov, P.I.

    1982-01-01

    Effect of mitomycin c and ultraviolet rays on spores and spore sprouts of 2 hour old of Streptomyces narbonensis of 2a producer of ν-1.3/1.4 glucanglucanhydrolase (ν-gluconase) has been studied. It is shown that the lethal effect of mitomycin c on spore sprouts is considerably higher than on producer spores. Mutageneous activity of mitomycin C is closely related to the process of spore germination. Under the effect of mitomycin C on spore sprouts noted is higher mutability as compared with the effect on spores. Frequency of morphological mutations is lower under the effect of ultraviolet rays as compared with the effect of mitomycin C. Under ultraviolet rays produced were mutants synthesizing during fermentation on medium without inductor of exotype ν-gluconase

  6. The small laccase from Streptomyces coelicolor

    Czech Academy of Sciences Publication Activity Database

    Dohnálek, Jan; Skálová, Tereza; Ostergaard, L. H.; Ostergaard, P. R.; Hašek, Jindřich

    2009-01-01

    Roč. 16, 1a (2009), b4-b5 ISSN 1211-5894. [Discussions in Structural Molecular Biology /7./. 12.03.2009-14.03.2009, Nové Hrady] R&D Projects: GA ČR GA305/07/1073 Institutional research plan: CEZ:AV0Z40500505 Keywords : laccase * Streptomyces coelicolor * enzymer Subject RIV: CD - Macromolecular Chemistry

  7. Pre-sporulation stages of Streptomyces differentiation: state-of-the-art and future perspectives

    Science.gov (United States)

    Yagüe, Paula; López-García, Maria T.; Rioseras, Beatriz; Sánchez, Jesús; Manteca, Ángel

    2013-01-01

    Streptomycetes comprise very important industrial bacteria, producing two-thirds of all clinically relevant secondary metabolites. They are mycelial microorganisms with complex developmental cycles that include programmed cell death (PCD) and sporulation. Industrial fermentations are usually performed in liquid cultures (large bioreactors), conditions in which Streptomyces strains generally do not sporulate, and it was traditionally assumed that there was no differentiation. In this work, we review the current knowledge on Streptomyces pre-sporulation stages of Streptomyces differentiation. PMID:23496097

  8. Streptomyces camponoticapitis sp. nov., an actinomycete isolated from the head of an ant (Camponotus japonicus Mayr).

    Science.gov (United States)

    Li, Yao; Ye, Lan; Wang, Xiangjing; Zhao, Junwei; Ma, Zhaoxu; Yan, Kai; Xiang, Wensheng; Liu, Chongxi

    2016-10-01

    A novel single-spore-producing actinomycete, designated strain 2H-TWYE14T, was isolated from the head of an ant (Camponotus japonicus Mayr) and characterized using a polyphasic approach. 16S rRNA gene sequence analysis showed that strain 2H-TWYE14T belongs to the genus Streptomyces, with highest sequence similarity to Streptomyces niveus NRRL 2466T (98.84 %). Analysis based on the gyrB gene also indicated that strain 2H-TWYE14T should be assigned to the genus Streptomyces. The chemotaxonomic properties of strain 2H-TWYE14T were consistent with those of members of the genus Streptomyces. The cell wall contained ll-diaminopimelic acid. The predominant menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were iso-C16 : 0 and iso-C15 : 0. DNA-DNA hybridization experiments and phenotypic tests were carried out between strain 2H-TWYE14T and its phylogenetically closely related strain S. niveus JCM 4251T, which further clarified their relatedness and demonstrated that 2H-TWYE14T could be distinguished from S. niveus. Therefore, it is concluded that strain 2H-TWYE14T can be classified as representing a novel species of the genus Streptomyces, for which the name Streptomyces camponoticapitis sp. nov. is proposed. The type strain is 2H-TWYE14T (=DSM 100523T=CGMCC 4.7275T).

  9. Isolation and characterization of stable mutants of Streptomyces

    Indian Academy of Sciences (India)

    Daunorubicin and its derivative doxorubicin are antitumour anthracycline antibiotics produced by Streptomyces peucetius. In this study we report isolation of stable mutants of S. peucetius blocked in different steps of the daunorubicin biosynthesis pathway. Mutants were screened on the basis of colony colour since producer ...

  10. Taxonomic evaluation of Streptomyces albus and related species using multilocus sequence analysis

    Science.gov (United States)

    In phylogenetic analyses of the genus Streptomyces using 16S rRNA gene sequences, Streptomyces albus subsp. albus NRRL B-1811T formed a cluster with 5 other species having identical or nearly identical 16S rRNA gene sequences. Moreover, the morphological and physiological characteristics of these ot...

  11. Antimicrobial activity of Streptomyces spp. Isolates from vegetable plantation soil

    Directory of Open Access Journals (Sweden)

    Isnaeni

    2016-05-01

    Full Text Available Fifteen Streptomyces isolates were isolated from soil in some different location on vegetable plantation at agriculture standard condition. The isolates were assessed for their antibacterial activity against Mycobacterium tuberculosis (MTB ATCC H37RV and mycobacterial which isolated from Dr. Soetomo Hospital patients in Surabaya. The International Streptomyces Project 4 (ISP4 and Middlebrook 7H9 (MB7H9 wwere used as growth or fermentation medium. The screening of inhibition activity was performed using turbidimetry and spot-test on agar medium. Results shown that 33.3% of the isolates (5 isolates have anti-mycobacterial activities. The first line anti tuberculosis drug rifampicin, (RIF, ethambutol (EMB, isoniazid (INH, and pyrazinamide (PZA were used as standards or positive controls with concentration 20 ppm. Optical density of crude fermentation broth concentrated from five isolates relatively lower than five anti-tuberculosis drug activity standard, although their activities against some microbial were similar to the standard at spot-test. The most efficient isolate shown anti-mycobacterial activity was Streptomyces B10 which identified as Streptomyces violaceousniger. In addition, fatty acid methyl ester (FAME profile of gas chromatography-mass spectrometry chromatogram of each isolates were studied and compared to Streptomyces spp. Keywords: Anti-mycobacterial, Mycobacterium tuberculosis, Streptomyces spp.

  12. HybProbes-based real-time PCR assay for specific identification of Streptomyces scabies and Streptomyces europaeiscabiei, the potato common scab pathogens.

    Science.gov (United States)

    Xu, R; Falardeau, J; Avis, T J; Tambong, J T

    2016-02-01

    The aim of this study was to develop and validate a HybProbes-based real-time PCR assay targeting the trpB gene for specific identification of Streptomyces scabies and Streptomyces europaeiscabiei. Four primer pairs and a fluorescent probe were designed and evaluated for specificity in identifying S. scabies and Streptomyces europaeiscabiei, the potato common scab pathogens. The specificity of the HybProbes-based real-time PCR assay was evaluated using 46 bacterial strains, 23 Streptomyces strains and 23 non-Streptomyces bacterial species. Specific and strong fluorescence signals were detected from all nine strains of S. scabies and Streptomyces europaeiscabiei. No fluorescence signal was detected from 14 strains of other Streptomyces species and all non-Streptomyces strains. The identification was corroborated by the melting curve analysis that was performed immediately after the amplification step. Eight of the nine S. scabies and S. europaeiscabiei strains exhibited a unique melting peak, at Tm of 69·1°C while one strain, Warba-6, had a melt peak at Tm of 65·4°C. This difference in Tm peaks could be attributed to a guanine to cytosine mutation in strain Warba-6 at the region spanning the donor HybProbe. The reported HybProbes assay provides a more specific tool for accurate identification of S. scabies and S. europaeiscabiei strains. This study reports a novel assay based on HybProbes chemistry for rapid and accurate identification of the potato common scab pathogens. Since the HybProbes chemistry requires two probes for positive identification, the assay is considered to be more specific than conventional PCR or TaqMan real-time PCR. The developed assay would be a useful tool with great potential in early diagnosis and detection of common scab pathogens of potatoes in infected plants or for surveillance of potatoes grown in soil environment. © 2015 Her Majesty the Queen in Right of Canada © 2015 The Society for Applied Microbiology.

  13. Enhancement of clavulanic acid production by Streptomyces sp MU ...

    African Journals Online (AJOL)

    1Chemistry of Natural and Microbial Products Dept., Pharmaceutical Industries Div., National Research Centre, 33 EL ... enzymes produced by many pathogenic bacteria, ... produced by the actinomycete Streptomyces ... enzymes, hence avoiding loss of the beta-lactam ...... strain will explore the economic outcome of.

  14. Focused Review: Cytotoxic and Antioxidant Potentials of Mangrove-Derived Streptomyces

    Directory of Open Access Journals (Sweden)

    Hooi-Leng Ser

    2017-11-01

    Full Text Available Human life expectancy is rapidly increasing with an associated increasing burden of chronic diseases, such as neurodegenerative diseases and cancer. However, there is limited progress in finding effective treatment for these conditions. For this reason, members of the genus Streptomyces have been explored extensively over the past decades as these filamentous bacteria are highly efficient in producing bioactive compounds with human health benefits. Being ubiquitous in nature, streptomycetes can be found in both terrestrial and marine environments. Previously, two Streptomyces strains (MUSC 137T and MUM 256 isolated from mangrove sediments in Peninsular Malaysia demonstrated potent antioxidant and cytotoxic activities against several human cancer cell lines on bioactivity screening. These results illustrate the importance of streptomycetes from underexplored regions aside from the terrestrial ecosystem. Here we provide the insights and significance of Streptomyces species in the search of anticancer and/or chemopreventive agents and highlight the impact of next generation sequencing on drug discovery from the Streptomyces arsenal.

  15. Focused Review: Cytotoxic and Antioxidant Potentials of Mangrove-Derived Streptomyces

    Science.gov (United States)

    Ser, Hooi-Leng; Tan, Loh Teng-Hern; Law, Jodi Woan-Fei; Chan, Kok-Gan; Duangjai, Acharaporn; Saokaew, Surasak; Pusparajah, Priyia; Ab Mutalib, Nurul-Syakima; Khan, Tahir Mehmood; Goh, Bey-Hing; Lee, Learn-Han

    2017-01-01

    Human life expectancy is rapidly increasing with an associated increasing burden of chronic diseases, such as neurodegenerative diseases and cancer. However, there is limited progress in finding effective treatment for these conditions. For this reason, members of the genus Streptomyces have been explored extensively over the past decades as these filamentous bacteria are highly efficient in producing bioactive compounds with human health benefits. Being ubiquitous in nature, streptomycetes can be found in both terrestrial and marine environments. Previously, two Streptomyces strains (MUSC 137T and MUM 256) isolated from mangrove sediments in Peninsular Malaysia demonstrated potent antioxidant and cytotoxic activities against several human cancer cell lines on bioactivity screening. These results illustrate the importance of streptomycetes from underexplored regions aside from the terrestrial ecosystem. Here we provide the insights and significance of Streptomyces species in the search of anticancer and/or chemopreventive agents and highlight the impact of next generation sequencing on drug discovery from the Streptomyces arsenal. PMID:29163380

  16. Streptomyces palmae sp. nov., isolated from oil palm (Elaeis guineensis) rhizosphere soil.

    Science.gov (United States)

    Sujarit, Kanaporn; Kudo, Takuji; Ohkuma, Moriya; Pathom-Aree, Wasu; Lumyong, Saisamorn

    2016-10-01

    Actinomycete strain CMU-AB204T was isolated from oil palm rhizosphere soil collected in Chiang Mai University (Chiang Mai, Thailand). Based on morphological and chemotaxonomic characteristics, the organism was considered to belong to the genus Streptomyces. Whole cell-wall hydrolysates consisted of ll-diaminopimelic acid, glucose, ribose and galactose. The predominant menaquinones were MK-9(H4), MK-9(H6), MK-9(H2) and MK-8(H4). The fatty acid profile contained iso-C15 : 0, iso-C16 : 0 and anteiso-C15 : 0 as major components. The principal phospholipids detected were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The DNA G+C content of strain CMU-AB204T was 70.9 mol%. Based on 16S rRNA gene sequence similarity, strain CMU-AB204T was closely related to Streptomyces orinoci JCM 4546T (98.7 %), Streptomyces lilacinus NBRC 12884T (98.5 %), Streptomyces abikoensis CGMCC 4.1662T (98.5 %), Streptomyces griseocarneus JCM 4905T (98.4 %) and Streptomyces xinghaiensis JCM 16958T (98.3 %). Phylogenetic trees revealed that the new strain had a distinct taxonomic position from closely related type strains of the genus Streptomyces. Spiny to hairy spores clearly differentiated strain CMU-AB204T from the five most closely related Streptomyces species, which produced smooth spores. On the basis of evidence from this polyphasic study, it is proposed that strain CMU-AB204T represents a novel species of the genus Streptomyces, namely Streptomyces palmae sp. nov. The type strain is CMU-AB204T (=JCM 31289T=TBRC 1999T).

  17. In situ reduction of WS{sub 2} nanosheets for WS{sub 2}/reduced graphene oxide composite with superior Li-ion storage

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Liyan [Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093 (China); National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093 (China); Yan, Shancheng, E-mail: yansc@njupt.edu.cn [School of Geography and Biological Information, Nanjing University of Posts and Telecommunications, Nanjing, 210023 (China); National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093 (China); Lin, Zixia [Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093 (China); National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093 (China); Shi, Yi, E-mail: yshi@nju.edu.cn [Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093 (China); National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093 (China)

    2016-03-01

    Two-dimensional transition-metal dichalcogenides, such as tungsten disulfide (WS{sub 2}), have been actively studied as suitable candidates for anode materials used in lithium ion batteries recently, due to their remarkable ion intercalation properties. However, the difficulties in the synthesis of phase-pure WS{sub 2}, restacking between WS{sub 2} nanosheets, low electronic conductivity and brittle nature of WS{sub 2} severely limit its Li-ion batteries application. Here, we adopt a one-pot method for synthesizing of WS{sub 2}/reduced Graphene Oxide (rGO) composite to improve the battery performance dramatically. The WS{sub 2}/rGO anode shows a stable discharge capacity of 431.2 mAh/g, at a current density of 0.1 A/g after 100 cycles, while the capacity of bare WS{sub 2} is only 65.5 mAh/g under the same condition. The added graphene oxide is reduced to rGO in reaction process and constitute stable composite with WS{sub 2}, not only avoiding the restacking between WS{sub 2} nanosheets and improving the conductive properties, but also promoting the reduction of WO{sub 3} effectively. Our work may provide a possible route to avoid oxygen impurities in transition metal dichalcogenides. - Highlights: • The WS{sub 2}/rGO composite were synthesized to improve the battery performance. • The WS{sub 2}/rGO anode shows a capacity of 431.2 mAh/g, much higher than WS{sub 2}. • The added graphene oxide is reduced to rGO, improving the conductive properties. • The rGO can avoid the restacking, and promote the reduction of WO{sub 3}.

  18. Streptomyces pini sp. nov., an actinomycete isolated from phylloplane of pine (Pinus sylvestris L.) needle-like leaves.

    Science.gov (United States)

    Madhaiyan, Munusamy; Poonguzhali, Selvaraj; Saravanan, Venkatakrishnan Sivaraj; Duraipandiyan, Veeramuthu; Al-Dhabi, Naif Abdullah; Pragatheswari, Dhandapani; Santhanakrishnan, Palani; Kim, Soo-Jin; Weon, Hang-Yeon; Kwon, Soon-Wo

    2016-10-01

    A novel siderophore-producing actinomycete, designated PL19T, was isolated from the Scots-pine needle-like leaves collected from TNAU campus, Coimbatore, India. The isolate was chemoorganotrophic in nutrition and able to grow at 30 °C, and the optimum pH and NaCl facilitated the growth pH 6-11 and 0-8 % (w/v), respectively. The cells are filamentous and the mycelia formed are basically of wide and intricately branched substrate mycelium from which aerial mycelia arises, later gets differentiated into spores that are warty and arranged spirally. The 16S rRNA gene of strain PL19T was sequenced and was highly similar to the type strains of species of the genus Streptomyces, including Streptomyces barkulensis RC1831T (98.8 % pairwise similarity), Streptomyces fenghuangensis GIMN4.003T (98.2 %), Streptomyces nanhaiensis SCSIO 01248T (98.0 %), Streptomyces radiopugnans R97T (97.9 %), Streptomyces atacamensis C60T (97.8 %) and Streptomyces macrosporus NBRC 14749T (97.2 %), all of which were subjected to taxonomical characterization using a polyphasic approach. The strains showed unique carbon utilization patterns, and it possesses iso-C16 : 0 anteiso-C15 : 0 and anteiso-C17 : 0 as a major cellular fatty acids. The cell-wall was dominated with ll-type diaminopimelic acid, and the menaquinone type was MK-9(H6, H8). These chemotaxonomic evidences placed strain PL19T within the genus Streptomyces. The determination of G+C ratio (69.5 mol%) and DNA-DNA hybridization values (13.4-31.8 % with the phylogenetically related species) helped in further hierarchical classification of strain PL19T. Based on morphological, physiological and chemotaxonomic data as well as DNA-DNA hybridization values, strain PL19T could be distinguished from the evolutionarily closest species currently available. All these collective data show that strain PL19T represents a novel species of the genus Streptomyces, for which the name Streptomyces pini sp. nov. is proposed

  19. Endophytic Streptomyces spp. as Biocontrol Agents of Rice Bacterial Leaf Blight Pathogen (Xanthomonas oryzae pv. oryzae

    Directory of Open Access Journals (Sweden)

    RATIH DEWI HASTUTI

    2012-12-01

    Full Text Available Xanthomonas oryzae pv. oryzae (Xoo, a causal agent of bacterial leaf blight (BLB, is one of the most important pathogens of rice. The effectiveness of ten Streptomyces spp. isolates in suppressing Xoo disease was assessed in planta and in vitro. In planta experiments were carried out in a greenhouse and arranged in a randomized completely block design (RCBD with three replications. Twenty treatments were tested which included plants inoculated with both Streptomyces spp. and Xoo, and plants inoculated with only Streptomyces spp. Plants inoculated with Xoo and sprayed with a chemical bactericide, and plants inoculated with only Xoo served as positive controls, whereas plants not inoculated with either Streptomyces spp. or Xoo were used as negative controls. The results showed that the effect of endophytic Streptomyces spp. on BLB disease expressed as area under disease progress curve (AUDPC was not significantly different to that on control plants (P > 0.05. However, plants inoculated with endophytic Streptomyces spp. were significantly taller and produced higher tiller number than control plants (P < 0.05. Streptomyces spp. isolate AB131-1 gave the highest plant height. In vitro studies on biocontrol mechanisms of selected Streptomyces spp. isolates showed that isolate LBR02 gave the highest inhibition activity on Xoo growth, followed by AB131-1 and AB131-2. Two isolates (AB131-1 and LBR02 were able to produce chitinase, phosphatase, and siderophore which included biocontrol characteristics. Morphological and colonization studies under SEM and light microscopy confirmed that the three isolates were endophytic Streptomyces spp. from different species. These studies found that the paddy plant which was inoculated with endophytic Streptomyces spp. AB131-1 and infected by Xoo could increase the height of plant and number of tillers.

  20. Glucosylglycerate Is an Osmotic Solute and an Extracellular Metabolite Produced by Streptomyces caelestis

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Stanislav; Halada, Petr; Petříček, Miroslav; Sedmera, Petr

    2007-01-01

    Roč. 52, č. 5 (2007), s. 451-456 ISSN 0015-5632 R&D Projects: GA AV ČR IAA600660607 Institutional research plan: CEZ:AV0Z50200510 Keywords : streptomyces caelestis * mass spectrometry Subject RIV: EE - Microbiology, Virology Impact factor: 0.989, year: 2007

  1. Monolayer Superconductivity in WS2

    NARCIS (Netherlands)

    Zheliuk, Oleksandr; Lu, Jianming; Yang, Jie; Ye, Jianting

    Superconductivity in monolayer tungsten disulfide (2H-WS2) is achieved by strong electrostatic electron doping of an electric double-layer transistor (EDLT). Single crystals of WS2 are grown by a scalable method - chemical vapor deposition (CVD) on standard Si/SiO2 substrate. The monolayers are

  2. Characterization of representative rpoB gene mutations leading to a significant change in toyocamycin production of Streptomyces diastatochromogenes 1628.

    Science.gov (United States)

    Ma, Zheng; Luo, Shuai; Xu, Xianhao; Bechthold, Andreas; Yu, Xiaoping

    2016-04-01

    Modification of enzymes involved in transcription- or translation-processes is an interesting way to increase secondary metabolite production in Streptomycetes. However, application of such methods has not been widely described for strains which produce nucleoside antibiotics. The nucleoside antibiotic toyocamycin (TM) is produced by Streptomyces diastatochromogenes 1628. For improving TM production in S. diastatochromogenes 1628, the strain was spread on rifamycin-resistant (Rif(r)) medium. Several spontaneous mutants were obtained with mutations in the rpoB gene which encodes a RNA polymerase β-subunit. The mutants which showed increased TM production were detected at a frequency of 7.5 % among the total Rif(r) mutants. Mutant 1628-T15 harboring amino acid substitution His437Arg was the best TM producer with a 4.5-fold increase in comparison to that of the wild-type strain. The worst producer was mutant 1628-T62 which also showed a poor sporulation behavior. RT-PCR was performed to study the transcription levels of the TM biosynthetic gene toyG in the parental strain as well as in mutants 1628-T15 and 1628-T62. The transcriptional level of toyG was higher in mutant 1628-T15 than that in parental strain 1628, while much lower in mutant 1628-T62. In mutant strain 1628-T62 the expression of adpA sd gene, which is required for morphological differentiation, was also much lower. Our studies also indicate that the introduction of mutations into rpoB is an effective strategy to improve the production of TM which is an important nucleoside antibiotic.

  3. Recent advances in understanding Streptomyces [version 1; referees: 4 approved

    Directory of Open Access Journals (Sweden)

    Keith F. Chater

    2016-11-01

    Full Text Available About 2,500 papers dated 2014–2016 were recovered by searching the PubMed database for Streptomyces, which are the richest known source of antibiotics. This review integrates around 100 of these papers in sections dealing with evolution, ecology, pathogenicity, growth and development, stress responses and secondary metabolism, gene expression, and technical advances. Genomic approaches have greatly accelerated progress. For example, it has been definitively shown that interspecies recombination of conserved genes has occurred during evolution, in addition to exchanges of some of the tens of thousands of non-conserved accessory genes. The closeness of the association of Streptomyces with plants, fungi, and insects has become clear and is reflected in the importance of regulators of cellulose and chitin utilisation in overall Streptomyces biology. Interestingly, endogenous cellulose-like glycans are also proving important in hyphal growth and in the clumping that affects industrial fermentations. Nucleotide secondary messengers, including cyclic di-GMP, have been shown to provide key input into developmental processes such as germination and reproductive growth, while late morphological changes during sporulation involve control by phosphorylation. The discovery that nitric oxide is produced endogenously puts a new face on speculative models in which regulatory Wbl proteins (peculiar to actinobacteria respond to nitric oxide produced in stressful physiological transitions. Some dramatic insights have come from a new model system for Streptomyces developmental biology, Streptomyces venezuelae, including molecular evidence of very close interplay in each of two pairs of regulatory proteins. An extra dimension has been added to the many complexities of the regulation of secondary metabolism by findings of regulatory crosstalk within and between pathways, and even between species, mediated by end products. Among many outcomes from the application of

  4. Strain improvement in Streptomyces galilaeus, a producer of anthracycline antibiotics galirubins

    International Nuclear Information System (INIS)

    Kralovcova, E.; Blumauerova, M.; Vanek, Z.

    1977-01-01

    The production of epsilon-pyrromycinone glycosides in Streptomyces galilaeus increased 12-fold, with respect to the wild strain, as a result of a sequential procedure including both natural selection and treatment with mutagens (nitrous acid, UV light and γ irradiation). Nitrous acid exhibited the highest mutagenic effect, both in increasing the productivity and in inducing blocked mutants. A mutant strain blocked in the biosynthesis of glycosides and accumulating free epsilon-pyrromycinone as the principal metabolite was obtained. (author)

  5. Identification of a novel DFA I-producing inulin fructotransferase from Streptomyces davawensis.

    Science.gov (United States)

    Zhu, Yingying; Yu, Shuhuai; Huang, Danyang; Zhang, Tao; Jiang, Bo; Mu, Wanmeng

    2016-11-01

    In this work, a novel gene encoding DFA I-forming inulin fructotransferase (IFTase) from Streptomyces davawensis SK39.001 was cloned and expressed in Escherichia coli. The enzyme was purified, identified, and characterized. The results showed that this IFTase (DFA I-forming) is a trimer (molecular weight of 125KDa) consisting of three identical subunits (the molecular weight as assayed by SDS-PAGE was approximately 40KDa). At pH 5.5 and 40°C, the maximum specific activity (approximately 100Umg -1 ) was achieved. Moreover, the enzyme was stable up to 70°C. K m and V max were 2.89±0.2mM and 1.94±0.9mMmin -1 , respectively. For exploring putative active sites and probable catalytic mechanisms, homology modelling and molecular docking methods after site-directed mutagenesis were applied to IFTase (DFA I-forming). The results revealed that D183 and E194 were potential catalytic residues of the purified enzyme. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Plant growth-promoting activities of Streptomyces spp. in sorghum and rice.

    Science.gov (United States)

    Gopalakrishnan, Subramaniam; Srinivas, Vadlamudi; Sree Vidya, Meesala; Rathore, Abhishek

    2013-01-01

    Five strains of Streptomyces (CAI-24, CAI-121, CAI-127, KAI-32 and KAI-90) were earlier reported by us as biological control agents against Fusarium wilt of chickpea caused by Fusarium oxysporum f. sp. ciceri (FOC). In the present study, the Streptomyces were characterized for enzymatic activities, physiological traits and further evaluated in greenhouse and field for their plant growth promotion (PGP) of sorghum and rice. All the Streptomyces produced lipase, β-1-3-glucanase and chitinase (except CAI-121 and CAI-127), grew in NaCl concentrations of up to 6%, at pH values between 5 and 13 and temperatures between 20 and 40°C and were highly sensitive to Thiram, Benlate, Captan, Benomyl and Radonil at field application level. When the Streptomyces were evaluated in the greenhouse on sorghum all the isolates significantly enhanced all the agronomic traits over the control. In the field, on rice, the Streptomyces significantly enhanced stover yield (up to 25%; except CAI-24), grain yield (up to 10%), total dry matter (up to 18%; except CAI-24) and root length, volume and dry weight (up to 15%, 36% and 55%, respectively, except CAI-24) over the control. In the rhizosphere soil, the Streptomyces significantly enhanced microbial biomass carbon (except CAI-24), nitrogen, dehydrogenase (except CAI-24), total N, available P and organic carbon (up to 41%, 52%, 75%, 122%, 53% and 13%, respectively) over the control. This study demonstrates that the selected Streptomyces which were antagonistic to FOC also have PGP properties.

  7. Isothermal crystallization kinetics of isotactic polypropylene with inorganic fullerene-like WS2 nanoparticles

    International Nuclear Information System (INIS)

    Naffakh, Mohammed; Martin, Zulima; Marco, Carlos; Gomez, Marian A.; Jimenez, Ignacio

    2008-01-01

    Nanometric-sized inorganic fullerene-like tungsten disulfide particles (IF-WS 2 ) were used to produce new isotactic polypropylene (iPP) nanocomposites. A remarkable increase of the crystallization rate of iPP in the nanocomposites was observed by DSC and X-ray diffraction techniques using synchrotron radiation. This fact was related to the high nucleation efficiency of IF-WS 2 nanoparticles on the α-form crystals of iPP. Other parameters such as the Avrami exponent, the equilibrium melting temperature, and the fold surface free energy of crystallization of iPP chains in the nanocomposites were obtained from the calorimetric data in order to determine the effect of the nanoparticles on them. A decrease in the fold surface free energy was calculated with increasing IF-WS 2 content

  8. Production of Antimicrobial Agent by Streptomyces violachromogenes

    International Nuclear Information System (INIS)

    Ahmed, Arwa A.

    2007-01-01

    The isolation of antibiotics from microorganisms improved the discovery of novel antibiotics, which is relatively easy as compared to chemical synthesis of antimicrobial agents. This study starts from isolation and purification of the antimicrobial producing Sterptomycetes obtained from soil habitat of Yemen. The good antimicrobial producing Sterptomycetes isolate was selected from a batch of Sterptomycetes isolates then identified. This isolate has bioactivity against some G+ve and G-ve bacteria. The antimicrobial agent isolated from Streptomyces violachromogenes (isolate no.YA118) was extracted with ethyl acetate at pH 3. The residue was applied to a silica gel column chromatography and eluted stepwise with many solvent systems. The active fractions were tested with B. subtilis NCTC10400. The purification of the antibiotic has been carried out by thin layer chromatography then the physical and chemical properties were studied to identify the antimicrobial agent. The isolated antimicrobial agent is an antibiotic belonging to the neomycin group. (author)

  9. [Antibacterial activity of rare Streptomyces species against clinical resistant bacteria].

    Science.gov (United States)

    Boughachiche, Faiza; Reghioua, Sihem; Zerizer, Habiba; Boulahrouf, Abderrahmane

    2012-01-01

    In the search for new antibiotics from Steptomyces, investigating extremes habitats enhances the probability of isolating novel producers. In this context, the antibacterial activity of four Streptomyces strains isolated from Ezzmoul saltpans was studied. Two of them showed antibacterial activity against antibiotic's resistant bacteria (Bacillus cereus: β-lactamines and sulfamides resistant, Streptococcus faecalis: penicillin, tetracycline and cotrimoxazole resistant, and Staphylococcus aureus Mu 50: vancomycine resistant). The most active Streptomyces strain produces one type of polar bioactive molecules that resists to temperature variation and light exposition. Its activity appears in the first culture day and reaches its maximal value in the fourth day. The second strain presents themoresistant activity that reaches its maximal value in the first culture day. It produces two types of bioactive molecules, one is polar and the second is non polar (according to thin layer chromatography technique results).

  10. Elastic properties and electronic structure of WS{sub 2} under pressure from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics; Civil Aviation Flight Univ. of China, Guanghan (China). Dept. of Physics; Zeng, Zhao-Yi [Chongqing Normal Univ., Chongqing (China). College of Physics and Electronic Engineering; Liang, Ting; Tang, Mei; Cheng, Yan [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics

    2017-07-01

    The influence of pressure on the elastic and mechanical properties of the hexagonal transition-metal dichalcogenide WS{sub 2} is investigated using the first-principles calculations. With the increase in pressure, the lattice parameters and the volume of WS{sub 2} decrease, which is exactly in agreement with the available experimental data and other calculated results. The elastic constants C{sub ij}, bulk modulus B, shear modulus G, Young's modulus E, and Poisson's ratio σ of WS{sub 2} also increase with pressure. At last, for the first time, the band gaps of energy, the partial density of states, and the total density of states under three different pressures are obtained and analysed. It is found that the band gap of WS{sub 2} decreases from 0.843 to 0 eV when the external pressure varies from 0 to 20 GPa, which implies that WS{sub 2} may transform from semiconductors to semimetal phase at a pressure about 20 GPa.

  11. A Single Streptomyces Symbiont Makes Multiple Antifungals to Support the Fungus Farming Ant Acromyrmex octospinosus

    Science.gov (United States)

    Seipke, Ryan F.; Barke, Jörg; Brearley, Charles; Hill, Lionel; Yu, Douglas W.; Goss, Rebecca J. M.; Hutchings, Matthew I.

    2011-01-01

    Attine ants are dependent on a cultivated fungus for food and use antibiotics produced by symbiotic Actinobacteria as weedkillers in their fungus gardens. Actinobacterial species belonging to the genera Pseudonocardia, Streptomyces and Amycolatopsis have been isolated from attine ant nests and shown to confer protection against a range of microfungal weeds. In previous work on the higher attine Acromyrmex octospinosus we isolated a Streptomyces strain that produces candicidin, consistent with another report that attine ants use Streptomyces-produced candicidin in their fungiculture. Here we report the genome analysis of this Streptomyces strain and identify multiple antibiotic biosynthetic pathways. We demonstrate, using gene disruptions and mass spectrometry, that this single strain has the capacity to make candicidin and multiple antimycin compounds. Although antimycins have been known for >60 years we report the sequence of the biosynthetic gene cluster for the first time. Crucially, disrupting the candicidin and antimycin gene clusters in the same strain had no effect on bioactivity against a co-evolved nest pathogen called Escovopsis that has been identified in ∼30% of attine ant nests. Since the Streptomyces strain has strong bioactivity against Escovopsis we conclude that it must make additional antifungal(s) to inhibit Escovopsis. However, candicidin and antimycins likely offer protection against other microfungal weeds that infect the attine fungal gardens. Thus, we propose that the selection of this biosynthetically prolific strain from the natural environment provides A. octospinosus with broad spectrum activity against Escovopsis and other microfungal weeds. PMID:21857911

  12. A single Streptomyces symbiont makes multiple antifungals to support the fungus farming ant Acromyrmex octospinosus.

    Directory of Open Access Journals (Sweden)

    Ryan F Seipke

    Full Text Available Attine ants are dependent on a cultivated fungus for food and use antibiotics produced by symbiotic Actinobacteria as weedkillers in their fungus gardens. Actinobacterial species belonging to the genera Pseudonocardia, Streptomyces and Amycolatopsis have been isolated from attine ant nests and shown to confer protection against a range of microfungal weeds. In previous work on the higher attine Acromyrmex octospinosus we isolated a Streptomyces strain that produces candicidin, consistent with another report that attine ants use Streptomyces-produced candicidin in their fungiculture. Here we report the genome analysis of this Streptomyces strain and identify multiple antibiotic biosynthetic pathways. We demonstrate, using gene disruptions and mass spectrometry, that this single strain has the capacity to make candicidin and multiple antimycin compounds. Although antimycins have been known for >60 years we report the sequence of the biosynthetic gene cluster for the first time. Crucially, disrupting the candicidin and antimycin gene clusters in the same strain had no effect on bioactivity against a co-evolved nest pathogen called Escovopsis that has been identified in ∼30% of attine ant nests. Since the Streptomyces strain has strong bioactivity against Escovopsis we conclude that it must make additional antifungal(s to inhibit Escovopsis. However, candicidin and antimycins likely offer protection against other microfungal weeds that infect the attine fungal gardens. Thus, we propose that the selection of this biosynthetically prolific strain from the natural environment provides A. octospinosus with broad spectrum activity against Escovopsis and other microfungal weeds.

  13. Implementing Workflow Reconfiguration in WS-BPEL

    DEFF Research Database (Denmark)

    Mazzara, Manuel; Dragoni, Nicola; Zhou, Mu

    2012-01-01

    This paper investigates the problem of dynamic reconfiguration by means of a workflow-based case study used for discussion. We state the requirements on a system implementing the workflow and its reconfiguration, and we describe the system’s design in BPMN. WS-BPEL, a language that would not natu......This paper investigates the problem of dynamic reconfiguration by means of a workflow-based case study used for discussion. We state the requirements on a system implementing the workflow and its reconfiguration, and we describe the system’s design in BPMN. WS-BPEL, a language that would...... not naturally support dynamic change, is used as a target for implementation. The WS-BPEL recovery framework is here exploited to implement the reconfiguration using principles derived from previous research in process algebra and two mappings from BPMN to WS-BPEL are presented, one automatic and only mostly...

  14. The adnAB Locus, Encoding a Putative Helicase-Nuclease Activity, Is Essential in Streptomyces

    Science.gov (United States)

    Zhang, Lingli; Nguyen, Hoang Chuong; Chipot, Ludovic; Piotrowski, Emilie; Bertrand, Claire

    2014-01-01

    Homologous recombination is a crucial mechanism that repairs a wide range of DNA lesions, including the most deleterious ones, double-strand breaks (DSBs). This multistep process is initiated by the resection of the broken DNA ends by a multisubunit helicase-nuclease complex exemplified by Escherichia coli RecBCD, Bacillus subtilis AddAB, and newly discovered Mycobacterium tuberculosis AdnAB. Here we show that in Streptomyces, neither recBCD nor addAB homologues could be detected. The only putative helicase-nuclease-encoding genes identified were homologous to M. tuberculosis adnAB genes. These genes are conserved as a single copy in all sequenced genomes of Streptomyces. The disruption of adnAB in Streptomyces ambofaciens and Streptomyces coelicolor could not be achieved unless an ectopic copy was provided, indicating that adnAB is essential for growth. Both adnA and adnB genes were shown to be inducible in response to DNA damage (mitomycin C) and to be independently transcribed. Introduction of S. ambofaciens adnAB genes in an E. coli recB mutant restored viability and resistance to UV light, suggesting that Streptomyces AdnAB could be a functional homologue of RecBCD and be involved in DNA damage resistance. PMID:24837284

  15. Characterization of the Deep-Sea Streptomyces sp. SCSIO 02999 Derived VapC/VapB Toxin-Antitoxin System in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Yunxue Guo

    2016-07-01

    Full Text Available Toxin-antitoxin (TA systems are small genetic elements that are ubiquitous in prokaryotes. Most studies on TA systems have focused on commensal and pathogenic bacteria; yet very few studies have focused on TAs in marine bacteria, especially those isolated from a deep sea environment. Here, we characterized a type II VapC/VapB TA system from the deep-sea derived Streptomyces sp. SCSIO 02999. The VapC (virulence-associated protein protein belongs to the PIN (PilT N-terminal superfamily. Overproduction of VapC strongly inhibited cell growth and resulted in a bleb-containing morphology in E. coli. The toxicity of VapC was neutralized through direct protein–protein interaction by a small protein antitoxin VapB encoded by a neighboring gene. Antitoxin VapB alone or the VapB/VapC complex negatively regulated the vapBC promoter activity. We further revealed that three conserved Asp residues in the PIN domain were essential for the toxic effect of VapC. Additionally, the VapC/VapB TA system stabilized plasmid in E. coli. Furthermore, VapC cross-activated transcription of several TA operons via a partially Lon-dependent mechanism in E. coli, and the activated toxins accumulated more preferentially than their antitoxin partners. Collectively, we identified and characterized a new deep sea TA system in the deep sea Streptomyces sp. and demonstrated that the VapC toxin in this system can cross-activate TA operons in E. coli.

  16. Characterization of the Deep-Sea Streptomyces sp. SCSIO 02999 Derived VapC/VapB Toxin-Antitoxin System in Escherichia coli.

    Science.gov (United States)

    Guo, Yunxue; Yao, Jianyun; Sun, Chenglong; Wen, Zhongling; Wang, Xiaoxue

    2016-07-01

    Toxin-antitoxin (TA) systems are small genetic elements that are ubiquitous in prokaryotes. Most studies on TA systems have focused on commensal and pathogenic bacteria; yet very few studies have focused on TAs in marine bacteria, especially those isolated from a deep sea environment. Here, we characterized a type II VapC/VapB TA system from the deep-sea derived Streptomyces sp. SCSIO 02999. The VapC (virulence-associated protein) protein belongs to the PIN (PilT N-terminal) superfamily. Overproduction of VapC strongly inhibited cell growth and resulted in a bleb-containing morphology in E. coli. The toxicity of VapC was neutralized through direct protein-protein interaction by a small protein antitoxin VapB encoded by a neighboring gene. Antitoxin VapB alone or the VapB/VapC complex negatively regulated the vapBC promoter activity. We further revealed that three conserved Asp residues in the PIN domain were essential for the toxic effect of VapC. Additionally, the VapC/VapB TA system stabilized plasmid in E. coli. Furthermore, VapC cross-activated transcription of several TA operons via a partially Lon-dependent mechanism in E. coli, and the activated toxins accumulated more preferentially than their antitoxin partners. Collectively, we identified and characterized a new deep sea TA system in the deep sea Streptomyces sp. and demonstrated that the VapC toxin in this system can cross-activate TA operons in E. coli.

  17. Determination of optimal conditions of oxytetracyclin production from streptomyces rimosus; Optimisation de la production de l'oxytetracycline par Streptomyces rimosus

    Energy Technology Data Exchange (ETDEWEB)

    Zouaghi, Atef [Institut National des Sciences Appliquees et de Technologie (Tunisia)

    2007-07-01

    Streptomyces rimosus is an oxytetracycline (OTC) antibiotic producing bacteria that exhibited activities against gram positive and negative bacteria. OTC is used widely not only in medicine but also in production industry. The antibiotic production of streptomyces covers a very wide range of condition. However, antibiotic producers are particularly fastidious cultivated by proper selection of media such as carbon source. In present study we have optimised conditions of OTC production (Composition of production media, p H, shaking and temperature). The results have been shown that bran barley is the optimal media for OTC production at 28C pH5.8 at 150rpm for 5 days. For antibiotic determination, OTC was extracted with different organic solvent. Thin-layer chromatography system was used for separation and identification of OTC antibiotic. High performance liquid chromatographic (HPLC) method with ultraviolet detection for the analysis of OTC is applied to the determination of OTC purification. (Author). 24 refs.

  18. Preparation and Characterization of WS2@SiO2 and WS2@PANI Core-Shell Nanocomposites

    Directory of Open Access Journals (Sweden)

    Hagit Sade

    2018-03-01

    Full Text Available Two tungsten disulfide (WS2-based core-shell nanocomposites were fabricated using readily available reagents and simple procedures. The surface was pre-treated with a surfactant couple in a layer-by-layer approach, enabling good dispersion of the WS2 nanostructures in aqueous media and providing a template for the polymerization of a silica (SiO2 shell. After a Stöber-like reaction, a conformal silica coating was achieved. Inspired by the resulting nanocomposite, a second one was prepared by reacting the surfactant-modified WS2 nanostructures with aniline and an oxidizing agent in an aqueous medium. Here too, a conformal coating of polyaniline (PANI was obtained, giving a WS2@PANI nanocomposite. Both nanocomposites were analyzed by electron microscopy, energy dispersive X-ray spectroscopy (EDS and FTIR, verifying the core-shell structure and the character of shells. The silica shell was amorphous and mesoporous and the surface area of the composite increases with shell thickness. Polyaniline shells slightly differ in their morphologies dependent on the acid used in the polymerization process and are amorphous like the silica shell. Electron paramagnetic resonance (EPR spectroscopy of the WS2@PANI nanocomposite showed variation between bulk PANI and the PANI shell. These two nanocomposites have great potential to expand the use of transition metals dichalcogenides (TMDCs for new applications in different fields.

  19. Biosynthesis of quinoxaline antibiotics: Purification and characterization of the quinoxaline-2-carboxylic acid activating enzyme from Streptomyces triostinicus

    International Nuclear Information System (INIS)

    Glund, K.; Schlumbohm, W.; Bapat, M.; Keller, U.

    1990-01-01

    A quinoxaline-2-carboxylic acid activating enzyme was purified to homogeneity from triostin-producing Streptomyces triostinicus. It could also be purified from quinomycin-producing Streptomyces echinatus. Triostins and quinomycins are peptide lactones that contain quinoxaline-2-carboxylic acid as chromophoric moiety. The enzyme catalyzes the ATP-pyrophosphate exchange reaction dependent on quinoxaline-2-carboxylic acid and the formation of the corresponding adenylate. Besides quinoxaline-2-carboxylic acid, the enzyme also catalyzes the formation of adenylates from quinoline-2-carboxylic acid and thieno[3,2-b]pyridine-5-carboxylic acid. No adenylates were seen from quinoline-3-carboxylic acid, quinoline-4-carboxylic acid, pyridine-2-carboxylic acid, and 2-pyrazinecarboxylic acid. Previous work revealed that quinoline-2-carboxylic acid and thieno[3,2-b]pyridine-5-carboxylic acid became efficiently incorporated into the corresponding quinoxaline antibiotic analogues in vivo. Together with the data described here, this suggests that the enzyme is part of the quinoxaline antibiotics synthesizing enzyme system. The enzyme displays a native molecular weight of 42,000, whereas in its denatured form it is a polypeptide of Mr 52,000-53,000. It resembles in its behavior actinomycin synthetase I, the chromophore activating enzyme involved in actinomycin biosynthesis

  20. All-optical phase shifter and switch near 1550nm using tungsten disulfide (WS2) deposited tapered fiber.

    Science.gov (United States)

    Wu, Kan; Guo, Chaoshi; Wang, Hao; Zhang, Xiaoyan; Wang, Jun; Chen, Jianping

    2017-07-24

    All-optical phase shifters and switches play an important role for various all-optical applications including all-optical signal processing, sensing and communication. In this paper, we demonstrate a fiber all-optical phase shifter using few-layer 2D material tungsten disulfide (WS 2 ) deposited on a tapered fiber. WS 2 absorbs injected 980 nm pump (control light) and generates heat, which changes the refractive index of both WS 2 and tapered fiber due to thermo-optic effect and achieves a maximum phase shift of 6.1π near 1550 nm. The device has a loss of 3.7 dB. By constructing a Mach-Zehnder interferometer with WS 2 based phase shifter in one arm, an all-optical switch is also obtained with an extinction ratio of 15 dB and a rise time of 7.3 ms. This all fiber low-cost and compact optical phase shifter and switch demonstrates the potential of 2D transition metal dichalcogenides for all-optical signal processing devices.

  1. Ab-initio study of structural and electronic properties of WS2/h-BN van der Waals heterostructure

    Science.gov (United States)

    Ghasemi majd, Zahra; Amiri, Peiman; Taghizadeh, Seyed Fardin

    2018-06-01

    First-principle calculations with different exchange-correlation functionals, including LDA, GGA, semi-empirical and ab-initio van der Waals in the forms of vdW-DF2B86R and vdW-DF2 were performed to evaluate the performance of different functionals in describing the bonding mechanism, adsorption energy and interlayer distance of WS2 monolayer on and between h-BN layers. The finding was that the vdW-DF2B86R seems to be the approach best lending itself to this purpose. In order to include the van der Waals (vdW) interactions in our calculations, we used the DFT-D2 and vdW methods, which gave rise to a physical adsorption with no net charge transfer between the WS2 layer and the corresponding substrates. In addition, we investigated the electronic and structural properties of WS2 and h-BN heterolayers, using vdW-DF2B86R functional. Based on density functional theory calculations, WS2 on and between h-BN layers showed a direct band gap at the K-point, which was experimentally observed.

  2. Colonization of wild potato plants by Streptomyces scabies

    Science.gov (United States)

    The bacterial pathogen Streptomyces scabies produces lesions on potato tubers, reducing their marketability and profitability. M6 and 524-8 are two closely related inbred diploid lines of the wild potato species Solanum chacoense. After testing in both field and greenhouse assays, it was found that ...

  3. Waste to wealth: Production of oxytetracycline using streptomyces ...

    African Journals Online (AJOL)

    The production of oxytetracycline by Streptomyces speibonae OXS1 in solid-state fermentation from cocoyam peels (household kitchen wastes of agricultural produce) was investigated. The proximate analyses of peels of the two cocoyam species showed that Colocasia esculenta had higher protein (1.39%) and fibre ...

  4. The MreB-like protein Mbl of Streptomyces coelicolor A3(2) depends on MreB for proper localization and contributes to spore wall synthesis.

    Science.gov (United States)

    Heichlinger, Andrea; Ammelburg, Moritz; Kleinschnitz, Eva-Maria; Latus, Annette; Maldener, Iris; Flärdh, Klas; Wohlleben, Wolfgang; Muth, Günther

    2011-04-01

    Most bacteria with a rod-shaped morphology contain an actin-like cytoskeleton consisting of MreB polymers, which form helical spirals underneath the cytoplasmic membrane to direct peptidoglycan synthesis for the elongation of the cell wall. In contrast, MreB of Streptomyces coelicolor is not required for vegetative growth but has a role in sporulation. Besides MreB, S. coelicolor encodes two further MreB-like proteins, Mbl and SCO6166, whose function is unknown. Whereas MreB and Mbl are highly similar, SCO6166 is shorter, lacking the subdomains IB and IIB of actin-like proteins. Here, we showed that MreB and Mbl are not functionally redundant but cooperate in spore wall synthesis. Expression analysis by semiquantitative reverse transcription-PCR revealed distinct expression patterns. mreB and mbl are induced predominantly during morphological differentiation. In contrast, sco6166 is strongly expressed during vegetative growth but switched off during sporulation. All genes could be deleted without affecting viability. Even a ΔmreB Δmbl double mutant was viable. Δsco6166 had a wild-type phenotype. ΔmreB, Δmbl, and ΔmreB Δmbl produced swollen, prematurely germinating spores that were sensitive to various kinds of stress, suggesting a defect in spore wall integrity. During aerial mycelium formation, an Mbl-mCherry fusion protein colocalized with an MreB-enhanced green fluorescent protein (MreB-eGFP) fusion protein at the sporulation septa. Whereas MreB-eGFP localized properly in the Δmbl mutant, Mbl-mCherry localization depended on the presence of a functional MreB protein. Our results revealed that MreB and Mbl cooperate in the synthesis of the thickened spore wall, while SCO6166 has a nonessential function during vegetative growth.

  5. Anomalous behavior of the excited state of the A exciton in bulk WS2

    DEFF Research Database (Denmark)

    Jindal, Vishwas; Bhuyan, Sumi; Deilmann, Thorsten

    2018-01-01

    Results of optical spectroscopy studies on bulk 2H-WS2 at energies close to its direct band gap are presented. Reflectance and absorption measurements at low temperature show only one dominant feature due to the A exciton of bulk WS2 at similar to 2.02 eV. However, a laser-modulated photoreflecta......Results of optical spectroscopy studies on bulk 2H-WS2 at energies close to its direct band gap are presented. Reflectance and absorption measurements at low temperature show only one dominant feature due to the A exciton of bulk WS2 at similar to 2.02 eV. However, a laser....... The experimental results are analyzed by comparison with many-body perturbation theory calculations, including the solutions of the Bethe-Salpeter equation. A* is identified as the first excited state of the A exciton, that is, A(n = 2). The anomalous behavior of A* is explained by its distinct wave function...... spread along the c axis, the direction of weak van der Waals bonding, which makes it more susceptible to perturbations. Our ab initio calculations suggest that the A exciton in the ground state has a two-dimensional (2D) nature with a large binding energy E-b, in fair agreement with E-b similar to 90...

  6. Streptomyces plicatus as a model biocontrol agent.

    Science.gov (United States)

    Abd-Allah, E F

    2001-01-01

    Three hundred and seventy two isolates belonging to the genus Streptomyces were isolated and screened for chitinase production. Streptomyces plicatus was found to be the best producer. The highest chitinase production were incubated for 3 d at 30 degrees C on buffered culture medium (pH 8.0) containing chitin plus sucrose and calcium nitrate as carbon and nitrogen sources. S. plicatus chitinase had a highly significant inhibitory effect on spore germination, germ tube elongation and radial growth of Fusarium oxysporum f.sp. lycopersici, Altrernaria alternata and Verticillium albo-atrum, the causal organisms of Fusarium wilt, stem canker and Verticillium wilt diseases of tomato. Application of S. plicatus to the root system of tomato plants before transplantation markedly protected tomato plants against the tested phytopathogenic fungi in vivo.

  7. Sc-Decorated WS_2 Nanoribbons as Hydrogen Storage Media

    International Nuclear Information System (INIS)

    Xu Bin; Wang Yu-Sheng; Zhang Jing; Song Na-Hong; Li Meng; Yi Lin

    2016-01-01

    The hydrogen storage behavior of Sc-decorated WS_2 monolayer and WS_2 nanoribbons is systematically studied by using first principles calculations based on the density functional theory. The present results indicate that an Sc-decorated WS_2 monolayer is not suitable for storing hydrogen due to the weak interaction between the monolayer WS_2 sheet and the Sc atoms. It is found that both the hybridization mechanism and the Coulomb attraction make the Sc atoms stably adsorb on the edges of WS_2 nanoribbons without clustering. The 2Sc/WS_2 NRs system can adsorb at most eight H_2 molecules with average adsorption energy of 0.20 eV/H_2. The results show that the desorption of H_2 is possible by lowering the pressure or by increasing the temperature. (paper)

  8. Dependable Workflow Reconfiguration in WS-BPEL

    DEFF Research Database (Denmark)

    Mazzara, Manuel; Dragoni, Nicola; Zhou, Mu

    2011-01-01

    This paper describes a work ow reconguration and how to implement it in WS-BPEL, a language that would not naturally support reconguration. We state the requirements on a system implementing the work ow and its reconguration, and we describe the system's de- sign in BPMN. The WS-BPEL recovery...

  9. Efficient utilization of xylanase and lipase producing thermophilic ...

    African Journals Online (AJOL)

    Efficient utilization of xylanase and lipase producing thermophilic marine actinomycetes ( Streptomyces albus and Streptomyces hygroscopicus ) in the production of ecofriendly alternative energy from waste.

  10. Genome Mining of the Marine Actinomycete Streptomyces sp. DUT11 and Discovery of Tunicamycins as Anti-complement Agents

    Directory of Open Access Journals (Sweden)

    Xiao-Na Xu

    2018-06-01

    Full Text Available Marine actinobacteria are potential producers of various secondary metabolites with diverse bioactivities. Among various bioactive compounds, anti-complement agents have received great interest for drug discovery to treat numerous diseases caused by inappropriate activation of the human complement system. However, marine streptomycetes producing anti-complement agents are still poorly explored. In this study, a marine-derived strain Streptomyces sp. DUT11 showing superior anti-complement activity was focused, and its genome sequence was analyzed. Gene clusters showing high similarities to that of tunicamycin and nonactin were identified, and their corresponding metabolites were also detected. Subsequently, tunicamycin I, V, and VII were isolated from Streptomyces sp. DUT11. Anti-complement assay showed that tunicamycin I, V, VII inhibited complement activation through the classic pathway, whereas no anti-complement activity of nonactin was detected. This is the first time that tunicamycins are reported to have such activity. In addition, genome analysis indicates that Streptomyces sp. DUT11 has the potential to produce novel lassopeptides and lantibiotics. These results suggest that marine Streptomyces are rich sources of anti-complement agents for drug discovery.

  11. Antibacterial studies of novel Cu2WS4 ternary chalcogenide synthesized by hydrothermal process

    Science.gov (United States)

    Kannan, Selvaraj; Vinitha, Perumal; Mohanraj, Kannusamy; Sivakumar, Ganesan

    2018-02-01

    This is the first report for the synthesis of L-cysteine mediated Cu2WS4 nanoparticles for different temperatures by an inexpensive and less pollutive hydrothermal method. The as-synthesized particles were characterized by XRD, FTIR, FESEM, UV-vis diffuse reflectance and PL spectra technique respectively. The phase purity and structural confirmation were studied by X-ray powder diffraction technique. It is observed that the synthesis temperature affecting the crystalline size. The optical analysis of the Cu2WS4 nanoparticles showed direct band gap in the range of 2.1-2.3 eV. The intensity of the PL emission spectra decreases with increase of reaction temperature. The antibacterial performance of Cu2WS4 nanoparticles were investigated by agar well diffusion method and the results confirm that the antibacterial activity of Cu2WS4 against Gram-positive (B. subtilis, M. luteus) and Gram-negative (E. coli, P. aeruginosa and K. pneumoniae) bacteria.

  12. Defense responses in plants of Eucalyptus elicited by Streptomyces and challenged with Botrytis cinerea.

    Science.gov (United States)

    Salla, Tamiris D; Astarita, Leandro V; Santarém, Eliane R

    2016-04-01

    Elicitation of E. grandis plants with Streptomyces PM9 reduced the gray-mold disease, through increasing the levels of enzymes directly related to the induction of plant defense responses, and accumulation of specific phenolic compounds. Members of Eucalyptus are economically important woody species, especially as a raw material in many industrial sectors. Species of this genus are susceptible to pathogens such as Botrytis cinerea (gray mold). Biological control of plant diseases using rhizobacteria is one alternative to reduce the use of pesticides and pathogen attack. This study evaluated the metabolic and phenotypic responses of Eucalyptus grandis and E. globulus plants treated with Streptomyces sp. PM9 and challenged with the pathogenic fungus B. cinerea. Metabolic responses were evaluated by assessing the activities of the enzymes polyphenol oxidase and peroxidase as well as the levels of phenolic compounds and flavonoids. The incidence and progression of the fungal disease in PM9-treated plants and challenged with B. cinerea were evaluated. Treatment with Streptomyces sp. PM9 and challenge with B. cinerea led to changes in the activities of polyphenol oxidase and peroxidase as well as in the levels of phenolic compounds in the plants at different time points. Alterations in enzymes of PM9-treated plants were related to early defense responses in E. grandis. Gallic and chlorogenic acids were on average more abundant, although caffeic acid, benzoic acid and catechin were induced at specific time points during the culture period. Treatment with Streptomyces sp. PM9 significantly delayed the establishment of gray mold in E. grandis plants. These results demonstrate the action of Streptomyces sp. PM9 in inducing plant responses against B. cinerea, making this organism a potential candidate for biological control in Eucalyptus.

  13. Scopranones with Two Atypical Scooplike Moieties Produced by Streptomyces sp. BYK-11038.

    Science.gov (United States)

    Uchida, Ryuji; Lee, Daiki; Suwa, Ibuki; Ohtawa, Masaki; Watanabe, Nozomu; Demachi, Ayumu; Ohte, Satoshi; Katagiri, Takenobu; Nagamitsu, Tohru; Tomoda, Hiroshi

    2017-11-03

    Three new compounds, designated scopranones A-C, were isolated from the culture broth of a soil isolate, Streptomyces sp. BYK-11038, and shown to be inhibitors of bone morphogenetic protein (BMP) induced alkaline phosphatase activity in a BMP receptor mutant cell line. The structures were elucidated using NMR and other spectral data. The scopranones have an unusual structure with two atypical scooplike moieties linked at the tails to form part of a unique 3-furanone ring.

  14. Isolation and characterization of bioactive metabolites producing marine Streptomyces parvulus strain sankarensis-A10

    Directory of Open Access Journals (Sweden)

    Mobeen Shaik

    2017-06-01

    Full Text Available The significance and frequency of marine microorganisms as producers of bioactive metabolites-a natural source of drug discovery had varied significantly during the last decades, making marine ecosystem a huge treasure trove of novel isolates and novel compounds. Among the twelve actinomycetes isolated from marine sediment sample (Lat. 17°41′962″N, Long. 83°19′633″E, amylase, protease, lipase and cellulase activities were exhibited by 8,7,4,3 isolates respectively. Five isolates exhibited l-asparaginase activity, while 5, 6, 2 isolates exhibited antibacterial, antifungal and antimicrobial activities respectively. One isolate VMS-A10 efficiently producing alpha-amylase (25.53 ± 0.50 U/mL, protease (19.26 ± 0.25 U/mL, lipase (36.25 ± 0.10 U/mL, cellulase (14.43 ± 0.513 U/mL, l-asparaginase (0.125 ± 0.004 U/mL, antimicrobial metabolites against B. subtilis (503.33 ± 5.77 U/mL, S. aureus (536.66 ± 5.77 U/mL, E. coli (533.33 ± 5.77 U/mL, P. aeruginosa (500.00 ± 10.0 U/mL, MRSA (538.33 ± 5.77 U/mL, C. albicans (353.33 ± 11.54 U/mL and A. niger (443.33 ± 15.27 U/mL was selected, identified on the basis of morphological, cultural, physiological, and biochemical properties together with 16S rDNA sequence, designated as Streptomyces parvulus strain sankarensis-A10 and sequencing product (1490 bp was deposited in the GenBank database under accession number KT906299, Culture Deposit No: NCIM-5601. Isolation and characterization of each potential actinobacteria having immense industrial and therapeutic value on an unprecedented scale from marine sediments of Visakhapatnam coast will have a burgeoning effect.

  15. Identification and analysis of the paulomycin biosynthetic gene cluster and titer improvement of the paulomycins in Streptomyces paulus NRRL 8115.

    Directory of Open Access Journals (Sweden)

    Jine Li

    Full Text Available The paulomycins are a group of glycosylated compounds featuring a unique paulic acid moiety. To locate their biosynthetic gene clusters, the genomes of two paulomycin producers, Streptomyces paulus NRRL 8115 and Streptomyces sp. YN86, were sequenced. The paulomycin biosynthetic gene clusters were defined by comparative analyses of the two genomes together with the genome of the third paulomycin producer Streptomyces albus J1074. Subsequently, the identity of the paulomycin biosynthetic gene cluster was confirmed by inactivation of two genes involved in biosynthesis of the paulomycose branched chain (pau11 and the ring A moiety (pau18 in Streptomyces paulus NRRL 8115. After determining the gene cluster boundaries, a convergent biosynthetic model was proposed for paulomycin based on the deduced functions of the pau genes. Finally, a paulomycin high-producing strain was constructed by expressing an activator-encoding gene (pau13 in S. paulus, setting the stage for future investigations.

  16. Photocatalytic and electrochemical performance of three-Dimensional reduced graphene Oxide/WS{sub 2}/Mg-doped ZnO composites

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Weiwei [College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410114 (China); Chen, Xi’an [Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, 325027 (China); Mei, Wei [College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410114 (China); Chen, Chuansheng, E-mail: 1666423158@qq.com [College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410114 (China); Tsang, Yuenhong [Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, 999077 (China)

    2017-04-01

    Highlights: • 3D graphene oxide/WS{sub 2}/Mg-doped ZnO composites were prepared by electrostatic self-assembly and coprecipitation methods. • A significant photocatalytic activity enhancement of rGWMZ was observed. • The enhancement for photocatalytic activity is ascribed to the synergistic effect of rGO and WS{sub 2} nanosheets. - Abstract: To improve the dispersion of reduced graphene oxide and enhance the photocatalytic property of reduced graphene oxide/Mg-doped ZnO composites (rGMZ), the reduced graphene oxide/WS{sub 2}/Mg-doped ZnO composites (rGWMZ) were prepared by electrostatic self-assembly and coprecipitation methods. The effects of mass ratio of WS{sub 2} nanosheets to reduced graphene oxide (WS{sub 2}/rGO wt.%) and calcination temperature on the photocatalytic and electrochemical property of rGWMZ composites were investigated. Experimental results showed that the photocatalytic efficiency of rGWMZ composites is three-fold compared with that of rGMZ composites when the WS{sub 2}/rGO wt.% is 20.8% and calcination temperature is 500 °C, in which the degradation ratio Rhodamin B (RhB) can reach 95% within 15 min under the UV light and 90% within 90 min under simulated solar light. In addition, the rGWMZ show larger capacitance and smaller resistance than rGMZ. The enhancement for photocatalytic activity and electrochemical performance of rGWMZ is ascribed to improving the specific surface area, electrical conductivity and electronic storage capability because of the synergistic effect of rGO and WS{sub 2} nanosheets.

  17. Partial characterization of cold active amylases and proteases of Streptomyces sp. from Antarctica

    Directory of Open Access Journals (Sweden)

    Mihaela Cotârleţ

    2011-09-01

    Full Text Available The aim of this study was to isolate novel enzyme-producing bacteria from vegetation samples from East Antarctica and also to characterize them genetically and biochemically in order to establish their phylogeny. The ability to grow at low temperature and to produce amylases and proteases cold-active was also tested. The results of the 16S rRNA gene sequence analysis showed that the 4 Alga rRNA was 100% identical to the sequences of Streptomyces sp. rRNA from Norway and from the Solomon Islands. The Streptomyces grew well in submerged system at 20ºC, cells multiplication up to stationary phase being drastically increased after 120 h of submerged cultivation. The beta-amylase production reached a maximum peak after seven days, while alpha-amylase and proteases were performing biosynthesis after nine days of submerged cultivation at 20ºC. Newly Streptomyces were able to produce amylase and proteases in a cold environment. The ability to adapt to low temperature of these enzymes could make them valuable ingredients for detergents, the food industry and bioremediation processes which require low temperatures.

  18. Bioremediation of acid fast red dye by Streptomyces globosus under ...

    African Journals Online (AJOL)

    Two different azo dyes known as acid fast red (AFR) and Congo red (CR) were examined for their decolorization by five strains of actinomycetes (Streptomyces globosus, Streptomyces alanosinicus, Streptomyces ruber, Streptomyces gancidicus, and Nocardiopsis aegyptia) under shake and static conditions. Streptomyces ...

  19. The MreB-Like Protein Mbl of Streptomyces coelicolor A3(2) Depends on MreB for Proper Localization and Contributes to Spore Wall Synthesis▿ †

    Science.gov (United States)

    Heichlinger, Andrea; Ammelburg, Moritz; Kleinschnitz, Eva-Maria; Latus, Annette; Maldener, Iris; Flärdh, Klas; Wohlleben, Wolfgang; Muth, Günther

    2011-01-01

    Most bacteria with a rod-shaped morphology contain an actin-like cytoskeleton consisting of MreB polymers, which form helical spirals underneath the cytoplasmic membrane to direct peptidoglycan synthesis for the elongation of the cell wall. In contrast, MreB of Streptomyces coelicolor is not required for vegetative growth but has a role in sporulation. Besides MreB, S. coelicolor encodes two further MreB-like proteins, Mbl and SCO6166, whose function is unknown. Whereas MreB and Mbl are highly similar, SCO6166 is shorter, lacking the subdomains IB and IIB of actin-like proteins. Here, we showed that MreB and Mbl are not functionally redundant but cooperate in spore wall synthesis. Expression analysis by semiquantitative reverse transcription-PCR revealed distinct expression patterns. mreB and mbl are induced predominantly during morphological differentiation. In contrast, sco6166 is strongly expressed during vegetative growth but switched off during sporulation. All genes could be deleted without affecting viability. Even a ΔmreB Δmbl double mutant was viable. Δsco6166 had a wild-type phenotype. ΔmreB, Δmbl, and ΔmreB Δmbl produced swollen, prematurely germinating spores that were sensitive to various kinds of stress, suggesting a defect in spore wall integrity. During aerial mycelium formation, an Mbl-mCherry fusion protein colocalized with an MreB-enhanced green fluorescent protein (MreB-eGFP) fusion protein at the sporulation septa. Whereas MreB-eGFP localized properly in the Δmbl mutant, Mbl-mCherry localization depended on the presence of a functional MreB protein. Our results revealed that MreB and Mbl cooperate in the synthesis of the thickened spore wall, while SCO6166 has a nonessential function during vegetative growth. PMID:21257777

  20. First-principle study of single TM atoms X (X=Fe, Ru or Os) doped monolayer WS2 systems

    Science.gov (United States)

    Zhu, Yuan-Yan; Zhang, Jian-Min

    2018-05-01

    We report the structural, magnetic and electronic properties of the pristine and single TM atoms X (X = Fe, Ru or Os) doped monolayer WS2 systems based on first-principle calculations. The results show that the W-S bond shows a stronger covalent bond, but the covalency is obviously weakened after the substitution of W atom with single X atoms, especially for Ru (4d75s1) with the easily lost electronic configuration. The smaller total energies of the doped systems reveal that the spin-polarized states are energetically favorable than the non-spin-polarized states, and the smallest total energy of -373.918 eV shows the spin-polarized state of the Os doped monolayer WS2 system is most stable among three doped systems. In addition, although the pristine monolayer WS2 system is a nonmagnetic-semiconductor with a direct band gap of 1.813 eV, single TM atoms Fe and Ru doped monolayer WS2 systems transfer to magnetic-HM with the total moments Mtot of 1.993 and 1.962 μB , while single TM atom Os doped monolayer WS2 systems changes to magnetic-metal with the total moments Mtot of 1.569 μB . Moreover, the impurity states with a positive spin splitting energies of 0.543, 0.276 and 0.1999 eV near the Fermi level EF are mainly contributed by X-dxy and X-dx2-y2 states hybridized with its nearest-neighbor atom W-dz2 states for Fe, Ru and Os doped monolayer WS2 system, respectively. Finally, we hope that the present study on monolayer WS2 will provide a useful theoretical guideline for exploring low-dimensional spintronic materials in future experiments.

  1. Overproduction of lactimidomycin by cross-overexpression of genes encoding Streptomyces antibiotic regulatory proteins.

    Science.gov (United States)

    Zhang, Bo; Yang, Dong; Yan, Yijun; Pan, Guohui; Xiang, Wensheng; Shen, Ben

    2016-03-01

    The glutarimide-containing polyketides represent a fascinating class of natural products that exhibit a multitude of biological activities. We have recently cloned and sequenced the biosynthetic gene clusters for three members of the glutarimide-containing polyketides-iso-migrastatin (iso-MGS) from Streptomyces platensis NRRL 18993, lactimidomycin (LTM) from Streptomyces amphibiosporus ATCC 53964, and cycloheximide (CHX) from Streptomyces sp. YIM56141. Comparative analysis of the three clusters identified mgsA and chxA, from the mgs and chx gene clusters, respectively, that were predicted to encode the PimR-like Streptomyces antibiotic regulatory proteins (SARPs) but failed to reveal any regulatory gene from the ltm gene cluster. Overexpression of mgsA or chxA in S. platensis NRRL 18993, Streptomyces sp. YIM56141 or SB11024, and a recombinant strain of Streptomyces coelicolor M145 carrying the intact mgs gene cluster has no significant effect on iso-MGS or CHX production, suggesting that MgsA or ChxA regulation may not be rate-limiting for iso-MGS and CHX production in these producers. In contrast, overexpression of mgsA or chxA in S. amphibiosporus ATCC 53964 resulted in a significant increase in LTM production, with LTM titer reaching 106 mg/L, which is five-fold higher than that of the wild-type strain. These results support MgsA and ChxA as members of the SARP family of positive regulators for the iso-MGS and CHX biosynthetic machinery and demonstrate the feasibility to improve glutarimide-containing polyketide production in Streptomyces strains by exploiting common regulators.

  2. Improvement of FK506 Production in the High-Yielding Strain Streptomyces sp. RM7011 by Engineering the Supply of Allylmalonyl-CoA Through a Combination of Genetic and Chemical Approach.

    Science.gov (United States)

    Mo, SangJoon; Lee, Sung-Kwon; Jin, Ying-Yu; Suh, Joo-Won

    2016-02-01

    FK506, a widely used immunosuppressant, is a 23-membered polyketide macrolide that is produced by several Streptomyces species. FK506 high-yielding strain Streptomyces sp. RM7011 was developed from the discovered Streptomyces sp. KCCM 11116P by random mutagenesis in our previous study. The results of transcript expression analysis showed that the transcription levels of tcsA, B, C, and D were increased in Streptomyces sp. RM7011 by 2.1-, 3.1-, 3.3-, and 4.1- fold, respectively, compared with Streptomyces sp. KCCM 11116P. The overexpression of tcsABCD genes in Streptomyces sp. RM7011 gave rise to approximately 2.5-fold (238.1 μg/ml) increase in the level of FK506 production compared with that of Streptomyces sp. RM7011. When vinyl pentanoate was added into the culture broth of Streptomyces sp. RM7011, the level of FK506 production was approximately 2.2-fold (207.7 μg/ml) higher than that of the unsupplemented fermentation. Furthermore, supplementing the culture broth of Streptomyces sp. RM7011 expressing tcsABCD genes with vinyl pentanoate resulted in an additional 1.7-fold improvement in the FK506 titer (498.1 μg/ml) compared with that observed under nonsupplemented condition. Overall, the level of FK506 production was increased approximately 5.2-fold by engineering the supply of allylmalonyl-CoA in the high-yielding strain Streptomyces sp. RM7011, using a combination of overexpressing tcsABCD genes and adding vinyl pentanoate, as compared with Streptomyces sp. RM7011 (95.3 μg/ml). Moreover, among the three precursors analyzed, pentanoate was the most effective precursor, supporting the highest titer of FK506 in the FK506 high-yielding strain Streptomyces sp. RM7011.

  3. A biotransformation process for the production of cucurbitacin B from its glycoside using a selected Streptomyces sp.

    Science.gov (United States)

    Mei, Jianfeng; Li, Sha; Jin, Hang; Tang, Lan; Yi, Yu; Wang, Hong; Ying, Guoqing

    2016-09-01

    Cucurbitacin B (CuB) and its glycoside, cucurbitacin B 2-o-β-D-glucoside (CuBg), abundantly occur in the pedicels of Cucumis melo. Compared with CuB, CuBg is not efficiently extracted from the pedicels. Furthermore, the anticancer activity of CuBg is lower than that of the aglycone. A process for CuBg biotransformation to CuB was developed for the first time. A strain of Streptomyces species that converts CuBg into CuB was isolated from an enrichment culture of C. melo pedicels. After optimization of conditions for enzyme production and biotransformation, a maximum conversion rate of 92.6 % was obtained at a CuBg concentration of 0.25 g/L. When biotransformation was performed on C. melo pedicel extracts, the CuB concentration in the extracts increased from 1.50 to 3.27 g/L. The conversion rate was almost 100 %. The developed process may be an effective biotransformation method for industrial production CuB from C. melo pedicels for pharmaceuticals.

  4. Analysis and optimization of triacylglycerol synthesis in novel oleaginous Rhodococcus and Streptomyces strains isolated from desert soil.

    Science.gov (United States)

    Röttig, Annika; Hauschild, Philippa; Madkour, Mohamed H; Al-Ansari, Ahmed M; Almakishah, Naief H; Steinbüchel, Alexander

    2016-05-10

    As oleaginous microorganisms represent an upcoming novel feedstock for the biotechnological production of lipids or lipid-derived biofuels, we searched for novel, lipid-producing strains in desert soil. This was encouraged by the hypothesis that neutral lipids represent an ideal storage compound, especially under arid conditions, as several animals are known to outlast long periods in absence of drinking water by metabolizing their body fat. Ten lipid-accumulating bacterial strains, affiliated to the genera Bacillus, Cupriavidus, Nocardia, Rhodococcus and Streptomyces, were isolated from arid desert soil due to their ability to synthesize poly(β-hydroxybutyrate), triacylglycerols or wax esters. Particularly two Streptomyces sp. strains and one Rhodococcus sp. strain accumulate significant amounts of TAG under storage conditions under optimized cultivation conditions. Rhodococcus sp. A27 and Streptomyces sp. G49 synthesized approx. 30% (w/w) fatty acids from fructose or cellobiose, respectively, while Streptomyces isolate G25 reached a cellular fatty acid content of nearly 50% (w/w) when cultivated with cellobiose. The stored triacylglycerols were composed of 30-40% branched fatty acids, such as anteiso-pentadecanoic or iso-hexadecanoic acid. To date, this represents by far the highest lipid content described for streptomycetes. A biotechnological production of such lipids using (hemi)cellulose-derived raw material could be used to obtain sustainable biodiesel with a high proportion of branched-chain fatty acids to improve its cold-flow properties and oxidative stability. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Production of actinorhodin-related ''blue pigments'' by Streptomyces coelicolor A3(2)

    NARCIS (Netherlands)

    Bystrykh, LV; FernandezMoreno, MA; Herrema, JK; Malpartida, F; Hopwood, DA; Dijkhuizen, L

    The genetically well-known strain Streptomyces coelicolor A3(2) produces the pH indicator (red/blue) antibiotic actinorhodin, but not all the ''blue pigment'' produced by this strain is actinorhodin. When the organism was subjected to various nutrient limitations (ammonium, nitrate, phosphate, or

  6. Streptomyces atlanticus sp. nov., a novel actinomycete isolated from marine sponge Aplysina fulva (Pallas, 1766).

    Science.gov (United States)

    Silva, Fábio Sérgio Paulino; Souza, Danilo Tosta; Zucchi, Tiago Domingues; Pansa, Camila Cristiane; de Figueiredo Vasconcellos, Rafael Leandro; Crevelin, Eduardo José; de Moraes, Luiz Alberto Beraldo; Melo, Itamar Soares

    2016-11-01

    The taxonomic position of a novel marine actinomycete isolated from a marine sponge, Aplysina fulva, which had been collected in the Archipelago of Saint Peter and Saint Paul (Equatorial Atlantic Ocean), was determined by using a polyphasic approach. The organism showed a combination of morphological and chemotaxonomic characteristics consistent with its classification in the genus Streptomyces and forms a distinct branch within the Streptomyces somaliensis 16S rRNA gene tree subclade. It is closely related to Streptomyces violascens ISP 5183 T (97.27 % 16S rRNA gene sequence similarity) and Streptomyces hydrogenans NBRC 13475 T (97.15 % 16S rRNA gene sequence similarity). The 16S rRNA gene similarities between the isolate and the remaining members of the subclade are lower than 96.77 %. The organism can be distinguished readily from other members of the S. violacens subclade using a combination of phenotypic properties. On the basis of these results, it is proposed that isolate 103 T (=NRRL B-65309 T  = CMAA 1378 T ) merits recognition as the type strain of a new Streptomyces species, namely Streptomyces atlanticus sp. nov.

  7. Photosynthetic acclimation of WS and WS-gpt2 in Arabidopsis thaliana under fluctuating natural light condition

    Science.gov (United States)

    Pa'ee, Furzani; Johnson, Giles

    2017-10-01

    Photoacclimation is a process by which photosynthetic capacity is regulated in response to environmental adjustments in terms of light regime. Photoacclimation is essential in determining the photosynthetic capacity to optimize light use and to avoid potentially damaging effects. Previous work in our laboratory has identified a gene, gpt2 (At1g61800) that is essential for plants to acclimate to an increase and decrease of growth irradiance, separately. To investigate the photoacclimation ability towards fluctuating natural light condition in Arabidopsis thaliana, photosynthetic capacity was measured in plants of the accession Wassileskija (WS) and in plants lacking expression of the gene At1g61800 (WS-gpt2). The experiment was carried out over a time span from early Autumn to early Spring season in 2010-2011 and 2011-2012. The seedlings were grown in an unheated greenhouse in Manchester, UK without supplementary lighting. Gas exchange measurements and chlorophyll content estimation were performed on WS and WS-gpt2 and it showed that both sets of plants were able to acclimate to fluctuating natural light condition. Therefore, it is suggested that the mechanisms of acclimation in a separate growth light condition is mechanistically distinct than the mechanism under fluctuating natural light condition.

  8. Streptomyces halophytocola sp. nov., an endophytic actinomycete isolated from the surface-sterilized stems of a coastal halophyte Tamarix chinensis Lour.

    Science.gov (United States)

    Qin, Sheng; Bian, Guang-Kai; Tamura, Tomohiko; Zhang, Yue-Ji; Zhang, Wen-Di; Cao, Cheng-Liang; Jiang, Ji-Hong

    2013-08-01

    A novel actinomycete, designated KLBMP 1284(T), was isolated from the surface-sterilized stems of a coastal halophyte Tamarix chinensis Lour. collected from the city of Nantong, Jiangsu Province, east China. The strain was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. Analysis of the 16S rRNA gene sequence of strain KLBMP 1284(T) revealed that the strain formed a distinct clade within the phylogenetic tree based on 16S rRNA gene sequences and the highest sequence similarity (99.43 %) was to Streptomyces sulphureus NRRL B-1627(T). 16S rRNA gene sequence similarity to other species of the genus Streptomyces was lower than 97 %. Based on DNA-DNA hybridization values and comparison of morphological and phenotypic data, KLBMP 1284(T) could be distinguished from the closest phylogenetically related species, Streptomyces sulphureus NRRL B-1627(T). Thus, based on these data, it is evident that strain KLBMP 1284(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces halophytocola sp. nov. is proposed. The type strain is KLBMP 1284(T) (= KCTC 19890(T) = NBRC 108770(T)).

  9. Streptomyces euryhalinus sp. nov., a new actinomycete isolated from a mangrove forest.

    Science.gov (United States)

    Biswas, Kaushik; Choudhury, Jayanta D; Mahansaria, Riddhi; Saha, Malay; Mukherjee, Joydeep

    2017-06-01

    A Gram-positive, aerobic, non-motile actinomycete (strain MS 3/20 T ) was isolated from the sediment of the Sundarbans mangrove forest in India. On International Streptomyces Project (ISP) medium 2, the isolate produced yellowish brown to red aerial hyphae that carried spiny-surfaced spores in a retinaculum-apertum arrangement. Whole-cell hydrolysate of the strain contained LL-diaminopimelic acid and galactose. Predominant menaquinones were MK-9(H 8 ) and MK-9(H 6 ). Diagnostic polar lipids were glycolipid, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, unidentified phospholipid and unidentified amino lipid. The major fatty acids were anteiso-C 15:0 (17.53%), iso-C 16:0 (23.89%) and anteiso-C 17:0 (10.29%). The strain showed 100% 16S ribosomal RNA (rRNA) gene sequence similarity with Streptomyces variabilis NBRC 12825 T , Streptomyces erythrogriseus LMG 19406 T , Streptomyces griseoincarnatus LMG 19316 T and Streptomyces labedae NBRC 15864 T . However, strain MS 3/20 T could be distinguished from these and seven other closely related species based on low levels of DNA-DNA relatedness (27.2-53.8%), supported by the unique banding pattern obtained from random amplified polymorphic DNA-PCR amplification and the distinctive matrix-assisted laser desorption/ionization-time-of-flight/mass spectrometry (MALDI-TOF/MS) profile of whole-cell proteins acquired for strain MS 3/20 T in comparison with its phylogenetic relatives. Disparate morphological, physiological and chemotaxonomic features, principally growth in NaCl, further corroborated the distinction of strain MS 3/20 T from other phylogenetic relatives. Strain MS 3/20 T is therefore suggested to be a novel species of the genus Streptomyces, for which the name Streptomyces euryhalinus sp. nov. is proposed. The type strain is MS 3/20 T (=CICC 11032 T =DSM 103378 T ).

  10. Laboratory Course on "Streptomyces" Genetics and Secondary Metabolism

    Science.gov (United States)

    Siitonen, Vilja; Räty, Kaj; Metsä-Ketelä, Mikko

    2016-01-01

    The "'Streptomyces' genetics and secondary metabolism" laboratory course gives an introduction to the versatile soil dwelling Gram-positive bacteria "Streptomyces" and their secondary metabolism. The course combines genetic modification of "Streptomyces"; growing of the strain and protoplast preparation, plasmid…

  11. Enzymology of lignocellulose bioconversion by Streptomyces viridosporus

    International Nuclear Information System (INIS)

    Ramachandra, M.

    1989-01-01

    Significant progress has been made in lignin biodegradation research since 1983, when lignin peroxidases were discovered in fungi. A similar breakthrough in bacterial lignin biodegradation research is anticipated. Several laboratories have successfully demonstrated the ability of bacteria to mineralize [ 14 C]-lignin lignocelluloses as well as 14 C-labelled synthetic lignins. Attempts are being made to identify the key enzymes involved. In this dissertation, two studies are presented which address the enzymology of lignin biodegradation by Streptomyces viridosporus. The first study compares selected extracellular enzyme of wild-type and genetically manipulated strains with enhanced abilities to produced a water soluble lignin degradation intermediate, designated acid-precipitable polymeric lignin (APPL). UV irradiation mutant T7A-81 and protoplast fusion recombinant SR-10 had higher and longer persisting peroxidase, esterase, and endoglucanase activity than did the wild type strain T7A. An extracellular lignocellulose-induced peroxidase with some similarities to fungal ligninases was described for the first time in Streptomyces. The second study describes purification and characterization of an extracellular lignin peroxidase produced by S. viridosporus T7A. This is the first report of a lignin peroxidase in any bacterium

  12. Molecular Regulation of Antibiotic Biosynthesis in Streptomyces

    Science.gov (United States)

    Liu, Gang; Chandra, Govind; Niu, Guoqing

    2013-01-01

    SUMMARY Streptomycetes are the most abundant source of antibiotics. Typically, each species produces several antibiotics, with the profile being species specific. Streptomyces coelicolor, the model species, produces at least five different antibiotics. We review the regulation of antibiotic biosynthesis in S. coelicolor and other, nonmodel streptomycetes in the light of recent studies. The biosynthesis of each antibiotic is specified by a large gene cluster, usually including regulatory genes (cluster-situated regulators [CSRs]). These are the main point of connection with a plethora of generally conserved regulatory systems that monitor the organism's physiology, developmental state, population density, and environment to determine the onset and level of production of each antibiotic. Some CSRs may also be sensitive to the levels of different kinds of ligands, including products of the pathway itself, products of other antibiotic pathways in the same organism, and specialized regulatory small molecules such as gamma-butyrolactones. These interactions can result in self-reinforcing feed-forward circuitry and complex cross talk between pathways. The physiological signals and regulatory mechanisms may be of practical importance for the activation of the many cryptic secondary metabolic gene cluster pathways revealed by recent sequencing of numerous Streptomyces genomes. PMID:23471619

  13. A Novel Insecticidal Peptide SLP1 Produced by Streptomyces laindensis H008 against Lipaphis erysimi

    Directory of Open Access Journals (Sweden)

    Lijian Xu

    2016-08-01

    Full Text Available Aphids are major insect pests for crops, causing damage by direct feeding and transmission of plant diseases. This paper was completed to discover and characterize a novel insecticidal metabolite against aphids from soil actinobacteria. An insecticidal activity assay was used to screen 180 bacterial strains from soil samples against mustard aphid, Lipaphis erysimi. The bacterial strain H008 showed the strongest activity, and it was identified by the phylogenetic analysis of the 16S rRNA gene and physiological traits as a novel species of genus Streptomyces (named S. laindensis H008. With the bioassay-guided method, the insecticidal extract from S. laindensis H008 was subjected to chromatographic separations. Finally, a novel insecticidal peptide was purified from Streptomyces laindensis H008 against L. erysimi, and it was determined to be S-E-P-A-Q-I-V-I-V-D-G-V-D-Y-W by TOF-MS and amino acid analysis.

  14. Growth of desferrioxamine-deficient Streptomyces mutants through xenosiderophore piracy of airborne fungal contaminations.

    Science.gov (United States)

    Arias, Anthony Argüelles; Lambert, Stéphany; Martinet, Loïc; Adam, Delphine; Tenconi, Elodie; Hayette, Marie-Pierre; Ongena, Marc; Rigali, Sébastien

    2015-07-01

    Due to the necessity of iron for housekeeping functions, nutrition, morphogenesis and secondary metabolite production, siderophore piracy could be a key strategy in soil and substrate colonization by microorganisms. Here we report that mutants of bacterium Streptomyces coelicolor unable to produce desferrioxamine siderophores could recover growth when the plates were contaminated by indoor air spores of a Penicillium species and Engyodontium album. UPLC-ESI-MS analysis revealed that the HPLC fractions with the extracellular 'resuscitation' factors of the Penicillium isolate were only those that contained siderophores, i.e. Fe-dimerum acid, ferrichrome, fusarinine C and coprogen. The restored growth of the Streptomyces mutants devoid of desferrioxamine is most likely mediated through xenosiderophore uptake as the cultivability depends on the gene encoding the ABC-transporter-associated DesE siderophore-binding protein. That a filamentous fungus allows the growth of desferrioxamine non-producing Streptomyces in cocultures confirms that xenosiderophore piracy plays a vital role in nutritional interactions between these taxonomically unrelated filamentous microorganisms. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Characterization of Streptomyces strain SLO-105 isolated from Lake ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... produce a vivid yellow pigment on most media except on the ISP5. The morphological and cultural characteristics of the isolate were compared with known Actinomycetes species described in Bergey's manual of systematic bacteriology and they suggested that SLO-105 strain belong to Streptomyces ...

  16. Streptomyces ciscaucasicus Sveshnikova et al. 1983 is a later subjective synonym of Streptomyces canus Heinemann et al. 1953.

    Science.gov (United States)

    Kämpfer, Peter; Rückert, Christian; Blom, Jochen; Goesmann, Alexander; Wink, Joachim; Kalinowski, Jörn; Glaeser, Stefanie P

    2018-01-01

    Streptomyces canuswas described in 1953 and the name was listed in the Approved List of Bacterial Names in 1980. Three years later, Streptomyces ciscaucasicus was published and the name was subsequently validated in Validation List no. 22 in 1986. On the basis of genome comparison and multilocus sequence analysis of the type strains of Streptomyces canus and Streptomyces ciscaucasicus it can now be shown that these two species despite some phenotypic differences are subjective synonyms. In such a case Rule 24 of the Bacteriological Code applies, in which priority of names is determined by the date of the original publication. Hence, we propose that S. ciscaucasicus is a later subjective synonym of S. canus.

  17. Crystallization, optimization and preliminary X-ray characterization of a metal-dependent PI-PLC from Streptomyces antibioticus

    International Nuclear Information System (INIS)

    Jackson, Michael R.; Selby, Thomas L.

    2012-01-01

    Crystallization and diffraction analysis of a Ca 2+ -dependent PI-PLC from Streptomyces is reported. Optimization of crystals was completed using a drop-pinning technique and heavy-atom soaks to achieve high-quality diffraction to 1.23 Å. A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) from Streptomyces antibioticus has been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space group P222, with unit-cell parameters a = 41.26, b = 51.86, c = 154.78 Å. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 Å resolution

  18. EPR study of N+-ion-induced free radical formation in antibiotic-producers

    International Nuclear Information System (INIS)

    Xie Liqing; Zhang Yinfen; Chen Ruyi; Gao Juncheng; Zhang Peiling; Ying Hengfeng.

    1995-01-01

    Under the room temperature, electron paramagnetic resonance (EPR) spectrometer was used to study free radical formation in antibiotic-producers in order to investigate antibiotic-producer mutagenic breeding, which were induced by N + ion implanting into antibiotic-producers (e.g., Streptomyces ribosidificus, Streptomyces kanamyceticus and the phage-resistant culture of Streptomyces kanamyceticus). The results show that a lot of free radicals can be induced by N + ion implanting into antibiotic-producers, and the yields of the free radicals increase with implanting dose. The death rate of antibiotic-producers rises due to the increase of N + -ion-induced free radical yields. (author)

  19. Targeted Gene Disruption of the Cyclo (L-Phe, L-Pro Biosynthetic Pathway in Streptomyces sp. US24 Strain

    Directory of Open Access Journals (Sweden)

    Samiha Sioud

    2007-01-01

    Full Text Available We have previously isolated a new actinomycete strain from Tunisian soil called Streptomyces sp. US24, and have shown that it produces two bioactive molecules including a Cyclo (L-Phe, L-Pro diketopiperazine (DKP. To identify the structural genes responsible for the synthesis of this DKP derivative, a PCR amplification (696 bp was carried out using the Streptomyces sp. US24 genomic DNA as template and two degenerate oligonucleotides designed by analogy with genes encoding peptide synthetases (NRPS. The detection of DKP derivative biosynthetic pathway of the Streptomyces sp. US24 strain was then achieved by gene disruption via homologous recombination using a suicide vector derived from the conjugative plasmid pSET152 and containing the PCR product. Chromatography analysis, biological tests and spectroscopic studies of supernatant cultures of the wild-type Streptomyces sp. US24 strain and three mutants obtained by this gene targeting disruption approach showed that the amplified DNA fragment is required for Cyclo (L-Phe, L-Pro biosynthesis in Streptomyces sp. US24 strain. This DKP derivative seems to be produced either directly via a nonribosomal pathway or as a side product in the course of nonribosomal synthesis of a longer peptide.

  20. Synthesis of blue photoluminescent WS2 quantum dots via ultrasonic cavitation

    International Nuclear Information System (INIS)

    Bayat, A.; Saievar-Iranizad, E.

    2017-01-01

    Blue photoluminescent WS 2 quantum dots (QDs) were synthesized using a simple top-down method from natural raw mineral tungsten disulfide via tip ultrasonication followed by centrifugation in a water-ethanol (0.7/0.3 ratio) as eco-friendly solvent. Cavitation process at a high power (300 W) led to the breaking of bulk WS 2 flakes to its quantum dots. The as synthesized WS 2 QDs showed blue photoluminescence upon UV excitation. The synthesized WS 2 QDs were analysed by UV–vis and photoluminescence spectrophotometry, transmission electron microscopy, atomic force microscopy and X-ray diffraction. According to the transmission electron microscopy images, the size of WS 2 QDs was obtained as 5 nm in average. - Highlights: •Large scale blue photoluminescent WS 2 quantum dots was synthesized using Ultrasonic probe (Cavitation Process). •A solution of water/ethanol (0.7/0.3) was used as eco-friendly solvent instead of unsuitable solvent such as NMP and ACN. •Edges of bulk WS 2 was increased with formation of its quantum dots. •Solution of WS 2 QDs was stable after 6 months.

  1. Genetic interrelations in the actinomycin biosynthetic gene clusters of Streptomyces antibioticus IMRU 3720 and Streptomyces chrysomallus ATCC11523, producers of actinomycin X and actinomycin C

    Science.gov (United States)

    Crnovčić, Ivana; Rückert, Christian; Semsary, Siamak; Lang, Manuel; Kalinowski, Jörn; Keller, Ullrich

    2017-01-01

    Sequencing the actinomycin (acm) biosynthetic gene cluster of Streptomyces antibioticus IMRU 3720, which produces actinomycin X (Acm X), revealed 20 genes organized into a highly similar framework as in the bi-armed acm C biosynthetic gene cluster of Streptomyces chrysomallus but without an attached additional extra arm of orthologues as in the latter. Curiously, the extra arm of the S. chrysomallus gene cluster turned out to perfectly match the single arm of the S. antibioticus gene cluster in the same order of orthologues including the the presence of two pseudogenes, scacmM and scacmN, encoding a cytochrome P450 and its ferredoxin, respectively. Orthologues of the latter genes were both missing in the principal arm of the S. chrysomallus acm C gene cluster. All orthologues of the extra arm showed a G +C-contents different from that of their counterparts in the principal arm. Moreover, the similarities of translation products from the extra arm were all higher to the corresponding translation products of orthologue genes from the S. antibioticus acm X gene cluster than to those encoded by the principal arm of their own gene cluster. This suggests that the duplicated structure of the S. chrysomallus acm C biosynthetic gene cluster evolved from previous fusion between two one-armed acm gene clusters each from a different genetic background. However, while scacmM and scacmN in the extra arm of the S. chrysomallus acm C gene cluster are mutated and therefore are non-functional, their orthologues saacmM and saacmN in the S. antibioticus acm C gene cluster show no defects seemingly encoding active enzymes with functions specific for Acm X biosynthesis. Both acm biosynthetic gene clusters lack a kynurenine-3-monooxygenase gene necessary for biosynthesis of 3-hydroxy-4-methylanthranilic acid, the building block of the Acm chromophore, which suggests participation of a genome-encoded relevant monooxygenase during Acm biosynthesis in both S. chrysomallus and S

  2. Analysis of the Pho regulon in Streptomyces tsukubaensis.

    Science.gov (United States)

    Ordóñez-Robles, María; Santos-Beneit, Fernando; Rodríguez-García, Antonio; Martín, Juan F

    2017-12-01

    Phosphate regulation of antibiotic biosynthesis in Streptomyces has been studied due to the importance of this genus as a source of secondary metabolites with biological activity. Streptomyces tsukubaensis is the main producer of tacrolimus (or FK506), an immunosuppressant macrolide that generates important benefits for the pharmaceutical market. However, the production of tacrolimus is under a negative control by phosphate and, therefore, is important to know the molecular mechanism of this regulation. Despite its important role, there are no reports about the Pho regulon in S. tsukubaensis. In this work we combined transcriptional studies on the response to phosphate starvation with the search for PHO boxes in the whole genome sequence of S. tsukubaensis. As a result, we identified a set of genes responding to phosphate starvation and containing PHO boxes that include common Pho regulon members but also new species-specific candidates. In addition, we demonstrate for the first time the functional activity of PhoP from S. tsukubaensis through complementation studies in a Streptomyces coelicolor ΔphoP strain. For this purpose, we developed an anhydrotetracycline inducible system that can be applied to the controlled expression of target genes. Copyright © 2017 Elsevier GmbH. All rights reserved.

  3. Biochemical studies on antibiotic production from Streptomyces sp.: Taxonomy, fermentation, isolation and biological properties

    OpenAIRE

    Houssam M. Atta

    2015-01-01

    Tunicamycin is a nucleotide antibiotic which was isolated from the fermentation broth of a Streptomyces strain No. T-4. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain T-4 was identified as Streptomyces torulosus. It is active in vitro against some microbial pathogenic viz: Staphylococcus aureus, NCTC 7447; Micrococcus lutea, ATCC 9341; Bacillus subtilis, NCTC 10400; B. pumilus, NCTC; Klebsiella pneumonia, NCIMB 9...

  4. Bioactive metabolite production by Streptomyces albolongus in favourable environment

    Directory of Open Access Journals (Sweden)

    Myn Uddin

    2013-06-01

    Full Text Available Objectives: Demand for new antibiotic is rising up due to continuous resistance risk against conventional antibiotic.This attempt was taken to find out a novel antimicrobial metabolite.Methods: Chili field antagonistic actinomycetes Streptomyces albolongus was isolated and tested for optimum antimicrobialmetabolite production. Primary screening was done by selective media and antibiotic assay was done by agarcup plate method. Fermented product was recovered by separating funnel using suitable solvent.Results: Maximum antimicrobial metabolite production was found at temperature 35°C and pH 9.0 and on 6th day ofincubation. The medium consisting of corn steep liquor (0.2%, glucose (1.0%, NaCl (0.5%, K2HPO4 (0.1% was screenedout as suitable medium for maximum antimicrobial production. Sucrose was found as the best carbon source amongfour sources. The antimicrobial metabolite was found to be stable at pH and temperature up to 11.0 and 100°C respectively.The active agent was best extracted with chloroform. The antimicrobial spectrum of the metabolite was wideand shows activity against Shigella dysenteriae (AE14612, Shigella sonnei (CRL, ICDDR, B, Salmonella typhi (AE14296,Vibrio cholerae (AE14748, Pseudomonas aeruginosa (CRL, ICDDR, B, Bacillus cereus (BTCC19, Staphylococcus aureus(ATCC6538, Bacillus subtilis (BTTC17 and Bacillus megaterium (BTTC18.Conclusions: The findings of antibacterial activity of S. albolongus against several species of human pathogens includingboth Gram-positive and Gram-negative bacteria indicated that our produced material might be an alternative antimicrobialsubstance to control human diseases. J Microbiol Infect Dis 2013; 3(2: 75-82Key words: Streptomyces albolongus, antimicrobial metabolite, optimum production, antimicrobial spectrum

  5. Proposals for revival of Streptomyces setonii and reclassification of S. fimicarius as a later synonym of S. setonii and S. albovinaceus as a later synonym of S. globisporus based on combined 16S rRNA-gyrB gene analysis

    Science.gov (United States)

    The 16S rRNA and gyrB genes of 22 Streptomyces species belonging to the Streptomyces griseus cluster were sequenced, and their taxonomic positions were re-evaluated. For correct analysis, all of the publicly available sequences of the species were collected and compared with those obtained in this s...

  6. Streptomyces xylanilyticus sp. nov., isolated from soil.

    Science.gov (United States)

    Moonmangmee, Duangtip; Kanchanasin, Pawina; Phongsopitanun, Wongsakorn; Tanasupawat, Somboon; Moonmangmee, Somporn

    2017-10-01

    A novel actinomycete, strain SR2-123 T , belonging to the genus Streptomyces, was isolated from a soil sample collected from the Sakaerat Environmental Research Station, Thailand Institute of Scientific and Technological Research, Nakhon Ratchasima Province, Thailand. The taxonomic position of the strain was characterized using a polyphasic study. Strain SR2-123 T contained ll-diaminopimelic acid, glucose, mannose and ribose in whole-cell hydrolysates. The N-acyl type of muramic acid was acetyl. Menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The predominant cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and iso-C17 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, an unknown phospholipid, unknown glycolipids, an unknown aminophospholipid, unknown lipids and an unknown aminolipid. The DNA G+C content was 74.8 mol%. The strain was closely related to Streptomyces coeruleorubidus JCM 4359 T (98.5 %), Streptomyces flavofungini JCM 4753 T (98.5 %), Streptomyces coerulescens NBRC 12758 T (98. 5 %) and Streptomyces alboflavus JCM 4615 T (98.4 %), based on 16S rRNA gene sequence similarities. The novel strain exhibited low DNA-DNA relatedness values with the type strains (11.4-25.0 %) of closely related species. On the basis of phenotypic and genotypic characteristics, strain SR2-123 T could be distinguished from closely related species of the genus Streptomyces and represents a novel species of the genus Streptomyces for which the name Streptomyces xylanilyticus sp. nov. is proposed. The type strain is SR2-123 T (=TISTR 2493 T =KCTC 39909 T ).

  7. Phonon shift in chemically exfoliated WS2 nanosheet

    Science.gov (United States)

    Sarkar, Abdus Salam; Pal, Suman Kalyan

    2018-04-01

    We have synthesized few layer WS2 nanosheets in a low boiling point solvent. Few layer of WS2 sheets are characterized by various techniques such as UV-visible and Raman spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and scanning electron microscopy (SEM). UV-Vis absorption spectra confirm the well dispersed in isopropyl alcohol. SEM and TEM images indicate the sheet like morphology of WS2. Atomic force microscopy image and room temperature Raman spectroscopy confirm the exfoliation of few layer (4-5 layer) of WS2. Further, Raman spectroscopy was used as a meteorology tool to determine the temperature co-efficient. We have systematically investigated the temperature dependent Raman spectroscopic behavior of few layer WS2. Our results depict the softening of the Raman modes E12g in plane vibration and A1g out of plane vibration with increasing the temperature from 77 K to 300 K. Softening of the Raman modes could be explained in terms of the double resonance which is active in the layered materials. The observed temperature coefficients for two Raman peaks E12g and A1g, are - 0.022 cm-1 and -0.009 cm-1, respectively.

  8. Streptomyces luozhongensis sp. nov., a novel actinomycete with antifungal activity and antibacterial activity.

    Science.gov (United States)

    Zhang, Renwen; Han, Xiaoxue; Xia, Zhanfeng; Luo, Xiaoxia; Wan, Chuanxing; Zhang, Lili

    2017-02-01

    A novel actinomycete strain, designated TRM 49605 T , was isolated from a desert soil sample from Lop Nur, Xinjiang, north-west China, and characterised using a polyphasic taxonomic approach. The strain exhibited antifungal activity against the following strains: Saccharomyces cerevisiae, Curvularia lunata, Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, Penicillium citrinum, Candida albicans and Candida tropicalis; Antibacterial activity against Bacillus subtilis, Staphylococcus epidermidis and Micrococcus luteus; and no antibacterial activity against Escherichia coli. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain TRM 49605 T to the genus Streptomyces. Strain TRM 49605 T shows high sequence similarities to Streptomyces roseolilacinus NBRC 12815 T (98.62 %), Streptomyces flavovariabilis NRRL B-16367 T (98.45 %) and Streptomyces variegatus NRRL B-16380 T (98.45 %). Whole cell hydrolysates of strain TRM 49605 T were found to contain LL-diaminopimelic acid as the diagnostic diamino acid and galactose, glucose, xylose and mannose as the major whole cell sugars. The major fatty acids in strain TRM 49605 T were identified as iso C 16:0 , anteiso C 15:0 , C 16:0 and Summed Feature 5 as defined by MIDI. The main menaquinones were identified as MK-9(H 4 ), MK-9(H 6 ), MK-9(H 8 ) and MK-10(H 6 ). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and phosphatidylinositol mannoside. The G+C content of the genomic DNA was determined to be 71.2 %. The DNA-DNA relatedness between strain TRM 49605 T and the phylogenetically related strain S. roseolilacinus NBRC 12815 T was 60.12 ± 0.06 %, which is lower than the 70 % threshold value for delineation of genomic prokaryotic species. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain TRM 49605 T (=CCTCC AA2015026 T  = KCTC 39666 T ) should be designated as the type strain of a novel species of the genus

  9. Igf1r+/CD34+ immature ICC are putative adult progenitor cells, identified ultrastructurally as fibroblast-like ICC in Ws/Ws rat colon

    DEFF Research Database (Denmark)

    Wang, X Y; Albertí, E; White, E J

    2009-01-01

    by ICC in the wild-type rat colon, suggesting them to be immature ICC. In addition, a marked increase in immunoreactivity for insulin-like growth factor 1 receptor (Igf1r) occurred, co-localized with CD34 but not with c-Kit. A significantly higher number of Igf1r(+)/CD34(+) cells were found in Ws....../Ws compared to wild-type rat colons. These CD34(+)/Igf1r(+) cells in the Ws/Ws colon occupied the same space as FL-ICC. Hence we propose that a subset of immature ICC (FL-ICC) consists of adult progenitor cells. Immunohistochemistry revealed a reduction of neurons positive for neuronal nitric oxide synthase...

  10. Streptomyces phyllanthi sp. nov., isolated from the stem of Phyllanthus amarus.

    Science.gov (United States)

    Klykleung, Nattaporn; Phongsopitanun, Wongsakorn; Pittayakhajonwut, Pattama; Ohkuma, Moriya; Kudo, Takuji; Tanasupawat, Somboon

    2016-10-01

    The novel endophytic actinomycete strain PA1-07T was isolated from the stem of Phyllanthus amarus. The strain displayed the consistent characteristics of members of the genus Streptomyces. The strain produced short spiral spore chains on aerial mycelia. It grew at pH 5-9, at 40 °C and with a maximum of 5 % (w/v) NaCl. It contained ll-diaminopimelic acid, glucose and ribose in the whole-cell hydrolysate. The major cellular menaquinones were MK-9(H4), MK-9(H6) and MK-9(H8), while the major cellular fatty acids were C16 : 0, iso-C14 : 0, iso-C16 : 0 and anteiso-C15 : 0. The polar lipids were composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside and four unknown lipids. The DNA G+C content of the strain was 71 mol%. The strain showed the highest 16S rRNA gene sequence similarity with Streptomyces curacoi JCM 4219T (98.77 %). The DNA-DNA relatedness values between strain PA1-07T and S. curacoi JCM 4219T were lower than 70 %, the cut-off level for assigning strains to the same species. On the basis of these phenotypic and genotypic characteristics, the strain could be distinguished from closely related species of the genus Streptomyces and thus represents a novel species of the genus Streptomyces, for which the name Streptomyces phyllanthi sp. nov. is proposed. The type strain is PA1-07T (=JCM 30865T=KCTC 39785T=TISTR 2346T).

  11. Pathogenic Streptomyces spp. abundance affected by potato cultivars.

    Science.gov (United States)

    Nahar, Kamrun; Goyer, Claudia; Zebarth, Bernie J; Burton, David L; Whitney, Sean

    2018-04-16

    Potato cultivars vary in their tolerance to common scab (CS), however how they affect CS-causing Streptomyces spp. populations over time is poorly understood. This study investigated the effects of potato cultivar on pathogenic Streptomyces spp. abundance, measured using quantitative PCR, in three spatial locations in a CS-infested field: 1) soil close to the plant (SCP); 2) rhizosphere (RS); and 3) geocaulosphere (GS) soils. Two tolerant (Gold Rush, Hindenburg) and two susceptible cultivars (Green Mountain, Agria) were tested. The abundance of pathogenic Streptomyces spp. significantly increased in late August compared with other dates in RS of susceptible cultivars in both years. Abundance of pathogenic Streptomyces spp., when averaged over locations and time, was significantly greater in susceptible cultivars compared with tolerant cultivars in 2014. Principal coordinates analysis showed that SCP and RS soil properties (pH, organic carbon and nitrogen concentrations) explained 68% and 76% of total variation in Streptomyces spp. abundance among cultivars in 2013, respectively, suggesting that cultivars influenced CS pathogen growth conditions. The results suggested that the genetic background of potato cultivars influenced the abundance of pathogenic Streptomyces spp., with 5 to 6 times more abundant Streptomyces spp. in RS of susceptible cultivars compared with tolerant cultivars, which would result in substantially more inoculum left in the field after harvest.  .

  12. Protoplasting impact on polyketide activity and characterization of the interspecific fusants from Streptomyces spp

    International Nuclear Information System (INIS)

    Slama, N.; Lazim, H.; Barkallah, Insaf; Abbassi, M.; Ben Hassen, A.; Limam, F.

    2009-01-01

    Streptomycetes are gram-positive, soil-inhabiting bacteria of the order Actinomycetales. These organisms exhibit an unusual, developmentally complex life cycle and produce many economically important secondary metabolites, such as antibiotics, immunosuppressants, insecticides, and antitumor agents. Streptomyces species have been the subject of genetic investigation for over 50 years, with many studies focusing on the production of bioactives compounds. The protoplast formation and regeneration are important processes, and they are a major step following genetic manipulations such as fusion and DNA-mediated transformation, which can improve antibiotic production. The protoplast fusion, transformation and improved fermentation features can be used to regenerate strains with increased antibiotic activity. Local Streptomyces spp. CN207 produce a broad range of secondary metabolites which is active against bacteria and fungi. This strain was used as a donor and S. coelicolor strain M145 was used as a recipient host for protoplast fusion. The protoplast fusion resulted in increased isolation of variants with higher antibiotic activity. Recombinant Streptomyces coelicolor PF04 was increased 10 times more than the wild strain. The antimicrobial activity from PF04 strain was studied using the disc method agar. TLC analysis confirmed that the Rf of cell extract for PF04 strain is identical to antimicrobial compound of Streptomyces CN207. Our results confirm the possibility of transferring antibiotics cluster genes by fusion. In fact, many of the selective markers such as Ticarcillin, Cefalotin, Oxacillin and Cefotaxim were transferred during the protoplast fusion. PFGE analysis and DNA-hybridization confirmed the presence of homologous fragments between a wild-type Streptomyces CN207 and a recombinant S. coelicolor PF04

  13. Determination of optimal conditions of oxytetracyclin production from streptomyces rimosus

    International Nuclear Information System (INIS)

    Zouaghi, Atef

    2007-01-01

    Streptomyces rimosus is an oxytetracycline (OTC) antibiotic producing bacteria that exhibited activities against gram positive and negative bacteria. OTC is used widely not only in medicine but also in production industry. The antibiotic production of streptomyces covers a very wide range of condition. However, antibiotic producers are particularly fastidious cultivated by proper selection of media such as carbon source. In present study we have optimised conditions of OTC production (Composition of production media, p H, shaking and temperature). The results have been shown that bran barley is the optimal media for OTC production at 28C pH5.8 at 150rpm for 5 days. For antibiotic determination, OTC was extracted with different organic solvent. Thin-layer chromatography system was used for separation and identification of OTC antibiotic. High performance liquid chromatographic (HPLC) method with ultraviolet detection for the analysis of OTC is applied to the determination of OTC purification. (Author). 24 refs

  14. Development of a gene cloning system in a fast-growing and moderately thermophilic Streptomyces species and heterologous expression of Streptomyces antibiotic biosynthetic gene clusters

    Science.gov (United States)

    2011-01-01

    Background Streptomyces species are a major source of antibiotics. They usually grow slowly at their optimal temperature and fermentation of industrial strains in a large scale often takes a long time, consuming more energy and materials than some other bacterial industrial strains (e.g., E. coli and Bacillus). Most thermophilic Streptomyces species grow fast, but no gene cloning systems have been developed in such strains. Results We report here the isolation of 41 fast-growing (about twice the rate of S. coelicolor), moderately thermophilic (growing at both 30°C and 50°C) Streptomyces strains, detection of one linear and three circular plasmids in them, and sequencing of a 6996-bp plasmid, pTSC1, from one of them. pTSC1-derived pCWH1 could replicate in both thermophilic and mesophilic Streptomyces strains. On the other hand, several Streptomyces replicons function in thermophilic Streptomyces species. By examining ten well-sporulating strains, we found two promising cloning hosts, 2C and 4F. A gene cloning system was established by using the two strains. The actinorhodin and anthramycin biosynthetic gene clusters from mesophilic S. coelicolor A3(2) and thermophilic S. refuineus were heterologously expressed in one of the hosts. Conclusions We have developed a gene cloning and expression system in a fast-growing and moderately thermophilic Streptomyces species. Although just a few plasmids and one antibiotic biosynthetic gene cluster from mesophilic Streptomyces were successfully expressed in thermophilic Streptomyces species, we expect that by utilizing thermophilic Streptomyces-specific promoters, more genes and especially antibiotic genes clusters of mesophilic Streptomyces should be heterologously expressed. PMID:22032628

  15. Tetroazolemycins A and B, Two New Oxazole-Thiazole Siderophores from Deep-Sea Streptomyces olivaceus FXJ8.012

    Directory of Open Access Journals (Sweden)

    Ying Huang

    2013-05-01

    Full Text Available Two new oxazole/thiazole derivatives, named tetroazolemycins A (1 and B (2, have been isolated from the acetone extract of the mycelium of Streptomyces olivaceus FXJ8.012 derived from deep-sea water, together with three known compounds, spoxazomicins A–C (3–5, isolated from the fermentation supernatant. The planar structure and relative configuration of tetroazolemycins were elucidated by a combination of spectroscopic analyses, including 1D- and 2D-NMR techniques, and showed to be new pyochelin-type antibiotics. Both compounds showed metal ion-binding activity and their Zn2+ complexes exhibited weak activity against pathogenic bacteria Klebsiella pneumoniae.

  16. Streptomyces fuscichromogenes sp. nov., an actinomycete from soil.

    Science.gov (United States)

    Zhang, Hao; Zheng, Jimei; Zhuang, Junli; Xin, Yuhua; Zheng, Xiaowei; Zhang, Jianli

    2017-01-01

    A novel actinomycete, designated strain m16T, was isolated from a soil sample collected from the tropical rain forest of Xishuangbanna, a prefecture in Yunnan Province, south-west China, and characterized by using polyphasic taxomomy. Cells were aerobic and Gram-reaction-positive, and spore chains were observed to be of the helical type, with elliptical spores and smooth spore surfaces. The novel strain grew over a temperature range of 15-35 °C, at pH 5.0-11.0 and in the presence of 0-3 % (w/v) NaCl. The DNA G+C content of strain m16T was 70.0 mol%. The main fatty acids were iso-C16 : 0 (29.3 %), iso-C15: 0 (15.4 %) and anteiso-C15:0 (14.6 %), and the predominant menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). Comparative 16S rRNA gene sequence analysis showed that strain m16T was most closely related to Streptomyces jiujiangensis KCTC 29262T (98.7 %), Streptomyces panaciradicis KACC 17632T (98.7 %), Streptomyces rhizophilus NBRC 108885T (98.5 %), Streptomyces shenzhenensis DSM 42034T (98.4 %), Streptomyces graminisoli JR-19T (98.4 %) and Streptomyces gramineus JR-43T (98.3 %). Phylogenetic, chemotaxonomic and phenotypic analyses indicated that strain m16T represents a novel species within the genus Streptomyces, for which the name Streptomyces fuscichromogenes is proposed. The type strain is m16T (=CGMCC 4.7110T=KCTC 29195T).

  17. Streptomyces exploration is triggered by fungal interactions and volatile signals.

    Science.gov (United States)

    Jones, Stephanie E; Ho, Louis; Rees, Christiaan A; Hill, Jane E; Nodwell, Justin R; Elliot, Marie A

    2017-01-03

    It has long been thought that the life cycle of Streptomyces bacteria encompasses three developmental stages: vegetative hyphae, aerial hyphae and spores. Here, we show interactions between Streptomyces and fungi trigger a previously unobserved mode of Streptomyces development. We term these Streptomyces cells 'explorers', for their ability to adopt a non-branching vegetative hyphal conformation and rapidly transverse solid surfaces. Fungi trigger Streptomyces exploratory growth in part by altering the composition of the growth medium, and Streptomyces explorer cells can communicate this exploratory behaviour to other physically separated streptomycetes using an airborne volatile organic compound (VOC). These results reveal that interkingdom interactions can trigger novel developmental behaviours in bacteria, here, causing Streptomyces to deviate from its classically-defined life cycle. Furthermore, this work provides evidence that VOCs can act as long-range communication signals capable of propagating microbial morphological switches.

  18. Comparative genomic hybridizations reveal absence of large Streptomyces coelicolor genomic islands in Streptomyces lividans

    OpenAIRE

    Jayapal, Karthik P; Lian, Wei; Glod, Frank; Sherman, David H; Hu, Wei-Shou

    2007-01-01

    Abstract Background The genomes of Streptomyces coelicolor and Streptomyces lividans bear a considerable degree of synteny. While S. coelicolor is the model streptomycete for studying antibiotic synthesis and differentiation, S. lividans is almost exclusively considered as the preferred host, among actinomycetes, for cloning and expression of exogenous DNA. We used whole genome microarrays as a comparative genomics tool for identifying the subtle differences between these two chromosomes. Res...

  19. Mutations in the paired domain of the human PAX3 gene cause Klein-Waardenburg syndrome (WS-III) as well as Waardenburg syndrome type I (WS-I).

    OpenAIRE

    Hoth, C F; Milunsky, A; Lipsky, N; Sheffer, R; Clarren, S K; Baldwin, C T

    1993-01-01

    Waardenburg syndrome type I (WS-I) is an autosomal dominant disorder characterized by sensorineural hearing loss, dystopia canthorum, pigmentary disturbances, and other developmental defects. Klein-Waardenburg syndrome (WS-III) is a disorder with many of the same characteristics as WS-I and includes musculoskeletal abnormalities. We have recently reported the identification and characterization of one of the first gene defects, in the human PAX3 gene, which causes WS-I. PAX3 is a DNA-binding ...

  20. Antagonistic Activities of Streptomyces against Root Knot Nematode of Kiwifruit

    Directory of Open Access Journals (Sweden)

    S. Bashiri

    2016-02-01

    Full Text Available Introduction: Iran is among the world leading kiwifruit producers with 2.816 ha cultivated and 31.567 tones production. Plant parasitic nematodes cause damages to a variety of agricultural crops throughout the world. Interest in biological control of nematodes has increased because of the need for alternative methods to fumigant and non-fumigant nematicides and overall improvement of IPM programs. Bacterial species with nematicidal activity have also been used with some success for controlling root-knot diseases, including Streptomyces spp., Serratia spp., Bacillus spp. and Pseudomonas spp. The goal of the current study was to isolate, identify and investigate the potential of local Streptomyces bacteria for controlling and reducing root-knot nematode population in the north of Iran. Materials and Methods: In order to evaluate the effect of antagonistic bacteria on control of root-knot nematode of Kiwifruit, 100 isolates of bacteria were collected from Kiwifruit rhizosphere in the north of Iran and screened for pigmented microorganisms especially Streptomyces by applying standard serial dilution plate technique, using starch casein nitrate agar and glycerol asparagine agar. Morphological characterizations were achieved by the microscopic method. The microscopic characterization was done by cover slip culture method. The mycelium structure, color and arrangement of conidiospore and arthrospore on the mycelium were observed through the oil immersion (100X. The observed structure was compared with Bergey’s Manual of Determinative Bacteriology and the organism was identified. Various biochemical tests performed for the identification of the potent isolates are as follows: casein hydrolysis, starch hydrolysis, urea hydrolysis, esculin hydrolysis, acid production from sugar, NaCl resistance, temperature tolerance. Soil samples (100g were collected, and then processed for nematode egg and larvae extraction Hussey method. The suspension was pipetted

  1. A novel gene: sawD related to the differentiation of streptomyces ansochromogenes.

    Science.gov (United States)

    Gang, L; Wei, C; Yuqing, T; Huarong, T; Chater, K F; Buttner, M J

    1999-01-01

    A 1.3 kb DNA fragment was cloned from a total DNA library of Streptomyces ansochromogenes using Southern hybridization. Nucleotide sequencing analysis indicated that the 1320 bp DNA fragment contained a complete open reading frame (ORF). In search of databases, the deduced product of ORF containing 213 amino acids is homologous to the serine protease of Caulobacter cresceatus, and a conserved serine-catalytic active site (GPSAG) exists. The gene was designated as sawD. The function of this gene was studied with the strategy of gene disruption, and the result showed that the sawD may be related to sporulation and especially to the spore septation in Streptomyces ansochromogenes. The preliminary result indicated that sawD mutant could produce abundant pigment in contrast with the wild type, it seems that sawD gene may be involved in pigment biosynthesis, and this gene is also dispensable for biosynthesis of nikkomycin in Streptomyces ansochromogenes.

  2. Phenolic polyketides from the co-cultivation of marine-derived Penicillium sp. WC-29-5 and Streptomyces fradiae 007.

    Science.gov (United States)

    Wang, Yi; Wang, Liping; Zhuang, Yibin; Kong, Fandong; Zhang, Cuixian; Zhu, Weiming

    2014-04-04

    Penicillium sp. WC-29-5 was co-cultured with Streptomyces fradiae 007 to produce five natural products (1-3, 4a and 4b) that were isolated and characterized by spectroscopic analysis. Interestingly, these compounds were found to be different from those produced in discrete fungal and bacterial controls. Among these compounds, the absolute configurations of compounds 4a and 4b were determined for the first time by X-ray single crystal diffraction experiments and electronic circular dichroism (ECD) calculations. An evaluation of the cytotoxic activities of these compounds revealed that 4b was moderately cytotoxic towards HL-60 and H1975 tumor cells with IC₅₀ values of 3.73 and 5.73 µM, respectively, whereas compound 4a was only moderately cytotoxic towards H1975 cells with an IC₅₀ value of 3.97 µM.

  3. Munumbicins, wide-spectrum antibiotics produced by Streptomyces NRRL 30562, endophytic on Kennedia nigriscans.

    Science.gov (United States)

    Castillo, Uvidelio F; Strobel, Gary A; Ford, Eugene J; Hess, Wilford M; Porter, Heidi; Jensen, James B; Albert, Heather; Robison, Richard; Condron, Margret A M; Teplow, David B; Stevens, Dennis; Yaver, Debbie

    2002-09-01

    Munumbicins A, B, C and D are newly described antibiotics with a wide spectrum of activity against many human as well as plant pathogenic fungi and bacteria, and a Plasmodium sp. These compounds were obtained from Streptomyces NRRL 3052, which is endophytic in the medicinal plant snakevine (Kennedia nigriscans), native to the Northern Territory of Australia. This endophyte was cultured, the broth was extracted with an organic solvent and the contents of the residue were purified by bioassay-guided HPLC. The major components were four functionalized peptides with masses of 1269.6, 1298.5, 1312.5 and 1326.5 Da. Numerous other related compounds possessing bioactivity, with differing masses, were also present in the culture broth extract in lower quantities. With few exceptions, the peptide portion of each component contained only the common amino acids threonine, aspartic acid (or asparagine), glutamic acid (or glutamine), valine and proline, in varying ratios. The munumbicins possessed widely differing biological activities depending upon the target organism. For instance, munumbicin B had an MIC of 2.5 microg x ml(-1) against a methicillin-resistant strain of Staphylococcus aureus, whereas munumbicin A was not active against this organism. In general, the munumbicins demonstrated activity against Gram-positive bacteria such as Bacillus anthracis and multidrug-resistant Mycobacterium tuberculosis. However, the most impressive biological activity of any of the munumbicins was that of munumbicin D against the malarial parasite Plasmodium falciparum, having an IC(50) of 4.5+/-0.07 ng x ml(-1). This report also describes the potential of the munumbicins in medicine and agriculture.

  4. Photoluminescence enhancement in few-layer WS2 films via Au nanoparticles

    Directory of Open Access Journals (Sweden)

    Sin Yuk Choi

    2015-06-01

    Full Text Available Nano-composites of two-dimensional atomic layered WS2 and Au nanoparticles (AuNPs have been fabricated by sulfurization of sputtered W films followed by immersing into HAuCl4 aqueous solution. The morphology, structure and AuNPs distribution have been characterized by electron microscopy. The decorated AuNPs can be more densely formed on the edge and defective sites of triangle WS2. We have compared the optical absorption and photoluminescence of bare WS2 and Au-decorated WS2 layers. Enhancement in the photoluminescence is observed in the Au-WS2 nano-composites, attributed to localized surface plasmonic effect. This work provides the possibility to develop photonic application in two-dimensional materials.

  5. Strain engineering in monolayer WS2, MoS2, and the WS2/MoS2 heterostructure

    KAUST Repository

    He, Xin; Li, Hai; Zhu, Zhiyong; Dai, Zhenyu; Yang, Yang; Yang, Peng; Zhang, Qiang; Li, Peng; Schwingenschlö gl, Udo; Zhang, Xixiang

    2016-01-01

    Mechanically exfoliated monolayers of WS2, MoS2 and their van der Waals heterostructure were fabricated on flexible substrate so that uniaxial tensile strain can be applied to the two-dimensional samples. The modification of the band structure under strain was investigated by micro-photoluminescence spectroscopy at room temperature as well as by first-principles calculations. Exciton and trion emissions were observed in both WS2 and the heterostructure at room temperature, and were redshifted by strain, indicating potential for applications in flexible electronics and optoelectronics.

  6. Strain engineering in monolayer WS2, MoS2, and the WS2/MoS2 heterostructure

    KAUST Repository

    He, Xin

    2016-10-27

    Mechanically exfoliated monolayers of WS2, MoS2 and their van der Waals heterostructure were fabricated on flexible substrate so that uniaxial tensile strain can be applied to the two-dimensional samples. The modification of the band structure under strain was investigated by micro-photoluminescence spectroscopy at room temperature as well as by first-principles calculations. Exciton and trion emissions were observed in both WS2 and the heterostructure at room temperature, and were redshifted by strain, indicating potential for applications in flexible electronics and optoelectronics.

  7. Transposition of Tn5096 from a temperature-sensitive transducible plasmid in Streptomyces spp.

    OpenAIRE

    McHenney, M A; Baltz, R H

    1991-01-01

    Transposon Tn5096 was inserted into a derivative of the temperature-sensitive plasmid pMT660 containing the bacteriophage FP43 pac site. The resulting plasmid, pRHB126, was transduced by FP43 into several Streptomyces species. Tn5096 transposed from pRHB126 into different sites in the genomes of Streptomyces ambofaciens, Streptomyces cinnamonensis, Streptomyces coelicolor A3(2), Streptomyces fradiae, Streptomyces griseofuscus, and Streptomyces thermotolerans.

  8. Mycolytic enzymes produced by Streptomyces violaceusniger and their role in antagonism towards wood-rotting fungi.

    Science.gov (United States)

    Nagpure, Anand; Choudhary, Bharti; Gupta, Rajinder K

    2014-05-01

    Extracellular mycolytic enzymes produced under submerged fermentation by the fungal antagonist Streptomyces violaceusniger MTCC 3959 were characterized. This streptomycete produced higher amounts of extracellular chitinase and protease during late exponential phase, whereas β-1,3-glucanase production was at peak in mid-stationary phase. Cell-free culture filtrate (CCF) exhibited a broad range of antifungal activity against both white rot and brown rot fungi. The inhibitory activity was completely lost after treatment with proteinase K and heat, indicating that extracellular antifungal metabolites are heat labile and proteinaceous in nature. Optimum pH and temperature for enzyme activity were: 9.0 and 60 °C for chitinase; 6.0 and 60 °C for β-1,3-glucanase; and 9.0 and 70 °C for protease. Mycolytic enzymes were moderately thermostable, and had a wide pH stability range extending from pH 5.0 to 10.0. The zymogram analysis of CCF revealed five chitinase isoenzymes with an apparent molecular weight of 20.8, 33.3, 45.6, 67.4, and 114.8 kDa, one β-1,3-glucanase appeared as a single band of ∼131.8 kDa and four protease isoenzymes with approximate molecular weights of 22.8, 62.52, 74.64, and 120.5 kDa. S. violaceusniger MTCC 3959 produced mycolytic enzymes that can be effectively used for suppression of phytopathogenic basidiomycetes. It has the potential to be an effective biofungicide. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Rapid Isolation and Molecular Detection of Streptomycin-Producing Streptomycetes

    Directory of Open Access Journals (Sweden)

    M Motovali-bashi

    2006-07-01

    Full Text Available Introduction: Streptomyces species are mycelial, aerobic gram-positive bacteria that are isolated from soil and produce a diverse range of antibiotics. Streptomyces griseus produces the antibiotic, streptomycin and forms spores even in a liquid culture. The gene cluster for the production of Streptomycin antibiotic contains strR gene that encodes StrR, a pathway-specific regulator. Then, this pathway-specific regulator induces transcription of other streptomycin production genes in the gene cluster. The overall aim of this work was rapid isolation and molecular detection of streptomycin-producing Streptomycetes, especially S. griseus, from Iranian soils in order to manipulate them for increased production of streptomycin. Methods: This research used new initiative half-specific medium for isolation of Streptomycetes from natural environments, called FZmsn. The fifty colonies of Streptomyces strains grown on the surface of FZmsn medium isolated from environmental samples were defined on the basis of their morphological characteristics and light microscope studies. A set of primers was designed to detect strR by OLIGO software. Results: In colony-PCR reactions followed by gel electrophoresis, 6 colonies from Streptomyces strains colonies were detected as S. griseus colonies. Conclusion: These native Streptomyces strains will be used for genetic manipulation of S. griseus in order to increase production levels of streptomycin.

  10. Streptomyces krungchingensis sp. nov., isolated from soil.

    Science.gov (United States)

    Sripreechasak, Paranee; Phongsopitanun, Wongsakorn; Tamura, Tomohiko; Tanasupawat, Somboon

    2017-01-01

    A novel actinomycete, designated strain KC-035T, was isolated from soil collected from Krung Ching Waterfall National Park, Nakhon Si Thammarat Province, Thailand. Its taxonomic position was determined using a polyphasic approach. The strain had morphological and chemotaxonomic properties typical of members of the genus Streptomyces: flexuous spore chain; ll-diaminopimelic acid in the cell-wall peptidoglycan; MK-9(H8), MK-9(H6) and MK-9(H4) as menaquinones; diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside as phospholipids; anteiso-C15 : 0, C16 : 0, iso-C16 : 0, iso-C15 : 0 and iso-C14 : 0 as major cellular fatty acids; and DNA G+C content of 72 mol%. 16S rRNA gene sequence analysis revealed that strain KC-035T showed high similarity to Streptomyces albiflavescens n20T (99.16 %) and Streptomyces siamensis KC-038T (98.43 %) as well as formed a monophyletic clade with them in the phylogenetic tree. On the basis of comparison of phenotypic properties and the low level of DNA-DNA relatedness, strain KC-035T could be distinguished from its closely related Streptomyces species and is considered to represent a novel species of the genus Streptomyces, for which the name Streptomyces krungchingensis sp. nov. is proposed. The type strain is KC-035T (=NBRC 110087T=KCTC 29503T=TISTR 2402T).

  11. Development and application of a T7 RNA polymerase-dependent expression system for antibiotic production improvement in Streptomyces.

    Science.gov (United States)

    Wei, Junhong; Tian, Jinjin; Pan, Guoqing; Xie, Jie; Bao, Jialing; Zhou, Zeyang

    2017-06-01

    To develop a reliable and easy to use expression system for antibiotic production improvement of Streptomyces. A two-compound T7 RNA polymerase-dependent gene expression system was developed to fulfill this demand. In this system, the T7 RNA polymerase coding sequence was optimized based on the codon usage of Streptomyces coelicolor. To evaluate the functionality of this system, we constructed an activator gene overexpression strain for enhancement of actinorhodin production. By overexpression of the positive regulator actII-ORF4 with this system, the maximum actinorhodin yield of engineered strain was 15-fold higher and the fermentation time was decreased by 48 h. The modified two-compound T7 expression system improves both antibiotic production and accelerates the fermentation process in Streptomyces. This provides a general and useful strategy for strain improvement of important antibiotic producing Streptomyces strains.

  12. Synthesis of blue photoluminescent WS{sub 2} quantum dots via ultrasonic cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, A.; Saievar-Iranizad, E., E-mail: saievare@modares.ac.ir

    2017-05-15

    Blue photoluminescent WS{sub 2} quantum dots (QDs) were synthesized using a simple top-down method from natural raw mineral tungsten disulfide via tip ultrasonication followed by centrifugation in a water-ethanol (0.7/0.3 ratio) as eco-friendly solvent. Cavitation process at a high power (300 W) led to the breaking of bulk WS{sub 2} flakes to its quantum dots. The as synthesized WS{sub 2} QDs showed blue photoluminescence upon UV excitation. The synthesized WS{sub 2} QDs were analysed by UV–vis and photoluminescence spectrophotometry, transmission electron microscopy, atomic force microscopy and X-ray diffraction. According to the transmission electron microscopy images, the size of WS{sub 2} QDs was obtained as 5 nm in average. - Highlights: •Large scale blue photoluminescent WS{sub 2} quantum dots was synthesized using Ultrasonic probe (Cavitation Process). •A solution of water/ethanol (0.7/0.3) was used as eco-friendly solvent instead of unsuitable solvent such as NMP and ACN. •Edges of bulk WS{sub 2} was increased with formation of its quantum dots. •Solution of WS{sub 2} QDs was stable after 6 months.

  13. Streptomyces solisilvae sp. nov., isolated from tropical forest soil.

    Science.gov (United States)

    Zhou, Shuangqing; Yang, Xiaobo; Huang, Dongyi; Huang, Xiaolong

    2017-09-01

    A novel streptomycete (strain HNM0141T) was isolated from tropical forest soil collected from Bawangling mountain of Hainan island, PR China and its taxonomic position was established in a polyphasic study. The organism had chemical and morphological properties consistent with its classification as a member of the Streptomyces violaceusnigerclade. On the basis of the results of 16S rRNA gene sequence analysis, HNM0141T showed highest similarity to Streptomyces malaysiensisCGMCC4.1900T (99.4 %), Streptomyces samsunensis DSM 42010T (98.9 %), Streptomyces yatensis NBRC 101000T (98.3 %), Streptomyces rhizosphaericus NBRC 100778T (98.0 %) and Streptomyces sporoclivatus NBRC 100767T (97.9 %). The strain formed a well-delineated subclade with S. malaysiensis CGMCC4.1900T and S. samsunensis DSM 42010T. The levels of DNA-DNA relatedness between HNM0141T and S. malaysiensis CGMCC4.1900T and S. samsunensis DSM 42010T were 62 and 44 %, respectively. On the basis of phenotypic and genotypic characteristics, HNM0141T represents a novel species in the S. violaceusnigerclade for which the name Streptomyces solisilvae sp. nov. is proposed. The type strain is HNM0141 T (=CCTCC AA 2016045T=KCTC 39905T).

  14. Antimicrobial activities of the Streptomyces ceolicolor strain AOB KF977550 isolated from a tropical estuary

    Directory of Open Access Journals (Sweden)

    Bamidele T. Odumosu

    2017-11-01

    Full Text Available The aim of this study was to screen for important antibiotic producing species of the genus Streptomyces from a tropical estuary. Five bacterial strains were isolated from the Lagos lagoon and identified by 16S rDNA gene sequencing as Streptomyces albogriseolus, S. aureus, S. coelicolor, S. albus, and S. pseudogriseolus. Ethyl acetate extracts of Streptomyces spp. fermented broths were evaluated against laboratory strains of MRSA Methicillin-resistant Staphyloccus aureus (MRSA 144 m, Bacillus coagulans UL001, and Escherichia coli as well as the standard strains Klebsiella pneumonia ATCC 8308, Gardnerella vaginalis ATCC 27853 and Salmonella typhi ATCC 13311 using the well diffusion method. The presence of secondary metabolites was determined and analysed using gas chromatography-mass spectrometry (GC-MS. A broad spectrum of activity was only observed for S. coelicolor on all of the tested bacteria except S. typhi, ant GC-MS analysis revealed the presence of 16 secondary metabolites with relevant antibiotic properties. The result of this study suggest that Lagos Lagoon is a potential source and reservoir of novel antibiotics. Keywords: Streptomyces, Antibiotics, Resistance, Secondary Metabolites

  15. Development of an antibiotic marker-free platform for heterologous protein production in Streptomyces.

    Science.gov (United States)

    Sevillano, Laura; Díaz, Margarita; Santamaría, Ramón I

    2017-09-26

    The industrial use of enzymes produced by microorganisms is continuously growing due to the need for sustainable solutions. Nevertheless, many of the plasmids used for recombinant production of proteins in bacteria are based on the use of antibiotic resistance genes as selection markers. The safety concerns and legal requirements surrounding the increased use of antibiotic resistance genes have made the development of new antibiotic-free approaches essential. In this work, a system completely free of antibiotic resistance genes and useful for the production of high yields of proteins in Streptomyces is described. This system is based on the separation of the two components of the yefM/yoeBsl (antitoxin/toxin) operon; the toxin (yoeBsl) gene, responsible for host death, is integrated into the genome and the antitoxin gene (yefMsl), which inactivates the toxin, is located in the expression plasmid. To develop this system, the toxin gene was integrated into the genome of a strain lacking the complete operon, and the antibiotic resistance gene integrated along with the toxin was eliminated by Cre recombinase to generate a final host strain free of any antibiotic resistance marker. In the same way, the antibiotic resistance gene from the final expression plasmid was removed by Dre recombinase. The usefulness of this system was analysed by checking the production of two hydrolases from different Streptomyces. Production of both proteins, with potential industrial use, was high and stable over time after strain storage and after serial subcultures. These results support the robustness and stability of the positive selection system developed. The total absence of antibiotic resistance genes makes this system a powerful tool for using Streptomyces as a host to produce proteins at the industrial level. This work is the first Streptomyces antibiotic marker-free system to be described. Graphical abstract Antibiotic marker-free platform for protein expression in Streptomyces

  16. Localized hydroxylamine mutagenesis, and cotransduction of threonine and lysine genes, in Streptomyces venezuelae.

    Science.gov (United States)

    Stuttard, C

    1983-01-01

    A lysate of the generalized transducing phage SV1, grown on the prototrophic type strain 10712 of Streptomyces venezuelae, was mutagenized with hydroxylamine and used to transduce a lysineless auxotroph to lysine independence on supplemented minimal agar. A complex threonine mutant, strain VS95, was isolated from among the transductants and was shown to be carrying at least two different thr mutations. These were about 50% cotransducible with alleles of four independently isolated lysA mutations, as were two other independently isolated threonine mutations, thr-1 and hom-5. The location of thr genes close to lysA occurs in at least three other streptomycetes, but apparently not in Streptomyces coelicolor A3(2), in which the lysA and thr loci are at diametrically opposite locations on the linkage map. This first observation of cotransduction between loci governing the biosynthesis of different amino acids in the genus Streptomyces demonstrates the feasibility of fine-structure genetic analysis by transduction in these antibiotic-producing bacteria. PMID:6411685

  17. Phenolic Polyketides from the Co-Cultivation of Marine-Derived Penicillium sp. WC-29-5 and Streptomyces fradiae 007

    Directory of Open Access Journals (Sweden)

    Yi Wang

    2014-04-01

    Full Text Available Penicillium sp. WC-29-5 was co-cultured with Streptomyces fradiae 007 to produce five natural products (1–3, 4a and 4b that were isolated and characterized by spectroscopic analysis. Interestingly, these compounds were found to be different from those produced in discrete fungal and bacterial controls. Among these compounds, the absolute configurations of compounds 4a and 4b were determined for the first time by X-ray single crystal diffraction experiments and electronic circular dichroism (ECD calculations. An evaluation of the cytotoxic activities of these compounds revealed that 4b was moderately cytotoxic towards HL-60 and H1975 tumor cells with IC50 values of 3.73 and 5.73 µM, respectively, whereas compound 4a was only moderately cytotoxic towards H1975 cells with an IC50 value of 3.97 µM.

  18. Mining and polishing of the treasure trove in the bacterial genus streptomyces.

    Science.gov (United States)

    Horinouchi, Sueharu

    2007-02-01

    The complex morphogenesis of the bacterial genus Streptomyces has made this genus a model prokaryote for study of multicellular differentiation, and its ability to produce a wide variety of secondary metabolites has made it an excellent supplier of biologically active substances, including antibiotics. This review summarizes our study of these two characteristics of Streptomyces, focusing on the A-factor regulatory cascade and work derived from the A-factor study. A microbial hormone, A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone), triggers morphological differentiation and secondary metabolism in Streptomyces griseus. The key steps in the A-factor regulatory cascade, including afsA, encoding the key enzyme for A-factor biosynthesis, arpA, encoding the A-factor receptor, and adpA, encoding a transcriptional activator, are elucidated. The target genes of the regulatory cascade include genes of various functions required for morphological development and secondary metabolite formation. The biosynthesis gene clusters for grixazone and hexahydroxyperylenequinone are examples. The former contains the enzymes for novel benzene ring formation and phenoxazinone formation, and the latter contains enzymes belonging to a type III polyketide synthase and a cytochrome P-450. Enzymes of various catalytic functions in Streptomyces are useful as members of an artificial gene cluster constructed in Escherichia coli for fermentative production of plant-specific flavonoids, including isoflavones and unnatural compounds.

  19. Vehicle handling and stability control by the cooperative control of 4WS and DYC

    Science.gov (United States)

    Shen, Huan; Tan, Yun-Sheng

    2017-07-01

    This paper proposes an integrated control system that cooperates with the four-wheel steering (4WS) and direct yaw moment control (DYC) to improve the vehicle handling and stability. The design works of the four-wheel steering and DYC control are based on sliding mode control. The integration control system produces the suitable 4WS angle and corrective yaw moment so that the vehicle tracks the desired yaw rate and sideslip angle. Considering the change of the vehicle longitudinal velocity that means the comfort of driving conditions, both the driving torque and braking torque are used to generate the corrective yaw moment. Simulation results show the effectiveness of the proposed control algorithm.

  20. Novel nonsense mutation of the endothelin-B receptor gene in a family with Waardenburg-Hirschsprung disease.

    Science.gov (United States)

    Syrris, P; Carter, N D; Patton, M A

    1999-11-05

    Waardenburg syndrome (WS) comprises sensorineural hearing loss, hypopigmentation of skin and hair, and pigmentary disturbances of the irides. Four types of WS have been classified to date; in WS type IV (WS4), patients additionally have colonic aganglionosis (Hirschsprung disease, HSCR). Mutations in the endothelin-3 (EDN3), endothelin-B receptor (EDNRB), and Sox10 genes have been identified as causative for WS type IV. We screened a family with a combined WS-HSCR phenotype for mutations in the EDNRB locus using standard DNA mutation analysis and sequencing techniques. We have identified a novel nonsense mutation at codon 253 (CGA-->TGA, Arg-->STOP). This mutation leads to a premature end of the translation of EDNRB at exon 3, and it is predicted to produce a truncated and nonfunctional endothelin-B receptor. All affected relatives were heterozygous for the Arg(253)-->STOP mutation, whereas it was not observed in over 50 unrelated individuals used as controls. These data confirm the role of EDNRB in the cause of the Waardenburg-Hirschsprung syndrome and demonstrate that in WS-HSCR there is a lack of correlation between phenotype and genotype and a variable expression of disease even within the same family. Copyright 1999 Wiley-Liss, Inc.

  1. Production of Actinorhodin-Related ‘‘Blue Pigments’’ by Streptomyces coelicolor A3(2)

    NARCIS (Netherlands)

    Bystrykh, Leonid V.; Fernández-Moreno, Miguel A.; Herrema, Jan K.; Malpartida, Francisco; Hopwood, David A.; Dijkhuizen, Lubbert

    1996-01-01

    The genetically well-known strain Streptomyces coelicolor A3(2) produces the pH indicator (red/blue) antibiotic actinorhodin, but not all the ‘‘blue pigment’’ produced by this strain is actinorhodin. When the organism was subjected to various nutrient limitations (ammonium, nitrate, phosphate, or

  2. Carbon fiber cloth supported interwoven WS{sub 2} nanosplates with highly enhanced performances for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Shang, Xiao; Chi, Jing-Qi [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Lu, Shan-Shan [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Gou, Jian-Xia [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Dong, Bin, E-mail: dongbin@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Li, Xiao; Liu, Yan-Ru; Yan, Kai-Li; Chai, Yong-Ming [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Chen-Guang, E-mail: cgliu@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China)

    2017-01-15

    Highlights: • WS{sub 2} nanoplates supported on carbon fiber cloth (WS{sub 2}/CFC) have been synthesized. • WS{sub 2}/CFC has the good dispersion and interwoven structure of WS{sub 2}. • CFC as substrate contributes to enhanced conductivity and close combination. • WS{sub 2}/CFC exhibits ultra-high activity and stability owing to CFC as support. - Abstract: The interwoven WS{sub 2} nanoplates supported on carbon fiber cloth (WS{sub 2}/CFC) have been successfully synthesized by a facile solvothermal process. XRD and XPS confirm the formation of WS{sub 2}/CFC. SEM images show the good dispersion of WS{sub 2} nanoplates with interwoven structures on the surface of CFC. Thanks to the 3D framework of CFC, WS{sub 2} nanoplates realize overall excellent-dispersion interwoven on the surface of CFC compared with pristine bulk WS{sub 2} with severe aggregation. Moreover, CFC not only serves as excellent conductive substrate to accelerate electron transport rate, but also contributes to the close combination between WS{sub 2} and CFC for long-term stability. The electrochemical measurements show that WS{sub 2}/CFC exhibit a high specific capacitance of 399 F g{sup −1} at 1.0 A g{sup −1}, demonstrating the obviously enhanced capability compared with pristine bulk WS{sub 2}. Furthermore, WS{sub 2}/CFC realizes ultra-stable cycling stability with 99% of retention of capacitance after 500 charge-discharge cycles. It may provide novel access of designing carbon-based transition metal disulfides composites for excellent super capacitive properties.

  3. Isolation, Purification, and Characterization of Five Active Diketopiperazine Derivatives from Endophytic Streptomyces SUK 25 with Antimicrobial and Cytotoxic Activities.

    Science.gov (United States)

    Alshaibani, Muhanna; Zin, Noraziah; Jalil, Juriyati; Sidik, Nik; Ahmad, Siti Junaidah; Kamal, Nurkhalida; Edrada-Ebel, Ruangelie

    2017-07-28

    In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as cyclo -( L -Val- L -Pro), cyclo -( L -Leu- L -Pro), cyclo -( L -Phe- L -Pro), cyclo -( L -Val- L -Phe), and N -(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus , with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.

  4. Charge Transfer Properties of Surface-treated WS2 Nanotubes and Fullerene-like Nanoparticles

    Directory of Open Access Journals (Sweden)

    Tiziana DI LUCCIO

    2011-10-01

    Full Text Available We studied the effect of incorporation of inorganic fullerene like nanoparticles (IF and inorganic nanotubes (INT of WS2 into device structures. In order to disperse in a uniform fashion the semiconducting INT/IF WS2 nanoparticles were functionalized with dodecyltrichlorosilane (DTS. Poly-3(hexylthiophene (P3HT has been used along with WS2 nanoparticles as an active layer for the solution processable material in the proposed OLED structure of the type: ITO/WS2/P3HT/LiF-Al to test the electrical effect of the WS2 and to obtain information on its energy levels. Based on the obtained results, we discuss the possibility to use the WS2 nanoparticles in organic electronic devices.

  5. Photoluminescence inhomogeneity and excitons in CVD-grown monolayer WS2

    Science.gov (United States)

    Ren, Dan-Dan; Qin, Jing-Kai; Li, Yang; Miao, Peng; Sun, Zhao-Yuan; Xu, Ping; Zhen, Liang; Xu, Cheng-Yan

    2018-06-01

    Transition metal dichalcogenides two-dimensional materials are of great importance for future electronic and optoelectronic applications. In this work, triangular WS2 monolayers with size up to 130 μm were prepared via chemical vapor deposition method. WS2 monolayers presented uniform Raman intensity, while quenched photoluminescence (PL) was observed in the center. The PL quenching in the central part of WS2 monolayer flakes was attributed to the gradually increasing sulfur vacancies toward the center. The proportion of negative trion (X-) in PL spectrum increases with increasing sulfur vacancies in WS2. The enhanced binding energy of X- suggests higher Fermi level and n-doping level with larger sulfur vacancy concentration. Our findings may be beneficial to the development of integrated devices, and also explore the defect-induced optical and electrical properties for nanophotonics.

  6. Synthesis of silver nanoparticles using the Streptomyces coelicolor klmp33 pigment: An antimicrobial agent against extended-spectrum beta-lactamase (ESBL) producing Escherichia coli

    International Nuclear Information System (INIS)

    Manikprabhu, Deene; Lingappa, K.

    2014-01-01

    The increasing emergence of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) occurred mainly due to continuous persistent exposure to antibiotics causing high morbidity and mortality so studies in controlling this infection are required. In the present investigation, we developed a synthesis for silver nanoparticles employing a pigment produced by Streptomyces coelicolor klmp33, and assessed the antimicrobial activity of these nanoparticles against ESBL producing E. coli. The ESBL producing E. coli were isolated from urine samples collected from the Gulbarga region in India. As can been seen from our studies, the silver nanoparticles having irregular shapes and size of 28–50 nm showed remarkable antimicrobial activity and moreover the synthesis time is just 20 min and thus the same can be used for formulating pharmaceutical remedies. - Highlights: • Silver nanoparticle synthesis by photo-irradiation method in just 20 min • Isolation of ESBL producing E. coli from urine samples from the Gulbarga region. • Antimicrobial activity of silver nanoparticles against ESBL producing E. coli • The minimum inhibitory concentration of silver nanoparticles against ESBL producing E. coli was 40 μL

  7. Synthesis of silver nanoparticles using the Streptomyces coelicolor klmp33 pigment: An antimicrobial agent against extended-spectrum beta-lactamase (ESBL) producing Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Manikprabhu, Deene; Lingappa, K., E-mail: lingappak123@gmail.com

    2014-12-01

    The increasing emergence of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) occurred mainly due to continuous persistent exposure to antibiotics causing high morbidity and mortality so studies in controlling this infection are required. In the present investigation, we developed a synthesis for silver nanoparticles employing a pigment produced by Streptomyces coelicolor klmp33, and assessed the antimicrobial activity of these nanoparticles against ESBL producing E. coli. The ESBL producing E. coli were isolated from urine samples collected from the Gulbarga region in India. As can been seen from our studies, the silver nanoparticles having irregular shapes and size of 28–50 nm showed remarkable antimicrobial activity and moreover the synthesis time is just 20 min and thus the same can be used for formulating pharmaceutical remedies. - Highlights: • Silver nanoparticle synthesis by photo-irradiation method in just 20 min • Isolation of ESBL producing E. coli from urine samples from the Gulbarga region. • Antimicrobial activity of silver nanoparticles against ESBL producing E. coli • The minimum inhibitory concentration of silver nanoparticles against ESBL producing E. coli was 40 μL.

  8. A study on mutagenic effects of antibiotic-producers by ion implantation

    International Nuclear Information System (INIS)

    Xie Liqing; Zhang Yinfen; Chen Ruyi; Zhou Ruiying; Zhang Peiling; Ying Hengfeng; Yang Guorong; Yang Guifang

    1995-01-01

    Mutagenic effects of Streptomyces ribosidificus, Streptomyces kanamyceticus and the phage-resistant culture of Streptomyces kanamyceticus induced by N + and C + ion implantation with different doses have been investigated. The experimental results show that the death rates of antibiotic-producers increase with the increase of ion implantation dose, and the form mutation of the antibiotic-producers is rather obvious. After N + ion implantation, the titer units increase by 10%-25%, 5.2%-12.1% and 2.1%-12.75% for the above three strains respectively; while after C + ion implantation the titer units increase by 10%-16.9%, 1.05%-3.08% and 5%-20% respectively. The selected strains of Micromonospora echimospoora and Streptomyces kanamyceticus after N + ion implantation have been used in the factory. The increase of production is 20% and 12.5% respectively and marked economic benefits are obtained

  9. Molecular cloning and characterization of l-methionine γ-lyase from Streptomyces avermitilis.

    Science.gov (United States)

    Kudou, Daizou; Yasuda, Eri; Hirai, Yoshiyuki; Tamura, Takashi; Inagaki, Kenji

    2015-10-01

    A pyridoxal 5'-phosphate-dependent methionine γ-lyase (MGL) was cloned from Streptomyces avermitilis catalyzed the degradation of methionine to α-ketobutyrate, methanethiol, and ammonia. The sav7062 gene (1,242 bp) was corresponded to 413 amino acid residues with a molecular mass of 42,994 Da. The deduced amino acid sequence showed a high degree of similarity to those of other MGL enzymes. The sav7062 gene was overexpressed in Escherichia coli. The enzyme was purified to homogeneity and exhibited the MGL catalytic activities. We cloned the enzyme that has the MGL activity in Streptomyces for the first time. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  10. Growth Promotion and Disease Suppression Ability of a Streptomyces sp. CB-75 from Banana Rhizosphere Soil

    Science.gov (United States)

    Chen, Yufeng; Zhou, Dengbo; Qi, Dengfeng; Gao, Zhufen; Xie, Jianghui; Luo, Yanping

    2018-01-01

    An actinomycete strain, CB-75, was isolated from the soil of a diseased banana plantation in Hainan, China. Based on phenotypic and molecular characteristics, and 99.93% sequence similarity with Streptomyces spectabilis NBRC 13424 (AB184393), the strain was identified as Streptomyces sp. This strain exhibited broad-spectrum antifungal activity against 11 plant pathogenic fungi. Type I polyketide synthase (PKS-I) and non-ribosomal peptide synthetase (NRPS) were detected, which were indicative of the antifungal compounds that Streptomyces sp. CB-75 could produce. An ethyl acetate extract from the strain exhibited the lowest minimum inhibitory concentration (MIC) against Colletotrichum musae (ATCC 96167) (0.78 μg/ml) and yielded the highest antifungal activity against Colletotrichum gloeosporioides (ATCC 16330) (50.0 μg/ml). Also, spore germination was significantly inhibited by the crude extract. After treatment with the crude extract of Streptomyces sp. CB-75 at the concentration 2 × MIC, the pathogenic fungi showed deformation, shrinkage, collapse, and tortuosity when observed by scanning electron microscopy (SEM). By gas chromatography-mass spectrometry (GC-MS) of the crude extract, 18 chemical constituents were identified; (Z)-13-docosenamide was the major constituent. Pot experiments showed that the incidence of banana seedlings was reduced after using Streptomyces sp. CB-75 treatment. The disease index was 10.23, and the prevention and control effect was 83.12%. Furthermore, Streptomyces sp. CB-75 had a growth-promoting effect on banana plants. The chlorophyll content showed 88.24% improvement, the leaf area, root length, root diameter, plant height, and stem showed 88.24, 90.49, 136.17, 61.78, and 50.98% improvement, respectively, and the shoot fresh weight, root fresh weight, shoot dry weight, and root dry weight showed 82.38, 72.01, 195.33, and 113.33% improvement, respectively, compared with treatment of fermentation broth without Streptomyces sp. CB-75

  11. Revelation and cloning of valinomycin synthetase genes in Streptomyces lavendulae ACR-DA1 and their expression analysis under different fermentation and elicitation conditions.

    Science.gov (United States)

    Sharma, Richa; Jamwal, Vijaylakshmi; Singh, Varun P; Wazir, Priya; Awasthi, Praveen; Singh, Deepika; Vishwakarma, Ram A; Gandhi, Sumit G; Chaubey, Asha

    2017-07-10

    Streptomyces species are amongst the most exploited microorganisms due to their ability to produce a plethora of secondary metabolites with bioactive potential, including several well known drugs. They are endowed with immense unexplored potential and substantial efforts are required for their isolation as well as characterization for their bioactive potential. Unexplored niches and extreme environments are host to diverse microbial species. In this study, we report Streptomyces lavendulae ACR-DA1, isolated from extreme cold deserts of the North Western Himalayas, which produces a macrolactone antibiotic, valinomycin. Valinomycin is a K + ionophoric non-ribosomal cyclodepsipeptide with a broad range of bioactivities including antibacterial, antifungal, antiviral and cytotoxic/anticancer activities. Production of valinomycin by the strain S. lavendulae ACR-DA1 was studied under different fermentation conditions like fermentation medium, temperature and addition of biosynthetic precursors. Synthetic medium at 10°C in the presence of precursors i.e. valine and pyruvate showed enhanced valinomycin production. In order to assess the impact of various elicitors, expression of the two genes viz. vlm1 and vlm2 that encode components of heterodimeric valinomycin synthetase, was analyzed using RT-PCR and correlated with quantity of valinomycin using LC-MS/MS. Annelid, bacterial and yeast elicitors increased valinomycin production whereas addition of fungal and plant elicitors down regulated the biosynthetic genes and reduced valinomycin production. This study is also the first report of valinomycin biosynthesis by Streptomyces lavendulae. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Taxonomic evaluation of Streptomyces hirsutus and related species using multi-locus sequence analysis

    Science.gov (United States)

    Phylogenetic analyses of species of Streptomyces based on 16S rRNA gene sequences resulted in a statistically well-supported clade (100% bootstrap value) containing 8 species having very similar gross morphology. These species, including Streptomyces bambergiensis, Streptomyces chlorus, Streptomyces...

  13. Production Of Vitamin B 12 By Streptomyces Fulvissimus | Atta ...

    African Journals Online (AJOL)

    Fifty five of actinomycete isolates were screened for vitamin B12 production by growing on soybean meal medium fortified with cobalt. Only one AZ-Z-88 among nine actinomycete cultures was found to produce significantly higher yield of the vitamin B12 (64.57 ug/ml). Determination of vitamin B12 production was carried out ...

  14. Taxonomy of Streptomyces strains isolated from rhizospheres of ...

    African Journals Online (AJOL)

    Taxonomy of Streptomyces strains isolated from rhizospheres of various plant species grown in Taif region, KSA, having antagonistic activities against some microbial tissue ... African Journal of Biotechnology ... Keywords: Taxonomy, Streptomyces, microbial tissue culture contaminants, antagonistic activities, 16S rRNA

  15. 75 FR 49992 - Peter W.S. Grigg, M.D.; Revocation of Registration

    Science.gov (United States)

    2010-08-16

    ... DEPARTMENT OF JUSTICE Drug Enforcement Administration Peter W.S. Grigg, M.D.; Revocation of... Order to Show Cause and Immediate Suspension of Registration to Peter W.S. Grigg, M.D. (Respondent), of... Registration, BG2107856, issued to Peter W.S. Grigg, M.D., be, and it hereby is, revoked. This Order is...

  16. Phosphoproteome analysis of streptomyces development reveals extensive protein phosphorylation accompanying bacterial differentiation

    DEFF Research Database (Denmark)

    Manteca, Angel; Ye, Juanying; Sánchez, Jesús

    2011-01-01

    Streptomycetes are bacterial species that undergo a complex developmental cycle that includes programmed cell death (PCD) events and sporulation. They are widely used in biotechnology because they produce most clinically relevant secondary metabolites. Although Streptomyces coelicolor is one...... events were detected during the presporulation and sporulation stages (80%). Most of these phosphorylations were not reported before in Streptomyces, and included sporulation factors, transcriptional regulators, protein kinases and other regulatory proteins. Several of the identified phosphorylated...... proteins, FtsZ, DivIVA, and FtsH2, were previously demonstrated to be involved in the sporulation process. We thus established for the first time the widespread occurrence and dynamic features of Ser/Thr/Tyr protein phosphorylation in a bacteria species and also revealed a previously unrecognized...

  17. StreptomycesInforSys: A web-enabled information repository.

    Science.gov (United States)

    Jain, Chakresh Kumar; Gupta, Vidhi; Gupta, Ashvarya; Gupta, Sanjay; Wadhwa, Gulshan; Sharma, Sanjeev Kumar; Sarethy, Indira P

    2012-01-01

    Members of Streptomyces produce 70% of natural bioactive products. There is considerable amount of information available based on polyphasic approach for classification of Streptomyces. However, this information based on phenotypic, genotypic and bioactive component production profiles is crucial for pharmacological screening programmes. This is scattered across various journals, books and other resources, many of which are not freely accessible. The designed database incorporates polyphasic typing information using combinations of search options to aid in efficient screening of new isolates. This will help in the preliminary categorization of appropriate groups. It is a free relational database compatible with existing operating systems. A cross platform technology with XAMPP Web server has been used to develop, manage, and facilitate the user query effectively with database support. Employment of PHP, a platform-independent scripting language, embedded in HTML and the database management software MySQL will facilitate dynamic information storage and retrieval. The user-friendly, open and flexible freeware (PHP, MySQL and Apache) is foreseen to reduce running and maintenance cost. www.sis.biowaves.org.

  18. Novel poly(3-hydroxybutyrate) nanocomposites containing WS{sub 2} inorganic nanotubes with improved thermal, mechanical and tribological properties

    Energy Technology Data Exchange (ETDEWEB)

    Naffakh, Mohammed, E-mail: mohammed.naffakh@upm.es [Universidad Politécnica de Madrid, Departamento de Ingeniería y Ciencia de los Materiales, Escuela Técnica Superior de Ingenieros Industriales, José Gutiérrez Abascal 2, 28006 Madrid (Spain); Marco, Carlos; Ellis, Gary [CSIC, Instituto de Ciencia y Tecnología de Polímeros (ICTP), Juan de la Cierva 3, 28006 Madrid (Spain); Cohen, Sidney R. [Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 76100 (Israel); Laikhtman, Alexander; Rapoport, Lev; Zak, Alla [Department of Sciences, Holon Institute of Technology, 52 Golomb St., Holon 58102 (Israel)

    2014-09-15

    Poly(3-hydroxybutyrate) (PHB) nanocomposites containing environmentally-friendly tungsten disulphide inorganic nanotubes (INT–WS{sub 2}) have been successfully prepared by a simple solution blending method. The dynamic and isothermal crystallization studies by differential scanning calorimetry (DSC) demonstrated that the INT–WS{sub 2} exhibits much more prominent nucleation activity on the crystallization of PHB than specific nucleating agents or other nanoscale fillers. Both crystallization rate and crystallinity significantly increase in the nanocomposites compared to neat PHB. These changes occur without modifying the crystalline structure of PHB in the nanocomposites, as shown by wide-angle X-ray diffraction (WAXS) and infrared/Raman spectroscopy. Other parameters such as the Avrami exponent, the equilibrium melting temperature, global rate constant and the fold surface free energy of PHB chains in the nanocomposites were obtained from the calorimetric data in order to determine the influence of the INT–WS{sub 2} filler. The addition of INT–WS{sub 2} remarkably influences the energetics and kinetics of nucleation and growth of PHB, reducing the fold surface free energy by up to 20%. Furthermore, these nanocomposites also show an improvement in both tribological and mechanical (hardness and modulus) properties with respect to pure PHB evidenced by friction and nanoindentation tests, which is of important potential interest for industrial and medical applications. - Highlights: • Environmentally-friendly INT–WS{sub 2} is used to produce advanced PHB NCPs. • Novel PHB NCPs are obtained without using modifiers or surfactants. • Novel INT–WS{sub 2} improve the thermal and mechanical properties of PHB. • INT–WS{sub 2} is effective in reducing the friction coefficient of PHB. • The benefits of using INTs compared to other nanoscale fillers are highlighted.

  19. Optimization and characterization of biosurfactant from Streptomyces griseoplanus NRRL-ISP5009 (MS1).

    Science.gov (United States)

    Elkhawaga, M A

    2018-03-01

    This work aimed to study, isolate, characterize and stabilize the biosurfactant isolated from actinomycetes found in petroleum contaminated soil. Optimized production of the biosurfactant from Streptomyces griseoplanus NRRL-ISP5009, SM1 was obtained on day 6 at 30°C, pH 7, 150 rev min -1 , in glycerol yeast extract broth medium supplemented with cellulose, yeast extract and 1% NaCl. The stability of the biosurfactant produced was studied at different temperatures, pH and different concentrations of NaCl. The produced biosurfactant was extracted and purified. Streptomyces griseoplanus NRRL-ISP5009, SM1 isolated from oil contaminated soil produced a biosurfactant exhibiting emulsification activity. The produced biosurfactant is a mixture of carbohydrate, lipid and protein. It has promising characteristics, including a higher stability at alkaline pH than at acidic pH, a salinity of 1-3% and stable in the temperature range from 0 and 100°C. Also, the potential antimicrobial activity of the purified biosurfactant was recorded. The research was focused on the isolation of a novel source of biosurfactants that have great importance in the manufacture of food, detergent, pharmaceutical and cosmetics. © 2017 The Society for Applied Microbiology.

  20. Streptomyces development in colonies and soils

    DEFF Research Database (Denmark)

    Manteca, Angel; Sanchez, Jesus

    2009-01-01

    Streptomyces development was analyzed under conditions resembling those in soil. The mycelial growth rate was much lower than that in standard laboratory cultures, and the life span of the previously named first compartmentalized mycelium was remarkably increased.......Streptomyces development was analyzed under conditions resembling those in soil. The mycelial growth rate was much lower than that in standard laboratory cultures, and the life span of the previously named first compartmentalized mycelium was remarkably increased....

  1. Mutants of Streptomyces coeruleorubidus impaired in the biosynthesis of daunomycinone glycosides and related metabolites

    International Nuclear Information System (INIS)

    Blumauerova, M.; Stajner, K.; Pokorny, V.; Hostalek, Z.; Vanek, Z.

    1978-01-01

    Mutants of Streptomyces coeruleorubidus, blocked in the biosynthesis of anthracycline antibiotics of the daunomycine complex, were isolated from the production strains after treatment with UV light, γ-radiation, nitrous acid, and after natural selection; according to their different biosynthetic activity the mutants were divided into five phenotypic groups. Mutants of two of these groups produced compounds that had not yet been described in Streptomyces coeruleorubidus (aklavinone, 7-deoxyaklavinone, zeta-rhodomycinone and glycosides of epsilon-rhodomycinone). The mutants differed from the parent strains and also mutually in morphological characteristics but no direct correlation between these changes and the biosynthetic activity could be observed in most cases. (author)

  2. Streptomyces effect on the bacterial microbiota associated to Crassostrea sikamea oyster.

    Science.gov (United States)

    García Bernal, M; Trabal Fernández, N; Saucedo Lastra, P E; Medina Marrero, R; Mazón-Suástegui, J M

    2017-03-01

    To determine the composition and diversity of the microbiota associated to Crassostrea sikamea treated during 30 days with Streptomyces strains N7 and RL8. DNA was extracted from oysters followed by 16S rRNA gene amplification and pyrosequencing. The highest and lowest species diversity richness was observed in the initial and final control group, whereas Streptomyces-treated oysters exhibited intermediate values. Proteobacteria was the most abundant phylum (81·4-95·1%), followed by Bacteroidetes, Actinobacteria and Firmicutes. The genera Anderseniella, Oceanicola, Roseovarius, Ruegeria, Sulfitobacter, Granulosicoccus and Marinicella encompassed the core microbiota of all experimental groups. The genus Bacteriovorax was detected in all groups except in the final control and the depurated N7, whereas Vibrio remained undetected in all Streptomyces-treated groups. RL8 was the only group that harboured the genus Streptomyces in its microbiota. Principal component analysis showed that Streptomyces strains significantly changed oyster microbiota with respect to the initial and final control. Crassostrea sikamea treated with Streptomyces showed high species diversity and a microbiota composition shift, characterized by keeping the predator genus Bacteriovorax and decreasing the pathogenic Vibrio. This is the first culture-independent study showing the effect of Streptomyces over the oyster microbiota. It also sheds light about the potential use of Streptomyces to improve mollusc health and safety for consumers after the depuration process. © 2016 The Society for Applied Microbiology.

  3. Dependence of atomic oxygen resistance and the tribological properties on microstructures of WS2 films

    International Nuclear Information System (INIS)

    Xu, Shusheng; Gao, Xiaoming; Hu, Ming; Sun, Jiayi; Jiang, Dong; Wang, Desheng; Zhou, Feng; Weng, Lijun; Liu, Weimin

    2014-01-01

    Graphical abstract: - Highlights: • Pure WS 2 and WS 2 -Al composite films with different structures were prepared. • The compactness of WS 2 film was significantly improved due to incorporation of Al. • Different mechanisms of atomic oxygen resistance of both the films were discussed. • Films before and after AO irradiation kept the unchanged tribological properties. • The composite films showed much better wear resistance than pure WS 2 film. - Abstract: To study the anti-oxidation mechanism of WS 2 films, the pure WS 2 , and Al doped WS 2 composite films were prepared via radio frequency sputtering and the atomic oxygen (AO) irradiation tests were conducted using a ground AO simulation facility. The tribological properties of both films before and after AO irradiation were evaluated using vacuum ball-on-disk tribo-tester. The incorporation of a small fraction of Al dopant resulted in microstructure change from loose columnar platelet with significant porosity for pure WS 2 film to very dense structure. In pure WS 2 film, WS 2 exists as crystalline phase with edge-plane preferential orientation, but nanocrystalline and amorphous phase coexists for the WS 2 -Al composite film. Even if large amount of AO transported into the interior through the longitudinal pores, the pure film showed good AO irradiation resistance owing to the basal plane of WS 2 crystal exhibiting much higher anti-oxidation capacity than the edge-plane. The composite film also had excellent AO irradiation resistance due to the formation of effective thinner WO 3 cladding layer in the sub-surface layer. Tribological results revealed that the composite films showed a significantly improved wear resistance, in comparison to the pure WS 2 film. Besides, due to the effective AO resistance, the tribological properties of WS 2 films remained almost unchanged before and after AO irradiation

  4. WS_2 nanosheets based on liquid exfoliation as effective electrocatalysts for hydrogen evolution reaction

    International Nuclear Information System (INIS)

    Han, Guan-Qun; Liu, Yan-Ru; Hu, Wen-Hui; Dong, Bin; Li, Xiao; Chai, Yong-Ming; Liu, Yun-Qi; Liu, Chen-Guang

    2015-01-01

    WS_2 nanosheets (WS_2 NSs) as electrocatalysts for hydrogen evolution reaction (HER) have been prepared based on liquid exfoliation in dimethyl-formamide (DMF) via a direct dispersion and ultrasonication method. X-ray diffraction (XRD) shows the decreasing crystalline of the exfoliated WS_2 (E-WS_2). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the as prepared E-WS_2 consists of a few two-dimensional nanosheets, with large wrinkles on the surface. Electrochemical measurements show an excellent activity and stability of the E-WS_2, with a low overpotential of 80 mV and high current density (10 mA cm"−"2, at η = 205 mV), which indicates that through the process of exfoliation in DMF, both the dispersion and the amount of active sites have been improved greatly. Therefore, DMF is a promising alternative for exfoliating two-dimensional nanomaterials for highly efficient HER electrocatalysts. - Highlights: • A facile exfoliation process in DMF has been used to prepare E-WS_2 for HER. • E-WS_2 shows the better electrocatalytic activity than bulk WS_2. • DMF provides a promising alternative for enhancing exfoliation of 2D materials.

  5. Synthesis of Large-Scale Single-Crystalline Monolayer WS2 Using a Semi-Sealed Method

    Directory of Open Access Journals (Sweden)

    Feifei Lan

    2018-02-01

    Full Text Available As a two-dimensional semiconductor, WS2 has attracted great attention due to its rich physical properties and potential applications. However, it is still difficult to synthesize monolayer single-crystalline WS2 at larger scale. Here, we report the growth of large-scale triangular single-crystalline WS2 with a semi-sealed installation by chemical vapor deposition (CVD. Through this method, triangular single-crystalline WS2 with an average length of more than 300 µm was obtained. The largest one was about 405 μm in length. WS2 triangles with different sizes and thicknesses were analyzed by optical microscope and atomic force microscope (AFM. Their optical properties were evaluated by Raman and photoluminescence (PL spectra. This report paves the way to fabricating large-scale single-crystalline monolayer WS2, which is useful for the growth of high-quality WS2 and its potential applications in the future.

  6. Streptomyces communities in soils polluted with heavy metals

    Science.gov (United States)

    Grishko, V. N.; Syshchikova, O. V.

    2009-02-01

    The contents of differently mobile heavy metal compounds and their influence on the formation of microbial cenoses (particularly, streptomyces communities) in technogenically disturbed soils are considered. Elevated concentrations of mobile Cu, Zn, Ni, Cd, and Fe compounds are shown to determine structural-functional changes in microbial cenoses that are displayed in a decreasing number of microorganisms and a narrower spectrum of the streptomyces species. Some specific features of the formation of streptomyces communities in technogenic soils were revealed on the basis of the analysis of their species structure with the use of the Margalef, Berger-Parker, and Sorensen indices of biodiversity.

  7. Variable antibiotic susceptibility patterns among Streptomyces species causing actinomycetoma in man and animals

    Directory of Open Access Journals (Sweden)

    Hamid Mohamed E

    2011-06-01

    Full Text Available Abstract Background Drug therapy is recommended in conjunction with surgery in treatment of actinomycetoma. The specific prescription depends on the type of bacteria (actinomycetoma or fungi (eumycetoma causing the disease and their in vitro antimicrobial susceptibility. Objectives To investigate the antimicrobial susceptibility among isolates of Streptomyces spp. isolated from cases of actinomycetoma in man and animals in Sudan. Methods Streptomyces strains (n = 18 isolated from cases of actinomycetoma were tested in vitro against 15 commonly prescribed antibacterial agents using MIC agar dilution method as per standard guidelines. Results Streptomyces strains isolated from actinomycetoma fall into various phenotypic groups. All of the strains were inhibited by novobiocin (8 μg/mL, gentamycin (8, 32 μg/mL and doxycycline (32 μg/mL. Fusidic acid (64 μg/mL inhibited 94.4% of the strains; bacitracin, streptomycin, cephaloridine, clindamycin, ampicillin, rifampicin and tetracycline (64 μg/mL inhibited between 61.1 and 77.8% of the strains. All strains were found resistant to amphotericin B (64 μg/mL, penicillin (20 μg/mL and sulphamethoxazole (64 μg/mL. Conclusions Saprophytic Streptomyces spp. cause actinomycetoma in man and animal belong to separate phenotypes and have a wide range of susceptibility patterns to antimicrobial agents, which pose a lot of difficulties in selecting effective in vivo treatment for actinomycetoma.

  8. Sporulation-specific cell division defects in ylmE mutants of Streptomyces coelicolor are rescued by additional deletion of ylmD.

    Science.gov (United States)

    Zhang, Le; Willemse, Joost; Hoskisson, Paul A; van Wezel, Gilles P

    2018-05-09

    Cell division during the reproductive phase of the Streptomyces life-cycle requires tight coordination between synchronous formation of multiple septa and DNA segregation. One remarkable difference with most other bacterial systems is that cell division in Streptomyces is positively controlled by the recruitment of FtsZ by SsgB. Here we show that deletion of ylmD (SCO2081) or ylmE (SCO2080), which lie in operon with ftsZ in the dcw cluster of actinomycetes, has major consequences for sporulation-specific cell division in Streptomyces coelicolor. Electron and fluorescence microscopy demonstrated that ylmE mutants have a highly aberrant phenotype with defective septum synthesis, and produce very few spores with low viability and high heat sensitivity. FtsZ-ring formation was also highly disturbed in ylmE mutants. Deletion of ylmD had a far less severe effect on sporulation. Interestingly, the additional deletion of ylmD restored sporulation to the ylmE null mutant. YlmD and YlmE are not part of the divisome, but instead localize diffusely in aerial hyphae, with differential intensity throughout the sporogenic part of the hyphae. Taken together, our work reveals a function for YlmD and YlmE in the control of sporulation-specific cell division in S. coelicolor, whereby the presence of YlmD alone results in major developmental defects.

  9. Native and engineered clifednamide biosynthesis in multiple Streptomyces spp.

    OpenAIRE

    Blodgett, Joshua; Ding, Edward; Qi, Yunci

    2017-01-01

    Polycyclic tetramate macrolactam (PTM) natural products are produced by actinomycetes and other bacteria. PTMs are often bioactive, and the simplicity of their biosynthetic clusters make them attractive for bioengineering. Clifednamide-type PTMs from Streptomyces sp. JV178 contain a distinctive ketone group, suggesting the existence of a novel PTM oxidizing enzyme. Here, we report the new cytochrome P450 enzyme (CftA) is required for clifednamide production. Genome mining was used to identify...

  10. Diverse and Abundant Secondary Metabolism Biosynthetic Gene Clusters in the Genomes of Marine Sponge Derived Streptomyces spp. Isolates

    Directory of Open Access Journals (Sweden)

    Stephen A. Jackson

    2018-02-01

    Full Text Available The genus Streptomyces produces secondary metabolic compounds that are rich in biological activity. Many of these compounds are genetically encoded by large secondary metabolism biosynthetic gene clusters (smBGCs such as polyketide synthases (PKS and non-ribosomal peptide synthetases (NRPS which are modular and can be highly repetitive. Due to the repeats, these gene clusters can be difficult to resolve using short read next generation datasets and are often quite poorly predicted using standard approaches. We have sequenced the genomes of 13 Streptomyces spp. strains isolated from shallow water and deep-sea sponges that display antimicrobial activities against a number of clinically relevant bacterial and yeast species. Draft genomes have been assembled and smBGCs have been identified using the antiSMASH (antibiotics and Secondary Metabolite Analysis Shell web platform. We have compared the smBGCs amongst strains in the search for novel sequences conferring the potential to produce novel bioactive secondary metabolites. The strains in this study recruit to four distinct clades within the genus Streptomyces. The marine strains host abundant smBGCs which encode polyketides, NRPS, siderophores, bacteriocins and lantipeptides. The deep-sea strains appear to be enriched with gene clusters encoding NRPS. Marine adaptations are evident in the sponge-derived strains which are enriched for genes involved in the biosynthesis and transport of compatible solutes and for heat-shock proteins. Streptomyces spp. from marine environments are a promising source of novel bioactive secondary metabolites as the abundance and diversity of smBGCs show high degrees of novelty. Sponge derived Streptomyces spp. isolates appear to display genomic adaptations to marine living when compared to terrestrial strains.

  11. Cloning of the staurosporine biosynthetic gene cluster from Streptomyces sp. TP-A0274 and its heterologous expression in Streptomyces lividans.

    Science.gov (United States)

    Onaka, Hiroyasu; Taniguchi, Shin-ichi; Igarashi, Yasuhiro; Furumai, Tamotsu

    2002-12-01

    Staurosporine is a representative member of indolocarbazole antibiotics. The entire staurosporine biosynthetic and regulatory gene cluster spanning 20-kb was cloned from Streptomyces sp. TP-A0274 and sequenced. The gene cluster consists of 14 ORFs and the amino acid sequence homology search revealed that it contains three genes, staO, staD, and staP, coding for the enzymes involved in the indolocarbazole aglycone biosynthesis, two genes, staG and staN, for the bond formation between the aglycone and deoxysugar, eight genes, staA, staB, staE, staJ, staI, staK, staMA, and staMB, for the deoxysugar biosynthesis and one gene, staR is a transcriptional regulator. Heterologous gene expression of a 38-kb fragment containing a complete set of the biosynthetic genes for staurosporine cloned into pTOYAMAcos confirmed its role in staurosporine biosynthesis. Moreover, the distribution of the gene for chromopyrrolic acid synthase, the key enzyme for the biosynthesis of indolocarbazole aglycone, in actinomycetes was investigated, and rebD homologs were shown to exist only in the strains producing indolocarbazole antibiotics.

  12. Purification, characterization, cytotoxicity and anticancer activities of L-asparaginase, anti-colon cancer protein, from the newly isolated alkaliphilic Streptomyces fradiae NEAE-82

    Science.gov (United States)

    El-Naggar, Noura El-Ahmady; Deraz, Sahar F.; Soliman, Hoda M.; El-Deeb, Nehal M.; El-Ewasy, Sara M.

    2016-01-01

    L-asparaginase is an important enzyme as therapeutic agents used in combination with other drugs in the treatment of acute lymphoblastic leukemia. A newly isolated actinomycetes strain, Streptomyces sp. NEAE-82, was potentially producing extracellular L-asparaginase, it was identified as Streptomyces fradiae NEAE-82, sequencing product was deposited in the GenBank database under accession number KJ467538. L-asparaginase was purified from the crude enzyme using ammonium sulfate precipitation, dialysis and ion exchange chromatography using DEAE Sepharose CL-6B. Further the kinetic studies of purified enzyme were carried out. The optimum pH, temperature and incubation time for maximum L-asparaginase activity were found to be 8.5, 40 °C and 30 min, respectively. The optimum substrate concentration was found to be 0.06 M. The Km and Vmax of the enzyme were 0.01007 M and 95.08 Uml−1min−1, respectively. The half-life time (T1/2) was 184.91 min at 50 °С, while being 179.53 min at 60 °С. The molecular weight of the subunits of L-asparaginase was found to be approximately 53 kDa by SDS–PAGE analysis. The purified L-asparaginase showed a final specific activity of 30.636 U/mg protein and was purified 3.338-fold. The present work for the first time reported more information in the production, purification and characterization of L-asparaginase produced by newly isolated actinomycetes Streptomyces fradiae NEAE-82. PMID:27605431

  13. Ultrathin MoS2 and WS2 layers on silver nano-tips as electron emitters

    Science.gov (United States)

    Loh, Tamie A. J.; Tanemura, Masaki; Chua, Daniel H. C.

    2016-09-01

    2-dimensional (2D) inorganic analogues of graphene such as MoS2 and WS2 present interesting opportunities for field emission technology due to their high aspect ratio and good electrical conductivity. However, research on 2D MoS2 and WS2 as potential field emitters remains largely undeveloped compared to graphene. Herein, we present an approach to directly fabricate ultrathin MoS2 and WS2 onto Ag nano-tips using pulsed laser deposition at low temperatures of 450-500 °C. In addition to providing a layer of chemical and mechanical protection for the Ag nano-tips, the growth of ultrathin MoS2 and WS2 layers on Ag led to enhanced emission properties over that of pristine nano-tips due to a reduction of the effective barrier height arising from charge injection from Ag to the overlying MoS2 or WS2. For WS2 on Ag nano-tips, the phasic mixture was also an important factor influencing the field emission performance. The presence of 1T-WS2 at the metal-WS2 interface in a hybrid film of 2H/1T-WS2 leads to improvement in the field emission capabilities as compared to pure 2H-WS2 on Ag nano-tips.

  14. Karakterisasi Parsial Streptomyces spp., Agens Pengendali Hayati Peyakit Lincat Tembakau

    Directory of Open Access Journals (Sweden)

    Triwidodo Arwiyanto

    2007-12-01

    Full Text Available Local isolates of Streptomyces spp. were proven could suppress "lincat disease" of tobacco in the field. Six isolates were chosen for partial characterization of their bacteriological properties as based for the next experiments purposes. The results indicated that the isolates produce miselium with spore chains, gram positive, aerob, catalase and oxidase positive. The isolates also hydrolize starch, gelatine and esculine; produce lecithinase enzyme, reduce nitrate to nitrite, do not produce melanine pigment, did not produce hydrogen sulfide. The isolates were sensitive against streptomycine and rifampicin; able to use several carbon and nitrogen sources tested. Capable to grow on several medium pH, from 4,3 to 8,0. The isolates were able to grow from 5° C to 45° C; able to grow on medium containing 4% to 7% NaCl and ion the medium containing 0,1% of phenol. Plant pathogenicity test result showed negative responses which indicated that the used isolates were non plant pathogenic. The ability in suppressing lincat pathogen (Ralstonia solanacearum and Meloidogyne incognita in vitro was vary between isolates.   Streptomyces spp, isolat lokal terbukti dapat menekan penyakit lunvat tembakau di lapangan. Sebanyak enam isolat dipilih untuk dicirikan sebagai sifat-sifat bakteriologinya sehingga dapat digunakan sebagai dasar dalam penelitian berikutnya. Penelitian dilakukan terhadap sifat morfologi, fisiologi dan sifat biokimia. Hasil penelitian menunjukkan bahwa isolat yang diteliti menghasilkan miselium yang memproduksi rangkaian spora, Gram positif, aerob, katalase dan oksidase positif. Isolat-isolat tersebut menghidrolisis pati, gelatin, eskulin; membentuk ensim lechitinase, mereduksi nitrat menjadi nitrit, tidak menghasilkan pigmen melanin, tidak membentuk hidrogen sulfida. Isolat yang diteliti peka terhadap antibiotik streptomisin dan nifampisin; mampu menggunakan beberapa sumber karbon dan sumber nitrogen yang diujikan, Kisaran pH untuk

  15. An approach for scalable production of silver (Ag) decorated WS2 nanosheets

    Science.gov (United States)

    Sumesh, C. K.; Kapatel, Sanni; Chaudhari, Arti

    2018-05-01

    In the Present study we report the synthesis of Ag nanoparticles (NPs) decorated WS2 nanosheets by sonochemical exfoliation followed by simple chemical reduction process at room temperature. The morphology and microstructure of the as-synthesized Ag-WS2 nanocomposite were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and optical absorption (UV-Vis.) spectroscopy. X-ray and TEM analysis shows the presence of Ag with significant peak over 38.08°, 44.22°, 64.37° and 77.33° at 2θ angle for (111), (200), (220) and (311) respectively. The Ag nanoparticles are randomly distributed throughout the surface of the WS2 nanosheets without undergoing further oxidation during the formation of composites. The formation of Ag-WS2 nanocomposites shows a clear blue shift in the absorption as we obtained the characteristics absorption valleys at 456, 536 and 631 nm from the UV Vis spectroscopy analysis compared to pure WS2 nanosheets. Henceforth a facile method for the Ag decoration on WS2 nanosheets was put forward and briefly discussed. The proposed synthesis method is very promising for the low cost and large-scale synthesis of other noble metal incorporation TMDC compounds.

  16. Enzymatic Hydrolysis of Mannan from Konjac (Amorphophallus sp. Using Mannanase from Streptomyces lipmanii to Produce Manno-oligosaccharides

    Directory of Open Access Journals (Sweden)

    Ashadi Sasongko

    2015-09-01

    Full Text Available Mannan is an abundant polysaccharide that can be found in konjac (Amorphophallus sp.. Mannan can be enzymatically hydrolyzed using mannanase to produce manno-oligosaccharides which can be used as a prebiotic. The aims of this research are to determine the production time of mannanase from Streptomyces lipmanii, perform enzyme characterization, optimize the hydrolysis time, and characterize the hydrolysis product. A qualitative assay using the indicator Congo red showed that S. lipmanii generated a clear zone, indicating that S. lipmanii produced mannanase in konjac medium and possessed mannanolytic activity. Enzyme activity was determined through reducing sugar measurement using the dinitrosalycylic acid method, and optimum enzyme production was achieved at the second day of culture. Characterization of the enzyme showed that hydrolysis was optimum at pH 7 and at a temperature of 50 oC. The reducing sugar content was increased by an increasing the hydrolysis time, and reached an optimum time at 2 h. The degree of polymerization value of three was achieved after 2 h hydrolysis of mannan from konjac, indicating the formation of oligosaccharides. Analysis by thin layer chromatography using butanol, acetic acid, and water in a ratio of 2:1:1 as eluent showed the presence of compounds with a retention time between those of mannose and mannotetrose. Confirmation was also performed by HPLC, based on the retention time

  17. The Bialaphos Resistance Gene (bar) Plays a Role in Both Self-Defense and Bialaphos Biosynthesis in Streptomyces hygroscopicus

    NARCIS (Netherlands)

    Kumada, Yoichi; Anzai, Hiroyuki; Takano, Eriko; Murakami, Takeshi; Hara, Osamu; Itoh, Reiko; Imai, Satoshi; Satoh, Atsuyuki; Nagaoka, Kozo

    1988-01-01

    We inactivated the bialaphos (BA) resistance gene (bar) of a BA producer, Streptomyces hygroscopicus, by the gene replacement technique. The resulting BA-sensitive mutant (Bar-) was able to produce little BA but considerable amount of an intermediate demethylphosphinothricin (DMPT). The Bar- mutant

  18. Optimization Conditions of Extracellular Proteases Production from a Newly Isolated Streptomyces Pseudogrisiolus NRC-15

    Directory of Open Access Journals (Sweden)

    El-Sayed E. Mostafa

    2012-01-01

    Full Text Available Microbial protease represents the most important industrial enzymes, which have an active role in biotechnological processes. The objective of this study was to isolate new strain of Streptomyces that produce proteolytic enzymes with novel properties and the development of the low-cost medium. An alkaline protease producer strain NRC-15 was isolated from Egyptian soil sample. The cultural, morphological, physiological characters and chemotaxonomic evidence strongly indicated that the NRC-15 strain represents a novel species of the genus Streptomyces, hence the name Strptomyces pseudogrisiolus NRC-15. The culture conditions for higher protease production by NRC-15 were optimized with respect to carbon and nitrogen sources, metal ions, pH and temperature. Maximum protease production was obtained in the medium supplemented with 1% glucose, 1% yeast extract, 6% NaCl and 100 μmol/L of Tween 20, initial pH 9.0 at 50 °C for 96 h. The current results confirm that for this strain, a great ability to produce alkaline proteases, which supports the use of applications in industry.

  19. Reducing the variability of antibiotic production in Streptomyces by cultivation in 24-square deepwell plates

    DEFF Research Database (Denmark)

    Siebenberg, S.; Bapat, Prashant Madhusudhan; Eliasson Lantz, Anna

    2010-01-01

    Highly reproducible production values of the aminocoumarin antibiotic novobiocin were achieved by cultivation of a heterologous Streptomyces producer strain in commercially available square deepwell plates consisting of 24 wells of 3 ml culture volume each. Between parallel cultivation batches...

  20. Streptomyces xinjiangensis sp. nov., an actinomycete isolated from Lop Nur region.

    Science.gov (United States)

    Cheng, Cong; Li, Yu-Qian; Asem, Mipeshwaree Devi; Lu, Chun-Yan; Shi, Xiao-Han; Chu, Xiao; Zhang, Wan-Qin; Di An, Deng-; Li, Wen-Jun

    2016-10-01

    A novel actinobacterial strain, designated LPA192(T), was isolated from a soil sample collected from Lop Nur, Xinjiang Uygur Autonomous Region, Northwest China. A polyphasic approach was used to investigate the taxonomic position of strain LPA192(T). The isolate showed morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. Peptidoglycan was found to contain LL-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were MK-9(H6) and MK-10(H4). Polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylinositol. Major cellular fatty acids consist of C16:0, anteiso-C15:0 and C18:1 ω9c. The sugar in whole-cell hydrolysates was mannose. Phylogenetic analysis indicated that strain LPA192(T) is closely related to Streptomyces tanashiensis LMG 20274(T) (99.3 %), Streptomyces gulbargensis DAS131(T) (99.3 %), Streptomyces nashvillensis NBRC 13064(T) (99.3 %), Streptomyces roseolus NBRC 12816(T) (99.2 %) and Streptomyces filamentosus NBRC 12767(T) (99.1 %) while showing below 98.5 % sequencing similarities with other validly published Streptomyces species. However, DNA-DNA relatedness values between LPA192(T) and the closely related type strains were below 40 %, which are much lower than 70 % threshold value for species delineation. The genomic DNA G + C content of strain LPA192(T) was 69.3 mol %. Based on the differences in genotypic and phenotypic characteristics from the closely related strains, strain LPA192(T) is considered to represent a novel species of the genus Streptomyces for which the name Streptomyces xinjiangensis sp. nov. is proposed. The type strain is LPA192(T) (=KCTC 39601(T) = CGMCC 4.7288(T)).

  1. CoP/WS2 nanoflake heterostructures as efficient electrocatalysts for significant improvement in hydrogen evolution activity

    Science.gov (United States)

    Chen, Yajie; Kang, Chuanhong; Wang, Ruihong; Ren, Zhiyu; Fu, Huiying; Xiao, Yuting; Tian, Guohui

    2018-06-01

    The CoP/WS2 nanoflake composites were synthesized via the sulfuration and subsequent phosphidation using the pre-prepared WO2.72 nanowires as precursors. Originally, WO2.72 nanowires were prepared and followed by sulfuration to obtain WS2 nanoflakes. The as-prepared WS2 nanoflakes were used as substrates, on which the Co3O4 nanoparticles were uniformly anchored to construct the Co3O4/WS2 nanoflakes. Finally, the Co3O4/WS2 composites were subjected to phosphidation and in-situ converted into CoP/WS2 nanoflakes. Because of the dual functionalities of both CoP and WS2, the abundant interfaces as well as their synergy, the CoP/WS2 nanoflakes exhibited much higher electrocatalytic activity, smaller overpotential (-81 mV), lower Tafel slope (62 mV decade-1), and higher stability toward hydrogen-evolution reaction than those for the single CoP and WS2.

  2. Frenolicins C–G, Pyranonaphthoquinones from Streptomyces sp. RM-4-15

    OpenAIRE

    Wang, Xiachang; Shaaban, Khaled A.; Elshahawi, Sherif I.; Ponomareva, Larissa V.; Sunkara, Manjula; Zhang, Yinan; Copley, Gregory C.; Hower, James C.; Morris, Andrew J.; Kharel, Madan K.; Thorson, Jon S.

    2013-01-01

    Appalachian active coal fire sites were selected for the isolation of bacterial strains belonging to the class actinobacteria. A comparison of high resolution electrospray ionization mass spectrometry (HR-ESI-MS) and ultraviolet (UV) absorption profiles from isolate extracts to natural product databases suggested Streptomyces sp. RM-4-15 to produce unique metabolites. Four new pyranonaphthoquinones, frenolicins C–F (1–4), along with three known analogues, frenolicin (6), ...

  3. Chemical analyses of wasp-associated streptomyces bacteria reveal a prolific potential for natural products discovery

    DEFF Research Database (Denmark)

    Poulsen, Michael; Oh, Dong-Chan; Clardy, Jon

    2011-01-01

    and solitary Hymenoptera. Here we test this possibility by examining two species of solitary mud dauber wasps, Sceliphron caementarium and Chalybion californicum. We performed enrichment isolations from 33 wasps and obtained more than 200 isolates of Streptomyces Actinobacteria. Chemical analyses of 15...... and antibacterial activity. The prevalence and anti-microbial properties of Actinobacteria associated with these two solitary wasp species suggest the potential role of these Streptomyces as antibiotic-producing symbionts, potentially helping defend their wasp hosts from pathogenic microbes. Finding...... phylogenetically diverse and chemically prolific Actinobacteria from solitary wasps suggests that insect-associated Actinobacteria can provide a valuable source of novel natural products of pharmaceutical interest....

  4. In-situ growth of AuNPs on WS2@U-bent optical fiber for evanescent wave absorption sensor

    Science.gov (United States)

    Zhang, Suzhen; Zhao, Yuefeng; Zhang, Chao; Jiang, Shouzhen; Yang, Cheng; Xiu, Xianwu; Li, Chonghui; Li, Zhen; Zhao, Xiaofei; Man, Baoyuan

    2018-05-01

    The sensitivity of the evanescent wave absorption sensor is always a hot topic which has been attracted researchers' discussion. It is still a challenge for developing the effective sensor to sensitively detect some biochemical molecules solution in a simple and low-cost way. In this paper, an evanescent wave absorption (EWA) sensor has been presented based on the U-bent multimode fiber coated with tungsten disulfide (WS2) film and in-situ growth of gold nanoparticles (AuNPs) for the detection of ethanol solution and sodium chloride (NaCl) solution. Benefitted from the effective light coupling produced between U-bent probe and AuNPs, we attained the optimal size of the AuNPs by changing the reaction time between WS2 and tetrachloroauric acid (HAuCl4). With the AuNPs/WS2@U-bent optical fiber, we discussed the behaviors of EWA sensor, such as sensitivity, reproducibility, fast response-recovery time and stability. The sensitivity (△A/△C) of the proposed AuNPs/WS2@U-bent optical fiber EWA sensor is 0.65 for the detection of the ethanol solution. Besides, the AuNPs/WS2@U-bent optical fiber EWA sensor exhibits high sensitivity in detection of the sodium chloride (NaCl), which can reach 1.5 when the proposed sensor was immersed into NaCl solution. Our work demonstrates that the U-bent optical fiber EWA sensor may have promising applications in testing the solution of concentration.

  5. Interactions between Streptomyces coelicolor and Bacillus subtilis: Role of surfactants in raising aerial structures.

    Science.gov (United States)

    Straight, Paul D; Willey, Joanne M; Kolter, Roberto

    2006-07-01

    Using mixed-species cultures, we have undertaken a study of interactions between two common spore-forming soil bacteria, Bacillus subtilis and Streptomyces coelicolor. Our experiments demonstrate that the development of aerial hyphae and spores by S. coelicolor is inhibited by surfactin, a lipopeptide surfactant produced by B. subtilis. Current models of aerial development by sporulating bacteria and fungi postulate a role for surfactants in reducing surface tension at air-liquid interfaces, thereby removing the major barrier to aerial growth. S. coelicolor produces SapB, an amphipathic peptide that is surface active and required for aerial growth on certain media. Loss of aerial hyphae in developmental mutants can be rescued by addition of purified SapB. While a surfactant from a fungus can substitute for SapB in a mutant that lacks aerial hyphae, not all surfactants have this effect. We show that surfactin is required for formation of aerial structures on the surface of B. subtilis colonies. However, in contrast to this positive role, our experiments reveal that surfactin acts antagonistically by arresting S. coelicolor aerial development and causing altered expression of developmental genes. Our observations support the idea that surfactants function specifically for a given organism regardless of their shared ability to reduce surface tension. Production of surfactants with antagonistic activity could provide a powerful competitive advantage during surface colonization and in competition for resources.

  6. Editors' Choice Growth of Layered WS2Electrocatalysts for Highly Efficient Hydrogen Production Reaction

    KAUST Repository

    Alsabban, Merfat M.; Min, Shixiong; Hedhili, Mohamed N.; Ming, Jun; Li, Lain-Jong; Huang, Kuo-Wei

    2016-01-01

    Seeking more economical alternative electrocatalysts without sacrificing much in performance to replace precious metal Pt is one of the major research topics in hydrogen evolution reactions (HER). Tungsten disulfide (WS2) has been recognized as a promising substitute for Pt owing to its high efficiency and low-cost. Since most existing works adopt solution-synthesized WS2 crystallites for HER, direct growth of WS2 layered materials on conducting substrates should offer new opportunities. The growth of WS2 by the thermolysis of ammonium tetrathiotungstate (NH4)(2)WS4 was examined under various gaseous environments. Structural analysis and electrochemical studies show that the H2S environment leads to the WS2 catalysts with superior HER performance with an extremely low overpotential (eta(10) = 184 mV). (C) The Author(s) 2016. Published by ECS. All rights reserved.

  7. Editors' Choice Growth of Layered WS2Electrocatalysts for Highly Efficient Hydrogen Production Reaction

    KAUST Repository

    Alsabban, Merfat M.

    2016-08-18

    Seeking more economical alternative electrocatalysts without sacrificing much in performance to replace precious metal Pt is one of the major research topics in hydrogen evolution reactions (HER). Tungsten disulfide (WS2) has been recognized as a promising substitute for Pt owing to its high efficiency and low-cost. Since most existing works adopt solution-synthesized WS2 crystallites for HER, direct growth of WS2 layered materials on conducting substrates should offer new opportunities. The growth of WS2 by the thermolysis of ammonium tetrathiotungstate (NH4)(2)WS4 was examined under various gaseous environments. Structural analysis and electrochemical studies show that the H2S environment leads to the WS2 catalysts with superior HER performance with an extremely low overpotential (eta(10) = 184 mV). (C) The Author(s) 2016. Published by ECS. All rights reserved.

  8. WS{sub 2} nanosheets based on liquid exfoliation as effective electrocatalysts for hydrogen evolution reaction

    Energy Technology Data Exchange (ETDEWEB)

    Han, Guan-Qun [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Yan-Ru; Hu, Wen-Hui [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Dong, Bin, E-mail: dongbin@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Li, Xiao; Chai, Yong-Ming; Liu, Yun-Qi [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Chen-Guang, E-mail: cgliu@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China)

    2015-11-01

    WS{sub 2} nanosheets (WS{sub 2} NSs) as electrocatalysts for hydrogen evolution reaction (HER) have been prepared based on liquid exfoliation in dimethyl-formamide (DMF) via a direct dispersion and ultrasonication method. X-ray diffraction (XRD) shows the decreasing crystalline of the exfoliated WS{sub 2} (E-WS{sub 2}). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the as prepared E-WS{sub 2} consists of a few two-dimensional nanosheets, with large wrinkles on the surface. Electrochemical measurements show an excellent activity and stability of the E-WS{sub 2}, with a low overpotential of 80 mV and high current density (10 mA cm{sup −2}, at η = 205 mV), which indicates that through the process of exfoliation in DMF, both the dispersion and the amount of active sites have been improved greatly. Therefore, DMF is a promising alternative for exfoliating two-dimensional nanomaterials for highly efficient HER electrocatalysts. - Highlights: • A facile exfoliation process in DMF has been used to prepare E-WS{sub 2} for HER. • E-WS{sub 2} shows the better electrocatalytic activity than bulk WS{sub 2}. • DMF provides a promising alternative for enhancing exfoliation of 2D materials.

  9. WS_2-Super P nanocomposites anode material with enhanced cycling stability for lithium ion batteries

    International Nuclear Information System (INIS)

    Huang, Jianfeng; Wang, Xin; Li, Jiayin; Cao, Liyun; Xu, Zhanwei; Wei, Hao

    2016-01-01

    WS_2-Super P nanocomposites are prepared for lithium battery anodes by a simple two-step process consisting of hydrothermal and sulfide reduction reactions. The addition of Super P (50 nm) as a conductive addictive is beneficial for decreasing the size of nanocomposites and improving their dispersibility, which could accelerate the insertion/extraction reaction between WS_2-Super P nanocomposite electrode and electrolyte. Compared to the pure WS_2, the WS_2-Super P nanocomposites exhibit highly improved electrochemical performance with initial discharge capacity of 421 mAh g"−"1, high initial Coulombic efficiency (81%), low charge transfer impedance (53 Ω) and good retentive capacity of 389 mAh g"−"1 after 200th cycles. The much improved electrochemical performance can be attributed to the incorporation of Super P, which facilitates the interface charge transfer and Li"+ diffusion. - Graphical abstract: The addition of Super P (50 nm) is beneficial for decreasing the size of WS_2-Super P nanocomposites, improving their dispersibility, accelerating the Li"+ transportation and the insertion/extraction reaction. The WS_2-Super P nanocomposites show higher cycling stability and rate performances than pure WS_2. - Highlights: • WS_2-Super P nanocomposites are prepared for LIBs anodes with good performances. • Super P as a conductive addictive is added into the WS_2 nanosheets. • The incorporation of Super P is beneficial for decreasing the size of composites. • Super P were embedded in WS_2 nanosheets for improving their dispersibility.

  10. Secretory production of tetrameric native full-length streptavidin with thermostability using Streptomyces lividans as a host.

    Science.gov (United States)

    Noda, Shuhei; Matsumoto, Takuya; Tanaka, Tsutomu; Kondo, Akihiko

    2015-01-13

    Streptavidin is a tetrameric protein derived from Streptomyces avidinii, and has tight and specific biotin binding affinity. Applications of the streptavidin-biotin system have been widely studied. Streptavidin is generally produced using protein expression in Escherichia coli. In the present study, the secretory production of streptavidin was carried out using Streptomyces lividans as a host. In this study, we used the gene encoding native full-length streptavidin, whereas the core region is generally used for streptavidin production in E. coli. Tetrameric streptavidin composed of native full-length streptavidin monomers was successfully secreted in the culture supernatant of S. lividans transformants, and had specific biotin binding affinity as strong as streptavidin produced by E. coli. The amount of Sav using S. lividans was about 9 times higher than using E. coli. Surprisingly, streptavidin produced by S. lividans exhibited affinity to biotin after boiling, despite the fact that tetrameric streptavidin is known to lose its biotin binding ability after brief boiling. We successfully produced a large amount of tetrameric streptavidin as a secretory-form protein with unique thermotolerance.

  11. Streptomyces rimosus GDS(L Lipase: Production, Heterologous Overexpression and Structure-Stability Relationship

    Directory of Open Access Journals (Sweden)

    Marija Abramić

    2003-01-01

    Full Text Available Streptomyces rimosus lipase gene has been overexpressed in a heterologous host, S. lividans TK23. The maximal lipase activity was determined in the culture filtrates of the late stationary phase. Time course of lipase production was monitored by a modified plate assay. S. rimosus lipase gene has been located on the AseI B fragment approximately 2 Mb far from the left end of the S. rimosus linear chromosome. Out of eight examined streptomycetes, the presence of this rare type of bacterial lipase gene was detected in two belonging to the S. rimosus taxonomic cluster, and in one non-related species. Comparison of protein sequences of the Streptomyces lipolytic enzymes was performed. The result indicated the best structural stability of the putative S. coelicolor lipase-2.

  12. Synthesis and Performance of Tungsten Disulfide/Carbon (WS2/C) Composite as Anode Material

    Science.gov (United States)

    Yuan, Zhengyong; Jiang, Qiang; Feng, Chuanqi; Chen, Xiao; Guo, Zaiping

    2018-01-01

    The precursors of an amorphous WS2/C composite were synthesized by a simple hydrothermal method using Na2WO4·2H2O and CH3CSNH2 as raw materials, polyethylene glycol as dispersant, and glucose as the carbon source. The as-synthesized precursors were further annealed at a low temperature in flowing argon to obtain the final materials (WS2/C composite). The structure and morphology of the WS2/C composite were characterized by x-ray diffraction, x-ray photoelectron spectroscopy, and scanning electron microscopy. The electrochemical properties were tested by galvanostatic charge/discharge testing and alternating current (AC) impedance measurements. The results show that the as-prepared amorphous WS2/C composite features both high specific capacity and good cycling performance at room temperature within the potential window from 3.0 V to 0.01 V (versus Li+/Li) at current density of 100 mAg-1. The achieved initial discharge capacity was 1080 mAhg-1, and 786 mAhg-1 was retained after 170 cycles. Furthermore, the amorphous WS2/C composite exhibited a lower charge/discharge plateau than bare WS2, which is more beneficial for use as an anode. The cyclic voltammetry and AC impedance testing further confirmed the change in the plateau and the decrease in the charge transfer resistance in the WS2/C composite. The chemical formation process and the electrochemical mechanism of the WS2/C composite are also presented. The amorphous WS2/C composite can be used as a new anode material for future applications.

  13. Streptomyces bryophytorum sp. nov., an endophytic actinomycete isolated from moss (Bryophyta).

    Science.gov (United States)

    Li, Chuang; Jin, Pinjiao; Liu, Chongxi; Ma, Zhaoxu; Zhao, Junwei; Li, Jiansong; Wang, Xiangjing; Xiang, Wensheng

    2016-09-01

    A novel endophytic actinomycete, designated strain NEAU-HZ10(T) was isolated from moss and characterised using a polyphasic approach. The strain was found to have morphological and chemotaxonomic characteristics typical of the genus Streptomyces. Strain NEAU-HZ10(T) formed grayish aerial mycelia, which differentiated into straight to flexuous chains of cylindrical spores. The cell wall peptidoglycan was found to contain LL-diaminopimelic acid. Predominant menaquinones were identified as MK-9(H6) and MK-9(H8). The polar lipid profile was found to consist of phosphatidylethanolamine, phosphatidylinositol and two unidentified phospholipids. The major fatty acids were identified as iso-C16:0, anteiso-C15:0 and C16:0. 16S rRNA gene sequence similarity studies showed that strain NEAU-HZ10(T) belongs to the genus Streptomyces and exhibits high sequence similarity to Streptomyces cocklensis DSM 42063(T) (98.9 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-HZ10(T) clustered with S. cocklensis DSM 42063(T), Streptomyces yeochonensis CGMCC 4.1882(T) (98.7 %), Streptomyces paucisporeus CGMCC 4.2025(T) (98.4 %) and Streptomyces yanglinensis CGMCC 4.2023(T) (98.1 %). However, a combination of DNA-DNA hybridisation results and some phenotypic characteristics indicated that strain NEAU-HZ10(T) can be distinguished from its phylogenetically closely related strains. Therefore, it is proposed that strain NEAU-HZ10(T) represents a novel species of the genus Streptomyces for which the name Streptomyces bryophytorum sp. nov. is proposed. The type strain is NEAU-HZ10(T) (= CGMCC 4.7151(T) = DSM 42138(T)).

  14. Genome-based phylogenetic analysis of Streptomyces and its relatives

    NARCIS (Netherlands)

    Alam, Mohammad Tauqeer; Merlo, Maria Elena; Takano, Eriko; Breitling, Rainer

    Motivation: Streptomyces is one of the best-studied genera of the order Actinomycetales due to its great importance in medical science, ecology and the biotechnology industry. A comprehensive, detailed and robust phylogeny of Streptomyces and its relatives is needed for understanding how this group

  15. Synthesis of freestanding WS{sub 2} trees and fibers on Au by chemical vapor deposition (CVD)

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Subash; Jaisi, Balaram Paudel; Sharma, Kamal Prasad; Ibrahim Araby, Mona; Kalita, Golap; Tanemura, Masaki [Department of Physical Science and Engineering, Nagoya Institute of Technology, Nagoya (Japan)

    2018-01-15

    In this work, we report the synthesis of two new forms of WS{sub 2} nanostructures - freestanding WS{sub 2} trees and fibers on Au by chemical vapor deposition. It is observed that dislocation-driven growth causes WS{sub 2} crystals to grow and merge in both vertical and horizontal directions to form the pyramidal tree. During the formation of WS{sub 2} fibers, the presence of two-step growth was demonstrated. It is observed that sulphurization of WO{sub 3} nanoparticle leads to formation of WS{sub 2} rod in the first stage, followed by second stage in which selective growth causes some WS{sub 2} layers grow faster compared to other ones leading to the formation of fibrous WS{sub 2} structure. Fibers synthesized by our reported method have highly exposed WS{sub 2} layers which can demonstrate interesting catalytic and edge related properties or can be functionalized for future applications. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Symmetrical synergy of hybrid CoS2-WS2 electrocatalysts for hydrogen evolution reaction

    KAUST Repository

    Zhou, Xiaofeng; Yang, Xiulin; Li, Henan; Hedhili, Mohamed N.; Huang, Kuo-Wei; Li, Lain-Jong; Zhang, Wenjing

    2017-01-01

    A highly active and stable hybrid electrocatalyst 3D hierarchical CoS2 nanosheets incorporated with WS2 (CoS2@WS2) has been developed via a one-step sulfurization method for the first time, where the contents of WS2 can be adjusted easily. We first prove the addition of small amounts of WS2 enhances the hydrogen evolution reaction (HER) performance of CoS2, and vise versa. In other words, we validated the symmetric synergy for HER between the Co- and W-based sulfide hybrid catalysts. In addition, we confirmed that the formation of nanointerfaces of Co-S-W between CoS2 and WS2 was responsible for the excellent HER activity (an overpotential of -97.2 mV at -10 mA/cm2, a small Tafel slope of 66.0 mV/dec, and prominent electrochemical stability) of hybrid electrocatalyst CoS2@WS2.

  17. Symmetrical synergy of hybrid CoS2-WS2 electrocatalysts for hydrogen evolution reaction

    KAUST Repository

    Zhou, Xiaofeng

    2017-06-05

    A highly active and stable hybrid electrocatalyst 3D hierarchical CoS2 nanosheets incorporated with WS2 (CoS2@WS2) has been developed via a one-step sulfurization method for the first time, where the contents of WS2 can be adjusted easily. We first prove the addition of small amounts of WS2 enhances the hydrogen evolution reaction (HER) performance of CoS2, and vise versa. In other words, we validated the symmetric synergy for HER between the Co- and W-based sulfide hybrid catalysts. In addition, we confirmed that the formation of nanointerfaces of Co-S-W between CoS2 and WS2 was responsible for the excellent HER activity (an overpotential of -97.2 mV at -10 mA/cm2, a small Tafel slope of 66.0 mV/dec, and prominent electrochemical stability) of hybrid electrocatalyst CoS2@WS2.

  18. Evolutionary Relationships among Actinophages and a Putative Adaptation for Growth in Streptomyces spp.

    Science.gov (United States)

    Hendrix, Roger W.; Dedrick, Rebekah; Mitchell, Kaitlin; Ko, Ching-Chung; Russell, Daniel; Bell, Emma; Gregory, Matthew; Bibb, Maureen J.; Pethick, Florence; Jacobs-Sera, Deborah; Herron, Paul; Buttner, Mark J.; Hatfull, Graham F.

    2013-01-01

    The genome sequences of eight Streptomyces phages are presented, four of which were isolated for this study. Phages R4, TG1, ϕHau3, and SV1 were isolated previously and have been exploited as tools for understanding and genetically manipulating Streptomyces spp. We also extracted five apparently intact prophages from recent Streptomyces spp. genome projects and, together with six phage genomes in the database, we analyzed all 19 Streptomyces phage genomes with a view to understanding their relationships to each other and to other actinophages, particularly the mycobacteriophages. Fifteen of the Streptomyces phages group into four clusters of related genomes. Although the R4-like phages do not share nucleotide sequence similarity with other phages, they clearly have common ancestry with cluster A mycobacteriophages, sharing many protein homologues, common gene syntenies, and similar repressor-stoperator regulatory systems. The R4-like phage ϕHau3 and the prophage StrepC.1 (from Streptomyces sp. strain C) appear to have hijacked a unique adaptation of the streptomycetes, i.e., use of the rare UUA codon, to control translation of the essential phage protein, the terminase. The Streptomyces venezuelae generalized transducing phage SV1 was used to predict the presence of other generalized transducing phages for different Streptomyces species. PMID:23995638

  19. Enhancement of clavulanic acid production by Streptomyces sp MU ...

    African Journals Online (AJOL)

    Purpose: To enhance clavulanic acid production using UV-mutagenesis on Streptomyces sp. NRC77. Methods: UV-mutagenesis was used to study the effect of Streptomyces sp. NRC77 on CA production. Phenotypic and genotypic identification methods of the promising mutant strain were characterized. Optimization of the ...

  20. Bioactive benzopyrone derivatives from new recombinant fusant of marine Streptomyces.

    Science.gov (United States)

    El-Gendy, Mervat M A; Shaaban, M; El-Bondkly, A M; Shaaban, K A

    2008-07-01

    In our searching program for bioactive secondary metabolites from marine Streptomycetes, three microbial benzopyrone derivatives (1-3), 7-methylcoumarin (1) and two flavonoides, rhamnazin (2) and cirsimaritin (3), were obtained during the working up of the ethyl acetate fraction of a marine Streptomyces fusant obtained from protoplast fusion between Streptomyces strains Merv 1996 and Merv 7409. The structures of the three compounds (1-3) were established by nuclear magnetic resonance, mass, UV spectra, and by comparison with literature data. Marine Streptomyces strains were identified based on their phenotypic and chemotypic characteristics as two different bioactive strains of the genus Streptomyces. We described here the fermentation, isolation, as well as the biological activity of these bioactive compounds. The isolated compounds (1-3) are reported here as microbial products for the first time.

  1. Characterization of Streptomyces isolates causing colour changes of mural paintings in ancient Egyptian tombs.

    Science.gov (United States)

    Abdel-Haliem, M E F; Sakr, A A; Ali, M F; Ghaly, M F; Sohlenkamp, C

    2013-08-25

    Paintings in ancient Egyptian tombs often suffer colour changes due to microbial growth and colonization. Streptomyces strains were isolated from mural paintings of Tell Basta and Tanis tombs (East of Nile Delta, Egypt) and were identified using biochemical and molecular methods. The16S rDNA sequences data indicated that isolated strains were closely related to S. coelicolor, S. albidofuscus, S. ambofaciens, S. canarius, S. parvullus, S. corchorusii, S. albidofuscus and S. nigrifaciens. It could be shown that Streptomyces strains are involved on a large scale in the colour changes of paintings and stone support by producing a wide range of metabolites such as acids (oxalic, citric and sulphuric acids), biopigments of melanin, carotenoids, and hydrogen sulphide. Copyright © 2013 Elsevier GmbH. All rights reserved.

  2. Streptomyces jeddahensis sp. nov., an oleaginous bacterium isolated from desert soil.

    Science.gov (United States)

    Röttig, Annika; Atasayar, Ewelina; Meier-Kolthoff, Jan Philipp; Spröer, Cathrin; Schumann, Peter; Schauer, Jennifer; Steinbüchel, Alexander

    2017-06-01

    A novel strain, G25T, was isolated from desert soil collected near Jeddah in Saudi Arabia. The strain could accumulate nearly 65 % of its cell dry weight as fatty acids, grow on a broad range of carbon sources and tolerate temperatures of up to 50 °C. With respect to to its 16S rRNA gene sequence, G25T is most closely related to Streptomyces massasporeus DSM 40035T, Streptomyces hawaiiensis DSM 40042T, Streptomyces indiaensis DSM 43803T, Streptomyces luteogriseus DSM 40483T and Streptomyces purpurascens DSM 40310T. Conventional DNA-DNA hybridization (DDH) values ranged from 18.7 to 46.9 % when G25T was compared with these reference strains. Furthermore, digital DDH values between the draft genome sequence of G25T and the genome sequences of other species of the genus Streptomyces were also significantly below the threshold of 70 %. The DNA G+C content of the draft genome sequence, consisting of 8.46 Mbp, was 70.3 %. The prevalent cellular fatty acids of G25T comprised anteiso-C15 : 0, iso-C15 : 0, C16 : 0 and iso-C16 : 0. The predominant menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The polar lipids profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylglycerol and phosphatidylinositol mannosides as well as unidentified phospholipids and phosphoaminolipids. The cell wall contained ll-diaminopimelic acid. Whole-cell sugars were predominantly glucose with small traces of ribose and mannose. The results of the polyphasic approach confirmed that this isolate represents a novel species of the genus Streptomyces, for which the name Streptomyces jeddahensis sp. nov. is proposed. The type strain of this species is G25T (=DSM 101878T =LMG 29545T =NCCB 100603T).

  3. Molecular studies on some soil-Streptomyces strains of western ...

    African Journals Online (AJOL)

    aghomotsegin

    2013-05-08

    May 8, 2013 ... Random amplified polymorphic of DNA-polymerase chain reaction (RAPD-PCR) analysis of the DNA extracted from seven Streptomyces strains of western region, KSA was the aim of this study. Partial sequence of 16S rRNA gene of Streptomyces polychromogenes was also attempted. Results show that.

  4. Nutritional control of antibiotic production by Streptomyces platensis MA7327: importance of L-aspartic acid

    OpenAIRE

    Falzone, Maria; Crespo, Emmanuel; Jones, Klarissa; Khan, Gulaba; Korn, Victoria L; Patel, Amreen; Patel, Mira; Patel, Krishnaben; Perkins, Carrie; Siddiqui, Sana; Stenger, Drew; Yu, Eileen; Gelber, Michael; Scheffler, Robert; Nayda, Vasyl

    2017-01-01

    Streptomyces platensis MA7327 is a bacterium producing interesting antibiotics, which act by the novel mechanism of inhibiting fatty acid biosynthesis. The antibiotics produced by this actinomycete are platensimycin and platencin plus some minor related antibiotics. Platensimycin and platencin have activity against antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus; they also lack toxicity in animal models. Platensimycin als...

  5. Streptomyces zhihengii sp. nov., isolated from rhizospheric soil of Psammosilene tunicoides.

    Science.gov (United States)

    Huang, Mei-Juan; Fei, Jing-Jing; Salam, Nimaichand; Kim, Chang-Jin; Hozzein, Wael N; Xiao, Min; Huang, Hai-Quan; Li, Wen-Jun

    2016-10-01

    An actinomycete strain, designated YIM T102(T), was isolated from the rhizospheric soil of Psammosilene tunicoides W. C. Wu et C. Y. Wu collected from Lijiang, Yunnan Province, China. The taxonomic position of the new isolate was investigated by a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YIM T102(T) belongs to the genus Streptomyces. Strain YIM T102(T) was most closely related to Streptomyces eurocidicus NRRL B-1676(T) with a pairwise 16S rRNA gene sequence similarity of 98.9 %. However, DNA-DNA relatedness value between strain YIM T102(T) and S. eurocidicus NBRC 13491(T) was found to be 37.8 ± 1.8 %. The menaquinone composition detected for strain YIM T102(T) was MK-9 (H6) and MK-9 (H8), while the major fatty acids were summed feature 4 (38.0 %), anteiso-C15:0 (13.1 %), iso-C16:0 (10.1 %), summed feature 3 (9.8 %) and C16:0 (9.0 %) and iso-C15:0 (5.2 %). The whole-cell hydrolysates contained galactose, glucose, ribose and mannose, along with LL-diaminopimelic acid as the diagnostic diamino acid in the peptidoglycan. The DNA G+C content was 70.7 mol%. Strain YIM T102(T) also exhibited antagonistic activity against Alternaria alternata, Alternaria brassicae and Colletotrichum nicotianae Averna, based on the findings from the comparative analyses of phenotypic and genotypic characteristics; it is proposed that strain YIM T102 represents a novel species of the genus Streptomyces, for which the name Streptomyces zhihengii sp. nov. is proposed. The type strain is YIM T102(T) (=KCTC 39115(T) = DSM 42176(T) = CGMCC 4.7248(T)).

  6. Production, Partial Purification and Characterization of Protease From Irradiated Streptomyces Spp

    International Nuclear Information System (INIS)

    Botros, H.W.; Ahmed, A.S.

    2011-01-01

    Production and partial purification of protease by the irradiated Streptomyces spp. was the aim of this study. Streptomyces spp. was allowed to grow in culture broth of 4% shrimp shells for purpose of inducing protease enzymes. Optimal conditions for protease production were 30 degree C, 0.3 kGy, ph 7, 5x10 4 /ml inoculum size and 7 days incubation period. Protease was purified by 80% ammonium sulphate saturation which exhibited 8.7 U/ml enzyme activity. Column chromatography using sephadex G-200 exerted 23.3 U/ml enzyme activity from pooled fraction (13-16). The molecular mass of protease was determined to be 39 kDa by SDS-PAGE. The enzyme was more stable over a wide range of ph 6-8 and temperature up to 40 degree C. The produced protease was activated by Ca, Mn and FeCl 2 and completely inhibited by ethylene-diamin tetraacetic acid (EDTA) at concentration of 1000 μg/ml

  7. Mycelium differentiation and development of Streptomyces coelicolor in lab-scale bioreactors: Programmed cell death, differentiation, and lysis are closely linked to undecylprodigiosin and actinorhodin production

    OpenAIRE

    Rioseras de Bustos, Beatriz; López García, María Teresa (Bio); Yagüe Menéndez, Paula; Sánchez Martín, Jesús; Manteca Fernández, Ángel

    2014-01-01

    Streptomycetes are mycelium-forming bacteria that produce two thirds of clinically relevant secondary metabolites. Secondary metabolite production is activated at specific developmental stages of Streptomyces life cycle. Despite this, Streptomyces differentiation in industrial bioreactors tends to be underestimated and the most important parameters managed are only indirectly related to differentiation: modifications to the culture media, optimization of productive strains by random or direct...

  8. High-Efficiency Genome Editing of Streptomyces Species by an Engineered CRISPR/Cas System.

    Science.gov (United States)

    Wang, Y; Cobb, R E; Zhao, H

    2016-01-01

    Next-generation sequencing technologies have rapidly expanded the genomic information of numerous organisms and revealed a rich reservoir of natural product gene clusters from microbial genomes, especially from Streptomyces, the largest genus of known actinobacteria at present. However, genetic engineering of these bacteria is often time consuming and labor intensive, if even possible. In this chapter, we describe the design and construction of pCRISPomyces, an engineered Type II CRISPR/Cas system, for targeted multiplex gene deletions in Streptomyces lividans, Streptomyces albus, and Streptomyces viridochromogenes with editing efficiency ranging from 70% to 100%. We demonstrate pCRISPomyces as a powerful tool for genome editing in Streptomyces. © 2016 Elsevier Inc. All rights reserved.

  9. Molecular studies on some soil- Streptomyces strains of western ...

    African Journals Online (AJOL)

    Random amplified polymorphic of DNA-polymerase chain reaction (RAPD-PCR) analysis of the DNA extracted from seven Streptomyces strains of western region, KSA was the aim of this study. Partial sequence of 16S rRNA gene of Streptomyces polychromogenes was also attempted. Results show that a total number of ...

  10. Crataegus Special Extract WS 1442 Effects on eNOS and microRNA 155.

    Science.gov (United States)

    Wang, Xinwen; Liang, Yan; Shi, Jian; Zhu, Hao-Jie; Bleske, Barry E

    2018-04-16

    Increased expression of microRNA 155 (miR-155) results in a decrease in endothelial nitric oxide synthase (eNOS) expression and impaired endothelial function. Factors that have been shown to increase expression of miR-155 may be mitigated by WS 1442, an extract of hawthorn leaves and flowers ( Crataegus special extract) that contains a range of pharmacologically active substances including oligomeric proanthocyanidins and flavonoids. The purpose of this study is to determine the effect of WS 1442 on the expression of miR-155 and eNOS in the presence of tumor necrosis factor (TNF- α ). Human umbilical vein endothelial cells (HUVECs) were studied after the exposure to TNF- α , with or without simvastatin (positive control) and WS 1442. The expression levels of eNOS, phosphorylated eNOS, and miR-155 in the different HUVEC treatment groups were determined by western blot and quantitative real-time polymerase chain reaction, respectively. To evaluate the effect of WS 1442 on the eNOS activity, the medium and intracellular nitrate/nitrite (NO) concentrations were also analyzed using a colorimetric Griess assay kit. The results demonstrated that TNF- α upregulated miR-155 expression and decreased eNOS expression and NO concentrations. WS 1442 also increased miR-155 expression and decreased eNOS expression but, unlike TNF- α , increased phosphorylated eNOS expression and NO concentrations. Surprisingly, WS 1442 increased miR-155 expression; however, WS 1442 mitigated the overall negative effect of miR-155 on decreasing eNOS expression by increasing expression of phosphorylated eNOS and resulting in an increase in NO concentrations. In the setting where miR-155 may be expressed, WS 1442 may offer vascular protection by increasing the expression of phosphorylated eNOS. Georg Thieme Verlag KG Stuttgart · New York.

  11. Apparent digenic inheritance of Waardenburg syndrome type 2 (WS2) and autosomal recessive ocular albinism (AROA).

    Science.gov (United States)

    Morell, R; Spritz, R A; Ho, L; Pierpont, J; Guo, W; Friedman, T B; Asher, J H

    1997-05-01

    Waardenburg syndrome (WS) is a clinically and genetically heterogeneous disease accounting for >2% of the congenitally deaf population. It is characterized by deafness in association with pigmentary anomalies and various defects of neural crest-derived tissues. At least four types are recognized (WS1, WS2, WS3 and WS4) on the basis of clinical and genetic criteria. Two previously described families seemed to delineate a new subtype characterized by WS2 in conjunction with ocular albinism (OA). Since mutations in the MITF gene are responsible for some instances of WS2, we screened for mutations in one of the WS2-OA families and discovered a 1 bp deletion in exon 8 of MITF. OA previously has been associated with compound heterozygosity for a mutant TYR allele and the TYR(R402Q) allele, a functionally significant polymorphism that is associated with moderately reduced tyrosinase catalytic activity. In this family, all of the individuals with the OA phenotype are either homozygous or heterozygous for TYR(R402Q), and heterozyous for the 1 bp deletion in MITF This suggests that the WS2-OA phenotype may result from digenic interaction between a gene for a transcription factor (MITF) and a gene that it regulates (TYR).

  12. A highly efficient targeted recombination system for engineering linear chromosomes of industrial bacteria Streptomyces.

    Science.gov (United States)

    Pan, Hung-Yin; Chen, Carton W; Huang, Chih-Hung

    2018-04-17

    Soil bacteria Streptomyces are the most important producers of secondary metabolites, including most known antibiotics. These bacteria and their close relatives are unique in possessing linear chromosomes, which typically harbor 20 to 30 biosynthetic gene clusters of tens to hundreds of kb in length. Many Streptomyces chromosomes are accompanied by linear plasmids with sizes ranging from several to several hundred kb. The large linear plasmids also often contain biosynthetic gene clusters. We have developed a targeted recombination procedure for arm exchanges between a linear plasmid and a linear chromosome. A chromosomal segment inserted in an artificially constructed plasmid allows homologous recombination between the two replicons at the homology. Depending on the design, the recombination may result in two recombinant replicons or a single recombinant chromosome with the loss of the recombinant plasmid that lacks a replication origin. The efficiency of such targeted recombination ranges from 9 to 83% depending on the locations of the homology (and thus the size of the chromosomal arm exchanged), essentially eliminating the necessity of selection. The targeted recombination is useful for the efficient engineering of the Streptomyces genome for large-scale deletion, addition, and shuffling.

  13. A Note on the W-S Lower Bound of the MEE Estimation

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    Badong Chen

    2014-02-01

    Full Text Available The minimum error entropy (MEE estimation is concerned with the estimation of a certain random variable (unknown variable based on another random variable (observation, so that the entropy of the estimation error is minimized. This estimation method may outperform the well-known minimum mean square error (MMSE estimation especially for non-Gaussian situations. There is an important performance bound on the MEE estimation, namely the W-S lower bound, which is computed as the conditional entropy of the unknown variable given observation. Though it has been known in the literature for a considerable time, up to now there is little study on this performance bound. In this paper, we reexamine the W-S lower bound. Some basic properties of the W-S lower bound are presented, and the characterization of Gaussian distribution using the W-S lower bound is investigated.

  14. Genomics of Sponge-Associated Streptomyces spp. Closely Related to Streptomyces albus J1074: Insights into Marine Adaptation and Secondary Metabolite Biosynthesis Potential

    Science.gov (United States)

    Ian, Elena; Malko, Dmitry B.; Sekurova, Olga N.; Bredholt, Harald; Rückert, Christian; Borisova, Marina E.; Albersmeier, Andreas; Kalinowski, Jörn; Gelfand, Mikhail S.; Zotchev, Sergey B.

    2014-01-01

    A total of 74 actinomycete isolates were cultivated from two marine sponges, Geodia barretti and Phakellia ventilabrum collected at the same spot at the bottom of the Trondheim fjord (Norway). Phylogenetic analyses of sponge-associated actinomycetes based on the 16S rRNA gene sequences demonstrated the presence of species belonging to the genera Streptomyces, Nocardiopsis, Rhodococcus, Pseudonocardia and Micromonospora. Most isolates required sea water for growth, suggesting them being adapted to the marine environment. Phylogenetic analysis of Streptomyces spp. revealed two isolates that originated from different sponges and had 99.7% identity in their 16S rRNA gene sequences, indicating that they represent very closely related strains. Sequencing, annotation, and analyses of the genomes of these Streptomyces isolates demonstrated that they are sister organisms closely related to terrestrial Streptomyces albus J1074. Unlike S. albus J1074, the two sponge streptomycetes grew and differentiated faster on the medium containing sea water. Comparative genomics revealed several genes presumably responsible for partial marine adaptation of these isolates. Genome mining targeted to secondary metabolite biosynthesis gene clusters identified several of those, which were not present in S. albus J1074, and likely to have been retained from a common ancestor, or acquired from other actinomycetes. Certain genes and gene clusters were shown to be differentially acquired or lost, supporting the hypothesis of divergent evolution of the two Streptomyces species in different sponge hosts. PMID:24819608

  15. Two Antimycin A Analogues from Marine-Derived Actinomycete Streptomyces lusitanus

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    Peiyuan Qian

    2012-03-01

    Full Text Available Two new antimycin A analogues, antimycin B1 and B2 (1–2, were isolated from a spent broth of a marine-derived bacterium, Streptomyces lusitanus. The structures of 1 and 2 were established on the basis of spectroscopic analyses and chemical methods. The isolated compounds were tested for their anti-bacterial potency. Compound 1 was found to be inactive against the bacteria Bacillus subtilis, Staphyloccocus aureus, and Loktanella hongkongensis. Compound 2 showed antibacterial activities against S. aureus and L. hongkongensis with MIC values of 32.0 and 8.0 μg/mL, respectively.

  16. Four new antibacterial xanthones from the marine-derived actinomycetes Streptomyces caelestis

    KAUST Repository

    Liu, Ling-Li; Xu, Ying; Han, Zhuang; Li, Yong-Xin; Lu, Liang; Lai, Pok-Yui; Zhong, Jia-Liang; Guo, Xian-Rong; Zhang, Xixiang; Qian, Pei-Yuan

    2012-01-01

    Four new polycyclic antibiotics, citreamicin ? A (1), citreamicin ? B (2), citreaglycon A (3), and dehydrocitreaglycon A (4), were isolated from marine-derived Streptomyces caelestis. The structures of these compounds were elucidated by 1D and 2D NMR spectra. All four compounds displayed antibacterial activity against Staphylococcus haemolyticus, Staphylococcus aureus, and Bacillus subtillis. Citreamicin ? A (1), citreamicin ? B (2) and citreaglycon A (3) also exhibited low MIC values of 0.25, 0.25, and 8.0 ?g/mL, respectively, against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300. 2012 by the authors; licensee MDPI.

  17. Four new antibacterial xanthones from the marine-derived actinomycetes Streptomyces caelestis

    KAUST Repository

    Liu, Ling-Li

    2012-11-20

    Four new polycyclic antibiotics, citreamicin ? A (1), citreamicin ? B (2), citreaglycon A (3), and dehydrocitreaglycon A (4), were isolated from marine-derived Streptomyces caelestis. The structures of these compounds were elucidated by 1D and 2D NMR spectra. All four compounds displayed antibacterial activity against Staphylococcus haemolyticus, Staphylococcus aureus, and Bacillus subtillis. Citreamicin ? A (1), citreamicin ? B (2) and citreaglycon A (3) also exhibited low MIC values of 0.25, 0.25, and 8.0 ?g/mL, respectively, against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300. 2012 by the authors; licensee MDPI.

  18. Genome plasticity and systems evolution in Streptomyces

    Science.gov (United States)

    2012-01-01

    Background Streptomycetes are filamentous soil-dwelling bacteria. They are best known as the producers of a great variety of natural products such as antibiotics, antifungals, antiparasitics, and anticancer agents and the decomposers of organic substances for carbon recycling. They are also model organisms for the studies of gene regulatory networks, morphological differentiation, and stress response. The availability of sets of genomes from closely related Streptomyces strains makes it possible to assess the mechanisms underlying genome plasticity and systems adaptation. Results We present the results of a comprehensive analysis of the genomes of five Streptomyces species with distinct phenotypes. These streptomycetes have a pan-genome comprised of 17,362 orthologous families which includes 3,096 components in the core genome, 5,066 components in the dispensable genome, and 9,200 components that are uniquely present in only one species. The core genome makes up about 33%-45% of each genome repertoire. It contains important genes for Streptomyces biology including those involved in gene regulation, secretion, secondary metabolism and morphological differentiation. Abundant duplicate genes have been identified, with 4%-11% of the whole genomes composed of lineage-specific expansions (LSEs), suggesting that frequent gene duplication or lateral gene transfer events play a role in shaping the genome diversification within this genus. Two patterns of expansion, single gene expansion and chromosome block expansion are observed, representing different scales of duplication. Conclusions Our results provide a catalog of genome components and their potential functional roles in gene regulatory networks and metabolic networks. The core genome components reveal the minimum requirement for streptomycetes to sustain a successful lifecycle in the soil environment, reflecting the effects of both genome evolution and environmental stress acting upon the expressed phenotypes. A

  19. Streptomyces ovatisporus sp. nov., isolated from deep marine sediment.

    Science.gov (United States)

    Veyisoglu, Aysel; Cetin, Demet; Inan Bektas, Kadriye; Guven, Kiymet; Sahin, Nevzat

    2016-11-01

    The taxonomic position of a Gram-staining-positive strain, designated strain S4702T was isolated from a marine sediment collected from the southern Black Sea coast, Turkey, determined using a polyphasic approach. The isolate was found to have chemotaxonomic, morphological and phylogenetic properties consistent with its classification as representing a member of the genus Streptomyces and formed a distinct phyletic line in the 16S rRNA gene tree. S4702T was found to be most closely related to the type strains of Streptomyces marinus(DSM 41968T; 97.8 % sequence similarity) and Streptomyces abyssalis (YIM M 10400T; 97.6 %). 16S rRNA gene sequence similarities with other members of the genus Streptomyces were lower than 97.5 %. DNA-DNA relatedness of S4702T and the most closely related strain S. marinus DSM 41968T was 21.0 %. The G+C content of the genomic DNA was 72.5 mol%. The cell wall of the strain contained l,l-diaminopimelic acid and the cell-wall sugars were glucose and ribose. The major cellular fatty acids were identified as anteiso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and iso-C15 : 0. The predominant menaquinone was MK-9(H8). The polar lipid profile of S4702T consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. S4702T could be distinguished from its closest phylogenetic neighbours using a combination of chemotaxonomic, morphological and physiological properties. Consequently, it is proposed that S4702T represents a novel species of the genus Streptomyces, for which the name Streptomyces ovatisporus sp. nov. is proposed. The type strain is S4702T (DSM 42103T=KCTC 29206T=CGMCC 4.7357T).

  20. Multilocus sequence analysis of phytopathogenic species of the genus Streptomyces

    Science.gov (United States)

    The identification and classification of species within the genus Streptomyces is difficult because there are presently 576 validly described species and this number increases every year. The value of the application of multilocus sequence analysis scheme to the systematics of Streptomyces species h...

  1. Refining the Roots of the Beewolf-Streptomyces Symbiosis: Antennal Symbionts in the Rare Genus Philanthinus (Hymenoptera, Crabronidae)

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    Yildirim, Erol; Gürbüz, M. Faruk; Herzner, Gudrun; Strohm, Erhard

    2012-01-01

    Insects engage in symbiotic associations with a large diversity of beneficial microorganisms. While the majority of well-studied symbioses have a nutritional basis, several cases are known in which bacteria protect their host from pathogen infestation. Solitary wasps of the genera Philanthus and Trachypus (beewolves; Hymenoptera, Crabronidae) cultivate the actinomycete “Candidatus Streptomyces philanthi” in specialized antennal gland reservoirs. The symbionts are transferred to the larval cocoon, where they provide protection against pathogenic fungi by producing at least nine different antibiotics. Here we investigated the closest relatives of Philanthus and Trachypus, the rare genus Philanthinus, for the presence of antennal gland reservoirs and symbiotic streptomycetes. Molecular analyses identified “Ca. Streptomyces philanthi” in reservoirs of Philanthinus quattuordecimpunctatus. Phylogenies based on the 16S rRNA gene suggest that P. quattuordecimpunctatus may have acquired “Ca. Streptomyces philanthi” by horizontal transfer from other beewolf species. In histological sections and three-dimensional reconstructions, the antennal gland reservoirs were found to occupy six antennal segments (as opposed to only five in Philanthus and Trachypus) and to be structurally less complex than those of the evolutionarily more derived genera of beewolves. The presence of “Ca. Streptomyces philanthi” in antennal glands of Philanthinus indicates that the symbiosis between beewolves and Streptomyces bacteria is much older than previously thought. It probably evolved along the branch leading to the monophyletic tribe Philanthini, as it seems to be confined to the genera Philanthus, Trachypus, and Philanthinus, which together comprise 172 described species of solitary wasps. PMID:22113914

  2. Studies on Optimization of Growth Parameters for L-Asparaginase Production by Streptomyces ginsengisoli

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    Neelima Deshpande

    2014-01-01

    Full Text Available A species of Streptomyces, Streptomyces ginsengisoli, a river isolate, was evaluated for production of an enzyme, L-asparaginase, with multiple functions mainly anticancer activity. The actinomycete was subjected to submerged fermentation by “shake flask” method. The quantity of L-asparaginase produced was estimated as 3.23 μmol/mL/min. The effect of various culture conditions on L-asparaginase production was studied by adopting a method of variation in one factor at a time. Of the various conditions tested, glucose (followed by starch and peptone served as good carbon and nitrogen sources, respectively, for maximal production of enzyme at pH 8. The temperature of 30°C and an incubation period of 5 days with 0.05 g% asparagine concentration were found to be optimum for L-asparaginase production.

  3. Gamma-butyrolactone and furan signaling systems in Streptomyces.

    Science.gov (United States)

    Sidda, John D; Corre, Christophe

    2012-01-01

    Streptomyces bacteria produce different classes of diffusible signaling molecules that trigger secondary metabolite production and/or morphological development within the cell population. The biosynthesis of gamma-butyrolactones (GBLs) and 2-alkyl-4-hydroxymethylfuran-3-carboxylic acids (AHFCAs) signaling molecules is related and involves an essential AfsA-like butenolide synthase. This chapter first describes the catalytic role of AfsA-like enzyme then provides details about methods for the discovery and characterization of potentially novel signaling molecules. In section 4, one approach for establishing the biological role of these signaling molecules is presented. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Bioprocessing of some agro-industrial residues for endoglucanase production by the new subsp.; Streptomyces albogriseolus subsp. cellulolyticus strain NEAE-J

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    Noura El-Ahmady El-Naggar

    2014-06-01

    Full Text Available The use of low cost agro-industrial residues for the production of industrial enzymes is one of the ways to reduce significantly production costs. Cellulase producing actinomycetes were isolated from soil and decayed agricultural wastes. Among them, a potential culture, strain NEAE-J, was selected and identified on the basis of morphological, cultural, physiological and chemotaxonomic properties, together with 16S rDNA sequence. It is proposed that strain NEAE-J should be included in the species Streptomyces albogriseolus as a representative of a novel sub-species, Streptomyces albogriseolus subsp. cellulolyticus strain NEAE-J and sequencing product was deposited in the GenBank database under accession number JN229412. This organism was tested for its ability to produce endoglucanase and release reducing sugars from agro-industrial residues as substrates. Sugarcane bagasse was the most suitable substrate for endoglucanase production. Effects of process variables, namely incubation time, temperature, initial pH and nitrogen source on production of endoglucanase by submerged fermentation using Streptomyces albogriseolus subsp. cellulolyticus have been studied. Accordingly optimum conditions have been determined. Incubation temperature of 30 ºC after 6 days, pH of 6.5, 1% sugarcane bagasse as carbon source and peptone as nitrogen source were found to be the optimum for endoglucanase production. Optimization of the process parameters resulted in about 2.6 fold increase in the endoglucanase activity. Therefore, Streptomyces albogriseolus subsp. cellulolyticus coud be potential microorganism for the intended application.

  5. Bioprocessing of some agro-industrial residues for endoglucanase production by the new subsp.; Streptomyces albogriseolus subsp. cellulolyticus strain NEAE-J

    Science.gov (United States)

    El-Naggar, Noura El-Ahmady; Abdelwahed, Nayera A.M.; Saber, Wesam I.A.; Mohamed, Asem A.

    2014-01-01

    The use of low cost agro-industrial residues for the production of industrial enzymes is one of the ways to reduce significantly production costs. Cellulase producing actinomycetes were isolated from soil and decayed agricultural wastes. Among them, a potential culture, strain NEAE-J, was selected and identified on the basis of morphological, cultural, physiological and chemotaxonomic properties, together with 16S rDNA sequence. It is proposed that strain NEAE-J should be included in the species Streptomyces albogriseolus as a representative of a novel sub-species, Streptomyces albogriseolus subsp. cellulolyticus strain NEAE-J and sequencing product was deposited in the GenBank database under accession number JN229412. This organism was tested for its ability to produce endoglucanase and release reducing sugars from agro-industrial residues as substrates. Sugarcane bagasse was the most suitable substrate for endoglucanase production. Effects of process variables, namely incubation time, temperature, initial pH and nitrogen source on production of endoglucanase by submerged fermentation using Streptomyces albogriseolus subsp. cellulolyticus have been studied. Accordingly optimum conditions have been determined. Incubation temperature of 30 °C after 6 days, pH of 6.5, 1% sugarcane bagasse as carbon source and peptone as nitrogen source were found to be the optimum for endoglucanase production. Optimization of the process parameters resulted in about 2.6 fold increase in the endoglucanase activity. Therefore, Streptomyces albogriseolus subsp. cellulolyticus coud be potential microorganism for the intended application. PMID:25242966

  6. Plant Community Richness Mediates Inhibitory Interactions and Resource Competition between Streptomyces and Fusarium Populations in the Rhizosphere.

    Science.gov (United States)

    Essarioui, Adil; LeBlanc, Nicholas; Kistler, Harold C; Kinkel, Linda L

    2017-07-01

    Plant community characteristics impact rhizosphere Streptomyces nutrient competition and antagonistic capacities. However, the effects of Streptomyces on, and their responses to, coexisting microorganisms as a function of plant host or plant species richness have received little attention. In this work, we characterized antagonistic activities and nutrient use among Streptomyces and Fusarium from the rhizosphere of Andropogon gerardii (Ag) and Lespedeza capitata (Lc) plants growing in communities of 1 (monoculture) or 16 (polyculture) plant species. Streptomyces from monoculture were more antagonistic against Fusarium than those from polyculture. In contrast, Fusarium isolates from polyculture had greater inhibitory capacities against Streptomyces than isolates from monoculture. Although Fusarium isolates had on average greater niche widths, the collection of Streptomyces isolates in total used a greater diversity of nutrients for growth. Plant richness, but not plant host, influenced the potential for resource competition between the two taxa. Fusarium isolates had greater niche overlap with Streptomyces in monoculture than polyculture, suggesting greater potential for Fusarium to competitively challenge Streptomyces in monoculture plant communities. In contrast, Streptomyces had greater niche overlap with Fusarium in polyculture than monoculture, suggesting that Fusarium experiences greater resource competition with Streptomyces in polyculture than monoculture. These patterns of competitive and inhibitory phenotypes among Streptomyces and Fusarium populations are consistent with selection for Fusarium-antagonistic Streptomyces populations in the presence of strong Fusarium resource competition in plant monocultures. Similarly, these results suggest selection for Streptomyces-inhibitory Fusarium populations in the presence of strong Streptomyces resource competition in more diverse plant communities. Thus, landscape-scale variation in plant species richness may be

  7. Prioritizing orphan proteins for further study using phylogenomics and gene expression profiles in Streptomyces coelicolor

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    Takano Eriko

    2011-09-01

    Full Text Available Abstract Background Streptomyces coelicolor, a model organism of antibiotic producing bacteria, has one of the largest genomes of the bacterial kingdom, including 7825 predicted protein coding genes. A large number of these genes, nearly 34%, are functionally orphan (hypothetical proteins with unknown function. However, in gene expression time course data, many of these functionally orphan genes show interesting expression patterns. Results In this paper, we analyzed all functionally orphan genes of Streptomyces coelicolor and identified a list of "high priority" orphans by combining gene expression analysis and additional phylogenetic information (i.e. the level of evolutionary conservation of each protein. Conclusions The prioritized orphan genes are promising candidates to be examined experimentally in the lab for further characterization of their function.

  8. The Cellular Mechanisms that Ensure an Efficient Secretion in Streptomyces

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    Sonia Gullón

    2018-04-01

    Full Text Available Gram-positive soil bacteria included in the genus Streptomyces produce a large variety of secondary metabolites in addition to extracellular hydrolytic enzymes. From the industrial and commercial viewpoints, the S. lividans strain has generated greater interest as a host bacterium for the overproduction of homologous and heterologous hydrolytic enzymes as an industrial application, which has considerably increased scientific interest in the characterization of secretion routes in this bacterium. This review will focus on the secretion machinery in S. lividans.

  9. Strain engineering of WS2, WSe2, and WTe2

    KAUST Repository

    Amin, Bin

    2014-01-01

    We perform first-principles calculations to investigate the structural, electronic, and vibrational properties of WS2, WSe2, and WTe2 monolayers, taking into account the strong spin orbit coupling. A transition from a direct to an indirect band gap is achieved for compressive strain of 1% for WS2, 1.5% for WSe2, and 2% for WTe 2, while the nature of the band gap remains direct in the case of tensile strain. The size of the band gap passes through a maximum under compressive strain and decreases monotonically under tensile strain. A strong spin splitting is found for the valence band in all three compounds, which is further enhanced by tensile strain. The mobility of the electrons grows along the series WS2 < WSe2 < WTe2. This journal is © the Partner Organisations 2014.

  10. Streptomyces rhizobacteria modulate the secondary metabolism of Eucalyptus plants.

    Science.gov (United States)

    Salla, Tamiris Daros; da Silva, Ramos; Astarita, Leandro Vieira; Santarém, Eliane Romanato

    2014-12-01

    The genus Eucalyptus comprises economically important species, such as Eucalyptus grandis and Eucalyptus globulus, used especially as a raw material in many industrial sectors. Species of Eucalyptus are very susceptible to pathogens, mainly fungi, which leads to mortality of plant cuttings in rooting phase. One alternative to promote plant health and development is the potential use of microorganisms that act as agents for biological control, such as plant growth-promoting rhizobacteria (PGPR). Rhizobacteria Streptomyces spp have been considered as PGPR. This study aimed at selecting strains of Streptomyces with ability to promote plant growth and modulate secondary metabolism of E. grandis and E. globulus in vitro plants. The experiments assessed the development of plants (root number and length), changes in key enzymes in plant defense (polyphenol oxidase and peroxidase) and induction of secondary compounds(total phenolic and quercetinic flavonoid fraction). The isolate Streptomyces PM9 showed highest production of indol-3-acetic acid and the best potential for root induction. Treatment of Eucalyptus roots with Streptomyces PM9 caused alterations in enzymes activities during the period of co-cultivation (1-15 days), as well as in the levels of phenolic compounds and flavonoids. Shoots also showed alteration in the secondary metabolism, suggesting induced systemic response. The ability of Streptomyces sp. PM9 on promoting root growth, through production of IAA, and possible role on modulation of secondary metabolism of Eucalyptus plants characterizes this isolate as PGPR and indicates its potential use as a biological control in forestry.

  11. Streptomyces tremellae sp. nov., isolated from a culture of the mushroom Tremella fuciformis.

    Science.gov (United States)

    Wen, Zhi-Qiang; Chen, Bingzhi; Li, Xiao; Li, Bing-Bing; Li, Cheng-Huan; Huang, Qing-Hua; Zhang, Qi-Hui; Dai, Wei-Hao; Jiang, Yu-Ji

    2016-12-01

    A novel actinomycete strain, designated Js-1T, was isolated from Tremella fuciformis collected from Gutian, Fujian Province, in southeastern China. The taxonomic status of this strain was determined by a polyphasic approach, which demonstrated that the novel strain was a member of the genus Streptomyces. The cell walls of this strain were found to contain ll-diaminopimelic acid, muramic acid and glycine. An analysis of whole-cell hydrolysates revealed that no characteristic sugar was present. The key identified menaquinones were MK-9 (H6) and MK-9 (H8), while the diagnostic polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylmethylethanolamine and phosphatidylglycerol. The main cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0, C16 : 0 and iso-C16 : 0. An analysis of an almost complete 16S rRNA gene sequence showed that the strain shared the highest levels of sequence similarity with Streptomyces sannanensisKC-7038T (97.87 %), Streptomyces hebeiensis YIM 001T (97.84 %), Streptomyces pathocidini NBRC 13812T (97.80 %), Streptomyces cocklensis BK168T (97.25 %), Streptomyces coerulescens NBRC 12758T (97.12 %), Streptomyces aurantiogriseus NBRC 12842T (97.06 %) and Streptomyces rimosussubsp. rimosus ATCC 10970T (97.04 %). The DNA G+C content of the genomic DNA of strain Js-1T was 70.1 mol%. Furthermore, DNA-DNA hybridization tests revealed that the relatedness values between strain Js-1T and the most closely related species ranged from 15.10 to 47.20 %. Based on its phenotypic and genotypic characteristics, strain Js-1T (=CCTCC M 2011365T=JCM 30846T) is considered to represent a novel species within the genus Streptomyces, which we classified as Streptomycestremellae sp. nov.

  12. Extracellular proteases from Streptomyces phaeopurpureus ExPro138 inhibit spore adhesion, germination and appressorium formation in Colletotrichum coccodes.

    Science.gov (United States)

    Palaniyandi, S A; Yang, S H; Suh, J-W

    2013-07-01

    To study the antifungal mechanism of proteases from Streptomyces phaeopurpureus strain ExPro138 towards Colletotrichum coccodes and to evaluate its utilization as biofungicide. We screened proteolytic Streptomyces strains from the yam rhizosphere with antifungal activity. Forty proteolytic Streptomyces were isolated, among which eleven isolates showed gelatinolytic activity and antagonistic activity on C. coccodes. Of the 11 isolates, protease preparation from an isolate designated ExPro138 showed antifungal activity. 16S rDNA sequence analysis of the strain showed 99% similarity with Streptomyces phaeopurepureus (EU841588.1). Zymography analysis of the ExPro138 culture filtrate revealed that the strain produced several extracellular proteases. The protease preparation inhibited spore germination, spore adhesion to polystyrene surface and appressorium formation. Microscopic study of the interaction between ExPro138 and C. coccodes revealed that ExPro138 was mycoparasitic on C. coccodes. The protease preparation also reduced anthracnose incidence on tomato fruits compared with untreated control. This study demonstrates possibility of utilizing antifungal proteases derived from antagonistic microbes as biofungicide. Microbial proteases having the ability to inhibit spore adhesion and appressorium formation could be used to suppress infection establishment by foliar fungal pathogens at the initial stages of the infection process. Journal of Applied Microbiology © 2013 The Society for Applied Microbiology.

  13. Streptomyces caldifontis sp. nov., isolated from a hot water spring of Tatta Pani, Kotli, Pakistan.

    Science.gov (United States)

    Amin, Arshia; Ahmed, Iftikhar; Khalid, Nauman; Osman, Ghenijan; Khan, Inam Ullah; Xiao, Min; Li, Wen-Jun

    2017-01-01

    A Gram-staining positive, non-motile, rod-shaped, catalase positive and oxidase negative bacterium, designated NCCP-1331 T , was isolated from a hot water spring soil collected from Tatta Pani, Kotli, Azad Jammu and Kashmir, Pakistan. The isolate grew at a temperature range of 18-40 °C (optimum 30 °C), pH 6.0-9.0 (optimum 7.0) and with 0-6 % NaCl (optimum 2 % NaCl (w/v)). The phylogenetic analysis based on 16S rRNA gene sequence revealed that strain NCCP-1331 T belonged to the genus Streptomyces and is closely related to Streptomyces brevispora BK160 T with 97.9 % nucleotide similarity, followed by Streptomyces drosdowiczii NRRL B-24297 T with 97.8 % nucleotide similarity. The DNA-DNA relatedness values of strain NCCP-1331 T with S. brevispora KACC 21093 T and S. drosdowiczii CBMAI 0498 T were 42.7 and 34.7 %, respectively. LL-DAP was detected as diagnostic amino acid along with alanine, glycine, leucine and glutamic acid. The isolate contained MK-9(H 8 ) as the predominant menaquinone. Major polar lipids detected in NCCP-1331 T were phosphatidylethanolamine, phosphatidylinositol and unidentified phospholipids. Major fatty acids were iso-C 16: 0 , summed feature 8 (18:1 ω7c/18:1 ω6c), anteiso-C 15:0 and C 16:0 . The genomic DNA G + C content was 69.8 mol %. On the basis of phylogenetic, phenotypic and chemotaxonomic analysis, it is concluded that strain NCCP-1331 T represents a novel species of the genus Streptomyces, for which the name Streptomyces caldifontis sp. nov. is proposed. The type strain is NCCP-1331 T (=KCTC 39537 T  = CPCC 204147 T ).

  14. Streptomyces capparidis sp. nov., a novel endophytic actinobacterium isolated from fruits of Capparis spinosa L.

    Science.gov (United States)

    Wang, Hong-Fei; Li, Qiu-Li; Xiao, Min; Zhang, Yong-Guang; Zhou, Xing-Kui; Narsing Rao, Manik Prabhu; Duan, Yan-Qing; Li, Wen-Jun

    2017-01-01

    A novel endophytic actinobacterial strain, designated EGI 6500195T, was isolated from fruits of Capparis spinosa. Growth occurred at 10-45 °C (optimum 30 °C), at pH 6-8 (optimum pH 7) and in the presence of 0-1 % (w/v) NaCl. Strain EGI 6500195T shared highest 16S rRNA gene sequence similarity (97.74 %) with Streptomyces vitaminophilus DSM 41686T and less than 97 % sequence similarity with other members of the genus Streptomyces. The diagnostic amino acid in the peptidoglycan was ll-diaminopimelic acid. Whole-cell hydrolysates contained glucose, ribose, fructose and mannose. The predominant menaquinones were MK-9(H6) and MK-9(H8). The polar lipid profile of strain EGI 6500195T included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylinositol, phosphatidylcholine, three unknown phospholipids, an unknown aminophospholipid and an unknown aminolipid. The cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0, iso-C15 : 0, iso-C16 : 0, anteiso-C17 : 1ω9c, summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B) and iso-C17 : 1ω9c. The DNA G+C content of strain EGI 6500195T was 74.1 mol%. The level of DNA-DNA relatedness between strain EGI 6500195T and Streptomyces. vitaminophilus DSM 41686T was 14.1±3.5 %. On the basis of the phenotypic, phylogenetic, chemotaxonomic and DNA-DNA hybridization data, strain EGI 6500195T represents a novel species of the genus Streptomyces, for which the name Streptomyces capparidis sp. nov. is proposed. The type strain is EGI 6500195T (=DSM 42145T=JCM 30089T).

  15. Chemical analyses of wasp-associated streptomyces bacteria reveal a prolific potential for natural products discovery.

    Directory of Open Access Journals (Sweden)

    Michael Poulsen

    2011-02-01

    Full Text Available Identifying new sources for small molecule discovery is necessary to help mitigate the continuous emergence of antibiotic-resistance in pathogenic microbes. Recent studies indicate that one potentially rich source of novel natural products is Actinobacterial symbionts associated with social and solitary Hymenoptera. Here we test this possibility by examining two species of solitary mud dauber wasps, Sceliphron caementarium and Chalybion californicum. We performed enrichment isolations from 33 wasps and obtained more than 200 isolates of Streptomyces Actinobacteria. Chemical analyses of 15 of these isolates identified 11 distinct and structurally diverse secondary metabolites, including a novel polyunsaturated and polyoxygenated macrocyclic lactam, which we name sceliphrolactam. By pairing the 15 Streptomyces strains against a collection of fungi and bacteria, we document their antifungal and antibacterial activity. The prevalence and anti-microbial properties of Actinobacteria associated with these two solitary wasp species suggest the potential role of these Streptomyces as antibiotic-producing symbionts, potentially helping defend their wasp hosts from pathogenic microbes. Finding phylogenetically diverse and chemically prolific Actinobacteria from solitary wasps suggests that insect-associated Actinobacteria can provide a valuable source of novel natural products of pharmaceutical interest.

  16. ­Genomic data mining of the marine actinobacteria Streptomyces sp. H-KF8 unveils insights into multi-stress related genes and metabolic pathways involved in antimicrobial synthesis

    Directory of Open Access Journals (Sweden)

    Agustina Undabarrena

    2017-02-01

    Full Text Available Streptomyces sp. H-KF8 is an actinobacterial strain isolated from marine sediments of a Chilean Patagonian fjord. Morphological characterization together with antibacterial activity was assessed in various culture media, revealing a carbon-source dependent activity mainly against Gram-positive bacteria (S. aureus and L. monocytogenes. Genome mining of this antibacterial-producing bacterium revealed the presence of 26 biosynthetic gene clusters (BGCs for secondary metabolites, where among them, 81% have low similarities with known BGCs. In addition, a genomic search in Streptomyces sp. H-KF8 unveiled the presence of a wide variety of genetic determinants related to heavy metal resistance (49 genes, oxidative stress (69 genes and antibiotic resistance (97 genes. This study revealed that the marine-derived Streptomyces sp. H-KF8 bacterium has the capability to tolerate a diverse set of heavy metals such as copper, cobalt, mercury, chromate and nickel; as well as the highly toxic tellurite, a feature first time described for Streptomyces. In addition, Streptomyces sp. H-KF8 possesses a major resistance towards oxidative stress, in comparison to the soil reference strain Streptomyces violaceoruber A3(2. Moreover, Streptomyces sp. H-KF8 showed resistance to 88% of the antibiotics tested, indicating overall, a strong response to several abiotic stressors. The combination of these biological traits confirms the metabolic versatility of Streptomyces sp. H-KF8, a genetically well-prepared microorganism with the ability to confront the dynamics of the fjord-unique marine environment.

  17. Enhanced photoresponse characteristics of transistors using CVD-grown MoS2/WS2 heterostructures

    Science.gov (United States)

    Shan, Junjie; Li, Jinhua; Chu, Xueying; Xu, Mingze; Jin, Fangjun; Fang, Xuan; Wei, Zhipeng; Wang, Xiaohua

    2018-06-01

    Semiconductor heterostructures based on transition metal dichalcogenides provide a broad platform to research two-dimensional nanomaterials and design atomically thin devices for fundamental and applied interests. The MoS2/WS2 heterostructure was prepared on SiO2/Si substrate by chemical vapor deposition (CVD) in our research. And the optical properties of the heterostructure was characterized by Raman and photoluminescence (PL) spectroscopy. The similar 2 orders of magnitude decrease of PL intensity in MoS2/WS2 heterostructures was tested, which is attribute to the electrical and optical modulation effects are connected with the interfacial charge transfer between MoS2 and WS2 films. Using MoS2/WS2 heterostructure as channel material of the phototransistor, we demonstrated over 50 folds enhanced photoresponsivity of multilayer MoS2 field-effect transistor. The results indicate that the MoS2/WS2 films can be a promising heterostructure material to enhance the photoresponse characteristics of MoS2-based phototransistors.

  18. PCR detection of oxytetracycline resistance genes otr(A) and otr(B) in tetracycline-resistant streptomycete isolates from diverse habitats

    NARCIS (Netherlands)

    Nikolakopoulou, T; Egan, S; van Overbeek, L; Guillaume, G; Heuer, H; Wellington, EMH; van Elsas, JD; Collard, JM; Smalla, K; Karagouni, A

    2005-01-01

    A range of European habitats was screened by PCR for detection of the oxytetracycline resistance genes otr(A) and otr(B), found in the oxytetracycline-producing strain Streptomyces rimosus. Primers were developed to detect these otr genes in tetracycline-resistant (Tc-R) streptomycete isolates from

  19. Characterization of naphthalene degradation by Streptomyces sp. QWE-5 isolated from active sludge.

    Science.gov (United States)

    Xu, Peng; Ma, Wencheng; Han, Hongjun; Hou, Baolin; Jia, Shengyong

    2014-01-01

    A bacterial strain, QWE-5, which utilized naphthalene as its sole carbon and energy source, was isolated and identified as Streptomyces sp. It was a Gram-positive, spore-forming bacterium with a flagellum, with whole, smooth, convex and wet colonies. The optimal temperature and pH for QWE-5 were 35 °C and 7.0, respectively. The QWE-5 strain was capable of completely degrading naphthalene at a concentration as high as 100 mg/L. At initial naphthalene concentrations of 10, 20, 50, 80 and 100 mg/L, complete degradation was achieved within 32, 56, 96, 120 and 144 h, respectively. Kinetics of naphthalene degradation was described using the Andrews equation. The kinetic parameters were as follows: qmax (maximum specific degradation rate) = 1.56 h⁻¹, Ks (half-rate constant) = 60.34 mg/L, and KI (substrate-inhibition constant) = 81.76 mg/L. Metabolic intermediates were identified by gas chromatography and mass spectrometry, allowing a new degradation pathway for naphthalene to be proposed. In this pathway, monooxygenation of naphthalene yielded naphthalen-1-ol. Further degradation by Streptomyces sp. QWE-5 produced acetophenone, followed by adipic acid, which was produced as a combination of decarboxylation and hydroxylation processes.

  20. Two novel homologous proteins of Streptomyces coelicolor and Streptomyces lividans are involved in the formation of the rodlet layer and mediate attachment to a hydrophobic surface

    NARCIS (Netherlands)

    Claessen, Dennis; Wösten, Han A.B.; Keulen, Geertje van; Faber, Onno G.; Alves, Alexandra M.C.R.; Meijer, Wim G.; Dijkhuizen, Lubbert

    The filamentous bacteria Streptomyces coelicolor and Streptomyces lividans exhibit a complex life cycle. After a branched submerged mycelium has been established, aerial hyphae are formed that may septate to form chains of spores. The aerial structures possess several surface layers of unknown

  1. Screening on the high yield validamycin producing strain by implantation with N+ and Ti+ ion source

    International Nuclear Information System (INIS)

    Yu Long; An Xiao

    2007-01-01

    In order to compared the mutagenic effects of the validamycin producing the strain (Streptomyces hygroscopicus var. Jingganggensis Yen.) was implanted with two kinds of ion sources. The results showed that when two kinds of ion sources implanted into the strain by turns, more positive mutants and higher yield would be acquired. Using this method, a high-yielding strain B1-3 was obtained, which produce the titer of validamycin A of 21514, and was 54.4% higher than that of the original strain. (authors)

  2. Novel Pathway of Salicylate Degradation by Streptomyces sp. Strain WA46

    OpenAIRE

    Ishiyama, Daisuke; Vujaklija, Dusica; Davies, Julian

    2004-01-01

    A novel salicylate-degrading Streptomyces sp., strain WA46, was identified by UV fluorescence on solid minimal medium containing salicylate; trace amounts of gentisate were detected by high-pressure liquid chromatography when strain WA46 was grown with salicylate. PCR amplification of WA46 DNA with degenerate primers for gentisate 1,2-dioxygenase (GDO) genes produced an amplicon of the expected size. Sequential PCR with nested GDO primers was then used to identify a salicylate degradation gen...

  3. Extracellular synthesis gold nanotriangles using biomass of Streptomyces microflavus.

    Science.gov (United States)

    Soltani Nejad, Meysam; Khatami, Mehrdad; Shahidi Bonjar, Gholam Hosein

    2016-02-01

    Applications of nanotechnology and nano-science have ever-expanding breakthroughs in medicine, agriculture and industries in recent years; therefore, synthesis of metals nanoparticle (NP) has special significance. Synthesis of NPs by chemical methods are long, costly and hazardous for environment so biosynthesis has been developing interest for researchers. In this regard, the extracellular biosynthesis of gold nanotriangles (AuNTs) performed by use of the soil Streptomycetes. Streptomycetes isolated from rice fields of Guilan Province, Iran, showed biosynthetic activity for producing AuNTs via in vitro experiments. Among all 15 Streptomyces spp. isolates, isolate No. 5 showed high biosynthesis activity. To determine the bacterium taxonomical identity at genus level, its colonies characterised morphologically by use of scanning electron microscope. The polymerase chain reaction (PCR) molecular analysis of active isolate represented its identity partially. In this regard, 16S rRNA gene of the isolate was amplified using universal bacterial primers FD1 and RP2. The PCR products were purified and sequenced. Sequence analysis of 16S rDNA was then conducted using National Center for Biotechnology Information Basic Local Alignment Search Tool method. The AuNTs obtained were characterised by ultraviolet-visible spectroscopy, atomic force microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction spectroscopy analyses. The authors results indicated that Streptomyces microflavus isolate 5 bio-synthesises extracellular AuNTs in the range of 10-100 nm. Synthesised SNPs size ranged from 10 to 100 nm. In comparison with chemical methods for synthesis of metal NPs, the biosynthesis of AuNTs by Streptomyces source is a fast, simple and eco-friendly method. The isolate is a good candidate for further investigations to optimise its production efficacy for further industrial goals in

  4. In vitro immunobiological activity of an Antarctic streptomyces polysaccharide

    International Nuclear Information System (INIS)

    Toshkova, R.; Yossifova, L.; Gardeva, E.; Zvetkova, E.; Ivanova, V.

    2010-01-01

    Antarctic Streptomyces sp. 1010, were obtained from sea water samples (Livingston Island, Antarctica), during the Third Bulgarian Antarctic Scientific Expedition (1994-1995). The ecophysiological methods for isolation and characterization of these active, cold-adapted, Gram-positive microorganisms (psychrophiles) in morphological, phenotypic, genetic and taxonomic aspects, have been earlier reported. In this study, a new extracellular polysaccharide (heteropolysaccharide) has been isolated and purified from cultured broth of the Antarctic Streptomyces sp. 1010. The monosaccharide content of the Antarctic streptomyces heteropolysaccharide has been examined by TLC and GC/MS. The mitogenic and immuno potential properties of the purified Antarctic Streptomyces polysaccharide (ASMP) have been studied in vitro - in the short-term cultures of human peripheral blood mononuclear cells (hPBMCs - lymphocytes and monocytes) and mouse spleen lymphocytes (mouse splenocytes - mSps). The results obtained show that ASMP has a double lectin-like effect on the proliferative activity of hPBMCs: similar to this of Con A on the lymphoid cells (preliminary T-lymphocytes) and to the effect of LPS on the mononuclear from monocyte-macrophage lineage. Expressed as proliferative index (PI), the mitogenic response of mSps to the in vitro influence of ASMP was also higher than PI in the negative, as well as in the positive controls (mSps, cultured in the presence of PHA, Con A and LPS). The new Antarctic Streptomyces' heteropolysaccharide examined could be useful in the future as an immunomodulative biologically active substance and its extracellular production may contribute to the development of thermobiochemistry, immunomodulative drug therapy and immunopharmaceutical industry. (authors)

  5. Colonization of lettuce rhizosphere and roots by tagged Streptomyces

    OpenAIRE

    Maria eBonaldi; Xiaoyulong eChen; Andrea eKunova; Cristina ePizzatti; Marco eSaracchi; Paolo eCortesi

    2015-01-01

    Beneficial microorganisms are increasingly used in agriculture, but their efficacy often fails due to limited knowledge of their interactions with plants and other microorganisms present in rhizosphere. We studied spatio-temporal colonization dynamics of lettuce roots and rhizosphere by genetically modified Streptomyces spp. Five Streptomyces strains, strongly inhibiting in vitro the major soil-borne pathogen of horticultural crops, Sclerotinia sclerotiorum, were transformed with pIJ8641 plas...

  6. Biological effects of N+ ion implantation and UV radiation on streptomyces albus

    International Nuclear Information System (INIS)

    Wu Jian; Dai Guifu

    2005-01-01

    The results of both 30 keV N + ion implantation and UV irradiation of Streptomyces albus showed complicate biological effects. The 'saddle shape' pattern of the dose-dependent curve formed by N + ion implantation with low energy was studied, and it proved that vacuum was not the reason, and the fact, the 'saddle shape' curve may be regarded as a HRS/IRR (hyper-radiosensitivity/increased radiaoresistance) effect caused by low dose irradiation. But Streptomyces albus UV irradiated after vacuum treatment only showed IRR effect or hormesis (survival rate >100%). The streptomycin resistance mutation of Streptomyces albus caused by low energy N + ion implantation and UV irradiation was also studied. the results showed that UV radiation is one effective means for streptomyces albus breeding. (authors)

  7. Streptomyces formicae sp. nov., a novel actinomycete isolated from the head of Camponotus japonicus Mayr.

    Science.gov (United States)

    Bai, Lu; Liu, Chongxi; Guo, Lifeng; Piao, Chenyu; Li, Zhilei; Li, Jiansong; Jia, Feiyu; Wang, Xiangjing; Xiang, Wensheng

    2016-02-01

    During a screening for novel and biotechnologically useful actinobacteria in insects, a novel actinomycete with antifungal activity, designated strain 1H-GS9(T), was isolated from the head of a Camponotus japonicus Mayr ant, which were collected from Northeast Agricultural University (Harbin, Heilongjiang, China). Strain 1H-GS9(T) was characterised using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. 16S rRNA gene sequence similarity studies showed that strain 1H-GS9(T) belongs to the genus Streptomyces with high sequence similarities to Streptomyces scopuliridis DSM 41917(T) (98.8 %) and Streptomyces mauvecolor JCM 5002(T) (98.6 %). However, phylogenetic analysis based on the 16S rRNA gene sequence indicated that it forms a monophyletic clade with Streptomyces kurssanovii JCM 4388(T) (98.6 %), Streptomyces xantholiticus JCM 4282(T) (98.6 %) and Streptomyces peucetius JCM 9920(T) (98.5 %). Thus, a combination of DNA-DNA hybridization experiments and phenotypic tests were carried out between strain 1H-GS9(T) and the above-mentioned five strains, which further clarified their relatedness and demonstrated that strain 1H-GS9(T) could be distinguished from these strains. Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces formicae sp. nov. is proposed. The type strain is 1H-GS9(T) (=CGMCC 4.7277(T) = DSM 100524(T)).

  8. The papain inhibitor (SPI) of Streptomyces mobaraensis inhibits bacterial cysteine proteases and is an antagonist of bacterial growth

    NARCIS (Netherlands)

    S. Zindel (Stephan); W.E. Kaman (Wendy); S. Fröls (Sabrina); F. Pfeifer (Felicitas); A. Peters (Annette); J.P. Hays (John); H.-L. Fuchsbauer (Hans-Lothar)

    2013-01-01

    textabstractA novel papain inhibitory protein (SPI) from Streptomyces mobaraensis was studied to measure its inhibitory effect on bacterial cysteine protease activity (Staphylococcus aureus SspB) and culture supernatants (Porphyromonas gingivalis, Bacillus anthracis). Further, growth of Bacillus

  9. Proposed standard-weight (Ws) equation and length-categorization standards for brown trout (Salmo trutta) in lentic habitats

    Science.gov (United States)

    Hyatt, M.W.; Hubert, W.A.

    2001-01-01

    We developed a standard-weight (Ws) equation for brown trout (Salmo trutta) in lentic habitats by applying the regression-line-percentile technique to samples from 49 populations in North America. The proposed Ws equation is log10 Ws = -5.422 + 3.194 log10 TL, when Ws is in grams and TL is total length in millimeters. The English-unit equivalent is log10 Ws = -3.592 + 3.194 log10 TL, when Ws is in pounds and TL is total length in inches. The equation is applicable for fish of 140-750 mm TL. Proposed length-category standards to evaluate fish within populations are: stock, 200 mm (8 in); quality, 300 mm (12 in); preferred, 400 mm (16 in); memorable, 500 mm (20 in); and trophy, 600 mm (24 in).

  10. Fabrication of biogenic antimicrobial silver nanoparticles by Streptomyces aegyptia NEAE 102 as eco-friendly nanofactory.

    Science.gov (United States)

    El-Naggar, Noura El-Ahmady; Abdelwahed, Nayera A M; Darwesh, Osama M M

    2014-04-01

    The current research was focused on the extracellular biosynthesis of bactericidal silver nanoparticles (AgNPs) using cell-free supernatant of a local isolate previously identified as a novel Streptomyces aegyptia NEAE 102. The biosynthesis of silver nanoparticles by Streptomyces aegyptia NEAE 102 was quite fast and required far less time than previously published strains. The produced particles showed a single surface plasmon resonance peak at 400 nm by UV-Vis spectroscopy, which confirmed the presence of AgNPs. Response surface methodology was chosen to evaluate the effects of four process variables (AgNO3 concentration, incubation period, pH levels, and inoculum size) on the biosynthesis of silver nanoparticles by Streptomyces aegyptia NEAE 102. Statistical analysis of the results showed that the linear and quadratic effects of incubation period, initial pH, and inoculum size had a significant effect (p silver nanoparticles by Streptomyces aegyptia NEAE 102. The maximum silver nanoparticles biosynthesis (2.5 OD, at 400 nm ) was achieved in runs number 5 and 14 under the conditions of 1 mM AgNO3 (1-1.5% (v/v)), incubation period (72-96 h), initial pH (9-10), and inoculum size (2-4% (v/v)). An overall 4-fold increase in AgNPs biosynthesis was obtained as compared with that of unoptimized conditions. The biosynthesized silver nanoparticles were characterized using UV-VIS spectrophotometer and Fourier transform infrared spectroscopy analysis, in addition to antimicrobial properties. The biosynthesized AgNPs significantly inhibited the growth of medically important pathogenic gram-positive (Staphylococcus aureus) and gram-negative bacteria (Pseudomonas aeruginosa) and yeast (Candida albicans).

  11. Streptomyces kalpinensis sp. nov., an actinomycete isolated from a salt water beach.

    Science.gov (United States)

    Ma, Guo-Quan; Xia, Zhan-Feng; Wan, Chuan-Xing; Zhang, Yao; Luo, Xiao-Xia; Zhang, Li-Li

    2017-12-01

    A novel actinobacterium designated TRM 46509 T was isolated from a salt water beach at Kalpin, Xinjiang, north-west China. The strain was aerobic and Gram-stain-positive, with an optimum NaCl concentration for growth of 1 % (w/v). The isolate formed sparse aerial mycelium and produced spiral spores at the end of the aerial mycelium on Gauze's No. 1 medium. The isolate contained ll-diaminopimelic acid as the diagnostic diamino acid and ribose as the major whole-cell sugar. The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol mannosides and an unidentified phospholipid. The predominant menaquinones were MK-9(H2), MK-9(H6) and MK-9(H8). The major fatty acids were C16:0, iso-C16 : 0, anteiso-C15 : 0, iso-C15 : 0 and iso-C14 : 0. The G+C content of the DNA was 69.3 mol%. Phylogenetic analysis showed that strain TRM 46509 T shared 16S rRNA gene sequence similarity of 97.6 % with the closest described species Streptomyces tacrolimicus ATCC 55098 T . On the basis of evidence from this polyphasic study, strain TRM 46509 T should be designated as representing a novel species of the genus Streptomyces, for which the name Streptomyces kalpinensis sp. nov. is proposed. The type strain is TRM 46509 T (=CCTCC AA 2015028 T =KCTC 39667 T ).

  12. Genome Sequences of the Oxytetracycline Production Strain Streptomyces rimosus R6-500 and Two Mutants with Chromosomal Rearrangements

    KAUST Repository

    Baranasic, Damir

    2014-07-17

    The genome sequence of Streptomyces rimosus R6-500, an industrially improved strain which produces high titers of the important antibiotic oxytetracycline, is reported, as well as the genome sequences of two derivatives arising due to the genetic instability of the strain.

  13. Genome Sequences of the Oxytetracycline Production Strain Streptomyces rimosus R6-500 and Two Mutants with Chromosomal Rearrangements

    KAUST Repository

    Baranasic, Damir; Zucko, Jurica; Nair, Mridul; Pain, Arnab; Long, Paul F.; Hranueli, Daslav; Cullum, John; Starcevic, Antonio

    2014-01-01

    The genome sequence of Streptomyces rimosus R6-500, an industrially improved strain which produces high titers of the important antibiotic oxytetracycline, is reported, as well as the genome sequences of two derivatives arising due to the genetic instability of the strain.

  14. Identification and characterization of lbpA, an indigoidine biosynthetic gene in the γ-butyrolactone signaling system of Streptomyces lavendulae FRI-5.

    Science.gov (United States)

    Pait, Ivy Grace Umadhay; Kitani, Shigeru; Kurniawan, Yohanes Novi; Asa, Maeda; Iwai, Takashi; Ikeda, Haruo; Nihira, Takuya

    2017-10-01

    Streptomyces lavendulae FRI-5 produces the blue pigment indigoidine and other secondary metabolites (d-cycloserine and nucleoside antibiotics). The production of these useful compounds is controlled by a signaling cascade mediated by the γ-butyrolactone autoregulator IM-2. Previously we revealed that the far regulatory island includes the IM-2 receptor, the IM-2 biosynthetic enzyme, and several transcriptional regulators, and that it contributes to the regulation of indigoidine production in response to the signaling molecule. Here, we found that the vicinity of the far regulatory island includes the putative gene cluster for the biosynthesis of indigoidine and unidentified compounds, and demonstrated that the expression of the gene cluster is under the control of the IM-2 regulatory system. Heterologous expression of lbpA, encoding a plausible nonribosomal peptide synthetase, in the versatile model host Streptomyces avermitilis SUKA22 led to indigoidine production, which was enhanced dramatically by feeding of the indigoidine precursor l-glutamine. These results confirmed that LbpA is an indigoidine biosynthetic enzyme in the IM-2 signaling cascade. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  15. Purification, crystallization and preliminary X-ray analysis of SGR6054, a Streptomyces homologue of the mycobacterial integration host factor mIHF

    International Nuclear Information System (INIS)

    Nomoto, Ryohei; Tezuka, Takeaki; Miyazono, Ken-ichi; Tanokura, Masaru; Horinouchi, Sueharu; Ohnishi, Yasuo

    2012-01-01

    A Streptomyces homologue of the mycobacterial integration host factor mIHF was heterologously produced, purified and crystallized in the presence of a 16-mer duplex DNA by the sitting-drop vapour-diffusion method. The best crystal diffracted X-rays to 2.22 Å resolution and belonged to space group C2. The mycobacterial integration host factor (mIHF) is a small nonspecific DNA-binding protein that is essential for the growth of Mycobacterium smegmatis. mIHF homologues are widely distributed among Actinobacteria, and a Streptomyces homologue of mIHF is involved in control of sporulation and antibiotic production in S. coelicolor A3(2). Despite their important biological functions, a structure of mIHF or its homologues has not been elucidated to date. Here, the S. griseus mIHF homologue (SGR6054) was expressed and purified from Escherichia coli and crystallized in the presence of a 16-mer duplex DNA by the sitting-drop vapour-diffusion method. The plate-shaped crystal belonged to space group C2, with unit-cell parameters a = 88.53, b = 69.35, c = 77.71 Å, β = 96.63°, and diffracted X-rays to 2.22 Å resolution

  16. Purification, crystallization and preliminary X-ray analysis of SGR6054, a Streptomyces homologue of the mycobacterial integration host factor mIHF

    Energy Technology Data Exchange (ETDEWEB)

    Nomoto, Ryohei; Tezuka, Takeaki; Miyazono, Ken-ichi; Tanokura, Masaru; Horinouchi, Sueharu; Ohnishi, Yasuo [Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan)

    2012-08-31

    A Streptomyces homologue of the mycobacterial integration host factor mIHF was heterologously produced, purified and crystallized in the presence of a 16-mer duplex DNA by the sitting-drop vapour-diffusion method. The best crystal diffracted X-rays to 2.22 Å resolution and belonged to space group C2. The mycobacterial integration host factor (mIHF) is a small nonspecific DNA-binding protein that is essential for the growth of Mycobacterium smegmatis. mIHF homologues are widely distributed among Actinobacteria, and a Streptomyces homologue of mIHF is involved in control of sporulation and antibiotic production in S. coelicolor A3(2). Despite their important biological functions, a structure of mIHF or its homologues has not been elucidated to date. Here, the S. griseus mIHF homologue (SGR6054) was expressed and purified from Escherichia coli and crystallized in the presence of a 16-mer duplex DNA by the sitting-drop vapour-diffusion method. The plate-shaped crystal belonged to space group C2, with unit-cell parameters a = 88.53, b = 69.35, c = 77.71 Å, β = 96.63°, and diffracted X-rays to 2.22 Å resolution.

  17. A Latitudinal Diversity Gradient in Terrestrial Bacteria of the Genus Streptomyces

    Science.gov (United States)

    Andam, Cheryl P.; Doroghazi, James R.; Campbell, Ashley N.; Kelly, Peter J.; Choudoir, Mallory J.

    2016-01-01

    ABSTRACT We show that Streptomyces biogeography in soils across North America is influenced by the regional diversification of microorganisms due to dispersal limitation and genetic drift. Streptomyces spp. form desiccation-resistant spores, which can be dispersed on the wind, allowing for a strong test of whether dispersal limitation governs patterns of terrestrial microbial diversity. We employed an approach that has high sensitivity for determining the effects of genetic drift. Specifically, we examined the genetic diversity and phylogeography of physiologically similar Streptomyces strains isolated from geographically distributed yet ecologically similar habitats. We found that Streptomyces beta diversity scales with geographic distance and both beta diversity and phylogenetic diversity manifest in a latitudinal diversity gradient. This pattern of Streptomyces biogeography resembles patterns seen for diverse species of plants and animals, and we therefore evaluated these data in the context of ecological and evolutionary hypotheses proposed to explain latitudinal diversity gradients. The data are consistent with the hypothesis that niche conservatism limits dispersal, and historical patterns of glaciation have limited the time for speciation in higher-latitude sites. Most notably, higher-latitude sites have lower phylogenetic diversity, higher phylogenetic clustering, and evidence of range expansion from lower latitudes. In addition, patterns of beta diversity partition with respect to the glacial history of sites. Hence, the data support the hypothesis that extant patterns of Streptomyces biogeography have been driven by historical patterns of glaciation and are the result of demographic range expansion, dispersal limitation, and regional diversification due to drift. PMID:27073097

  18. Establishing a high yielding streptomyces-based cell-free protein synthesis system.

    Science.gov (United States)

    Li, Jian; Wang, He; Kwon, Yong-Chan; Jewett, Michael C

    2017-06-01

    Cell-free protein synthesis (CFPS) has emerged as a powerful platform for applied biotechnology and synthetic biology, with a range of applications in synthesizing proteins, evolving proteins, and prototyping genetic circuits. To expand the current CFPS repertoire, we report here the development and optimization of a Streptomyces-based CFPS system for the expression of GC-rich genes. By developing a streamlined crude extract preparation protocol and optimizing reaction conditions, we were able to achieve active enhanced green fluorescent protein (EGFP) yields of greater than 50 μg/mL with batch reactions lasting up to 3 h. By adopting a semi-continuous reaction format, the EGFP yield could be increased to 282 ± 8 μg/mL and the reaction time was extended to 48 h. Notably, our extract preparation procedures were robust to multiple Streptomyces lividans and Streptomyces coelicolor strains, although expression yields varied. We show that our optimized Streptomyces lividans system provides benefits when compared to an Escherichia coli-based CFPS system for increasing percent soluble protein expression for four Streptomyces-originated high GC-content genes that are involved in biosynthesis of the nonribosomal peptides tambromycin and valinomycin. Looking forward, we believe that our Streptomyces-based CFPS system will contribute significantly towards efforts to express complex natural product gene clusters (e.g., nonribosomal peptides and polyketides), providing a new avenue for obtaining and studying natural product biosynthesis pathways. Biotechnol. Bioeng. 2017;114: 1343-1353. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. A Latitudinal Diversity Gradient in Terrestrial Bacteria of the Genus Streptomyces

    Directory of Open Access Journals (Sweden)

    Cheryl P. Andam

    2016-04-01

    Full Text Available We show that Streptomyces biogeography in soils across North America is influenced by the regional diversification of microorganisms due to dispersal limitation and genetic drift. Streptomyces spp. form desiccation-resistant spores, which can be dispersed on the wind, allowing for a strong test of whether dispersal limitation governs patterns of terrestrial microbial diversity. We employed an approach that has high sensitivity for determining the effects of genetic drift. Specifically, we examined the genetic diversity and phylogeography of physiologically similar Streptomyces strains isolated from geographically distributed yet ecologically similar habitats. We found that Streptomyces beta diversity scales with geographic distance and both beta diversity and phylogenetic diversity manifest in a latitudinal diversity gradient. This pattern of Streptomyces biogeography resembles patterns seen for diverse species of plants and animals, and we therefore evaluated these data in the context of ecological and evolutionary hypotheses proposed to explain latitudinal diversity gradients. The data are consistent with the hypothesis that niche conservatism limits dispersal, and historical patterns of glaciation have limited the time for speciation in higher-latitude sites. Most notably, higher-latitude sites have lower phylogenetic diversity, higher phylogenetic clustering, and evidence of range expansion from lower latitudes. In addition, patterns of beta diversity partition with respect to the glacial history of sites. Hence, the data support the hypothesis that extant patterns of Streptomyces biogeography have been driven by historical patterns of glaciation and are the result of demographic range expansion, dispersal limitation, and regional diversification due to drift.

  20. Streptomyces roietensis sp. nov., an endophytic actinobacterium isolated from the surface-sterilized stem of jasmine rice, Oryza sativa KDML 105.

    Science.gov (United States)

    Kaewkla, Onuma; Franco, Christopher Milton Mathew

    2017-11-01

    An endophytic actinobacterium, strain WES2 T , was isolated from the stem of a jasmine rice plant collected from a paddy field in Thung Gura Rong Hai, Roi Et province, Thailand. As a result of a polyphasic study, this strain was identified as representing a novel member of the genus Streptomyces. This strain was a Gram-stain-positive, aerobic actinobacterium with well-developed substrate mycelia and forming chains of looped spores. The closest phylogenetic relations, which shared the highest 16S rRNA gene sequence similarity, were Streptomyces nogalater JCM 4799 T and Streptomyces lavenduligriseus NRRL-ISP 5487 T at 99.1 and 99.0 %, respectively. Chemotaxonomic data, including major fatty acids, cell wall components and major menaquinones, confirmed the affiliation of WES2 T to the genus Streptomyces. The data from the phylogenetic analysis, including physiological and biochemical studies and DNA-DNA hybridization, revealed the genotypic and phenotypic differentiation of WES2 T from the most closely related species with validly published names. The name proposed for the novel species is Streptomycesroietensis sp. nov. The type strain is WES2 T (=DSM 101729=NRRL B-65344).

  1. New carbasugars from Streptomyces lincolnensis

    Czech Academy of Sciences Publication Activity Database

    Sedmera, Petr; Halada, Petr; Pospíšil, Stanislav

    2009-01-01

    Roč. 47, č. 5 (2009), s. 519-522 ISSN 0749-1581 Institutional research plan: CEZ:AV0Z50200510 Keywords : H-1 NMR * C-13 NMR * Streptomyces lincolnensis Subject RIV: EE - Microbiology, Virology Impact factor: 1.612, year: 2009

  2. Production of fibrinolytic protease from Streptomyces lusitanus isolated from marine sediments

    Science.gov (United States)

    SudeshWarma, S.; Merlyn keziah, S.; Subathra Devi, C.

    2017-11-01

    This study aim was to isolate, screen, characterize and optimize marine Streptomyces for fibrinolytic enzyme production. The potent actinomycete isolate was subjected to optimization. The parameters for optimization included pH, temperature, carbon, nitrogen sources. The crude supernatant produced was purified using size exclusion gel filtration chromatography. The optimized parameters for maximum productivity were found to be pH 7, 37°C, maltose and peptone respectively. The molecular weight of the purified enzyme was found to be 21kDa.

  3. Streptomyces cerasinus sp. nov., isolated from soil in Thailand.

    Science.gov (United States)

    Kanchanasin, Pawina; Moonmangmee, Duangtip; Phongsopitanun, Wongsakorn; Tanasupawat, Somboon; Moonmangmee, Somporn

    2017-10-01

    A novel actinomycete, strain SR3-134 T , belonging to the genus Streptomyces, was isolated from soil collected from the Sakaerat Environmental Research Station, Thailand Institute of Scientific and Technological Research, Nakhon Ratchasima Province, Thailand. The taxonomic position of the strain was characterized by using a polyphasic approach. ll-Diaminopimelic acid, glucose, mannose and ribose were detected in its whole-cell hydrolysates. The N-acyl type of muramic acid was acetyl. The menaquinones were MK-9(H8), MK-9(H6), MK-9(H4) and MK-9(H2). The predominant cellular fatty acids were anteiso-C15 : 0, iso-C16 : 0, C16 : 0, iso-C15 : 0, anteiso-C17 : 0 and iso-C14 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. blast analysis of the almost-complete 16S rRNA gene showed 98.7 % sequence similarities to Streptomyces lanatus JCM 4588 T and Streptomyces psammoticus JCM 4434 T . The DNA G+C content was 71.4 mol%. Strain SR3-134 T showed low DNA-DNA relatedness (12.9±4.0-44.1±1.0 %) to S. lanatus JCM 4588 T and S. psammoticus JCM 4434 T . The new strain could also be distinguished from its closely related strains by differences in their phenotypic characteristics. The results of taxonomic analysis suggested that strain SR3-134 T represented a novel species of the genus Streptomyces for which the name Streptomyces cerasinus sp. nov. is proposed. The type strain is SR3-134 T (=TISTR 2494 T =KCTC 39910 T ).

  4. Modification of WS2 nanosheets with controllable layers via oxygen ion irradiation

    Science.gov (United States)

    Song, Honglian; Yu, Xiaofei; Chen, Ming; Qiao, Mei; Wang, Tiejun; Zhang, Jing; Liu, Yong; Liu, Peng; Wang, Xuelin

    2018-05-01

    As one kind of two-dimensional materials, WS2 nanosheets have drawn much attention with different kinds of research methods. Yet ion irradiation method was barely used for WS2 nanosheets. In this paper, the structure, composition and optical band gap (Eg) of the multilayer WS2 films deposited by chemical vapor deposition (CVD) method on sapphire substrates before and after oxygen ion irradiation with different energy and fluences were studied. Precise tailored layer-structures and a controllable optical band gap of WS2 nanosheets were achieved after oxygen ion irradiation. The results shows higher energy oxygen irradiation changed the shape from triangular shaped grains to irregular rectangle shape but did not change 2H-WS2 phase structure. The intensity of E2g1 (Г) and A1g (Г) modes decreased and have small shifts after oxygen ion irradiation. The peak frequency difference between the E2g1 (Г) and A1g (Г) modes (Δω) decreased after oxygen ion irradiation, and this result indicates the number of layers decreased after oxygen ion irradiation. The Eg decreased with the increase of the energy and the fluence of oxygen ions. The number of layers, thickness and optical band gap changed after ion irradiation with different ion fluences and energies. The results proposed a new strategy for precise control of multilayer nanosheets and demonstrated the high applicability of ion irradiation in super-capacitors, field effect transistors and other applications.

  5. Crecimiento, estructura y comportamientode la fricción de recubrimientos duros delnanocompuesto WS2-Ti Growth, structure and friction behavior of the nanocomposite hard coatings WS2-Ti

    Directory of Open Access Journals (Sweden)

    Federico Sequeda

    2010-06-01

    ambientes húmedos y altas temperaturas, reduciendo la oxidación y mejorando el tiempo de vida de las piezas. Esta forma de obtener mejores condiciones de trabajo ha sido poco estudiada en detalle y se presenta un mecanismo de reacción que permite explicar dicho fenómeno utilizando técnicas novedosas de análisis como FIB.Tungsten disulphide (WS2 and titanium doped tungsten disulphide (Ti-WS2 nanocomposites were deposited on silicon substrates, varying substrate temperature and target power, using magnetron co–sputtering in order to obtain different Ti contents in the nanocomposite. The films were analyzed using X-ray difraction (XRD, high resolution scanning electron micrscopy (HRSEM/EDS and high resolution transmision electron microscopy (HRTEM to observe the crystallinity and morphology behavior respect the induced Ti percentage and the substrate temperature variation. The inclusion of Ti on the co–sputtering process prevents the WS2 crystallization forming dispersed amorphous nanocrystals (1-3 nm. The friction tests performed in a Pin on Disk (POD at low temperatures, shows that the room temperature and low Ti concentrations films (between 5 and 14%at possesses higher life times that pure WS2 films but no significant changes in friction coefficients (COF were observed. The same effect is determined in high temperature POD tests (500◦C with higher changes in COF. To study solid lubricant mechanisms, samples prepared by focus ion bean (FIB, were analyzed by Raman spectroscopy, determining surface deformation and tribo-chemical compounds formation in the wear track. The formation of WO3 in the surface during wear (tribo–oxidation and transfer to the counterface (third body generation was observed. Ti doping, producing a nanocomposite, is a procedure that improves tribological properties of the material in humid and high temperature environments. Obtaining these improvements by means of element doping has been poorly studied in detail and a reaction mechanism is

  6. 40 CFR 180.1253 - Streptomyces lydicus WYEC 108; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Streptomyces lydicus WYEC 108... RESIDUES IN FOOD Exemptions From Tolerances § 180.1253 Streptomyces lydicus WYEC 108; exemption from the... the microbial pesticide Streptomyces lydicus WYEC 108 when used in or on all agricultural commodities...

  7. Generating WS-SecurityPolicy documents via security model transformation

    DEFF Research Database (Denmark)

    Jensen, Meiko

    2009-01-01

    When SOA-based business processes are to be enhanced with security properties, the model-driven business process development approach enables an easier and more reliable security definition compared to manually crafting the security realizations afterwards. In this paper, we outline an appropriat...... security model definition and transformation approach, targeting the WS-SecurityPolicy and WS-BPEL specifications, in order to enable a Web-Service-based secure business process development.......When SOA-based business processes are to be enhanced with security properties, the model-driven business process development approach enables an easier and more reliable security definition compared to manually crafting the security realizations afterwards. In this paper, we outline an appropriate...

  8. Production of vitamin B12 and labeled vitamin B12 by Streptomyces griseus

    International Nuclear Information System (INIS)

    Mazaheri Tehrani, M.; Ghorbanzadeh Mashkani, S.; Tajer Mohammad Ghazvini, P.; Nazari, A.; Aflakee, F.

    2009-01-01

    In this study, the production of labeled vitamin B 12 with one strain of actinomycet in a novel synthetic medium by batch fermentation method was investigated. After releasing vitamin B 12 from microbial cells, the solution containing cobalamin analogues was fixed on amberlite XAD-4 exchanger and eluted by various solutions. Vitamin B 12 in the collected fractions were measured by HPLC method and also in order to confirm the existence of cobalamin compounds in the samples, TLC technique was used. In the optimal conditions, production of vitamin B 12 by this microorganism was 1456μg/1. The best recoveries of vitamin B 12 from the column were obtained when the column was eluted by ethanol followed by acetone. The R f , values for cyanocobalamin and methylcobalamin, produced by this microorganism were the same as the standard values of R f . The desorption of labeled vitamine B 12 was carried out by different eluants, including acetone, ethanol (absolute), ethanol 25% and deionized water. The activity of labeled vitamin B 12 was 8.55, 6.90, 0.79, 5.75 Bq/ml, respectively. Therefore, the total specific activity of 21.99 Bq/ml was obtained for labeled vitamin B 12 .

  9. High yield antibiotic producing mutants of Streptomyces erythreus induced by low energy ion implantation

    Science.gov (United States)

    Yu, Chen; Zhixin, Lin; Zuyao, Zou; Feng, Zhang; Duo, Liu; Xianghuai, Liu; Jianzhong, Tang; Weimin, Zhu; Bo, Huang

    1998-05-01

    Conidia of Streptomyces erythreus, an industrial microbe, were implanted by nitrogen ions with energy of 40-60 keV and fluence from 1 × 10 11 to 5 × 10 14 ions/cm 2. The logarithm value of survival fraction had good linear relationship with the logarithm value of fluence. Some mutants with a high yield of erythromycin were induced by ion implantation. The yield increment was correlated with the implantation fluence. Compared with the mutation results induced by ultraviolet rays, mutation effects of ion implantation were obvious having higher increasing erythromycin potency and wider mutation spectrum. The spores of Bacillus subtilis were implanted by arsenic ions with energy of 100 keV. The distribution of implanted ions was measured by Rutherford Backscattering Spectrometry (RBS) and calculated in theory. The mechanism of mutation induced by ion implantation was discussed.

  10. Visible-light-induced hydrogen evolution reaction with WS x Se 2

    Indian Academy of Sciences (India)

    ... of ternary sulphoselenides of tungsten (WS x Se 2 − x ) by the dye-sensitized hydrogen evolution.WSxSe2−x solidsolutions are found to exhibit high activity reaching 2339 μ mol h − 1 g − 1 for WSSe, which is three times higher than that of WS2 alone (866 μ mol h − 1 g − 1 ). The turnover frequency is also high (0.7 h − 1 ).

  11. Heterologous expression of pikromycin biosynthetic gene cluster using Streptomyces artificial chromosome system.

    Science.gov (United States)

    Pyeon, Hye-Rim; Nah, Hee-Ju; Kang, Seung-Hoon; Choi, Si-Sun; Kim, Eung-Soo

    2017-05-31

    Heterologous expression of biosynthetic gene clusters of natural microbial products has become an essential strategy for titer improvement and pathway engineering of various potentially-valuable natural products. A Streptomyces artificial chromosomal conjugation vector, pSBAC, was previously successfully applied for precise cloning and tandem integration of a large polyketide tautomycetin (TMC) biosynthetic gene cluster (Nah et al. in Microb Cell Fact 14(1):1, 2015), implying that this strategy could be employed to develop a custom overexpression scheme of natural product pathway clusters present in actinomycetes. To validate the pSBAC system as a generally-applicable heterologous overexpression system for a large-sized polyketide biosynthetic gene cluster in Streptomyces, another model polyketide compound, the pikromycin biosynthetic gene cluster, was preciously cloned and heterologously expressed using the pSBAC system. A unique HindIII restriction site was precisely inserted at one of the border regions of the pikromycin biosynthetic gene cluster within the chromosome of Streptomyces venezuelae, followed by site-specific recombination of pSBAC into the flanking region of the pikromycin gene cluster. Unlike the previous cloning process, one HindIII site integration step was skipped through pSBAC modification. pPik001, a pSBAC containing the pikromycin biosynthetic gene cluster, was directly introduced into two heterologous hosts, Streptomyces lividans and Streptomyces coelicolor, resulting in the production of 10-deoxymethynolide, a major pikromycin derivative. When two entire pikromycin biosynthetic gene clusters were tandemly introduced into the S. lividans chromosome, overproduction of 10-deoxymethynolide and the presence of pikromycin, which was previously not detected, were both confirmed. Moreover, comparative qRT-PCR results confirmed that the transcription of pikromycin biosynthetic genes was significantly upregulated in S. lividans containing tandem

  12. Production and characterization of a biosurfactant produced by Streptomyces sp. DPUA 1559 isolated from lichens of the Amazon region.

    Science.gov (United States)

    Santos, A P P; Silva, M D S; Costa, E V L; Rufino, R D; Santos, V A; Ramos, C S; Sarubbo, L A; Porto, A L F

    2017-12-11

    Surfactants are amphipathic compounds containing both hydrophilic and hydrophobic groups, capable to lower the surface or interfacial tension. Considering the advantages of the use of biosurfactants produced by microorganisms, the aim of this paper was to develop and characterize a biosurfactant produced by Streptomyces sp. DPUA1559 isolated from lichens of the Amazon region. The microorganism was cultured in a mineral medium containing 1% residual frying soybean oil as the carbon source. The kinetics of biosurfactant production was accompanied by reducing the surface tension of the culture medium from 60 to values around 27.14 mN/m, and by the emulsification index, which showed the efficiency of the biosurfactant as an emulsifier of hydrophobic compounds. The yield of the isolated biosurfactant was 1.74 g/L, in addition to the excellent capability of reducing the surface tension (25.34 mN/m), as observed from the central composite rotational design when the biosurfactant was produced at pH 8.5 at 28°C. The critical micelle concentration of the biosurfactant was determined as 0.01 g/mL. The biosurfactant showed thermal and pH stability regarding the surface tension reduction, and tolerance under high salt concentrations. The isolated biosurfactant showed no toxicity to the micro-crustacean Artemia salina, and to the seeds of lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L.). The biochemistry characterization of the biosurfactant showed a single protein band, an acid character and a molecular weight around 14.3 kDa, suggesting its glycoproteic nature. The results are promising for the industrial application of this new biosurfactant.

  13. A whole genome analysis reveals the presence of a plant PR1 sequence in the potato pathogen Streptomyces scabies and other Streptomyces species.

    Science.gov (United States)

    Armijos-Jaramillo, Vinicio; Santander-Gordón, Daniela; Soria, Rosa; Pazmiño-Betancourth, Mauro; Echeverría, María Cristina

    2017-09-01

    Streptomyces scabies is a common soil bacterium that causes scab symptoms in potatoes. Strong evidence indicates horizontal gene transfer (HGT) among bacteria has influenced the evolution of this plant pathogen and other Streptomyces spp. To extend the study of the HGT to the Streptomyces genus, we explored the effects of the inter-domain HGT in the S. scabies genome. We employed a semi-automatic pipeline based on BLASTp searches and phylogenetic reconstruction. The data show low impact of inter-domain HGT in the S. scabies genome; however, we found a putative plant pathogenesis related 1 (PR1) sequence in the genome of S. scabies and other species of the genus. It is possible that this gene could be used by S. scabies to out-compete other soil organisms. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Crystallization and diffraction analysis of thioredoxin reductase from Streptomyces coelicolor

    International Nuclear Information System (INIS)

    Koháryová, Michaela; Brynda, Jiří; Řezáčová, Pavlína; Kollárová, Marta

    2011-01-01

    Thioredoxin reductase from S. coelicolor was crystallized and diffraction data were collected to 2.4 Å resolution. Thioredoxin reductases are homodimeric flavoenzymes that catalyze the transfer of electrons from NADPH to oxidized thioredoxin substrate. Bacterial thioredoxin reductases represent a promising target for the development of new antibiotics. Recombinant thioredoxin reductase TrxB from Streptomyces coelicolor was crystallized using the hanging-drop vapour-diffusion method. X-ray diffraction data were collected from cryocooled crystals to 2.4 Å resolution using a synchrotron-radiation source. The crystals belonged to the primitive monoclinic space group P2 1 , with unit-cell parameters a = 82.9, b = 60.6, c = 135.4 Å, α = γ = 90.0, β = 96.5°

  15. Inorganic fullerene-type WS2 nanoparticles: processing, characterization and its photocatalytic performance on malachite green

    Science.gov (United States)

    Hazarika, Saurabh Jyoti; Mohanta, Dambarudhar

    2017-05-01

    In this work, we have employed a hydrothermal route for the synthesis of fullerene-type tungsten disulfide (WS2) nanoparticles. X-ray diffraction analysis signifies a hexagonal crystal structure of WS2 with the crystallites experiencing preferred orientations along (002) and (103) planes. The agglomerated nanoparticles and inorganic fullerene (IF)-type structures are apparently observable from the high-resolution electron micrographs. Raman spectrum shows prominent E1_{{2{{g}}}} and A 1g modes emanating from the IF nano-WS2 system. The Tauc's plot obtained from the optical absorption data predicts a direct band gap of 1.91 eV for the nano-WS2 system; whereas, photoluminescence analysis reveals a broad emission peak located at 638 nm and is ascribed to the associated transition from the indirect to direct nature of the band gap. The photocatalytic decomposition of malachite green (MG) solution (30 mg/l) by WS2 (100 mg/l) under UV and visible light irradiation has been evaluated. The latter condition exhibited a better photocatalytic response with the MG degradation as high as 71.2%, revealed for 120 min. Photocatalytic and optoelectronic features of IF-type nano-WS2 would bring new insights not only to resolve issues related to environmental hazards, but also in functional devices of technological relevance.

  16. Effect of layer number on recovery rate of WS{sub 2} nanosheets for ammonia detection at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Ziyu [State Key Laboratory of Materials Processing and Die Mould Technology, Huazhong University of Science and Technology (HUST), No. 1037, Luoyu Road, Wuhan 430074 (China); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062 (China); Zeng, Dawen, E-mail: dwzeng@mail.hust.edu.cn [State Key Laboratory of Materials Processing and Die Mould Technology, Huazhong University of Science and Technology (HUST), No. 1037, Luoyu Road, Wuhan 430074 (China); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Wuhan 430062 (China); Zhang, Jia; Wu, Congyi; Wen, Yanwei; Shan, Bin; Xie, Changsheng [State Key Laboratory of Materials Processing and Die Mould Technology, Huazhong University of Science and Technology (HUST), No. 1037, Luoyu Road, Wuhan 430074 (China)

    2017-08-31

    Highlights: • Reasons for room-temperature difficult recovery of WS{sub 2} sensors for NH{sub 3} detection. • The excellent recovery within 271.9 s was observed for single-layer WS{sub 2} sensor. • The recovery time of WS{sub 2} sensor has a anti-linear relation with number of layer. - Abstract: Tungsten disulfide (WS{sub 2}), as a representative layered transition metal dichalcogenides (TMDs), is expected as a promising candidate for high-performance NH{sub 3} sensor at room temperature. Unfortunately, the common WS{sub 2} based NH{sub 3} sensors are difficult to recovery at room temperature, which severely limits its application. Hence, how to improve recovery has become an urgent problem to be solved. Herein, we prepare five types of WS{sub 2} nanosheets with different layer numbers from bulk to monolayer, and find that the recovery time of NH{sub 3} gas sensor is rapidly linear shorten as the number of layers decreasing. Through the first-principles calculation of the interaction between NH{sub 3} and WS{sub 2} substance, the different binding energy between ammonia and the surface (−0.179 eV) and interlayer (−0.356 eV) of layered WS{sub 2}, as well as the different electron transfer way, should be responsible for the difficult recovery rate of various WS{sub 2} samples. Therefore, reducing the number of layer of WS{sub 2} is a promising approach to speed up recovery. Based on this conclusion, we successfully prepare a fast recoverable ammonia gas sensor based on single layer WS{sub 2}, which exhibits exciting fast recovery within 271.9 s at room temperature without any condition. Moreover, our work also can act as a reference for other gas detection of TMDs based gas sensor to improve the gas performance at room-temperature.

  17. Faecal carriage of extended-spectrum b-lactamase-producing and AMpC b-lactamase-producing bacteria among Danish army recruits

    DEFF Research Database (Denmark)

    Hammerum, A.M; Lester, C.H; Jakobsen, L

    2011-01-01

    During May and June 2008, 84 Danish army recruits were tested for faecal carriage of extended-spectrum b-lactamase (ESBL)- producing and AmpC b-lactamase-producing bacteria. Three ESBL-producing (CTX-M-14a) Escherichia coli isolates, two AmpC-producing (CMY-2) E. coli isolates and one Amp...

  18. Streptomyces flavogriseus HS1: isolation and characterization of extracellular proteases and their compatibility with laundry detergents.

    Science.gov (United States)

    Ghorbel, Sofiane; Kammoun, Maher; Soltana, Hala; Nasri, Moncef; Hmidet, Noomen

    2014-01-01

    The present study describes the isolation of a new protease producing Streptomyces strain HS1 and the biochemical characterization of the secreted proteases. By sequencing of its noted 16S rDNA, HS1 strain was found to have a 100% identity with Streptomyces flavogriseus. The highest protease production was found using FermII media. In these conditions maximum protease production (99 U/mL) was obtained after 96 h incubation at 30°C and 150 rpm. HS1 strain produced at least five proteases as revealed by zymogram technique. The enzyme preparation exhibited activity over a broad range of pH (5-11) and temperature (25-70°C). Optimum activity was observed at a pH of 7.0 and a temperature of 50°C. Proteolytic activity was significantly unaffected by Ca(2+) and Mg(2+). EDTA and PMSF highly decreased the original activity. The crude extracellular proteases showed high stability when used as a detergent additive. These properties offer an interesting potential for enzymatic hydrolysis at the industrial level.

  19. Carbon catabolite regulation in Streptomyces: new insights and lessons learned.

    Science.gov (United States)

    Romero-Rodríguez, Alba; Rocha, Diana; Ruiz-Villafán, Beatriz; Guzmán-Trampe, Silvia; Maldonado-Carmona, Nidia; Vázquez-Hernández, Melissa; Zelarayán, Augusto; Rodríguez-Sanoja, Romina; Sánchez, Sergio

    2017-09-01

    One of the most significant control mechanisms of the physiological processes in the genus Streptomyces is carbon catabolite repression (CCR). This mechanism controls the expression of genes involved in the uptake and utilization of alternative carbon sources in Streptomyces and is mostly independent of the phosphoenolpyruvate phosphotransferase system (PTS). CCR also affects morphological differentiation and the synthesis of secondary metabolites, although not all secondary metabolite genes are equally sensitive to the control by the carbon source. Even when the outcome effect of CCR in bacteria is the same, their essential mechanisms can be rather different. Although usually, glucose elicits this phenomenon, other rapidly metabolized carbon sources can also cause CCR. Multiple efforts have been put through to the understanding of the mechanism of CCR in this genus. However, a reasonable mechanism to explain the nature of this process in Streptomyces does not yet exist. Several examples of primary and secondary metabolites subject to CCR will be examined in this review. Additionally, recent advances in the metabolites and protein factors involved in the Streptomyces CCR, as well as their mechanisms will be described and discussed in this review.

  20. Two dynamin-like proteins stabilize FtsZ rings during Streptomyces sporulation.

    Science.gov (United States)

    Schlimpert, Susan; Wasserstrom, Sebastian; Chandra, Govind; Bibb, Maureen J; Findlay, Kim C; Flärdh, Klas; Buttner, Mark J

    2017-07-25

    During sporulation, the filamentous bacteria Streptomyces undergo a massive cell division event in which the synthesis of ladders of sporulation septa convert multigenomic hyphae into chains of unigenomic spores. This process requires cytokinetic Z-rings formed by the bacterial tubulin homolog FtsZ, and the stabilization of the newly formed Z-rings is crucial for completion of septum synthesis. Here we show that two dynamin-like proteins, DynA and DynB, play critical roles in this process. Dynamins are a family of large, multidomain GTPases involved in key cellular processes in eukaryotes, including vesicle trafficking and organelle division. Many bacterial genomes encode dynamin-like proteins, but the biological function of these proteins has remained largely enigmatic. Using a cell biological approach, we show that the two Streptomyces dynamins specifically localize to sporulation septa in an FtsZ-dependent manner. Moreover, dynamin mutants have a cell division defect due to the decreased stability of sporulation-specific Z-rings, as demonstrated by kymographs derived from time-lapse images of FtsZ ladder formation. This defect causes the premature disassembly of individual Z-rings, leading to the frequent abortion of septum synthesis, which in turn results in the production of long spore-like compartments with multiple chromosomes. Two-hybrid analysis revealed that the dynamins are part of the cell division machinery and that they mediate their effects on Z-ring stability during developmentally controlled cell division via a network of protein-protein interactions involving DynA, DynB, FtsZ, SepF, SepF2, and the FtsZ-positioning protein SsgB.

  1. Characterization of Xylanase Streptomyces spp. SKK1-8

    Directory of Open Access Journals (Sweden)

    ANJA MERYANDINI

    2006-12-01

    Full Text Available Streptomyces spp. SKK1-8 producing xylanase was isolated from soil sample from Sukabumi West Java. The xylanase have an optimum condition at pH 6 and 50 °C. Addition of 5 mM Cu2+ decreased the xylanase activity up to about 77%, whereas not by other cations. The xylanase was stable at 3 °C for 48 hours, and the enzyme half lifetime was 1 hour 45 minute at 50 °C. This xylanase showed the highest activity on oatspelt xylan, and their molecular masses were estimated approximately 16.80, 15.21, and 13.86 kDa. HPLC analysis showed that xylosa and arabinosa were the main hydrolytic product of birchwood xylan.

  2. Penggunaan Streptomyces sp. Sebagai Biokontrol Penyakit Layu Pada Tanaman Cabai Merah (Capsicum annuum L. yang Disebabkan Oleh Fusarium oxysporum f.sp. capsici

    Directory of Open Access Journals (Sweden)

    ANINDA OKTAVIA RAHARINI

    2014-01-01

    Full Text Available A research has been conducted to find out Streptomyces bacteria at Bukit Jimbaran, to inhibitionpotency of Streptomyces sp. to pathogenic fungi Fusarium oxysporum f.sp. capsici, and to find outantifungal activity of Streptomyces filtrate to F.oxysporum f.sp. capsici in chili (Capsicum annuumL. plants. Streptomyces sp. isolation was done by platting method with selective media YMA (ISP4.Identification of Streptomyces sp. used Bergey’s book entitled Manual Determinative Bacteriology.Test inhibition against F.oxysporum f.sp. capsici and in vivo test used by dying the roots of the chili(C.annuum L. plant with F.oxysporum f.sp. capsici and after 30 seconds the roots were dying withStreptomyces sp. culture, furthermore sterile soil on polybag watered by F.oxysporum f.sp. capsicispore and Streptomyces sp. culture at the same time. The result found five isolates Streptomyces sp.with different morphological. The antagonis test showed Streptomyces sp. 4 had ability (82% againstFusarium, Streptomyces sp.1 (72%, Streptomyces sp.2 (64%, Streptomyces sp.3 (76%, andStreptomyces sp. 5 (32%. All Streptomyces suppressed the growth of Fusarium on chili plants inglass house (p<0,05. Streptomyces sp.4 suppressed Fusarium wilt disease in chili from 80% in controlto 8%.

  3. Identification of three homologous latex-clearing protein (lcp) genes from the genome of Streptomyces sp. strain CFMR 7.

    Science.gov (United States)

    Nanthini, Jayaram; Ong, Su Yean; Sudesh, Kumar

    2017-09-10

    Rubber materials have greatly contributed to human civilization. However, being a polymeric material does not decompose easily, it has caused huge environmental problems. On the other hand, only few bacteria are known to degrade rubber, with studies pertaining them being intensively focusing on the mechanism involved in microbial rubber degradation. The Streptomyces sp. strain CFMR 7, which was previously confirmed to possess rubber-degrading ability, was subjected to whole genome sequencing using the single molecule sequencing technology of the PacBio® RS II system. The genome was further analyzed and compared with previously reported rubber-degrading bacteria in order to identify the potential genes involved in rubber degradation. This led to the interesting discovery of three homologues of latex-clearing protein (Lcp) on the chromosome of this strain, which are probably responsible for rubber degrading activities. Genes encoding oxidoreductase α-subunit (oxiA) and oxidoreductase β-subunit (oxiB) were also found downstream of two lcp genes which are located adjacent to each other. In silico analysis reveals genes that have been identified to be involved in the microbial degradation of rubber in the Streptomyces sp. strain CFMR 7. This is the first whole genome sequence of a clear-zone-forming natural rubber- degrading Streptomyces sp., which harbours three Lcp homologous genes with the presence of oxiA and oxiB genes compared to the previously reported Gordonia polyisoprenivorans strain VH2 (with two Lcp homologous genes) and Nocardia nova SH22a (with only one Lcp gene). Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Situated Word Learning: Words of the Year (WsOY) and Social Studies Inquiry

    Science.gov (United States)

    Heafner, Tina L.; Triplett, Nicholas; Handler, Laura; Massey, Dixie

    2018-01-01

    Current events influence public interest and drive Internet word searches. For over a decade, linguists and dictionary publishers have analyzed big data from Internet word searches to designate "Words of the Year" (WsOY). In this study, we examine how WsOY can foster critical digital literacy and illuminate essential aspects of inquiry…

  5. Streptomyces castaneus sp. nov., a novel actinomycete isolated from the rhizosphere of Peucedanum praeruptorum Dunn.

    Science.gov (United States)

    Zhou, Shuyu; Li, Zhilei; Bai, Lu; Yan, Kai; Zhao, Junwei; Lu, Chang; Liu, Chongxi; Wang, Xiangjing; Xiang, Wensheng

    2017-01-01

    During an investigation of microbial diversity in medicinal herbs, a novel actinomycete, strain NEAU-QHHV11 T was isolated from the rhizosphere of Peucedanum praeruptorum Dunn collected from Xianglu Mountain in Heilongjiang Province, northeast China and characterized using a polyphasic approach. The organism was found to have typical characteristics of the genus Streptomyces. Phylogenetic analysis based on 16S rRNA gene sequence also indicated that strain NEAU-QHHV11 T belongs to the genus Streptomyces and was most closely related to Streptomyces graminilatus NBRC 108882 T (98.7 % sequence similarity) and Streptomyces turgidiscabies NBRC 16080 T (98.7 % sequence similarity). The results of DNA-DNA hybridization and some phenotypic characteristics indicated that strain NEAU-QHHV11 T could be distinguished from its close phylogenetic relatives. Thus, strain NEAU-QHHV11 T represents a novel species of the genus Streptomyces, for which the name Streptomyces castaneus sp. nov. is proposed. The type strain is NEAU-QHHV11 T (=CGMCC 4.7235 T  = DSM 100520 T ).

  6. A neural-network potential through charge equilibration for WS2: From clusters to sheets

    Science.gov (United States)

    Hafizi, Roohollah; Ghasemi, S. Alireza; Hashemifar, S. Javad; Akbarzadeh, Hadi

    2017-12-01

    In the present work, we use a machine learning method to construct a high-dimensional potential for tungsten disulfide using a charge equilibration neural-network technique. A training set of stoichiometric WS2 clusters is prepared in the framework of density functional theory. After training the neural-network potential, the reliability and transferability of the potential are verified by performing a crystal structure search on bulk phases of WS2 and by plotting energy-area curves of two different monolayers. Then, we use the potential to investigate various triangular nano-clusters and nanotubes of WS2. In the case of nano-structures, we argue that 2H atomic configurations with sulfur rich edges are thermodynamically more stable than the other investigated configurations. We also studied a number of WS2 nanotubes which revealed that 1T tubes with armchair chirality exhibit lower bending stiffness.

  7. Inorganic fullerene-type WS_2 nanoparticles: processing, characterization and its photocatalytic performance on malachite green

    International Nuclear Information System (INIS)

    Hazarika, Saurabh Jyoti; Mohanta, Dambarudhar

    2017-01-01

    In this work, we have employed a hydrothermal route for the synthesis of fullerene-type tungsten disulfide (WS_2) nanoparticles. X-ray diffraction analysis signifies a hexagonal crystal structure of WS_2 with the crystallites experiencing preferred orientations along (002) and (103) planes. The agglomerated nanoparticles and inorganic fullerene (IF)-type structures are apparently observable from the high-resolution electron micrographs. Raman spectrum shows prominent E"1_2_g and A_1_g modes emanating from the IF nano-WS_2 system. The Tauc's plot obtained from the optical absorption data predicts a direct band gap of ∝1.91 eV for the nano-WS_2 system; whereas, photoluminescence analysis reveals a broad emission peak located at ∝638 nm and is ascribed to the associated transition from the indirect to direct nature of the band gap. The photocatalytic decomposition of malachite green (MG) solution (30 mg/l) by WS_2 (100 mg/l) under UV and visible light irradiation has been evaluated. The latter condition exhibited a better photocatalytic response with the MG degradation as high as 71.2%, revealed for 120 min. Photocatalytic and optoelectronic features of IF-type nano-WS_2 would bring new insights not only to resolve issues related to environmental hazards, but also in functional devices of technological relevance. (orig.)

  8. Streptomyces gamaensis sp. nov., a novel actinomycete with antifungal activity isolated from soil in Gama, Chad.

    Science.gov (United States)

    Zhao, Shanshan; Ye, Lan; Liu, Chongxi; Abagana, Adam Yacoub; Zheng, Weiwei; Sun, Pengyu; Li, Jiansong; Xiang, Wensheng; Wang, Xiangjing

    2017-04-01

    During an investigation exploring potential sources of novel species and natural products, a novel actinomycete with antifungal activity, designated strain NEAU-Gz11 T , was isolated from a soil sample, which was collected from Gama, Chad. The isolate was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. 16S rRNA gene sequence similarity studies showed that strain NEAU-Gz11 T belongs to the genus Streptomyces with high sequence similarity to Streptomyces hiroshimensis JCM 4098 T (98.0 %). Similarities to other type strains of the genus Streptomyces were lower than 98.0 %. However, the physiological and biochemical characteristics and low levels of DNA-DNA relatedness could differentiate the isolate genotypically and phenotypically from S. hiroshimensis JCM 4098 T . Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces gamaensis sp. nov. is proposed. The type strain is NEAU-Gz11 T (=CGMCC 4.7304 T =DSM 101531 T ).

  9. Chemical vapor deposition based tungsten disulfide (WS2) thin film transistor

    KAUST Repository

    Hussain, Aftab M.

    2013-04-01

    Tungsten disulfide (WS2) is a layered transition metal dichalcogenide with a reported band gap of 1.8 eV in bulk and 1.32-1.4 eV in its thin film form. 2D atomic layers of metal dichalcogenides have shown changes in conductivity with applied electric field. This makes them an interesting option for channel material in field effect transistors (FETs). Therefore, we show a highly manufacturable chemical vapor deposition (CVD) based simple process to grow WS2 directly on silicon oxide in a furnace and then its transistor action with back gated device with room temperature field effect mobility of 0.1003 cm2/V-s using the Schottky barrier contact model. We also show the semiconducting behavior of this WS2 thin film which is more promising than thermally unstable organic materials for thin film transistor application. Our direct growth method on silicon oxide also holds interesting opportunities for macro-electronics applications. © 2013 IEEE.

  10. Antimicrobial Activity and Morphological Changes of Streptomyces Ascendable and Streptomyces Eighty-three's as Affected by Environmental Conditions and Gamma Radiation

    International Nuclear Information System (INIS)

    Moussa, L.A.A.; Abou El-Nour, S.A.M.; Mansour, F.A.; Serag, M.S.

    2004-01-01

    Fourteen actinomycetes out of thirty isolates were recovered from different Egyptian soils and exhibited antimicrobial activities. Streptomyces ascendable and Streptomyces eighty-three's used in the present work showed the most active antimicrobial potentialities against bacteria, moulds and yeasts. The optimum temperature and acidity for their growth and production of microbial activity were 50 degree and ph 7.0, while the maximum biomass yield and the highest antimicrobial activity were attained 10 days of incubation. Among carbon sources starch at 30 gm/L highly supported the growth and antimicrobial activity by the two species, while sodium nitrate (3 gm/L) and dipotassium hydrogen phosphate (0.75 gm/L) were the most favorable for both isolates. The presence of microelements such as manganese chloride, zinc sulphate, ferrous sulphate and copper sulphate in the growth medium at a concentration of 1 mg/L for each had a good stimulatory effect on the growth and antimicrobial activity for both Streptomyces species. As different irradiation doses were used (up to 5.0 kGy), the high levels clearly affected the morphological characteristics of both tested isolates either in the first or second generation

  11. Purification and Characterization of Streptomyces sp. SKK1-8 xylanase

    Directory of Open Access Journals (Sweden)

    Nunuk Widhyastuti

    2008-11-01

    Full Text Available Streptomyces sp. SKK1-8 is a xylanase produced bacteria. Purified xylanase has an optimum condition at pH 4.5 and 50oC. The molecular mass of purified xylanase were determined to be 14.4 kDa and 13.4 kDa. The xylanase was capable of hydrolysing p-NP-α-L-arabinofuranoside, p-NP-β-D-xylanopiranoside, p-NP-β-D-glucopiranoside, p-NP-α-D-galactopiranoside. The Km and Vmax values at 50oC measured on Birchwood xylan were 0.101 mg/ml and 0.1796 μmoles/minute/ml.

  12. Direct Observation of 2D Electrostatics and Ohmic Contacts in Template-Grown Graphene/WS2 Heterostructures.

    Science.gov (United States)

    Zheng, Changxi; Zhang, Qianhui; Weber, Bent; Ilatikhameneh, Hesameddin; Chen, Fan; Sahasrabudhe, Harshad; Rahman, Rajib; Li, Shiqiang; Chen, Zhen; Hellerstedt, Jack; Zhang, Yupeng; Duan, Wen Hui; Bao, Qiaoliang; Fuhrer, Michael S

    2017-03-28

    Large-area two-dimensional (2D) heterojunctions are promising building blocks of 2D circuits. Understanding their intriguing electrostatics is pivotal but largely hindered by the lack of direct observations. Here graphene-WS 2 heterojunctions are prepared over large areas using a seedless ambient-pressure chemical vapor deposition technique. Kelvin probe force microscopy, photoluminescence spectroscopy, and scanning tunneling microscopy characterize the doping in graphene-WS 2 heterojunctions as-grown on sapphire and transferred to SiO 2 with and without thermal annealing. Both p-n and n-n junctions are observed, and a flat-band condition (zero Schottky barrier height) is found for lightly n-doped WS 2 , promising low-resistance ohmic contacts. This indicates a more favorable band alignment for graphene-WS 2 than has been predicted, likely explaining the low barriers observed in transport experiments on similar heterojunctions. Electrostatic modeling demonstrates that the large depletion width of the graphene-WS 2 junction reflects the electrostatics of the one-dimensional junction between two-dimensional materials.

  13. Frenolicins C-G, pyranonaphthoquinones from Streptomyces sp. RM-4-15.

    Science.gov (United States)

    Wang, Xiachang; Shaaban, Khaled A; Elshahawi, Sherif I; Ponomareva, Larissa V; Sunkara, Manjula; Zhang, Yinan; Copley, Gregory C; Hower, James C; Morris, Andrew J; Kharel, Madan K; Thorson, Jon S

    2013-08-23

    Appalachian active coal fire sites were selected for the isolation of bacterial strains belonging to the class actinobacteria. A comparison of high-resolution electrospray ionization mass spectrometry (HRESIMS) and ultraviolet (UV) absorption profiles from isolate extracts to natural product databases suggested Streptomyces sp. RM-4-15 to produce unique metabolites. Four new pyranonaphthoquinones, frenolicins C-F (1-4), along with three known analogues, frenolicin (6), frenolicin B (7), and UCF76-A (8), were isolated from the fermentation of this strain. An additional new analogue, frenolicin G (5), along with two known compounds, deoxyfrenolicin (9) and UCF 13 (10), were isolated from the fermentation supplied with 18 mg/L of scandium chloride, the first example, to the best of our knowledge, wherein scandium chloride supplementation led to the confirmed production of new bacterial secondary metabolites. Structures 1-5 were elucidated on the basis of spectral analysis and chemical modification. While frenolicins are best known for their anticoccidial activity, the current study revealed compounds 6-9 to exhibit moderate cytotoxicity against the human lung carcinoma cell line (A549) and thereby extends the anticancer SAR for this privileged scaffold.

  14. Complete Genome Sequence of Streptomyces albus SM254, a Potent Antagonist of Bat White-Nose Syndrome Pathogen Pseudogymnoascus destructans.

    Science.gov (United States)

    Badalamenti, Jonathan P; Erickson, Joshua D; Salomon, Christine E

    2016-04-14

    We sequenced and annotated the complete 7,170,504-bp genome of a novel secondary metabolite-producingStreptomycesstrain,Streptomyces albusSM254, isolated from copper-rich subsurface fluids at ~220-m depth within the Soudan Iron Mine (Soudan, MN, USA). Copyright © 2016 Badalamenti et al.

  15. The Five Ws (and one H of Super-Hydrophobic Surfaces in Medicine

    Directory of Open Access Journals (Sweden)

    Francesco Gentile

    2014-05-01

    Full Text Available Super-hydrophobic surfaces (SHSs are bio-inspired, artificial microfabricated interfaces, in which a pattern of cylindrical micropillars is modified to incorporate details at the nanoscale. For those systems, the integration of different scales translates into superior properties, including the ability of manipulating biological solutions. The five Ws, five Ws and one H or the six Ws (6W, are questions, whose answers are considered basic in information-gathering. They constitute a formula for getting the complete story on a subject. According to the principle of the six Ws, a report can only be considered complete if it answers these questions starting with an interrogative word: who, why, what, where, when, how. Each question should have a factual answer. In what follows, SHSs and some of the most promising applications thereof are reviewed following the scheme of the 6W. We will show how these surfaces can be integrated into bio-photonic devices for the identification and detection of a single molecule. We will describe how SHSs and nanoporous silicon matrices can be combined to yield devices with the capability of harvesting small molecules, where the cut-off size can be adequately controlled. We will describe how this concept is utilized for obtaining a direct TEM image of a DNA molecule.

  16. 40 CFR 180.1120 - Streptomyces sp. strain K61; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Streptomyces sp. strain K61; exemption... FOOD Exemptions From Tolerances § 180.1120 Streptomyces sp. strain K61; exemption from the requirement of a tolerance. The biological pesticide Streptomyces sp. strain K61 is exempted from the requirement...

  17. Stable, highly-responsive and broadband photodetection based on large-area multilayered WS2 films grown by pulsed-laser deposition

    Science.gov (United States)

    Yao, J. D.; Zheng, Z. Q.; Shao, J. M.; Yang, G. W.

    2015-09-01

    The progress in the field of graphene has aroused a renaissance of keen research interest in layered transition metal dichalcogenides (TMDs). Tungsten disulfide (WS2), a typical TMD with favorable semiconducting band gap and strong light-matter interaction, exhibits great potential for highly-responsive photodetection. However, WS2-based photodetection is currently unsatisfactory due to the low optical absorption (2%-10%) and poor carrier mobility (0.01-0.91 cm2 V-1 s-1) of the thin WS2 layers grown by chemical vapor deposition (CVD). Here, we introduce pulsed-laser deposition (PLD) to prepare multilayered WS2 films. Large-area WS2 films of the magnitude of cm2 are achieved. Comparative measurements of a WS2-based photoresistor demonstrate its stable broadband photoresponse from 370 to 1064 nm, the broadest range demonstrated in WS2 photodetectors. Benefiting from the large optical absorbance (40%-85%) and high carrier mobility (31 cm2 V-1 s-1), the responsivity of the device approaches a high value of 0.51 A W-1 in an ambient environment. Such a performance far surpasses the CVD-grown WS2-based photodetectors (μA W-1). In a vacuum environment, the responsivity is further enhanced to 0.70 A W-1 along with an external quantum efficiency of 137% and a photodetectivity of 2.7 × 109 cm Hz1/2 W-1. These findings stress that the PLD-grown WS2 film may constitute a new paradigm for the next-generation stable, broadband and highly-responsive photodetectors.The progress in the field of graphene has aroused a renaissance of keen research interest in layered transition metal dichalcogenides (TMDs). Tungsten disulfide (WS2), a typical TMD with favorable semiconducting band gap and strong light-matter interaction, exhibits great potential for highly-responsive photodetection. However, WS2-based photodetection is currently unsatisfactory due to the low optical absorption (2%-10%) and poor carrier mobility (0.01-0.91 cm2 V-1 s-1) of the thin WS2 layers grown by chemical vapor

  18. Production of endoglucanase by the native strains of Streptomyces isolates in submerged fermentation

    Directory of Open Access Journals (Sweden)

    P. Chellapandi

    2008-03-01

    Full Text Available Cellulase is a complex enzyme system, commercially produced by filamentous fungi under solid-state and submerged cultivation. It has wide applicability in textile, food and beverage industry for effective saccharification process. In this study, cellulolytic enzyme activity, particularly endoglucanase of 26 Streptomyces strains isolated from garden soil was examined, including two isolates selected on the basis of potential cellulolytic activity on Bennett's agar medium. To enhance the endoglucanase formation in broth culture, different conditions including carbon and nitrogen sources, and growth conditions were tested. The maximum endoglucanase activity (11.25-11.90 U/mL was achieved within 72-88 h in fermentation medium containing Tween-80, followed by phosphate sources. Both cellulolytic Streptomyces isolates gave almost equal quantity of enzyme in all trials. However the effect of medium ingredients on endoglucanase induction diverged with strains in some extent.A celulase é um sistema enzimático complexo, produzido comercialmente a partir de fungos filamentosos através de cultivo em estádio sólido e submerso. Tem uma grande aplicação na indústria têxtil e de alimentos e bebidas no processo de sacarificação. Nesse estudo, examinou-se a atividade celulolítica, especialmente de englucanase, de 26 cepas de Streptomyces isoladas de solo, incluindo duas cepas selecionadas por sua atividade celulolítica no ágar Bennett. Para estimular a produção de englucanase em meio de cultura, diferentes condições de cultivo, incluindo fonte de carbono e nitrogênio e condições de crescimento, foram avaliadas. A atividade máxima de glucanase (11,25 a 11,90 U/mL foi obtida em 72-88h em meio de cultura contendo Tween-80, seguido por fontes de fosfato. Ambas as cepas celulolíticas de Streptomyces produziram quase a mesma quantidade de enzima em todos os experimentos. Entretanto, o efeito dos ingredientes do meio na indução da glucanase

  19. Metabolomic Profiling and Genomic Study of a Marine Sponge-Associated Streptomyces sp

    Science.gov (United States)

    Viegelmann, Christina; Margassery, Lekha Menon; Kennedy, Jonathan; Zhang, Tong; O’Brien, Ciarán; O’Gara, Fergal; Morrissey, John P.; Dobson, Alan D. W.; Edrada-Ebel, RuAngelie

    2014-01-01

    Metabolomics and genomics are two complementary platforms for analyzing an organism as they provide information on the phenotype and genotype, respectively. These two techniques were applied in the dereplication and identification of bioactive compounds from a Streptomyces sp. (SM8) isolated from the sponge Haliclona simulans from Irish waters. Streptomyces strain SM8 extracts showed antibacterial and antifungal activity. NMR analysis of the active fractions proved that hydroxylated saturated fatty acids were the major components present in the antibacterial fractions. Antimycin compounds were initially putatively identified in the antifungal fractions using LC-Orbitrap. Their presence was later confirmed by comparison to a standard. Genomic analysis of Streptomyces sp. SM8 revealed the presence of multiple secondary metabolism gene clusters, including a gene cluster for the biosynthesis of the antifungal antimycin family of compounds. The antimycin gene cluster of Streptomyces sp. SM8 was inactivated by disruption of the antimycin biosynthesis gene antC. Extracts from this mutant strain showed loss of antimycin production and significantly less antifungal activity than the wild-type strain. Three butenolides, 4,10-dihydroxy-10-methyl-dodec-2-en-1,4-olide (1), 4,11-dihydroxy-10-methyl-dodec-2-en-1,4-olide (2), and 4-hydroxy-10-methyl-11-oxo-dodec-2-en-1,4-olide (3) that had previously been reported from marine Streptomyces species were also isolated from SM8. Comparison of the extracts of Streptomyces strain SM8 and its host sponge, H. simulans, using LC-Orbitrap revealed the presence of metabolites common to both extracts, providing direct evidence linking sponge metabolites to a specific microbial symbiont. PMID:24893324

  20. Metabolomic Profiling and Genomic Study of a Marine Sponge-Associated Streptomyces sp.

    Directory of Open Access Journals (Sweden)

    Christina Viegelmann

    2014-06-01

    Full Text Available Metabolomics and genomics are two complementary platforms for analyzing an organism as they provide information on the phenotype and genotype, respectively. These two techniques were applied in the dereplication and identification of bioactive compounds from a Streptomyces sp. (SM8 isolated from the sponge Haliclona simulans from Irish waters. Streptomyces strain SM8 extracts showed antibacterial and antifungal activity. NMR analysis of the active fractions proved that hydroxylated saturated fatty acids were the major components present in the antibacterial fractions. Antimycin compounds were initially putatively identified in the antifungal fractions using LC-Orbitrap. Their presence was later confirmed by comparison to a standard. Genomic analysis of Streptomyces sp. SM8 revealed the presence of multiple secondary metabolism gene clusters, including a gene cluster for the biosynthesis of the antifungal antimycin family of compounds. The antimycin gene cluster of Streptomyces sp. SM8 was inactivated by disruption of the antimycin biosynthesis gene antC. Extracts from this mutant strain showed loss of antimycin production and significantly less antifungal activity than the wild-type strain. Three butenolides, 4,10-dihydroxy-10-methyl-dodec-2-en-1,4-olide (1, 4,11-dihydroxy-10-methyl-dodec-2-en-1,4-olide (2, and 4-hydroxy-10-methyl-11-oxo-dodec-2-en-1,4-olide (3 that had previously been reported from marine Streptomyces species were also isolated from SM8. Comparison of the extracts of Streptomyces strain SM8 and its host sponge, H. simulans, using LC-Orbitrap revealed the presence of metabolites common to both extracts, providing direct evidence linking sponge metabolites to a specific microbial symbiont.

  1. Foliar Application of Extract from an Azalomycin-Producing Streptomyces malaysiensis Strain MJM1968 Suppresses Yam Anthracnose Caused by Colletotrichum gloeosporioides.

    Science.gov (United States)

    Arunachalam Palaniyandi, Sasikumar; Yang, Seung Hwan; Suh, Joo-Woh

    2016-06-28

    Yam anthracnose caused by Colletotrichum gloeosporioides (C.g) is the most devastating disease of yam (Dioscorea sp.). In the present study, we evaluated the culture filtrate extract (CFE) of azalomycin-producing Streptomyces malaysiensis strain MJM1968 for the control of yam anthracnose. MJM1968 showed strong antagonistic activity against C.g in vitro. Furthermore, the MJM1968 CFE was tested for inhibition of spore germination in C.g, where it completely inhibited spore germination at a concentration of 50 μg/ml. To assess the in planta efficacy of the CFE and spores of MJM1968 against C.g, a detached leaf bioassay was conducted, which showed both the treatments suppressed anthracnose development on detached yam leaves. Furthermore, a greenhouse study was conducted to evaluate the CFE from MJM1968 as a fungicide for the control of yam anthracnose. The CFE non-treated plants showed a disease severity of >92% after 90 days of artificial inoculation with C.g, whereas the disease severity of CFE-treated and benomyl-treated yam plants was reduced to 26% and 15%, respectively, after 90 days. Analysis of the yam tubers from the CFE-treated and non-treated groups showed that tubers from the CFE-treated plants were larger than that of non-treated plants, which produced abnormal smaller tubers typical of anthracnose. This study demonstrated the utility of the CFE from S. malaysiensis strain MJM1968 as a biofungicide for the control of yam anthracnose.

  2. Changes of in vivo fluxes through central metabolic pathways during the production of nystatin by Streptomyces noursei in batch culture

    DEFF Research Database (Denmark)

    Jonsbu, E.; Christensen, Bjarke; Nielsen, Jens

    2001-01-01

    The central carbon metabolism of the nystatin-producing strain Streptomyces noursei ATCC 11455 was evaluated by C-13-labelling experiments. A batch fermentation was examined during the idiophase by GC-MS measurements of the labelling patterns of amino acids in the biomass. The labelling patterns...

  3. Isolation, characterization and antimicrobial activity of Streptomyces ...

    African Journals Online (AJOL)

    DR TONUKARI

    2013-12-18

    Dec 18, 2013 ... Available online at http://www.academicjournals.org/AJB ... Key words: Characterization, streptomyces, antimicrobial activity, hot ... MATERIALS AND METHODS ..... chain reaction (PCR) which is currently used as a sen-.

  4. Ecological approach of macrolide-lincosamides-streptogramin producing actinomyces from Cuban soils.

    Science.gov (United States)

    González, I; Niebla, A; Lemus, M; González, L; Iznaga, I O; Pérez, M E; Vallin, C

    1999-09-01

    We report in this study the frequency of Streptomyces strains to produce macrolide-lincosamide-streptogramin (MLS) antibiotics isolated from Cuban soils. The screening assay is based on the induction of MLS-resistance phenotype in a clinical isolated strain of Staphylococcus aureus S-18. Our results suggest that of 800 Streptomyces strains isolated from different soil samples, 6% were positives in the screening test used. The ferralitic red soil from Pinar del Río (north) provided the major percentage (3.6%) of MLS producing strains. The other soil samples tested belonging to Guira de Melena and Bauta in Havana, Matanzas City, Topes De Collantes (Villa Clara), and Soroa Mountains (Pinar del Rio) hill reached very low percentages.

  5. Measurement of Exciton Binding Energy of Monolayer WS2

    Science.gov (United States)

    Chen, Xi; Zhu, Bairen; Cui, Xiaodong

    Excitonic effects are prominent in monolayer crystal of transition metal dichalcogenides (TMDCs) because of spatial confinement and reduced Coulomb screening. Here we use linear differential transmission spectroscopy and two-photon photoluminescence excitation spectroscopy (TP-PLE) to measure the exciton binding energy of monolayer WS2. Peaks for excitonic absorptions of the direct gap located at K valley of the Brillouin zone and transitions from multiple points near Γ point of the Brillouin zone, as well as trion side band are shown in the linear absorption spectra of WS2. But there is no gap between distinct excitons and the continuum of the interband transitions. Strong electron-phonon scattering, overlap of excitons around Γ point and the transfer of the oscillator strength from interband continuum to exciton states make it difficult to resolve the electronic interband transition edge even down to 10K. The gap between excited states of the band-edge exciton and the single-particle band is probed by TP-PLE measurements. And the energy difference between 1s exciton and the single-particle gap gives the exciton binding energy of monolayer WS2 to be about 0.71eV. The work is supported by Area of excellency (AoE/P-04/08), CRF of Hong Kong Research Grant Council (HKU9/CRF/13G) and SRT on New Materials of The University of Hong Kong.

  6. Lethal and mutagenic effects of fast neutrons of different energy on Streptomyces griseus spores

    International Nuclear Information System (INIS)

    Podgorskaya, M.E.; Tulina, G.G.; Serdechnaya, A.I.; Matselyukh, B.P.

    1986-01-01

    A study was made of lethal and mutagenic effects of fast neutrons of different energy on spores of prototrophic and auxotrophic strains of Streptomyces griseus. Relative biological effectiveness of fast neutrons is higher than that of γ-rays and depends on beam energy. Neutrons of 22-50 MeV induce Streptomyces griseus mutations more frequently (by one order of magnitude) than neutrons of 1.4-1.6 MeV do. The obtained mutants can be used in studying Streptomyces griseus genetics

  7. Streptomyces songpinggouensis sp. nov., a Novel Actinomycete Isolated from Soil in Sichuan, China.

    Science.gov (United States)

    Guan, Xuejiao; Li, Wenchao; Liu, Chongxi; Jin, Pinjiao; Guo, Siyu; Wang, Xiangjing; Xiang, Wensheng

    2016-12-01

    During a screening for novel and biotechnologically useful actinobacteria, a novel actinobacteria with weak antifungal activity, designated strain NEAU-Spg19 T , was isolated from a soil sample collected from pine forest in Songpinggou, Sichuan, southwest China. The strain was characterized using a polyphasic taxonomic approach which confirmed that it belongs to the genus Streptomyces. Growth occurred at a temperature range of 10-30 °C, pH 5.0-11.0 and NaCl concentrations of 0-5 %. The cell wall peptidoglycan consisted of LL-diaminopimelic acid and glycine. The major menaquinones were MK-9(H 6 ), MK-9(H 8 ) and MK-9(H 4 ). The phospholipid profile contained diphosphatidylglycerol (DPG), phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were iso-C 15:0 , iso-C 16:0 , and C 16:0 . 16S rRNA gene sequence similarity studies showed that strain NEAU-Spg19 T belongs to the genus Streptomyces with the highest sequence similarities to Streptomyces tauricus JCM 4837 T (98.6 %) and Streptomyces rectiviolaceus JCM 9092 T (98.3 %). Some physiological and biochemical properties and low DNA-DNA relatedness values enabled the strain to be differentiated from S. tauricus JCM 4837 T and S. rectiviolaceus JCM 9092 T . Hence, on the basis of phenotypic and genetic analyses, it is proposed that strain NEAU-Spg19 T represents a novel species of the genus Streptomyces, for which the name Streptomyces songpinggouensis sp. nov. is proposed. The type strain is NEAU-Spg19 T (=CGMCC 4.7140 T =DSM 42141 T ).

  8. Streptomyces sp. Sebagai Biofungisida Patogen Fusarium oxysporum (Schlecht. f.sp. lycopersici (Sacc. Snyd. et Hans. Penyebab Penyakit Layu Pada Tanaman Tomat (Solanum lycopersicum L.

    Directory of Open Access Journals (Sweden)

    NURI MANDAN SARI

    2014-01-01

    Full Text Available A research was conducted to isolate Streptomyces sp. of soil Udayana University campus in theBukit-Jimbaran, to obtain the most effective Streptomyces sp. which is effective in inhibit the growth ofFusarium oxysporum f.sp. lycopersici, and to test response of tomato plants with Streptomyces sp.culture against Fusarium wilt desease. Implementation phases of the research consisted of isolation andidentification of Streptomyces sp, test the inhibition against F. oxysporum f.sp. lycopersici, and in vivotest used by dyeing the roots of the tomato plant (Solanum lycopersicum with Fusarium spores andafter 30 seconds the roots were dyeing Streptomyces culture. Furthermore, sterile soil in polybagwatered by Fusarium spores and Streptomyces culture at the same time. Based on morphologicalcharacteristic it found five isolates of Streptomyces sp.. The antagonist test showed Streptomyces sp.1 had ability (75% against Fusarium, Streptomyces sp 2 (68,3%, Streptomyces sp. 3 (71,6%,Streptomyces sp. 4 (63,3%, and Streptomyces sp. 5 (21,6%. All Streptomyces suppressed thegrowth of Fusarium on tomato plants in glass house (p<0,05. Streptomyces sp.3 suppressed Fusariumwilt disease in tomato from 88% in control to 20%.

  9. Inorganic fullerene-type WS{sub 2} nanoparticles: processing, characterization and its photocatalytic performance on malachite green

    Energy Technology Data Exchange (ETDEWEB)

    Hazarika, Saurabh Jyoti; Mohanta, Dambarudhar [Tezpur University, Nanoscience and Soft Matter Laboratory, Department of Physics, Tezpur, Assam (India)

    2017-05-15

    In this work, we have employed a hydrothermal route for the synthesis of fullerene-type tungsten disulfide (WS{sub 2}) nanoparticles. X-ray diffraction analysis signifies a hexagonal crystal structure of WS{sub 2} with the crystallites experiencing preferred orientations along (002) and (103) planes. The agglomerated nanoparticles and inorganic fullerene (IF)-type structures are apparently observable from the high-resolution electron micrographs. Raman spectrum shows prominent E{sup 1}{sub 2g} and A{sub 1g} modes emanating from the IF nano-WS{sub 2} system. The Tauc's plot obtained from the optical absorption data predicts a direct band gap of ∝1.91 eV for the nano-WS{sub 2} system; whereas, photoluminescence analysis reveals a broad emission peak located at ∝638 nm and is ascribed to the associated transition from the indirect to direct nature of the band gap. The photocatalytic decomposition of malachite green (MG) solution (30 mg/l) by WS{sub 2} (100 mg/l) under UV and visible light irradiation has been evaluated. The latter condition exhibited a better photocatalytic response with the MG degradation as high as 71.2%, revealed for 120 min. Photocatalytic and optoelectronic features of IF-type nano-WS{sub 2} would bring new insights not only to resolve issues related to environmental hazards, but also in functional devices of technological relevance. (orig.)

  10. Antibiofilm activity of Streptomyces toxytricini Fz94 against Candida albicans ATCC 10231

    Directory of Open Access Journals (Sweden)

    Sheir DH

    2017-06-01

    Full Text Available Candida albicans is a significant cause of morbidity and mortality in immunocompromised patients worldwide. Biofilm formation by Candida species is a significant virulence factor for disease pathogenesis. Keeping in view the importance of Streptomyces' metabolites, the present study was initiated during the bioprospecting programme of Egyptian Streptomyces carried by the authors since 2013. Native Streptomyces isolates were recovered from soil samples collected from different governorates. Antifungal activity of forty isolates of Streptomyces were performed against planktonic (free cells of C. albicans ATCC 10231 and resistant clinical Candida isolates. Streptomyces isolates showed high inhibition activity against free cells of Candida were further assayed against biofilm of C. albicans reference strain. The most active Streptomyces sp. (no.6 was identified phenotypically, biochemically and by using 16S rRNA. The 16S rRNA sequences obtained were compared with those deposited in the GenBank Database and registered with accession number KM052378 as S. toxytricini Fz94. Screening of S. toxytricini Fz94 extract capability in prevention and destruction of C. albicans reference strain biolfilm was assessed by resazurin dye adopted technique. In the pre-exposure scheme, the lowest concentration of 5 gL-1 showed biofilm viability inhibition of 92% after 120 min, while Ketoconazole® gave 90 % inhibition at concentration of 2 gL-1. In post exposure, the concentration of S. toxytricini Fz94 extract 7gL-1 caused 82 % inhibition of biofilms viability after 120 min, while Ketoconazole did not show any destruction capability. The cytotoxicity of S. toxytricini Fz94 crude extract results showed that it was nontoxic at 10 gL-1. S. toxytricini Fz94 is maintained in the Fungarium of Arab Society for Fungal Conservation (ASFC with accession number FSCU-2017-1110.

  11. The five Ws (and one H) of super-hydrophobic surfaces in medicine

    KAUST Repository

    Gentile, F.

    2014-05-05

    Super-hydrophobic surfaces (SHSs) are bio-inspired, artificial microfabricated interfaces, in which a pattern of cylindrical micropillars is modified to incorporate details at the nanoscale. For those systems, the integration of different scales translates into superior properties, including the ability of manipulating biological solutions. The five Ws, five Ws and one H or the six Ws (6W), are questions, whose answers are considered basic in information-gathering. They constitute a formula for getting the complete story on a subject. According to the principle of the six Ws, a report can only be considered complete if it answers these questions starting with an interrogative word: who, why, what, where, when, how. Each question should have a factual answer. In what follows, SHSs and some of the most promising applications thereof are reviewed following the scheme of the 6W. We will show how these surfaces can be integrated into bio-photonic devices for the identification and detection of a single molecule. We will describe how SHSs and nanoporous silicon matrices can be combined to yield devices with the capability of harvesting small molecules, where the cut-off size can be adequately controlled. We will describe how this concept is utilized for obtaining a direct TEM image of a DNA molecule. 2014 by the authors; licensee MDPI, Basel, Switzerland.

  12. Mutation effect of streptomyces kitasatoensis after exposure to heavy ions radiation

    International Nuclear Information System (INIS)

    Liu Jing; Chen Jihong; Wang Shuyang; Li Wenjian

    2011-01-01

    To define the optimum dose of heavy ion beams for selecting high productive strains, we should study mortality and mutation effects of Streptomyces kitasatoensis irradiated by heavy ion beams in different doses. In this research, spores of Streptomyces kitasatoensis were irradiated by heavy ion beams with different doses. And survival rate, mortality rate, positive mutation and negative mutation were analyzed statistically. The results showed that high mortality rate appeared from 5 Gy and then the mortality rate curve became gently. Compared the positive and negative mutations in different doses, highest positive mutation was obtained in 40 Gy, while the negative mutation was lower in this dose, and the survival rate was 0.92%. So we defined that optimum dose of heavy ions radiation for Streptomyces kitasatoensis selection was 40 Gy in this experiment. (authors)

  13. Ecofriendly application of cellulase and xylanase producing marine ...

    African Journals Online (AJOL)

    windows

    2012-06-05

    Jun 5, 2012 ... producing marine Streptomyces clavuligerus as enhancer in ... pretreatment of cellulase, xylanase and the combination of enzymes. ... Energy from biomass holds a promising scope under ... investment, simplification of the fermentation media, ... biodegradation of lignocellulosic residues and enhanced ...

  14. Inorganic fullerene-like IF-WS_2/PVB nanocomposites of improved thermo-mechanical and tribological properties

    International Nuclear Information System (INIS)

    Simić, Danica; Stojanović, Dušica B.; Kojović, Aleksandar; Dimić, Mirjana; Totovski, Ljubica; Uskoković, Petar S.; Aleksić, Radoslav

    2016-01-01

    The subject of this research is to explore the possibility of preparation of nanocomposite material of improved thermo-mechanical and tribological properties, using inorganic fullerene-like tungsten disulfide nanostructures (IF-WS_2) as reinforcement in poly(vinyl butyral) (PVB). This paper also reports investigation of the effects of using different solvents in preparation of PVB/IF-WS_2 nanocomposite on the thermo-mechanical behavior of the resulting material. PVB was dissolved in ethanol, isopropanol, n-butanol and ethyl acetate. IF-WS_2 nanoparticles were added to these PVB solutions and dispersed by different deagglomeration techniques. Samples were dried and thin films were obtained. Their microstructure and the quality of IF-WS_2 dispersion and deagglomeration in PVB matrix was analyzed by scanning electron microscope (SEM). The reinforcing effect of IF-WS_2 is examined by determining hardness, reduced modulus of elasticity and coefficient of friction, by nanoindentation and nanoscratch test, in terms of the different solvents applied in preparation of the samples, mode of stirring and different contents of IF-WS_2. The glass transition temperature (T_g) was determined for the prepared samples using differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMA). Storage modulus and mechanical loss factor were observed in a defined temperature range using DMA. - Highlights: • Poly(vinyl butyral)/tungsten disulfide nanocomposites were examined. • Different solvents and deagglomeration methods affect the properties of composites. • Nanoindentation and scratch test, PSD, SEM, DSC and DMTA were analyzed. • Thermo-mechanical and antifriction properties of composite material are improved.

  15. Crystallization of the novel S-adenosyl-l-methionine-dependent C-methyltransferase CouO from Streptomyces rishiriensis and preliminary diffraction data analysis

    International Nuclear Information System (INIS)

    Lyskowski, Andrzej; Tengg, Martin; Steinkellner, Georg; Schwab, Helmut; Gruber-Khadjawi, Mandana; Gruber, Karl

    2012-01-01

    Recombinant Q9F8T9 protein from Streptomyces rishiriensis (CouO), an S-adenosyl-l-methionine-dependent C-methyltransferase, has been successfully cloned, expressed and purified. Recombinant Q9F8T9 protein from Streptomyces rishiriensis (CouO), an S-adenosyl-l-methionine-dependent C-methyltransferase, has been successfully cloned, expressed and purified. CouO was crystallized from a single condition in the Morpheus crystallization screen. A vitrified crystal diffracted to 2.05 Å resolution and belonged to space group P2 1 , with unit-cell parameters a = 33.02, b = 82.87, c = 76.77 Å, β = 96.93°

  16. Crataegus special extract WS 1442: up-to-date review of experimental and clinical experiences.

    Science.gov (United States)

    Zorniak, M; Szydlo, B; Krzeminski, T F

    2017-08-01

    Extracts and tinctures made from Crataegus spp. (Hawthorn) have been used as cardioprotective remedies since ancient times. WS 1442 special extract, manufactured by Dr. W. Schwabe Pharmaceuticals©, made from Crataegus spp. Leaves and flowers is one of the most studied and popular of preparations received from Hawthorn. It is integral, and most important active component of such herbal drugs as Crataegutt® novo 450, and CardioMax®. This standardized extract contains 18.75% oligomeric procyanidins (OPC), which have beneficial cardioprotective values and play a role as free-radicals scavengers, that protect the ischemic heart tissue from neutrophile elastase action successions. Moreover, WS 1442 also carries proven vasorelaxant activity, via affecting eNOS synthase, and prevents ischemic heart tissue swelling by influence on calcium signaling pathways, and thus detain hyperpermeability of endothelium. Actions of WS 1442 special extract were investigated in in vitro as well as in vivo studies including large clinical trials. In this review authors present current state of knowledge about possible beneficial effects of WS 1442 special extract on cardiovascular system.

  17. Natalamycin A, an ansamycin from a termite-associated Streptomyces sp

    DEFF Research Database (Denmark)

    Kim, Ki Hyun; Ramadhar, Timothy R.; Beemelmanns, Christine

    2014-01-01

    We report a preliminary functional and complete structural characterization of a highly unusual geldanamycin analog, natalamycin A, that was isolated from Streptomyces strain M56 recovered from a South African nest of Macrotermes natalensis termites. Bioassay-guided fractionation based on antifun......We report a preliminary functional and complete structural characterization of a highly unusual geldanamycin analog, natalamycin A, that was isolated from Streptomyces strain M56 recovered from a South African nest of Macrotermes natalensis termites. Bioassay-guided fractionation based...

  18. Continuous cultivations of a Penicillium chrysogenum strain expressing the expandase gene from Streptomyces clavuligerus: Kinetics of adipoyl-7-aminodeacetoxycephalosporanic acid and byproduct formations

    DEFF Research Database (Denmark)

    Robin, Jarno Jacky Christian; Bruheim, P.; Nielsen, M.L.

    2003-01-01

    The production kinetics of a transformed strain of Penicillium chrysogenum expressing the expandase gene from Streptomyces clavuligerus was investigated in chemostat cultivations. The recombinant strain produces adipoyl-7-aminodeacetoxycephalosporanic acid (ad-7-ADCA) as the major product; however...

  19. Isolation and characterization of mesophilic, oxalate-degrading Streptomyces from plant rhizosphere and forest soils

    Science.gov (United States)

    Sahin, Nurettin

    2004-10-01

    The present work was aimed at the isolation of additional new pure cultures of oxalate-degrading Streptomyces and its preliminary characterization for further work in the field of oxalate metabolism and taxonomic studies. Mesophilic, oxalate-degrading Streptomyces were enriched and isolated from plant rhizosphere and forest soil samples. Strains were examined for cultural, morphological (spore chain morphology, spore mass colour, diffusible and melanin pigment production), physiological (antibiosis, growth in the presence of inhibitory compounds, assimilation of organic acids and enzyme substrates) and chemotaxonomic characters (cellular lipid components and diagnostic cell-wall diamino acid). The taxonomic data obtained were analysed by using the simple matching (SSM) and Jaccard (SJ) coefficients, clustering was achieved using the UPGMA algorithm. All strains were able to utilize sodium-, potassium-, calcium- and ammonium-oxalate salts. Based on the results of numerical taxonomy, isolates were grouped into five cluster groups with a ≥70% SSM similarity level. Streptomyces rochei was the most common of the cluster groups, with a Willcox probability of P>0.8. Streptomyces antibioticus, S. anulatus, S. fulvissimus, S. halstedii and S. violaceusniger are newly reported as oxalate-utilizing Streptomyces.

  20. Lateral Gene Transfer Dynamics in the Ancient Bacterial Genus Streptomyces

    Directory of Open Access Journals (Sweden)

    Bradon R. McDonald

    2017-06-01

    Full Text Available Lateral gene transfer (LGT profoundly shapes the evolution of bacterial lineages. LGT across disparate phylogenetic groups and genome content diversity between related organisms suggest a model of bacterial evolution that views LGT as rampant and promiscuous. It has even driven the argument that species concepts and tree-based phylogenetics cannot be applied to bacteria. Here, we show that acquisition and retention of genes through LGT are surprisingly rare in the ubiquitous and biomedically important bacterial genus Streptomyces. Using a molecular clock, we estimate that the Streptomyces bacteria are ~380 million years old, indicating that this bacterial genus is as ancient as land vertebrates. Calibrating LGT rate to this geologic time span, we find that on average only 10 genes per million years were acquired and subsequently maintained. Over that same time span, Streptomyces accumulated thousands of point mutations. By explicitly incorporating evolutionary timescale into our analyses, we provide a dramatically different view on the dynamics of LGT and its impact on bacterial evolution.

  1. Discoloration of Ancient Egyptian Mural Paintings by Streptomyces Strains and Methods of Its Removal

    Directory of Open Access Journals (Sweden)

    Akmal Ali SAKR

    2012-12-01

    Full Text Available Streptomyces isolated from mural paintings at Tell Basta and Tanis tombs were identified using 16S rDNA sequencing method. These Streptomyces strains caused discoloration of mural paintings with irreversible red stains of carotenoid pigment. A mixture of n-hexan and acetone (92:8 v/v was the best solvent for extracting and purification of red pigment from biomass of Streptomyces. Dimethyl sulfoxide (DMSO and N,N-dimethylformamide (DMF were the most effective in treatment of these red stains without changing the paintings or stone surfaces.

  2. Biodegradation of degradable plastic polyethylene by phanerochaete and streptomyces species.

    Science.gov (United States)

    Lee, B; Pometto, A L; Fratzke, A; Bailey, T B

    1991-03-01

    The ability of lignin-degrading microorganisms to attack degradable plastics was investigated in pure shake flask culture studies. The degradable plastic used in this study was produced commercially by using the Archer-Daniels-Midland POLYCLEAN masterbatch and contained pro-oxidant and 6% starch. The known lignin-degrading bacteria Streptomyces viridosporus T7A, S. badius 252, and S. setonii 75Vi2 and fungus Phanerochaete chrysosporium were used. Pro-oxidant activity was accelerated by placing a sheet of plastic into a drying oven at 70 degrees C under atmospheric pressure and air for 0, 4, 8, 12, 16, or 20 days. The effect of 2-, 4-, and 8-week longwave UV irradiation at 365 nm on plastic biodegradability was also investigated. For shake flask cultures, plastics were chemically disinfected and incubated-shaken at 125 rpm at 37 degrees C in 0.6% yeast extract medium (pH 7.1) for Streptomyces spp. and at 30 degrees C for the fungus in 3% malt extract medium (pH 4.5) for 4 weeks along with an uninoculated control for each treatment. Weight loss data were inconclusive because of cell mass accumulation. For almost every 70 degrees C heat-treated film, the Streptomyces spp. demonstrated a further reduction in percent elongation and polyethylene molecular weight average when compared with the corresponding uninoculated control. Significant (P < 0.05) reductions were demonstrated for the 4- and 8-day heat-treated films by all three bacteria. Heat-treated films incubated with P. chrysosporium consistently demonstrated higher percent elongation and molecular weight average than the corresponding uninoculated controls, but were lower than the corresponding zero controls (heat-treated films without 4-week incubation). The 2- and 4-week UV-treated films showed the greatest biodegradation by all three bacteria. Virtually no degradation by the fungus was observed. To our knowledge, this is the first report demonstrating bacterial degradation of these oxidized polyethylenes in

  3. Subcompartmentalization by cross-membranes during early growth of Streptomyces hyphae

    DEFF Research Database (Denmark)

    Yagüe, Paula; Willemse, Joost; Koning, Roman I

    2016-01-01

    Bacteria of the genus Streptomyces are a model system for bacterial multicellularity. Their mycelial life style involves the formation of long multinucleated hyphae during vegetative growth, with occasional cross-walls separating long compartments. Reproduction occurs by specialized aerial hyphae......, which differentiate into chains of uninucleoid spores. While the tubulin-like FtsZ protein is required for the formation of all peptidoglycan-based septa in Streptomyces, canonical divisome-dependent cell division only occurs during sporulation. Here we report extensive subcompartmentalization in young...... vegetative hyphae of Streptomyces coelicolor, whereby 1 μm compartments are formed by nucleic acid stain-impermeable barriers. These barriers possess the permeability properties of membranes and at least some of them are cross-membranes without detectable peptidoglycan. Z-ladders form during the early growth...

  4. Proximity-induced spin-valley polarization in silicene or germanene on F-doped WS2

    KAUST Repository

    Sattar, Shahid

    2016-11-11

    Silicene and germanene are key materials for the field of valleytronics. However, interaction with the substrate, which is necessary to support the electronically active medium, becomes a major obstacle. In the present work, we propose a substrate (F-doped WS2) that avoids detrimental effects and at the same time induces the required valley polarization, so that no further steps are needed for this purpose. The behavior is explained by proximity effects on silicene or germanene, as demonstrated by first-principles calculations. Broken inversion symmetry due to the presence of WS2 opens a substantial band gap in silicene or germanene. F doping of WS2 results in spin polarization, which, in conjunction with proximity-enhanced spin-orbit coupling, creates sizable spin-valley polarization.

  5. Heterologous expression of oxytetracycline biosynthetic gene cluster in Streptomyces venezuelae WVR2006 to improve production level and to alter fermentation process.

    Science.gov (United States)

    Yin, Shouliang; Li, Zilong; Wang, Xuefeng; Wang, Huizhuan; Jia, Xiaole; Ai, Guomin; Bai, Zishang; Shi, Mingxin; Yuan, Fang; Liu, Tiejun; Wang, Weishan; Yang, Keqian

    2016-12-01

    Heterologous expression is an important strategy to activate biosynthetic gene clusters of secondary metabolites. Here, it is employed to activate and manipulate the oxytetracycline (OTC) gene cluster and to alter OTC fermentation process. To achieve these goals, a fast-growing heterologous host Streptomyces venezuelae WVR2006 was rationally selected among several potential hosts. It shows rapid and dispersed growth and intrinsic high resistance to OTC. By manipulating the expression of two cluster-situated regulators (CSR) OtcR and OtrR and precursor supply, the OTC production level was significantly increased in this heterologous host from 75 to 431 mg/l only in 48 h, a level comparable to the native producer Streptomyces rimosus M4018 in 8 days. This work shows that S. venezuelae WVR2006 is a promising chassis for the production of secondary metabolites, and the engineered heterologous OTC producer has the potential to completely alter the fermentation process of OTC production.

  6. Streptomyces colonosanans sp. nov., A Novel Actinobacterium Isolated from Malaysia Mangrove Soil Exhibiting Antioxidative Activity and Cytotoxic Potential against Human Colon Cancer Cell Lines

    Science.gov (United States)

    Law, Jodi Woan-Fei; Ser, Hooi-Leng; Duangjai, Acharaporn; Saokaew, Surasak; Bukhari, Sarah I.; Khan, Tahir M.; Ab Mutalib, Nurul-Syakima; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2017-01-01

    Streptomyces colonosanans MUSC 93JT, a novel strain isolated from mangrove forest soil located at Sarawak, Malaysia. The bacterium was noted to be Gram-positive and to form light yellow aerial and vivid yellow substrate mycelium on ISP 2 agar. The polyphasic approach was used to determine the taxonomy of strain MUSC 93JT and the strain showed a range of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus Streptomyces. Phylogenetic and 16S rRNA gene sequence analysis indicated that closely related strains include Streptomyces malachitofuscus NBRC 13059T (99.2% sequence similarity), Streptomyces misionensis NBRC 13063T (99.1%), and Streptomyces phaeoluteichromatogenes NRRL 5799T (99.1%). The DNA–DNA relatedness values between MUSC 93JT and closely related type strains ranged from 14.4 ± 0.1 to 46.2 ± 0.4%. The comparison of BOX-PCR fingerprints indicated MUSC 93JT exhibits a unique DNA profile. The genome of MUSC 93JT consists of 7,015,076 bp. The DNA G + C content was determined to be 69.90 mol%. The extract of strain MUSC 93JT was demonstrated to exhibit potent antioxidant activity via ABTS, metal chelating, and SOD assays. This extract also exhibited anticancer activity against human colon cancer cell lines without significant cytotoxic effect against human normal colon cells. Furthermore, the chemical analysis of the extract further emphasizes the strain is producing chemo-preventive related metabolites. Based on this polyphasic study of MUSC 93JT, it is concluded that this strain represents a novel species, for which the name Streptomyces colonosanans sp. nov. is proposed. The type strain is MUSC 93JT (= DSM 102042T = MCCC 1K02298T). PMID:28559892

  7. Streptomyces colonosanans sp. nov., A Novel Actinobacterium Isolated from Malaysia Mangrove Soil Exhibiting Antioxidative Activity and Cytotoxic Potential against Human Colon Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Jodi Woan-Fei Law

    2017-05-01

    Full Text Available Streptomyces colonosanans MUSC 93JT, a novel strain isolated from mangrove forest soil located at Sarawak, Malaysia. The bacterium was noted to be Gram-positive and to form light yellow aerial and vivid yellow substrate mycelium on ISP 2 agar. The polyphasic approach was used to determine the taxonomy of strain MUSC 93JT and the strain showed a range of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus Streptomyces. Phylogenetic and 16S rRNA gene sequence analysis indicated that closely related strains include Streptomyces malachitofuscus NBRC 13059T (99.2% sequence similarity, Streptomyces misionensis NBRC 13063T (99.1%, and Streptomyces phaeoluteichromatogenes NRRL 5799T (99.1%. The DNA–DNA relatedness values between MUSC 93JT and closely related type strains ranged from 14.4 ± 0.1 to 46.2 ± 0.4%. The comparison of BOX-PCR fingerprints indicated MUSC 93JT exhibits a unique DNA profile. The genome of MUSC 93JT consists of 7,015,076 bp. The DNA G + C content was determined to be 69.90 mol%. The extract of strain MUSC 93JT was demonstrated to exhibit potent antioxidant activity via ABTS, metal chelating, and SOD assays. This extract also exhibited anticancer activity against human colon cancer cell lines without significant cytotoxic effect against human normal colon cells. Furthermore, the chemical analysis of the extract further emphasizes the strain is producing chemo-preventive related metabolites. Based on this polyphasic study of MUSC 93JT, it is concluded that this strain represents a novel species, for which the name Streptomyces colonosanans sp. nov. is proposed. The type strain is MUSC 93JT (= DSM 102042T = MCCC 1K02298T.

  8. Exciton Binding Energy of Monolayer WS2

    Science.gov (United States)

    Zhu, Bairen; Chen, Xi; Cui, Xiaodong

    2015-03-01

    The optical properties of monolayer transition metal dichalcogenides (TMDC) feature prominent excitonic natures. Here we report an experimental approach to measuring the exciton binding energy of monolayer WS2 with linear differential transmission spectroscopy and two-photon photoluminescence excitation spectroscopy (TP-PLE). TP-PLE measurements show the exciton binding energy of 0.71 +/- 0.01 eV around K valley in the Brillouin zone.

  9. Structure of restacked MoS{sub 2} and WS{sub 2} elucidated by electron crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Heising, J; Kanatzidis, M G

    1999-02-03

    There has been a lot of confusion about the nature of restacked MoS{sub 2} and WS{sub 2}. The structure has been proposed to be trigonal TiS{sub 2} type with octahedral M{sup 4} and called 1T-MoS{sub 2}. The presence of a distortion in the metal plane that gives rise to a superstructure has been suggested. Electron crystallographic studies on small (submicron) single crystal domains of restacked WS{sub 2} and MoS{sub 2} have been performed to solve their superstructure. It was shown that what initially seems to be a trigonal crystal is actually a triplet of three individual orthorhombic crystals. Using two-dimensional hk0 data from films for both triple and single crystals the authors calculated corresponding Patterson projections, which reveal a severe distortion in the Mo/W plane, forming infinite zigzag chains. The projection of the structure suggests M-M distances of 2.92 and 2.74 {angstrom} for MoS{sub 2} and Ws{sub 2}, respectively. Least-squares refinement from the single-crystal data gives R{sub 1} = 13.3% for WS{sub 2} and R{sub 1} = 15.3% for MoS{sub 2}. Therefore, it is proposed that restacked MoS{sub 2} and WS{sub 2} are not 1T form but rather WTe{sub 2} type.

  10. Antioxidative Potential of a Streptomyces sp. MUM292 Isolated from Mangrove Soil

    Directory of Open Access Journals (Sweden)

    Loh Teng-Hern Tan

    2018-01-01

    Full Text Available Mangrove derived microorganisms constitute a rich bioresource for bioprospecting of bioactive natural products. This study explored the antioxidant potentials of Streptomyces bacteria derived from mangrove soil. Based on 16S rRNA phylogenetic analysis, strain MUM292 was identified as the genus Streptomyces. Strain MUM292 showed the highest 16S rRNA gene sequence similarity of 99.54% with S. griseoruber NBRC12873T. Furthermore, strain MUM292 was also characterized and showed phenotypic characteristics consistent with Streptomyces bacteria. Fermentation and extraction were performed to obtain the MUM292 extract containing the secondary metabolites of strain MUM292. The extract displayed promising antioxidant activities, including DPPH, ABTS, and superoxide radical scavenging and also metal-chelating activities. The process of lipid peroxidation in lipid-rich product was also retarded by MUM292 extract and resulted in reduced MDA production. The potential bioactive constituents of MUM292 extract were investigated using GC-MS and preliminary detection showed the presence of pyrazine, pyrrole, cyclic dipeptides, and phenolic compound in MUM292 extract. This work demonstrates that Streptomyces MUM292 can be a potential antioxidant resource for food and pharmaceutical industries.

  11. Cadmium biosorption by Streptomyces sp. F4 isolated from former uranium mine.

    Science.gov (United States)

    Siñeriz, Manuel Louis; Kothe, Erika; Abate, Carlos Mauricio

    2009-09-01

    46 actinomycetes were isolated from two polluted sites and one unpolluted site. One strain, F4, was selected through primary qualitative screening assays because of its cadmium resistance, and physiologically and taxonomically characterized. F4 was able to grow at 7.5% NaCl and 100 microg/ml lysozyme and at a pH between 6 and 10. 16S rDNA sequence analysis showed that F4 was closely related to Streptomyces tendae. Growth of Streptomyces sp. F4 on culture medium with 8 mg/l Cd(2+) for 8 days showed 80% inhibition. Maximum specific biosorption was 41.7 mg Cd(2+)/g dry weight after 7 days of growth and highest Cd(2+ )concentration was found in the cell wall (41.2%). The exopolysaccharide layer only contained 7.4%, whereas 39.4% of Cd(2+) was found in the cytosolic fraction. Twelve % was found in the ribosomes and membrane fraction. This was verified with TEM, showing Streptomyces sp. F4 cytoplasm with dark granulate appearance. This study could present the potential capacity of Streptomyces sp. F4 for Cd(2+) bioremediation. Copyright 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Modeling process for bioproduction of xylanase by Streptomyces spp. p12-137 on lignocelluloses agro-wastes

    Directory of Open Access Journals (Sweden)

    Gigi COMAN

    2012-12-01

    Full Text Available The production of xylanase without cellulase is required for the prebleaching of pulps, paper and food industry. The strain Streptomyces spp.P12-137 developed from the spores of the wild type organism was used in this work. Cultures in Erlenmeyer flasks, under shaking condition (150 rpm at temperature and pH values (28°C, 5.0 respectively revealed a xylanase activity of 27.77 IU·mL-1 after 120 h fermentation. This study demonstrates that Streptomyces spp. P12-137 is able to produce xylanase when wheat bran is used as a substrate. Fermentation was performed in a glass bioreactor withforced aeration. Data obtained have been compared to data from mathematical model obtained by numerical simulation using Matlab 7.9.0.529 (MathWorks, Inc. USA. The numerical simulation of the bioprocess could be a useful tool for adopting a control strategy to achieve increased xylanases yields under pilot or industrial conditions.

  13. TMG-chitotriomycin, an enzyme inhibitor specific for insect and fungal beta-N-acetylglucosaminidases, produced by actinomycete Streptomyces anulatus NBRC 13369.

    Science.gov (United States)

    Usuki, Hirokazu; Nitoda, Teruhiko; Ichikawa, Misato; Yamaji, Nahoko; Iwashita, Takashi; Komura, Hajime; Kanzaki, Hiroshi

    2008-03-26

    A novel beta-N-acetylglucosaminidase (GlcNAcase) inhibitor named TMG-chitotriomycin (1) was isolated from the culture filtrate of Streptomyces anulatus NBRC13369. The strain produced 1 only when colloidal chitin was used as the sole carbon source in the production medium. The structure of 1 was determined by spectral and constitutive sugar analyses of the corresponding alditol derivatives to be an equilibrated mixture of alpha-d-N,N,N-triMeGlcNH2-(1,4)-beta-d-GlcNAc-(1,4)-beta-d-GlcNAc-(1,4)-d-GlcNAc and its C-2 epimer of the reducing end residue. TMG-chitotriomycin (1) showed potent and selective inhibition of insect and fungal GlcNAcases with no inhibition of mammalian and plant GlcNAcases. In contrast, the known GlcNAcase inhibitor nagstatin potently inhibited all GlcNAcases. It should be emphasized that synthesized d-N,N,N-triMeGlcNH2, which is the component sugar of 1, showed no inhibition of the insect Spodoptera litura GlcNAcase. These results suggest that the (GlcNAc)3 unit positioned at the reducing end of 1 is essential for its enzyme inhibitory activity. The unique inhibitory spectrum of 1 will be useful to study chitinolytic systems and to develop selective fungicides or pesticides.

  14. Angucycline Glycosides from Mangrove-Derived Streptomyces diastaticus subsp. SCSIO GJ056

    Directory of Open Access Journals (Sweden)

    Chun Gui

    2018-05-01

    Full Text Available Nine new angucycline glycosides designated urdamycins N1–N9 (1–9, together with two known congener urdamycins A (10 and B (11, were obtained from a mangrove-derived Streptomyces diastaticus subsp. SCSIO GJ056. The structures of new compounds were elucidated on the basis of extensive spectroscopic data analysis. The absolute configurations of 6–9 were assigned by electronic circular dichroism calculation method. Urdamycins N6 (6 and N9 (9 represent the first naturally occurring (5R, 6R-angucycline glycosides, which are diastereomers of urdamycins N7 (7 and N8 (8, respectively.

  15. Homogeneous time-resolved fluoroimmunoassay of microcystin-LR using layered WS2 nanosheets as a transducer

    Science.gov (United States)

    Qin, Xiaodan; Wang, Yuanxiu; Song, Bo; Wang, Xin; Ma, Hua; Yuan, Jingli

    2017-06-01

    A homogeneous time-resolved fluoroimmunoassay method for rapid and sensitive detection of microcystin-LR (MC-LR) in water samples was developed based on the interaction between water-soluble WS2 nanosheets and the conjugate of MC-LR with a luminescent Eu3+ complex BHHBCB-Eu3+ (BHHBCB: 1,2-bis[4‧-(1″,1″,1″,2″,2″,3″,3″-heptafluoro-4″,6″-hexanedion-6″-yl)- benzyl]-4-chlorosulfobenzene). The large lateral dimensions and high surface areas of two-dimensional layered WS2 nanosheets enable easy adsorption of the MC-LR-BHHBCB-Eu3+ conjugate, that lead to efficient quenching of the luminescence of Eu3+ complex via energy transfer or electron transfer process. However, the addition of monoclonal anti-MC-LR antibody can induce the formation of MC-LR-BHHBCB-Eu3+/antibody immune complex, which prevents the interaction between WS2 nanosheets and MC-LR-BHHBCB-Eu3+ to result in the restoration of Eu3+ luminescence. This signal transduction mechanism made it possible for analysis of the target MC-LR in a homogeneous system. The present method has advantages of rapidity and simplicity since the B/F (bound reagent/free reagent) separation steps, the solid-phase carrier and antibody labeling or modification process are not necessary. The proposed immunosensing system displayed a wide linear range, good precision and accuracy, and comparable sensitivity with a detection limit of 0.3 μg l-1, which satisfied the World Health Organization (WHO) provisional guideline limit of 1.0 μg l-1 for MC-LR in drinking water.

  16. Glucose(xylose isomerase production by Streptomyces sp. CH7 grown on agricultural residues

    Directory of Open Access Journals (Sweden)

    Kankiya Chanitnun

    2012-09-01

    Full Text Available Streptomyces sp. CH7 was found to efficiently produce glucose(xylose isomerase when grown on either xylan or agricultural residues. This strain produced a glucose(xylose isomerase activity of roughly 1.8 U/mg of protein when it was grown in medium containing 1% xylose as a carbon source. Maximal enzymatic activities of about 5 and 3 U/mg were obtained when 1% xylan and 2.5% corn husks were used, respectively. The enzyme was purified from a mycelial extract to 16-fold purity with only two consecutive column chromatography steps using Macro-prep DEAE and Sephacryl-300, respectively. The approximate molecular weight of the purified enzyme is 170 kDa, and it has four identical subunits of 43.6 kDa as estimated by SDS-PAGE. Its Km values for glucose and xylose were found to be 258.96 and 82.77 mM, respectively, and its Vmax values are 32.42 and 63.64 μM/min/mg, respectively. The purified enzyme is optimally active at 85ºC and pH 7.0. It is stable at pH 5.5-8.5 and at temperatures up to 60ºC after 30 min. These findings indicate that glucose(xylose isomerase from Streptomyces sp. CH7 has the potential for industrial applications, especially for high-fructose syrup production and bioethanol fermentation from hemicellulosic hydrolysates by Saccharomyces cerevisiae.

  17. Inorganic fullerene-like IF-WS{sub 2}/PVB nanocomposites of improved thermo-mechanical and tribological properties

    Energy Technology Data Exchange (ETDEWEB)

    Simić, Danica [Military Technical Institute, Ratka Resanovića 1, 11132 Belgrade (Serbia); Stojanović, Dušica B., E-mail: duca@tmf.bg.ac.rs [University of Belgrade, Faculty of Technology and Metallurgy, 11120 Belgrade (Serbia); Kojović, Aleksandar [University of Belgrade, Faculty of Technology and Metallurgy, 11120 Belgrade (Serbia); Dimić, Mirjana; Totovski, Ljubica [Military Technical Institute, Ratka Resanovića 1, 11132 Belgrade (Serbia); Uskoković, Petar S.; Aleksić, Radoslav [University of Belgrade, Faculty of Technology and Metallurgy, 11120 Belgrade (Serbia)

    2016-12-01

    The subject of this research is to explore the possibility of preparation of nanocomposite material of improved thermo-mechanical and tribological properties, using inorganic fullerene-like tungsten disulfide nanostructures (IF-WS{sub 2}) as reinforcement in poly(vinyl butyral) (PVB). This paper also reports investigation of the effects of using different solvents in preparation of PVB/IF-WS{sub 2} nanocomposite on the thermo-mechanical behavior of the resulting material. PVB was dissolved in ethanol, isopropanol, n-butanol and ethyl acetate. IF-WS{sub 2} nanoparticles were added to these PVB solutions and dispersed by different deagglomeration techniques. Samples were dried and thin films were obtained. Their microstructure and the quality of IF-WS{sub 2} dispersion and deagglomeration in PVB matrix was analyzed by scanning electron microscope (SEM). The reinforcing effect of IF-WS{sub 2} is examined by determining hardness, reduced modulus of elasticity and coefficient of friction, by nanoindentation and nanoscratch test, in terms of the different solvents applied in preparation of the samples, mode of stirring and different contents of IF-WS{sub 2}. The glass transition temperature (T{sub g}) was determined for the prepared samples using differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMA). Storage modulus and mechanical loss factor were observed in a defined temperature range using DMA. - Highlights: • Poly(vinyl butyral)/tungsten disulfide nanocomposites were examined. • Different solvents and deagglomeration methods affect the properties of composites. • Nanoindentation and scratch test, PSD, SEM, DSC and DMTA were analyzed. • Thermo-mechanical and antifriction properties of composite material are improved.

  18. Lateral Gene Transfer Dynamics in the Ancient Bacterial Genus Streptomyces.

    Science.gov (United States)

    McDonald, Bradon R; Currie, Cameron R

    2017-06-06

    Lateral gene transfer (LGT) profoundly shapes the evolution of bacterial lineages. LGT across disparate phylogenetic groups and genome content diversity between related organisms suggest a model of bacterial evolution that views LGT as rampant and promiscuous. It has even driven the argument that species concepts and tree-based phylogenetics cannot be applied to bacteria. Here, we show that acquisition and retention of genes through LGT are surprisingly rare in the ubiquitous and biomedically important bacterial genus Streptomyces Using a molecular clock, we estimate that the Streptomyces bacteria are ~380 million years old, indicating that this bacterial genus is as ancient as land vertebrates. Calibrating LGT rate to this geologic time span, we find that on average only 10 genes per million years were acquired and subsequently maintained. Over that same time span, Streptomyces accumulated thousands of point mutations. By explicitly incorporating evolutionary timescale into our analyses, we provide a dramatically different view on the dynamics of LGT and its impact on bacterial evolution. IMPORTANCE Tree-based phylogenetics and the use of species as units of diversity lie at the foundation of modern biology. In bacteria, these pillars of evolutionary theory have been called into question due to the observation of thousands of lateral gene transfer (LGT) events within and between lineages. Here, we show that acquisition and retention of genes through LGT are exceedingly rare in the bacterial genus Streptomyces , with merely one gene acquired in Streptomyces lineages every 100,000 years. These findings stand in contrast to the current assumption of rampant genetic exchange, which has become the dominant hypothesis used to explain bacterial diversity. Our results support a more nuanced understanding of genetic exchange, with LGT impacting evolution over short timescales but playing a significant role over long timescales. Deeper understanding of LGT provides new

  19. Streptopyrrole: An antimicrobial metabolite from Streptomyces armeniacus

    DEFF Research Database (Denmark)

    Breinholt, J.; Gürtler, Hanne; Kjær, Anders

    1998-01-01

    A colourless, crystalline metabolite, C14H12ClNO4, named streptopyrrole, has been isolated from submerged fermentation cultures of Streptomyces armeniacus by extraction, followed by chromatographic purification. Its tricyclic molecular framework, seemingly without natural product precedents. as w...

  20. Cytochromes P450 for natural product biosynthesis in Streptomyces: sequence, structure, and function.

    Science.gov (United States)

    Rudolf, Jeffrey D; Chang, Chin-Yuan; Ma, Ming; Shen, Ben

    2017-08-30

    Covering: up to January 2017Cytochrome P450 enzymes (P450s) are some of the most exquisite and versatile biocatalysts found in nature. In addition to their well-known roles in steroid biosynthesis and drug metabolism in humans, P450s are key players in natural product biosynthetic pathways. Natural products, the most chemically and structurally diverse small molecules known, require an extensive collection of P450s to accept and functionalize their unique scaffolds. In this review, we survey the current catalytic landscape of P450s within the Streptomyces genus, one of the most prolific producers of natural products, and comprehensively summarize the functionally characterized P450s from Streptomyces. A sequence similarity network of >8500 P450s revealed insights into the sequence-function relationships of these oxygen-dependent metalloenzymes. Although only ∼2.4% and structurally characterized, respectively, the study of streptomycete P450s involved in the biosynthesis of natural products has revealed their diverse roles in nature, expanded their catalytic repertoire, created structural and mechanistic paradigms, and exposed their potential for biomedical and biotechnological applications. Continued study of these remarkable enzymes will undoubtedly expose their true complement of chemical and biological capabilities.

  1. Lack of A-factor production induces the expression of nutrient scavenging and stress-related proteins in Streptomyces griseus.

    Science.gov (United States)

    Birkó, Zsuzsanna; Swiatek, Magdalena; Szájli, Emília; Medzihradszky, Katalin F; Vijgenboom, Erik; Penyige, András; Keseru, Judit; van Wezel, Gilles P; Biró, Sándor

    2009-10-01

    The small gamma-butyrolactone A-factor is an important autoregulatory signaling molecule for the soil-inhabiting streptomycetes. Starvation is a major trigger for development, and nutrients are provided by degradation of the vegetative mycelium via a process of programmed cell death, reusing proteins, nucleic acids, and cell wall material. The A-factor regulon includes many extracellular hydrolases. Here we show via proteomics analysis that many nutrient-scavenging and stress-related proteins were overexpressed in an A-factor non-producing mutant of Streptomyces griseus B-2682. Transcript analysis showed that this is primarily due to differential transcription of the target genes during early development. The targets include proteins relating to nutrient stress and environmental stress and an orthologue of the Bacillus sporulation control protein Spo0M. The enhanced expression of these proteins underlines the stress that is generated by the absence of A-factor. Wild-type developmental gene expression was restored to the A-factor non-producing mutant by the signaling protein Factor C in line with our earlier observation that Factor C triggers A-factor production.

  2. Flocculation mechanism of the actinomycete Streptomyces sp. hsn06 on Chlorella vulgaris.

    Science.gov (United States)

    Li, Yi; Xu, Yanting; Zheng, Tianling; Wang, Hailei

    2017-09-01

    In this study, an actinomycete Streptomyces sp. hsn06 with the ability to harvest Chlorella vulgaris biomass was used to investigate the flocculation mechanism. Streptomyces sp. hsn06 exhibited flocculation activity on algal cells through mycelial pellets with adding calcium. Calcium was determined to promote flocculation activity of mycelial pellets as a bridge binding with mycelial pellets and algal cells, which implied that calcium bridging is the main flocculation mechanism for mycelial pellets. Characteristics of flocculation activity confirmed proteins in mycelial pellets involved in flocculation procedure. The morphology and structure of mycelial pellets also caused dramatic effects on flocculation activity of mycelial pellets. According to the results, Streptomyces sp. hsn06 can be used as a novel flocculating microbial resource for high-efficiency harvesting of microalgae biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Electrical transport properties of individual WS2 nanotubes and their dependence on water and oxygen absorption

    Science.gov (United States)

    Zhang, Chaoying; Ning, Zhiyuan; Liu, Yang; Xu, Tingting; Guo, Yao; Zak, Alla; Zhang, Zhiyong; Wang, Sheng; Tenne, Reshef; Chen, Qing

    2012-09-01

    The electrical properties of WS2 nanotubes (NTs) were studied through measuring 59 devices. Important electrical parameters, such as the carrier concentration, mobility, and effective barrier height at the contacts, were obtained through fitting experimental non-linear I-V curves using a metal-semiconductor-metal model. The carrier mobility was found to be several orders of magnitude higher than that have been reported previously for WS2 NTs. Water absorption was found to decrease the conductivity and carrier mobility of the NTs, and could be removed when the sample was dried. Oxygen absorption also slightly decreased the conductivity of WS2 NTs.

  4. Fabrication of a saturable absorber WS2 and its mode locking in solid-state laser

    Science.gov (United States)

    Zhang, Chun-Yu; Zhang, Ling; Tang, Xiao-Ying; Yang, Ying-Ying

    2018-04-01

    We report on a passively mode-locked Nd : LuVO4 laser using a type saturable absorber of tungsten disulfide (WS2) fabricated by chemical vapor deposition method. At the pump power of 3.3 W, 1.18-W average output power of continuous-wave mode-locked laser with optical conversion efficiency of 36% was achieved. To the best of our knowledge, this is the highest output power of passively mode-locked solid-state laser based on WS2. The repetition rate of passively mode-locked pulse was 80 MHz with the pulse energy of 14.8 nJ. Our experimental results show that WS2 is an excellent type of saturable absorber.

  5. Detection and properties of A-factor-binding protein from Streptomyces griseus

    International Nuclear Information System (INIS)

    Miyake, K.; Horinouchi, S.; Yoshida, M.; Chiba, N.; Mori, K.; Nogawa, N.; Morikawa, N.; Beppu, T.

    1989-01-01

    The optically active form of tritium-labeled A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone), a pleiotropic autoregulator responsible for streptomycin production, streptomycin resistance, and sporulation in Streptomyces griseus, was chemically synthesized. By using the radioactive A-factor, a binding protein for A-factor was detected in the cytoplasmic fraction of this organism. The binding protein had an apparent molecular weight of approximately 26,000, as determined by gel filtration. Scatchard analysis suggested that A-factor bound the protein in the molar ratio of 1:1 with a binding constant, Kd, of 0.7 nM. The number of the binding protein was roughly estimated to be 37 per genome. The inducing material virginiae butanolide C (VB-C), which has a structure very similar to that of A-factor and is essential for virginiamycin production in Streptomyces virginiae, did not inhibit binding. In addition, no protein capable of specifically binding 3 H-labeled VB-C was found in S. griseus. Together with the observation that VB-C had almost no biological activity on the restoration of streptomycin production or sporulation in an A-factor-deficient mutant of S. griseus, these results indicated that the binding protein had a strict ligand specificity. Examination for an A-factor-binding protein in Streptomyces coelicolor A3(2) and Streptomyces lividans showed the absence of any specifically binding protein

  6. Cloning and recombinant expression of a cellulase from the cellulolytic strain Streptomyces sp. G12 isolated from compost

    Directory of Open Access Journals (Sweden)

    Amore Antonella

    2012-12-01

    Full Text Available Abstract Background The use of lignocellulosic materials for second generation ethanol production would give several advantages such as minimizing the conflict between land use for food and fuel production, providing less expensive raw materials than conventional agricultural feedstock, allowing lower greenhouse gas emissions than those of first generation ethanol. However, cellulosic biofuels are not produced at a competitive level yet, mainly because of the high production costs of the cellulolytic enzymes. Therefore, this study was aimed at discovering new cellulolytic microorganisms and enzymes. Results Different bacteria isolated from raw composting materials obtained from vegetable processing industry wastes were screened for their cellulolytic activity on solid medium containing carboxymethylcellulose. Four strains belonging to the actinomycetes group were selected on the basis of their phenotypic traits and cellulolytic activity on solid medium containing carboxymethylcellulose. The strain showing the highest cellulolytic activity was identified by 16S rRNA sequencing as belonging to Streptomyces genus and it was designated as Streptomyces sp. strain G12. Investigating the enzymes responsible for cellulase activity produced by Streptomyces G12 by proteomic analyses, two endoglucanases were identified. Gene coding for one of these enzymes, named CelStrep, was cloned and sequenced. Molecular analysis showed that the celstrep gene has an open reading frame encoding a protein of 379 amino acid residues, including a signal peptide of 37 amino acid residues. Comparison of deduced aminoacidic sequence to the other cellulases indicated that the enzyme CelStrep can be classified as a family 12 glycoside hydrolase. Heterologous recombinant expression of CelStrep was carried out in Escherichia coli, and the active recombinant enzyme was purified from culture supernatant and characterized. It catalyzes the hydrolysis of carboxymethylcellulose

  7. Cloning and recombinant expression of a cellulase from the cellulolytic strain Streptomyces sp. G12 isolated from compost

    Science.gov (United States)

    2012-01-01

    Background The use of lignocellulosic materials for second generation ethanol production would give several advantages such as minimizing the conflict between land use for food and fuel production, providing less expensive raw materials than conventional agricultural feedstock, allowing lower greenhouse gas emissions than those of first generation ethanol. However, cellulosic biofuels are not produced at a competitive level yet, mainly because of the high production costs of the cellulolytic enzymes. Therefore, this study was aimed at discovering new cellulolytic microorganisms and enzymes. Results Different bacteria isolated from raw composting materials obtained from vegetable processing industry wastes were screened for their cellulolytic activity on solid medium containing carboxymethylcellulose. Four strains belonging to the actinomycetes group were selected on the basis of their phenotypic traits and cellulolytic activity on solid medium containing carboxymethylcellulose. The strain showing the highest cellulolytic activity was identified by 16S rRNA sequencing as belonging to Streptomyces genus and it was designated as Streptomyces sp. strain G12. Investigating the enzymes responsible for cellulase activity produced by Streptomyces G12 by proteomic analyses, two endoglucanases were identified. Gene coding for one of these enzymes, named CelStrep, was cloned and sequenced. Molecular analysis showed that the celstrep gene has an open reading frame encoding a protein of 379 amino acid residues, including a signal peptide of 37 amino acid residues. Comparison of deduced aminoacidic sequence to the other cellulases indicated that the enzyme CelStrep can be classified as a family 12 glycoside hydrolase. Heterologous recombinant expression of CelStrep was carried out in Escherichia coli, and the active recombinant enzyme was purified from culture supernatant and characterized. It catalyzes the hydrolysis of carboxymethylcellulose following a Michaelis

  8. Genomic and secondary metabolite analyses of Streptomyces sp. 2AW provide insight into the evolution of the cycloheximide pathway

    Directory of Open Access Journals (Sweden)

    Elizabeth eStulberg

    2016-05-01

    Full Text Available The dearth of new antibiotics in the face of widespread antimicrobial resistance makes developing innovative strategies for discovering new antibiotics critical for the future management of infectious disease. Understanding the genetics and evolution of antibiotic producers will help guide the discovery and bioengineering of novel antibiotics. We discovered an isolate in Alaskan boreal forest soil that had broad antimicrobial activity. We elucidated the corresponding antimicrobial natural products and sequenced the genome of this isolate, designated Streptomyces sp. 2AW. This strain illustrates the chemical virtuosity typical of the Streptomyces genus, producing cycloheximide as well as two other biosynthetically unrelated antibiotics, neutramycin and hygromycin A. Combining bioinformatic and chemical analyses, we identified the gene clusters responsible for antibiotic production. Interestingly, 2AW appears dissimilar from other cycloheximide producers in that the gene encoding the polyketide synthase resides on a separate part of the chromosome from the genes responsible for tailoring cycloheximide-specific modifications. This gene arrangement and our phylogenetic analyses of the gene products suggest that 2AW holds an evolutionarily ancestral lineage of the cycloheximide pathway. Our analyses support the hypothesis that the 2AW glutaramide gene cluster is basal to the lineage wherein cycloheximide production diverged from other glutarimide antibiotics. This study illustrates the power of combining modern biochemical and genomic analyses to gain insight into the evolution of antibiotic-producing microorganisms.

  9. Genome Content and Phylogenomics Reveal both Ancestral and Lateral Evolutionary Pathways in Plant-Pathogenic Streptomyces Species

    Science.gov (United States)

    Huguet-Tapia, Jose C.; Lefebure, Tristan; Badger, Jonathan H.; Guan, Dongli; Stanhope, Michael J.

    2016-01-01

    Streptomyces spp. are highly differentiated actinomycetes with large, linear chromosomes that encode an arsenal of biologically active molecules and catabolic enzymes. Members of this genus are well equipped for life in nutrient-limited environments and are common soil saprophytes. Out of the hundreds of species in the genus Streptomyces, a small group has evolved the ability to infect plants. The recent availability of Streptomyces genome sequences, including four genomes of pathogenic species, provided an opportunity to characterize the gene content specific to these pathogens and to study phylogenetic relationships among them. Genome sequencing, comparative genomics, and phylogenetic analysis enabled us to discriminate pathogenic from saprophytic Streptomyces strains; moreover, we calculated that the pathogen-specific genome contains 4,662 orthologs. Phylogenetic reconstruction suggested that Streptomyces scabies and S. ipomoeae share an ancestor but that their biosynthetic clusters encoding the required virulence factor thaxtomin have diverged. In contrast, S. turgidiscabies and S. acidiscabies, two relatively unrelated pathogens, possess highly similar thaxtomin biosynthesis clusters, which suggests that the acquisition of these genes was through lateral gene transfer. PMID:26826232

  10. Cephamycins, a New Family of β-Lactam Antibiotics I. Production by Actinomycetes, Including Streptomyces lactamdurans sp. n1

    Science.gov (United States)

    Stapley, E. O.; Jackson, M.; Hernandez, S.; Zimmerman, S. B.; Currie, S. A.; Mochales, S.; Mata, J. M.; Woodruff, H. B.; Hendlin, D.

    1972-01-01

    A number of actinomycetes isolated from soil were found to produce one or more members of a new family of antibiotics, the cephamycins, which are structurally related to cephalosporin C. The cephamycins were produced in submerged fermentation in a wide variety of media by one or more of eight different species of Streptomyces, including a newly described species, S. lactamdurans. These antibiotics exhibit antibacterial activity against a broad spectrum of bacteria which includes many that are resistant to the cephalosporins and penicillins. PMID:4790552

  11. Taxonomic evaluation of species in the Streptomyces hirsutus clade using multi-locus sequence analysis and proposals to reclassify several species in this clade

    Science.gov (United States)

    Previous phylogenetic analyses of species of Streptomyces based on 16S rRNA gene sequences resulted in a statistically well-supported clade (100% bootstrap value) containing 8 species that exhibited very similar gross morphology in producing open looped (Retinaculum-Apertum) to spiral (Spira) chains...

  12. Improved yields of daunomycinone glycosides in developmental mutants of Streptomyces coeruleorubidus

    International Nuclear Information System (INIS)

    Blumauerova, M.; Pokorny, V.; Stastna, J.; Hostalek, Z.; Vanek, Z.

    1978-01-01

    When improving Streptomyces coeruleorubidus JA 10092, a producer of antibiotics of the daunomycinone complex, the most active variants were found among isolates of morphological types bld-1 (with a suppressed production of the aerial mycelium on organic media containing glucose) and whi (with an asporogenic aerial mycelium on glucose media and with the bald phenotype on media containing starch). Submerged cultures of the whi mutants produced increased quantities of daunomycinone glycosides in the antibiotic complex, the amount of free anthracyclinones being simultaneously decreased. The whi strains differed from the wild type also in higher demands for aeration, concentration of glucose and in an increased production capacity in starch media. The overall antibiotic activity increased more than 40 times after a six-step selection (application of UV light, γ-radiation, nitrous acid and natural spreads) combined with an altered fermentation technology. (author)

  13. Aromatic Polyketide GTRI-02 is a Previously Unidentified Product of the act Gene Cluster in Streptomyces coelicolor A3(2).

    Science.gov (United States)

    Wu, Changsheng; Ichinose, Koji; Choi, Young Hae; van Wezel, Gilles P

    2017-07-18

    The biosynthesis of aromatic polyketides derived from type II polyketide synthases (PKSs) is complex, and it is not uncommon that highly similar gene clusters give rise to diverse structural architectures. The act biosynthetic gene cluster (BGC) of the model actinomycete Streptomyces coelicolor A3(2) is an archetypal type II PKS. Here we show that the act BGC also specifies the aromatic polyketide GTRI-02 (1) and propose a mechanism for the biogenesis of its 3,4-dihydronaphthalen-1(2H)-one backbone. Polyketide 1 was also produced by Streptomyces sp. MBT76 after activation of the act-like qin gene cluster by overexpression of the pathway-specific activator. Mining of this strain also identified dehydroxy-GTRI-02 (2), which most likely originated from dehydration of 1 during the isolation process. This work shows that even extensively studied model gene clusters such as act of S. coelicolor can still produce new chemistry, offering new perspectives for drug discovery. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Biodegradation of Degradable Plastic Polyethylene by Phanerochaete and Streptomyces Species †

    Science.gov (United States)

    Lee, Byungtae; Pometto, Anthony L.; Fratzke, Alfred; Bailey, Theodore B.

    1991-01-01

    The ability of lignin-degrading microorganisms to attack degradable plastics was investigated in pure shake flask culture studies. The degradable plastic used in this study was produced commercially by using the Archer-Daniels-Midland POLYCLEAN masterbatch and contained pro-oxidant and 6% starch. The known lignin-degrading bacteria Streptomyces viridosporus T7A, S. badius 252, and S. setonii 75Vi2 and fungus Phanerochaete chrysosporium were used. Pro-oxidant activity was accelerated by placing a sheet of plastic into a drying oven at 70°C under atmospheric pressure and air for 0, 4, 8, 12, 16, or 20 days. The effect of 2-, 4-, and 8-week longwave UV irradiation at 365 nm on plastic biodegradability was also investigated. For shake flask cultures, plastics were chemically disinfected and incubated-shaken at 125 rpm at 37°C in 0.6% yeast extract medium (pH 7.1) for Streptomyces spp. and at 30°C for the fungus in 3% malt extract medium (pH 4.5) for 4 weeks along with an uninoculated control for each treatment. Weight loss data were inconclusive because of cell mass accumulation. For almost every 70°C heat-treated film, the Streptomyces spp. demonstrated a further reduction in percent elongation and polyethylene molecular weight average when compared with the corresponding uninoculated control. Significant (P < 0.05) reductions were demonstrated for the 4- and 8-day heat-treated films by all three bacteria. Heat-treated films incubated with P. chrysosporium consistently demonstrated higher percent elongation and molecular weight average than the corresponding uninoculated controls, but were lower than the corresponding zero controls (heat-treated films without 4-week incubation). The 2- and 4-week UV-treated films showed the greatest biodegradation by all three bacteria. Virtually no degradation by the fungus was observed. To our knowledge, this is the first report demonstrating bacterial degradation of these oxidized polyethylenes in pure culture. PMID:16348434

  15. Hierarchical Layered WS2 /Graphene-Modified CdS Nanorods for Efficient Photocatalytic Hydrogen Evolution.

    Science.gov (United States)

    Xiang, Quanjun; Cheng, Feiyue; Lang, Di

    2016-05-10

    Graphene-based ternary composite photocatalysts with genuine heterostructure constituents have attracted extensive attention in photocatalytic hydrogen evolution. Here we report a new graphene-based ternary composite consisting of CdS nanorods grown on hierarchical layered WS2 /graphene hybrid (WG) as a high-performance photocatalyst for hydrogen evolution under visible light irradiation. The optimal content of layered WG as a co-catalyst in the ternary CdS/WS2 /graphene composites was found to be 4.2 wt %, giving a visible light photocatalytic H2 -production rate of 1842 μmol h(-1)  g(-1) with an apparent quantum efficiency of 21.2 % at 420 nm. This high photocatalytic H2 -production activity is due to the deposition of CdS nanorods on layered WS2 /graphene sheets, which can efficiently suppress charge recombination, improve interfacial charge transfer, and provide reduction active sites. The proposed mechanism for the enhanced photocatalytic activity of CdS nanorods modified with hierarchical layered WG was further confirmed by transient photocurrent response. This work shows that a noble-metal-free hierarchical layered WS2 /graphene nanosheets hybrid can be used as an effective co-catalyst for photocatalytic water splitting. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The Level of AdpA Directly Affects Expression of Developmental Genes in Streptomyces coelicolor ▿ †

    OpenAIRE

    Wolański, Marcin; Donczew, Rafał; Kois-Ostrowska, Agnieszka; Masiewicz, Paweł; Jakimowicz, Dagmara; Zakrzewska-Czerwińska, Jolanta

    2011-01-01

    AdpA is a key regulator of morphological differentiation in Streptomyces. In contrast to Streptomyces griseus, relatively little is known about AdpA protein functions in Streptomyces coelicolor. Here, we report for the first time the translation accumulation profile of the S. coelicolor adpA (adpASc) gene; the level of S. coelicolor AdpA (AdpASc) increased, reaching a maximum in the early stage of aerial mycelium formation (after 36 h), and remained relatively stable for the next several hour...

  17. Deletion of the signalling molecule synthase ScbA has pleiotropic effects on secondary metabolite biosynthesis, morphological differentiation and primary metabolism in Streptomyces coelicolor A3(2)

    NARCIS (Netherlands)

    D'Alia, Davide; Eggle, D.; Nieselt, K.; Hu, W.-S.; Breitling, R.; Takano, E.

    2011-01-01

    Streptomycetes have high biotechnological relevance as producers of diverse metabolites widely used in medical and agricultural applications. The biosynthesis of these metabolites is controlled by signalling molecules, gamma-butyrolactones, that act as bacterial hormones. In Streptomyces coelicolor,

  18. Crystal Structure of the Zorbamycin-Binding Protein ZbmA, the Primary Self-Resistance Element in Streptomyces flavoviridis ATCC21892

    Energy Technology Data Exchange (ETDEWEB)

    Rudolf, Jeffrey D. [Scripps Research Inst., Jupiter, FL (United States); Bigelow, Lance [Argonne National Lab. (ANL), Argonne, IL (United States); Chang, Changsoo [Argonne National Lab. (ANL), Argonne, IL (United States); Cuff, Marianne E. [Argonne National Lab. (ANL), Argonne, IL (United States); Lohman, Jeremy R. [Scripps Research Inst., Jupiter, FL (United States); Chang, Chin-Yuan [Scripps Research Inst., Jupiter, FL (United States); Ma, Ming [Scripps Research Inst., Jupiter, FL (United States); Yang, Dong [Scripps Research Inst., Jupiter, FL (United States); Clancy, Shonda [Argonne National Lab. (ANL), Argonne, IL (United States); Babnigg, Gyorgy [Argonne National Lab. (ANL), Argonne, IL (United States); Joachimiak, Andrzej [Argonne National Lab. (ANL), Argonne, IL (United States); Phillips, George N. [Rice Univ., Houston, TX (United States); Shen, Ben [Scripps Research Inst., Jupiter, FL (United States)

    2015-11-17

    The bleomycins (BLMs), tallysomycins (TLMs), phleomycin, and zorbamycin (ZBM) are members of the BLM family of glycopeptide-derived antitumor antibiotics. The BLM-producing Streptomyces verticillus ATCC15003 and the TLM-producing Streptoalloteichus hindustanus E465-94 ATCC31158 both possess at least two self-resistance elements, an N-acetyltransferase and a binding protein. The N-acetyltransferase provides resistance by disrupting the metal-binding domain of the antibiotic that is required for activity, while the binding protein confers resistance by sequestering the metal-bound antibiotic and preventing drug activation via molecular oxygen. We recently established that the ZBM producer, Streptomyces flavoviridis ATCC21892, lacks the N-acetyltransferase resistance gene and that the ZBM-binding protein, ZbmA, is sufficient to confer resistance in the producing strain. To investigate the resistance mechanism attributed to ZbmA, we determined the crystal structures of apo and Cu(II)-ZBM-bound ZbmA at high resolutions of 1.90 and 1.65 angstrom, respectively. A comparison and contrast with other structurally characterized members of the BLM-binding protein family revealed key differences in the protein ligand binding environment that fine-tunes the ability of ZbmA to sequester metal-bound ZBM and supports drug sequestration as the primary resistance mechanism in the producing organisms of the BLM family of antitumor antibiotics.

  19. Biosynthesis of Tropolones in Streptomyces spp: Interweaving Biosynthesis and Degradation of Phenylacetic Acid and Hydroxylations on Tropone Ring.

    Science.gov (United States)

    Chen, Xuefei; Xu, Min; Lü, Jin; Xu, Jianguo; Wang, Yemin; Lin, Shuangjun; Deng, Zixin; Tao, Meifeng

    2018-04-13

    Tropolonoids are important natural products that contain a unique seven-membered aromatic tropolone core and exhibit remarkable biological activities. 3,7-Dihydroxytropolone (DHT) isolated from Streptomyces species is a multiply hydroxylated tropolone exhibiting antimicrobial, anticancer, and antiviral activities. Herein, we determined the DHT biosynthetic pathway by heterologous expression, gene deletion, and bioconversion. Nine trl genes and some of the aerobic phenylacetic acid degradation pathway genes ( paa ) located outside of the trl biosynthetic gene cluster are required for the heterologous production of DHT. The trlA gene encodes a single-domain protein homologous to the C-terminal enoyl-CoA hydratase domain of PaaZ. TrlA truncates the phenylacetic acid catabolic pathway and redirects it towards the formation of heptacyclic intermediates. TrlB is a 3-deoxy-D-arabino-heptulosonic acid-7-phosphate (DAHP) synthase homolog. TrlH is an unusual bifunctional protein bearing an N-terminal prephenate dehydratase domain and a C-terminal chorismate mutase domain. TrlB and TrlH enhanced de novo biosynthesis of phenylpyruvate, thereby providing abundant precursor for the prolific production of DHT in Streptomyces Six seven-membered carbocyclic compounds were identified from the gene deletion mutants of trlC , trlD , trlE , and trlF Four of these chemicals, including 1,4,6-cycloheptatriene-1-carboxylic acid, tropone, tropolone and 7-hydroxytropolone, were verified as key biosynthetic intermediates. TrlF is required for the conversion of 1,4,6-cycloheptatriene-1-carboxylic acid into tropone. Monooxygenases TrlE and TrlCD catalyze the regioselective hydroxylations of tropone to afford DHT. This study reveals a natural association of anabolism of chorismate and phenylpyruvate, catabolism of phenylacetic acid, and biosynthesis of tropolones in Streptomyces spp. IMPORTANCE Tropolonoids are promising drug lead compounds because of their versatile bioactivities attributed to

  20. Haploinsufficiency of BAZ1B contributes to Williams syndrome through transcriptional dysregulation of neurodevelopmental pathways.

    Science.gov (United States)

    Lalli, Matthew A; Jang, Jiwon; Park, Joo-Hye C; Wang, Yidi; Guzman, Elmer; Zhou, Hongjun; Audouard, Morgane; Bridges, Daniel; Tovar, Kenneth R; Papuc, Sorina M; Tutulan-Cunita, Andreea C; Huang, Yadong; Budisteanu, Magdalena; Arghir, Aurora; Kosik, Kenneth S

    2016-04-01

    Williams syndrome (WS) is a neurodevelopmental disorder caused by a genomic deletion of ∼28 genes that results in a cognitive and behavioral profile marked by overall intellectual impairment with relative strength in expressive language and hypersocial behavior. Advancements in protocols for neuron differentiation from induced pluripotent stem cells allowed us to elucidate the molecular circuitry underpinning the ontogeny of WS. In patient-derived stem cells and neurons, we determined the expression profile of the Williams-Beuren syndrome critical region-deleted genes and the genome-wide transcriptional consequences of the hemizygous genomic microdeletion at chromosome 7q11.23. Derived neurons displayed disease-relevant hallmarks and indicated novel aberrant pathways in WS neurons including over-activated Wnt signaling accompanying an incomplete neurogenic commitment. We show that haploinsufficiency of the ATP-dependent chromatin remodeler, BAZ1B, which is deleted in WS, significantly contributes to this differentiation defect. Chromatin-immunoprecipitation (ChIP-seq) revealed BAZ1B target gene functions are enriched for neurogenesis, neuron differentiation and disease-relevant phenotypes. BAZ1B haploinsufficiency caused widespread gene expression changes in neural progenitor cells, and together with BAZ1B ChIP-seq target genes, explained 42% of the transcriptional dysregulation in WS neurons. BAZ1B contributes to regulating the balance between neural precursor self-renewal and differentiation and the differentiation defect caused by BAZ1B haploinsufficiency can be rescued by mitigating over-active Wnt signaling in neural stem cells. Altogether, these results reveal a pivotal role for BAZ1B in neurodevelopment and implicate its haploinsufficiency as a likely contributor to the neurological phenotypes in WS. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Sensor combination and chemometric variable selection for online monitoring of Streptomyces coelicolor fed-batch cultivations

    DEFF Research Database (Denmark)

    Ödman, Peter; Johansen, C.L.; Olsson, L.

    2010-01-01

    of biomass and substrate (casamino acids) concentrations, respectively. The effect of combination of fluorescence and gas analyzer data as well as of different variable selection methods was investigated. Improved prediction models were obtained by combination of data from the two sensors and by variable......Fed-batch cultivations of Streptomyces coelicolor, producing the antibiotic actinorhodin, were monitored online by multiwavelength fluorescence spectroscopy and off-gas analysis. Partial least squares (PLS), locally weighted regression, and multilinear PLS (N-PLS) models were built for prediction...

  2. SIGNALS AND REGULATORS THAT GOVERN STREPTOMYCES DEVELOPMENT

    Science.gov (United States)

    McCormick, Joseph R.; Flärdh, Klas

    2012-01-01

    Streptomyces coelicolor is the genetically best characterized species of a populous genus belonging to the Gram-positive Actinobacteria. Streptomycetes are filamentous soil organisms, well known for the production of a plethora of biologically active secondary metabolic compounds. The Streptomyces developmental life cycle is uniquely complex, and involves coordinated multicellular development with both physiological and morphological differentiation of several cell types, culminating in production of secondary metabolites and dispersal of mature spores. This review presents a current appreciation of the signaling mechanisms used to orchestrate the decision to undergo morphological differentiation, and the regulators and regulatory networks that direct the intriguing development of multigenomic hyphae, first to form specialized aerial hyphae, and then to convert them into chains of dormant spores. This current view of S. coelicolor development is destined for rapid evolution as data from “-omics” studies shed light on gene regulatory networks, new genetic screens identify hitherto unknown players, and the resolution of our insights into the underlying cell biological processes steadily improve. PMID:22092088

  3. Oxalic acid biosynthesis and oxalacetate acetylhydrolase activity in Streptomyces cattleya

    International Nuclear Information System (INIS)

    Houck, D.R.; Inamine, E.

    1987-01-01

    In addition to producing the antibiotic thienamycin, Streptomyces cattleya accumulates large amounts of oxalic acid during the course of a fermentation. Washed cell suspensions were utilized to determine the specific incorporation of carbon-14 into oxalate from a number of labeled organic and amino acids. L-[U- 14 C]aspartate proved to be the best precursor, whereas only a small percentage of label from [1,5- 14 C]citrate was found in oxalate. Cell-free extracts catalyzed the formation of [ 14 C]oxalate and [ 14 C]acetate from L-[U- 14 C]aspartate. When L-[4- 14 C]aspartate was the substrate only [ 14 C]acetate was formed. The cell-free extracts were found to contain oxalacetate acetylhydrolase, the enzyme that catalyzes the hydrolysis of oxalacetate to oxalate and acetate. The enzyme is constitutive and is analogous to enzymes in fungi that produce oxalate from oxalacetate. Properties of the crude enzyme were examined

  4. Formalizing WS-BPEL and Higher Order Mobile Embedded Business Processes in the Bigraphical Programming Languages (BPL) Tool

    DEFF Research Database (Denmark)

    Bundgaard, Mikkel; Glenstrup, Arne John; Hildebrandt, Thomas

    is the starting point of an endeavor to provide a completely formalized and extensible business process engine within the Computer Supported Mobile Adaptive Business Processes (CosmoBiz) research project at the IT University of Copenhagen. Building upon the formalization of WS-BPEL we propose and formalize Home......BPEL, a higher-order WS-BPEL-like business process execution language where processes are first-class values that can be stored in variables, passed as messages, and activated as embedded sub-instances. A sub-instance is similar to a WS-BPEL scope, except that it can be dynamically frozen and stored as a process...

  5. Structural and Chemical Analysis of Gadolinium Halides Encapsulated within WS 2 Nanotubes

    KAUST Repository

    Anumol, E A

    2016-05-18

    The hollow cavities of nanotubes could serve as templates for the growth of size- and shape-confined functional nanostructures, giving rise to novel materials and properties. In this work, considering their potential application as MRI contrast agents, gadolinium halides are encapsulated within the hollow cavities of inorganic nanotubes of WS2 by capillary filling to obtain GdX3@WS2 nanotubes (where X = Cl, Br or I and @ means encapsulated in). Aberration corrected scanning/transmission electron microscopy (S/TEM) and spectroscopy is employed to understand the morphology and composition of the GdI3@WS2 nanotubes. The three dimensional morphology is studied with STEM tomography but understanding the compositional information is a non-trivial matter due to the presence of multiple high atomic number elements. Therefore, energy dispersive X-ray spectroscopy (EDS) tomography was employed revealing the three dimensional chemical composition. Molecular dynamics simulations of the filling procedure shed light into the mechanics behind the formation of the confined gadolinium halide crystals. The quasi-1D system employed here serves as an example of a TEM-based chemical nanotomography method that could be extended to other materials, including beam-sensitive soft materials.

  6. Structural and Chemical Analysis of Gadolinium Halides Encapsulated within WS 2 Nanotubes

    KAUST Repository

    Anumol, E A; Enyashin, Andrey; Batra, Nitin M; Da Costa, Pedro M. F. J.; Francis, Leonard Deepak

    2016-01-01

    The hollow cavities of nanotubes could serve as templates for the growth of size- and shape-confined functional nanostructures, giving rise to novel materials and properties. In this work, considering their potential application as MRI contrast agents, gadolinium halides are encapsulated within the hollow cavities of inorganic nanotubes of WS2 by capillary filling to obtain GdX3@WS2 nanotubes (where X = Cl, Br or I and @ means encapsulated in). Aberration corrected scanning/transmission electron microscopy (S/TEM) and spectroscopy is employed to understand the morphology and composition of the GdI3@WS2 nanotubes. The three dimensional morphology is studied with STEM tomography but understanding the compositional information is a non-trivial matter due to the presence of multiple high atomic number elements. Therefore, energy dispersive X-ray spectroscopy (EDS) tomography was employed revealing the three dimensional chemical composition. Molecular dynamics simulations of the filling procedure shed light into the mechanics behind the formation of the confined gadolinium halide crystals. The quasi-1D system employed here serves as an example of a TEM-based chemical nanotomography method that could be extended to other materials, including beam-sensitive soft materials.

  7. Streptomyces xiangtanensis sp. nov., isolated from a manganese-contaminated soil.

    Science.gov (United States)

    Mo, Ping; Yu, Yi-Zun; Zhao, Jia-Rong; Gao, Jian

    2017-03-01

    An actinomycete strain, designated strain LUSFXJ T , was isolated from a soil sample obtained near the Xiangtan Manganese Mine, Central-South China and characterised using a polyphasic taxonomic approach. The 16S rRNA gene sequence-based phylogenetic analysis indicated that this strain belongs to the genus Streptomyces. The DNA-DNA relatedness between this strain and two closely related type strains, Streptomyces echinatus CGMCC 4.1642 T and Streptomyces lanatus CGMCC 4.137 T , were 28.7 ± 0.4 and 19.9 ± 2.0%, respectively, values which are far lower than the 70% threshold for the delineation of a novel prokaryotic species. The DNA G+C content of strain LUSFXJ T is 75.0 mol%. Chemotaxonomic analysis revealed that the menaquinones of strain LUSFXJ T are MK-9(H 6 ), MK-9(H 8 ), MK-9(H 2 ) and MK-8(H 8 ). The polar lipid profile of strain LUSFXJ T was found to contain diphosphatidylglycerol and an unidentified polar lipid. The major cellular fatty acids were identified as iso-C 15:0 , anteiso-C 15:0 , iso-C 16:0 , C 16:0 and Summed feature 3. Strain LUSFXJ T was found to contain meso-diaminopimelic acid as the diagnostic cell wall diamino acid and the whole cell hydrolysates were found to be rich in ribose, mannose and glucose. Based on phenotypic, phylogenetic and chemotaxonomic characteristics, it is concluded that strain LUSFXJ T represents a novel species of the genus Streptomyces, for which the name S. xiangtanensis sp. nov. is proposed. The type strain is LUSFXJ T (=GDMCC 4.133 T  = KCTC 39829 T ).

  8. Production of diketopiperazine derivative cyclo (l-leu-l-arg) by streptomyces sp. tn262 after exposure to heat-killed fungus fusarium sp

    International Nuclear Information System (INIS)

    Elleuch, L.; Smaoui, S.; Najah, S.; Sellem, I

    2013-01-01

    In a screening program for new active secondary metabolites producers, a strain of Streptomyces called TN262 was isolated from Tunisian soil and selected for its ability to produce eleven active compounds in pure culture conditions. In this work, the effect of different concentrations of heat-killed fungus Fusarium sp. on the production of active compounds by TN262 strain was studied. The ethyl acetate extract from the culture of Streptomyces sp. TN262 combined with heat-killed Fusarium sp. at 50 micro g/ml inhibited the growth of the three used indicator microorganisms. In fact, an increase of 36%, 21% and 20% in inhibitory activity was obtained against Micrococcus luteus LB 14110, Escherichia coli ATCC 8739 and Fusarium sp. respectively. The HPLC chromatographic profiles of the ethyl acetate extracts from both culture conditions were different and an additional active compound was produced only under induced conditions. This active component was isolated and identified as Cyclo (L-Leu-L-Arg) (1), a diketopiperazine derivative, possessing antibacterial and antifungal activity. Consequently, this study showed that the addition of heat-killed fungus is a useful method for inducing the production of bioactive compounds. (author)

  9. Strain engineering of WS2, WSe2, and WTe2

    KAUST Repository

    Amin, Bin; Kaloni, Thaneshwor P.; Schwingenschlö gl, Udo

    2014-01-01

    We perform first-principles calculations to investigate the structural, electronic, and vibrational properties of WS2, WSe2, and WTe2 monolayers, taking into account the strong spin orbit coupling. A transition from a direct to an indirect band gap

  10. Elimination of indigenous linear plasmids in Streptomyces hygroscopicus var. jinggangensis and Streptomyces sp. FR008 to increase validamycin A and candicidin productivities.

    Science.gov (United States)

    Lu, Chenyang; Wu, Hang; Su, Xiurong; Bai, Linquan

    2017-05-01

    Giant linear plasmids, which replicate independently of the chromosomes, widely exist in actinobacteria. Previous studies mostly focused on the replication and evolution of the linear plasmids or the secondary metabolite gene clusters and the resistance gene clusters therein. However, the relationships of the linear plasmids to the productivities of secondary metabolites have not been studied. In this work, we developed a method to eliminate the indigenous linear plasmid pSHJG1 in Streptomyces hygroscopicus var. jinggangensis, and validamycin A titer increased by 12.5% (from 19.16 ± 1.93 to 21.56 ± 2.25 g/L) in the high-yielding strain TL01 and 43.7% (from 4.67 ± 0.05 to 6.71 ± 0.21 g/L) in the wild-type strain 5008, whereas the cellular growth of the plasmid-cured mutant was reduced. Subsequently, the plasmid-cured mutant was complemented with three structure genes involved in cellular growth in pSHJG1 under the control of a strong PvalA promoter. Among them, the complementation of genes pSHJG1.069 and pSHJG1.072, encoding a putative hydrolase and putative P-loop ATPase, respectively, resulted in the restoration of cellular growth and validamycin A titer. Furthermore, the elimination of indigenous linear plasmid pHZ228 in the candicidin producer Streptomyces sp. FR008 also led to enhanced candicidin production and reduced cellular growth. Because of the wide distribution of indigenous linear plasmids in actinobacteria, the engineering strategy described here could be implemented in a variety of strains for the overproduction of various natural products.

  11. EFEKTIFITAS DAYA HAMBAT BAKTERI Streptomyces sp TERHADAP Erwinia sp PENYEBAB PENYAKIT BUSUK REBAH PADA TANAMAN LIDAH BUAYA (Aloe barbadensis Mill

    Directory of Open Access Journals (Sweden)

    SARMILA TASNIM

    2013-05-01

    Full Text Available Streptomyces sp was conducted from December 2010 - June 2011 at the Laboratoryof Microbiology, Biology Department, Math and Science Faculty, UdayanaUniversity Bukit Jimbaran-Bali. Implementation stages of the research consisted ofisolation and testing of the antibiotic activity Streptomyces sp to inhibit growthbacterial pathogens Erwinia sp as a cause of disease in plants fallen foul (Soft rot ofAloe barbadensis Mill.The results of this study have eight isolates of Streptomyces spwith macroscopic and microscopic characters are varied. Furthermore, all isolateswere obtained and then tested against antibiotic activity to inhibit growth the bacteriaErwinia sp. Test results obtained by Streptomyces sp that has the most effective ininhibiting the ability of the bacteria Erwinia sp isolates are Streptomyces sp2for (45%.

  12. Streptomyces sp. MC10 SUŞUNUN ALFA AMİLAZ ÜRETİM KABİLİYETİNİN BELİRLENMESİ - DETERMINATION OF ABILITY OF ALPHA AMYLASE PRODUCTION BY Streptomyces sp. MC10 STRAIN

    OpenAIRE

    ÖZDEMİR, Ali; SIDAL, Uğur

    2013-01-01

    Streptomyces sp. MC10 SUŞUNUN ALFA AMİLAZ ÜRETİM KABİLİYETİNİN BELİRLENMESİAmilazlar en önemli endüstriyel enzimlerden biridir. Amilaz üreticisi olan Streptomyces MC10 suşu Manisa Celal Bayar Üniversitesinden alınan toprak örneklerinden izole edilmiştir. Bu çalışmada Streptomyces MC10 suşundan α-amilaz üretimi ve karakterizasyonu gerçekleştirilmiştir. Bu amaçla suşun besiyerinde üremesi ve α-amilaz üretme yeteneği ve aktivite gösterdiği optimum sıcaklık, pH, inkübasyon süresi ve substrat kons...

  13. Utilizing Interlayer Excitons in Bilayer WS2 for Increased Photovoltaic Response in Ultrathin Graphene Vertical Cross-Bar Photodetecting Tunneling Transistors.

    Science.gov (United States)

    Zhou, Yingqiu; Tan, Haijie; Sheng, Yuewen; Fan, Ye; Xu, Wenshuo; Warner, Jamie H

    2018-04-19

    Here we study the layer-dependent photoconductivity in Gr/WS 2 /Gr vertical stacked tunneling (VST) cross-bar devices made using two-dimensional (2D) materials all grown by chemical vapor deposition. The larger number of devices (>100) enables a statistically robust analysis on the comparative differences in the photovoltaic response of monolayer and bilayer WS 2 , which cannot be achieved in small batch devices made using mechanically exfoliated materials. We show a dramatic increase in photovoltaic response for Gr/WS 2 (2L)/Gr compared to monolayers because of the long inter- and intralayer exciton lifetimes and the small exciton binding energy (both interlayer and intralayer excitons) of bilayer WS 2 compared with that of monolayer WS 2 . Different doping levels and dielectric environments of top and bottom graphene electrodes result in a potential difference across a ∼1 nm vertical device, which gives rise to large electric fields perpendicular to the WS 2 layers that cause band structure modification. Our results show how precise control over layer number in all 2D VST devices dictates the photophysics and performance for photosensing applications.

  14. Enhanced production and application of acidothermophilic Streptomyces cellulase.

    Science.gov (United States)

    Budihal, Saikumar R; Agsar, Dayanand; Patil, Sarvamangala R

    2016-01-01

    An efficient cellulolytic and acidothermophilic actinobacterium was isolated from soil, adhered to decomposing tree bark and was identified as Streptomyces DSK59. Screening of synthetic media and the media components identified that, a medium based on starch casein minerals containing carboxy methyl cellulose (CMC) and beef extract (BE) could support enhanced cellulase production by the organism. CMC, BE, NaCl, temperature and pH were accounted as significant for cellulase production and these were optimized using a response surface central composite design (CCD). Optimization of cellulase production resulted in an enhancement of endoglucanase activity to 27IUml(-1). Acidothermophillic Streptomyces cellulase was found to be efficient for hydrolysis of pretreated sorghum stover and liberated 0.413gg(-1) of total reducing sugars which was higher than previously reported sugar yields obtained using fungal enzymes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Streptomyces lunalinharesii 235 prevents the formation of a sulfate-reducing bacterial biofilm

    Directory of Open Access Journals (Sweden)

    Juliana Pacheco da Rosa

    Full Text Available ABSTRACT Streptomyces lunalinharesii strain 235 produces an antimicrobial substance that is active against sulfate reducing bacteria, the major bacterial group responsible for biofilm formation and biocorrosion in petroleum reservoirs. The use of this antimicrobial substance for sulfate reducing bacteria control is therefore a promising alternative to chemical biocides. In this study the antimicrobial substance did not interfere with the biofilm stability, but the sulfate reducing bacteria biofilm formation was six-fold smaller in carbon steel coupons treated with the antimicrobial substance when compared to the untreated control. A reduction in the most probable number counts of planktonic cells of sulfate reducing bacteria was observed after treatments with the sub-minimal inhibitory concentration, minimal inhibitory concentration, and supra-minimal inhibitory concentration of the antimicrobial substance. Additionally, when the treated coupons were analyzed by scanning electron microscopy, the biofilm formation was found to be substantially reduced when the supra-minimal inhibitory concentration of the antimicrobial substance was used. The coupons used for the biofilm formation had a small weight loss after antimicrobial substance treatment, but corrosion damage was not observed by scanning electron microscopy. The absence of the dsrA gene fragment in the scraped cell suspension after treatment with the supra-minimal inhibitory concentration of the antimicrobial substance suggests that Desulfovibrio alaskensis was not able to adhere to the coupons. This is the first report on an antimicrobial substance produced by Streptomyces active against sulfate reducing bacteria biofilm formation. The application of antimicrobial substance as a potential biocide for sulfate reducing bacteria growth control could be of great interest to the petroleum industry.

  16. Streptomyces Somalinesiscausing Mycetomas in South India

    Directory of Open Access Journals (Sweden)

    V V Taralakshmi

    1982-01-01

    Full Text Available Biopsy specimens from 102 patients with mycetoma were examined histologically; Streptomyces somaliensis was found in 5 cases. The clinical features, radiology and histology of actinomycotic mycetoma due to S. somaliensis ar ′ e described. The geographic distribution of the organism, its incidence and prevalence in India and the importance of histological examination in the diagnosis of the infection are discussed.

  17. Nutrient use preferences among soil Streptomyces suggest greater resource competition in monoculture than polyculture plant communities

    Science.gov (United States)

    Nutrient use overlap among sympatric Streptomyces populations is correlated with pathogen inhibitory capacity, yet there is little information on either the factors that influence nutrient use overlap among coexisting populations or the diversity of nutrient use among soil Streptomyces. We examined ...

  18. Water stable isotope measurements of Antarctic samples by means of IRMS and WS-CRDS techniques

    Science.gov (United States)

    Michelini, Marzia; Bonazza, Mattia; Braida, Martina; Flora, Onelio; Dreossi, Giuliano; Stenni, Barbara

    2010-05-01

    of the sample in the box. In the WS-CRDS the path of laser is longer, producing higher-sensitivity measurements. The instrument is paired with an autosampler and can be used without it and the vaporizer to analyze directly the isotopic composition of the water vapour in the atmosphere. In addition, the instrument can be moved from the laboratory and also used for outdoor measurements. The more important improvements over traditional IRMS techniques are that WS-CRDS needs less sample in order to perform the analysis (water equilibration techniques) and the analyses are faster. Coversely, memory effects may affect the measurements so there is the need to increase the number of injection to have a high precision measurement. The laboratory of Isotope Geochemistry of the Department of Geosciences has recently acquired a WS-CRDS system from PICARRO. The isotopic data obtained with this new method have been compared with the ones obtained by means of IRMS methods. An HDO device coupled with a Thermo Finnigan Delta Plus Advantage mass spectrometer has been used, using the well know CO2 and H2/water equilibration technique. At the moment of the writing of the abstract the mean difference between the values obtained using PICARRO and using the traditional IRMS method is of the order of 0.1 per mil for the ratio 18O/16O and 1.00 per mil for the ratio D/H, but further measurements are currently underway. O'Keef A., Deacon D.A.G., 1988. Cavity ring-down optical spectrometer for absorption measurements using pulsed laser sources, Rev. Sci. Instrum., 59, 2544.

  19. Improvement of transformation efficiency by strategic circumvention of restriction barriers in Streptomyces griseus.

    Science.gov (United States)

    Suzuki, Hirokazu; Takahashi, Shunji; Osada, Hiroyuki; Yoshida, Ken-Ichi

    2011-07-01

    DNA methylation in Streptomyces griseus IFO 13350 was analyzed by high-performance liquid chromatographic analysis and bisulfite-based analysis to reveal two methylation sites, 5'-GC5mCGGC-3' and 5'-GAG5mCTC-3'. The methylation was reconstituted in Escherichia coli by simultaneous expression of S. griseus SGR4675 and S. achromogenes M.SacI. The E. coli cells produced plasmids that mimicked the methylation profile of S. griseus DNA, which was readily introduced into S. griseus. The results of this study raise the possibility of a promising approach to establish efficient transformation in several streptomycetes.

  20. Cycloheximide congeners produced by Streptomyces sp. SC0581 and photoinduced interconversion between (E- and (Z-2,3-dehydroanhydrocycloheximides

    Directory of Open Access Journals (Sweden)

    Li Yang

    2017-05-01

    Full Text Available Three new cycloheximide congeners, 2,3-dehydro-α-epi-isocycloheximide (1, (E- and (Z-2,3-dehydroanhydrocycloheximides (2 and 3, together with three known compounds, anhydroisoheximide (4, cycloheximide (5, and isocycloheximide (6, were obtained from the cultures of Streptomyces sp. SC0581. Their structures were elucidated by extensive spectroscopic analysis in combination with theoretical conformational analysis and ECD computations. The photoinduced interconversion between 2 and 3 was observed and verified and the possible reaction path and mechanism were proposed by theoretical computations. The antifungal and cytotoxic activities of 1–6 were evaluated and suggested that 2,3-dehydrogenation results in the loss of the activities and supported that the OH-α is important to the activities of cycloheximide congeners.

  1. Amide-transforming activity of Streptomyces: possible application to the formation of hydroxy amides and aminoalcohols.

    Science.gov (United States)

    Yamada, Shinya; Miyagawa, Taka-Aki; Yamada, Ren; Shiratori-Takano, Hatsumi; Sayo, Noboru; Saito, Takao; Takano, Hideaki; Beppu, Teruhiko; Ueda, Kenji

    2013-07-01

    To develop an efficient bioconversion process for amides, we screened our collection of Streptomyces strains, mostly obtained from soil, for effective transformers. Five strains, including the SY007 (NBRC 109343) and SY435 (NBRC 109344) of Streptomyces sp., exhibited marked conversion activities from the approximately 700 strains analyzed. These strains transformed diverse amide compounds such as N-acetyltetrahydroquinoline, N-benzoylpyrrolidine, and N-benzoylpiperidine into alcohols or N,O-acetals with high activity and regioselectivity. N,O-acetal was transformed into alcohol by serial tautomerization and reduction reactions. As such, Streptomyces spp. can potentially be used for the efficient preparation of hydroxy amides and aminoalcohols.

  2. Structuring Pd Nanoparticles on 2H-WS2 Nanosheets Induces Excellent Photocatalytic Activity for Cross-Coupling Reactions under Visible Light.

    Science.gov (United States)

    Raza, Faizan; Yim, DaBin; Park, Jung Hyun; Kim, Hye-In; Jeon, Su-Ji; Kim, Jong-Ho

    2017-10-18

    Effective photocatalysts and their surface engineering are essential for the efficient conversion of solar energy into chemical energy in photocatalyzed organic transformations. Herein, we report an effective approach for structuring Pd nanoparticles (NPs) on exfoliated 2H-WS 2 nanosheets (WS 2 /PdNPs), resulting in hybrids with extraordinary photocatalytic activity in Suzuki reactions under visible light. Pd NPs of different sizes and densities, which can modulate the photocatalytic activity of the as-prepared WS 2 /PdNPs, were effectively structured on the basal plane of 2H-WS 2 nanosheets via a sonic wave-assisted nucleation method without any reductants at room temperature. As the size of Pd NPs on WS 2 /PdNPs increased, their photocatalytic activity in Suzuki reactions at room temperature increased substantially. In addition, it was found that protic organic solvents play a crucial role in activating WS 2 /PdNPs catalysts in photocatalyzed Suzuki reactions, although these solvents are generally considered much less effective than polar aprotic ones in the conventional Suzuki reactions promoted by heterogeneous Pd catalysts. A mechanistic investigation suggested that photogenerated holes are transferred to protic organic solvents, whereas photogenerated electrons are transferred to Pd NPs. This transfer makes the Pd NPs electron-rich and accelerates the rate-determining step, i.e., the oxidative addition of aryl halides under visible light. WS 2 /PdNPs showed the highest turnover frequency (1244 h -1 ) for photocatalyzed Suzuki reactions among previously reported photocatalysts.

  3. Structure of a putative fluorinated natural product from Streptomyces sp. TC1.

    Science.gov (United States)

    Aldemir, Hülya; Kohlhepp, Stefanie V; Gulder, Tanja; Gulder, Tobias A M

    2014-11-26

    Fluorine-containing natural products are extremely rare. The recent report on the isolation and biological activity of the bacterial secondary metabolite 3-(3,5-di-tert-butyl-4-fluorophenyl)propionic acid was thus highly remarkable. The compound contained the first aromatic fluorine substituent known to date in any natural product. The promise to discover an enzyme capable of aromatic fluorination in the producing strain Streptomyces sp. TC1 prompted our immediate interest. A close inspection of the originally reported analytical data of the fluoro metabolite revealed inconsistencies that triggered us to validate the reported structure. The results of these efforts are presented in this communication.

  4. Clavulanic acid production by the MMS 150 mutant obtained from wild type Streptomyces clavuligerus ATCC 27064

    Directory of Open Access Journals (Sweden)

    Eliton da Silva Vasconcelos

    2013-12-01

    Full Text Available Clavulanic acid (CA is a powerful inhibitor of the beta-lactamases, enzymes produced by bacteria resistants to penicillin and cefalosporin. This molecule is produced industrially by strains of Streptomyces clavuligerus in complex media which carbon and nitrogen resources are supplied by inexpensive compounds still providing high productivity. The genetic production improvement using physical and chemical mutagenic agents is an important strategy in programs of industrial production development of bioactive metabolites. However, parental strains are susceptible to loss of their original productivity due genetic instability phenomenona. In this work, some S. clavuligerus mutant strains obtained by treatment with UV light and with MMS are compared with the wild type (Streptomyces clavuligerus ATCC 27064. The results indicated that the random mutations originated some strains with different phenotypes, most divergent demonstrated by the mutants strains named AC116, MMS 150 and MMS 54, that exhibited lack of pigmentation in their mature spores. Also, the strain MMS 150 presented a larger production of CA when cultivated in semi-synthetics media. Using other media, the wild type strain obtained a larger CA production. Besides, using the modifed complex media the MMS 150 strain showed changes in its lipolitic activity and a larger production of CA. The studies also allowed finding the best conditions for a lipase activity exhibited by wild type S. clavuligerus and the MMS150 mutant.

  5. Clavulanic acid production by the MMS 150 mutant obtained from wild type Streptomyces clavuligerus ATCC 27064.

    Science.gov (United States)

    da Silva Vasconcelos, Eliton; de Lima, Vanderlei Aparecido; Goto, Leandro Seiji; Cruz-Hernández, Isara Lourdes; Hokka, Carlos Osamu

    2013-12-01

    Clavulanic acid (CA) is a powerful inhibitor of the beta-lactamases, enzymes produced by bacteria resistants to penicillin and cefalosporin. This molecule is produced industrially by strains of Streptomyces clavuligerus in complex media which carbon and nitrogen resources are supplied by inexpensive compounds still providing high productivity. The genetic production improvement using physical and chemical mutagenic agents is an important strategy in programs of industrial production development of bioactive metabolites. However, parental strains are susceptible to loss of their original productivity due genetic instability phenomenona. In this work, some S. clavuligerus mutant strains obtained by treatment with UV light and with MMS are compared with the wild type (Streptomyces clavuligerus ATCC 27064). The results indicated that the random mutations originated some strains with different phenotypes, most divergent demonstrated by the mutants strains named AC116, MMS 150 and MMS 54, that exhibited lack of pigmentation in their mature spores. Also, the strain MMS 150 presented a larger production of CA when cultivated in semi-synthetics media. Using other media, the wild type strain obtained a larger CA production. Besides, using the modifed complex media the MMS 150 strain showed changes in its lipolitic activity and a larger production of CA. The studies also allowed finding the best conditions for a lipase activity exhibited by wild type S. clavuligerus and the MMS150 mutant.

  6. The construction of a library of synthetic promoters revealed some specific features of strong Streptomyces promoters

    DEFF Research Database (Denmark)

    Seghezzi, Nicolas; Amar, Patrick; Købmann, Brian

    2011-01-01

    Streptomyces are bacteria of industrial interest whose genome contains more than 73% of bases GC. In order to define, in these GC-rich bacteria, specific sequence features of strong promoters, a library of synthetic promoters of various sequence composition was constructed in Streptomyces. To do so...... cloned into the promoter-probe plasmid pIJ487 just upstream of the promoter-less aphII gene that confers resistance to neomycin. This synthetic promoter library was transformed into Streptomyces lividans, and the resulting transformants were screened for their ability to grow in the presence of different...... projects. Thirty-eight promoters were sequenced, and the sequences of the 14 weakest and 14 strongest promoters were compared using the WebLogo software with small sample correction. This comparison revealed that the −10 box, the −10 extended motif as well as the spacer of the strong Streptomyces promoters...

  7. Integration of the gUSE/WS-PGRADE and InSilicoLab portals with DIRAC

    International Nuclear Information System (INIS)

    Navarro, A Puig; Casals, D Viana; Díaz, R Graciani; Ramo, A Casajús; Á Balaskó; P Kacksuk; D Harezlak; J Kocot

    2012-01-01

    The gUSE (Grid User Support Environment) framework allows to create, store and distribute application workflows. This workflow architecture includes a wide variety of payload execution operations, such as loops, conditional execution of jobs and combination of output. These complex multi-job workflows can easily be created and modified by application developers through the WS-PGRADE portal. The portal also allows end users to download and use existing workflows, as well as executing them. The DIRAC framework for distributed computing, a complete Grid solution for a community of users needing access to distributed computing resources, has been integrated into the gUSE/WS-PGRADE system. This integration allows the execution of gUSE workflows in a distributed computing environment, thus greatly expanding the capability of the portal to several Grids and Cloud Computing facilities. The main features and possibilities of the gUSE/WS-PGRADE-DIRAC system, as well as the benefits for users, will be outlined and discussed.

  8. Biological control of anthracnose (Colletotrichum gloeosporioides) in yam by Streptomyces sp.MJM5763.

    Science.gov (United States)

    Palaniyandi, S A; Yang, S H; Cheng, J H; Meng, L; Suh, J-W

    2011-08-01

    To find a suitable biocontrol agent for yam anthracnose caused by Colletotrichum gloeosporioides. An actinobacterial strain, MJM5763, showing strong antifungal activity, multiple biocontrol and plant growth-promoting traits was isolated from a yam cultivation field in Yeoju, South Korea. Based on morphological and physiological characteristics and analysis of the 16S rDNA sequence, strain MJM5763 was identified as a novel strain of Streptomyces and was designated as Streptomyces sp. MJM5763. Treatment with MJM5763 and the crude culture filtrate extract (CCFE) was effective in suppressing anthracnose in detached yam leaves in vitro and reduced incidence and severity of anthracnose in yam plants under greenhouse conditions. The CCFE treatment was the most effective of all the treatments and reduced the anthracnose severity by 85-88% and the incidence by 79-81%, 90 days after inoculation with the pathogen. CCFE treatment was also effective under field conditions and showed a reduction of 86 and 75% of anthracnose severity and incidence, respectively. Streptomyces sp. strain MJM5763 was effective in biocontrolling anthracnose in yam caused by C. gloeosporioides. Streptomyces sp. MJM5763 is a potential alternative to chemical fungicides for reducing yield losses to anthracnose in yam. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  9. Performance analysis of WS-EWC coded optical CDMA networks with/without LDPC codes

    Science.gov (United States)

    Huang, Chun-Ming; Huang, Jen-Fa; Yang, Chao-Chin

    2010-10-01

    One extended Welch-Costas (EWC) code family for the wavelength-division-multiplexing/spectral-amplitude coding (WDM/SAC; WS) optical code-division multiple-access (OCDMA) networks is proposed. This system has a superior performance as compared to the previous modified quadratic congruence (MQC) coded OCDMA networks. However, since the performance of such a network is unsatisfactory when the data bit rate is higher, one class of quasi-cyclic low-density parity-check (QC-LDPC) code is adopted to improve that. Simulation results show that the performance of the high-speed WS-EWC coded OCDMA network can be greatly improved by using the LDPC codes.

  10. Optimization of medium for antimycotic production by Streptomyces spp.

    Directory of Open Access Journals (Sweden)

    Bajić Bojana Ž.

    2013-01-01

    Full Text Available Numerous species of the genus Streptomyces, on the appropriate cultivation medium in the process of submerged biosynthesis, as a product of the secondary metabolism, and under aerobic conditions synthesize pharmacologically active compounds. The aim of presented study was optimization of different nitrogen sources in the cultivation medium for the production of antimycotics using a strain of Streptomyces spp. isolated from the environment. Experiments were carried out in accordance with Box-Behnken design with three factors at three levels (peptone: 3.0 g/l, 7.0 g/l and 11.0 g/l; yeast extract: 1.0 g/l, 3.0 g/l and 5.0 g/l; soybean meal: 5.0 g/l, 15.0 g/l and 25.0 g/l and three repetitions in the central point. Cultivation mediums were analyzed for determination of residual sugar, residual nitrogen, pellet diameter and RNA. Also, antimycotic activity of the obtained culti­vation mediums was determined using diffusion disc method on the Aspergillus spp. as the test microorganism. For the optimization of selected parameters, a Response Surface Methodology was used and the obtained data were analyzed using the software package DESIGN EXPERT 8.1. Achieved model with a coefficient of determination (R of 0.952 predicted that the maximum inhibition zone diameter (24.0 mm against microorganism Aspergillus spp. and the minimum amount of residual sugar (0.551528 g/l under applied experimental conditions was produced when the contents of varied nitrogen sources were: peptone 11.0 g/l, yeast extract 4.32 g/l and soybean meal 25.00 g/l.

  11. Isolation of antimicrobial producing Actinobacteria from soil samples.

    Science.gov (United States)

    Elbendary, Afaf Ahmed; Hessain, Ashgan Mohamed; El-Hariri, Mahmoud Darderi; Seida, Ahmed Adel; Moussa, Ihab Mohamed; Mubarak, Ayman Salem; Kabli, Saleh A; Hemeg, Hassan A; El Jakee, Jakeen Kamal

    2018-01-01

    Emergence of multidrug resistant bacteria has made the search for novel bioactive compounds from natural and unexplored habitats a necessity. Actinobacteria have important bioactive substances. The present study investigated antimicrobial activity of Actinobacteria isolated from soil samples of Egypt. One hundred samples were collected from agricultural farming soil of different governorates. Twelve isolates have produced activity against the tested microorganisms ( S. aureus , Bacillus cereus , E. coli , K. pneumoniae , P. aeruginosa , S. Typhi, C. albicans , A. niger and A. flavus ). By VITEK 2 system version: 07.01 the 12 isolates were identified as Kocuria kristinae , Kocuria rosea , Streptomyces griseus , Streptomyces flaveolus and Actinobacteria . Using ethyl acetate extraction method the isolates culture's supernatants were tested by diffusion method against indicator microorganisms. These results indicate that Actinobacteria isolated from Egypt farms could be sources of antimicrobial bioactive substances.

  12. STREPTOMYCETE Producing Antibiotics Isolated From Egyptian Soil

    International Nuclear Information System (INIS)

    SALAMA, S.M; MAHMOUD, S.M; ELKABBANY, H.M.

    2010-01-01

    An investigation was concerned the distribution of Streptomyces species in some types of Egyptian soils. Thirty nine actinomycetes isolates were obtained from 7 types of Egyptian soils; 8 isolates exhibited antimicrobial activities against all tested organisms and three of them were identified as Streptomyces griseoluteus (YM23), Streptomyces aurantiogriseus (S15) and Streptomyces nogalator (H12). RAPD-PCR showed correlation between 8 isolates in 3 clades. The active metabolite was extracted with ethyl acetate and concentrated in vacuum and the crude fraction was purified using thin layer and column chromatography

  13. Formal semantics and analysis of control flow in WS-BPEL

    NARCIS (Netherlands)

    Ouyang, C.; Verbeek, H.M.W.; Aalst, van der W.M.P.; Breutel, S.; Dumas, M.; Hofstede, ter A.H.M.

    2007-01-01

    Web service composition refers to the creation of new (Web) services by combining functionalities provided by existing ones. A number of domain-specific languages for service composition have been proposed, with consensus being formed around a process-oriented language known as WS-BPEL (or BPEL).

  14. Identification of excitons, trions and biexcitons in single-layer WS{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Plechinger, Gerd; Nagler, Philipp; Kraus, Julia; Paradiso, Nicola; Strunk, Christoph; Schueller, Christian; Korn, Tobias [Institut fuer Experimentelle und Angewandte Physik, Universitaet Regensburg, 93040, Regensburg (Germany)

    2015-08-15

    Single-layer WS{sub 2} is a direct-gap semiconductor showing strong excitonic photoluminescence features in the visible spectral range. Here, we present temperature-dependent photoluminescence measurements on mechanically exfoliated single-layer WS{sub 2}, revealing the existence of neutral and charged excitons at low temperatures as well as at room temperature. By applying a gate voltage, we can electrically control the ratio of excitons and trions and assert a residual n-type doping of our samples. At high excitation densities and low temperatures, an additional peak at energies below the trion dominates the photoluminescence, which we identify as biexciton emission. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. The Aminolysis Reaction of Streptomyces S9 Aminopeptidase Promotes the Synthesis of Diverse Prolyl Dipeptides▿ †

    Science.gov (United States)

    Arima, Jiro; Morimoto, Masazumi; Usuki, Hirokazu; Mori, Nobuhiro; Hatanaka, Tadashi

    2010-01-01

    Prolyl dipeptide synthesis by S9 aminopeptidase from Streptomyces thermocyaneoviolaceus (S9AP-St) has been demonstrated. In the synthesis, S9AP-St preferentially used l-Pro-OBzl as the acyl donor, yielding synthesized dipeptides having an l-Pro-Xaa structure. In addition, S9AP-St showed broad specificity toward the acyl acceptor. Furthermore, S9AP-St produced cyclo (l-Pro-l-His) with a conversion ratio of substrate to cyclo (l-Pro-l-His) higher than 40%. PMID:20418423

  16. Photometric Characterization of the Reductive Amination Scope of the Imine Reductases from Streptomyces tsukubaensis and Streptomyces ipomoeae.

    Science.gov (United States)

    Matzel, Philipp; Krautschick, Lukas; Höhne, Matthias

    2017-10-18

    Imine reductases (IREDs) have emerged as promising enzymes for the asymmetric synthesis of secondary and tertiary amines starting from carbonyl substrates. Screening the substrate specificity of the reductive amination reaction is usually performed by time-consuming GC analytics. We found two highly active IREDs in our enzyme collection, IR-20 from Streptomyces tsukubaensis and IR-Sip from Streptomyces ipomoeae, that allowed a comprehensive substrate screening with a photometric NADPH assay. We screened 39 carbonyl substrates combined with 17 amines as nucleophiles. Activity data from 663 combinations provided a clear picture about substrate specificity and capabilities in the reductive amination of these enzymes. Besides aliphatic aldehydes, the IREDs accepted various cyclic (C 4 -C 8 ) and acyclic ketones, preferentially with methylamine. IR-Sip also accepted a range of primary and secondary amines as nucleophiles. In biocatalytic reactions, IR-Sip converted (R)-3-methylcyclohexanone with dimethylamine or pyrrolidine with high diastereoselectivity (>94-96 % de). The nucleophile acceptor spectrum depended on the carbonyl substrate employed. The conversion of well-accepted substrates could also be detected if crude lysates were employed as the enzyme source. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Catabolic fate of Streptomyces viridosporus T7A-Produced, acid precipitable polymeric lignin upon incubation with ligninolytic Streptomyces species and Phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    Pometto, A.L. III; Crawford, D.L.

    1986-01-01

    Degradation of ground and hot-water-extracted corn stover (Zea mays) lignocellulose by Streptomyces viridosporus T7A generates a water-soluble lignin degradation intermediate termed acid-precipitable polymeric lignin (APPL). The further catabolism of T7A-APPL by S. viridosporus T7A, S. badius 252, and S. setonii75Vi2 was followed for 3 weeks. APPL catabolism by Phanerochaete chrysosporium was followed in stationary cultures in a low-nitrogen medium containing 1% (wt/vol) glucose and 0.05% (wt/vol) T7A-APPL. Metabolism of the APPL was followed by turbidometric assay (600 nm) and by direct measurement of APPL recoverable from the medium. Accumulation and disappearance of soluble low-molecular-weight products of APPL catabolism were followed by gas-liquid chromatography and by high-pressure liquid chromatography, utilizing a diode array detector. Mineralization of a [ 14 C-lignin]APPL was also followed. The percent 14 C recovered as 14 CO 2 , 14 C-APPL, 14 C-labeled water-soluble products, and cell mass-associated radioactivity, were determined for each microorganism after 1 and 3 weeks of incubation in bubbler tube cultures at 37 0 C. P. chrysosporium evolved the most 14 CO 2 , and S. viridosporus gave the greatest decrease in recoverable 14 C-APPL. The results show that S. badius was not able to significantly degrade the APPL, while the other microorganisms demonstrated various APPL-degrading abilities

  18. Formation and dispersion of mycelial pellets of Streptomyces coelicolor A3(2).

    Science.gov (United States)

    Kim, Yul-Min; Kim, Jae-heon

    2004-03-01

    The pellets from a culture of Streptomyces coelicolor A3(2) that were submerged shaken were disintegrated into numerous hyphal fragments by DNase treatment. The pellets were increasingly dispersed by hyaluronidase treatment, and mycelial fragments were easily detached from the pellets. The submerged mycelium grew by forming complexes with calcium phosphate precipitates or kaolin, a soil particle. Therefore, the pellet formation of Streptomyces coelicolor A3(2) can be considered a biofilm formation, including the participation of adhesive extracellular polymers and the insoluble substrates.

  19. Development of a Terpenoid-Production Platform in Streptomyces reveromyceticus SN-593.

    Science.gov (United States)

    Khalid, Ammara; Takagi, Hiroshi; Panthee, Suresh; Muroi, Makoto; Chappell, Joe; Osada, Hiroyuki; Takahashi, Shunji

    2017-12-15

    Terpenoids represent the largest class of natural products, some of which are resources for pharmaceuticals, fragrances, and fuels. Generally, mass production of valuable terpenoid compounds is hampered by their low production levels in organisms and difficulty of chemical synthesis. Therefore, the development of microbial biosynthetic platforms represents an alternative approach. Although microbial terpenoid-production platforms have been established in Escherichia coli and yeast, an optimal platform has not been developed for Streptomyces species, despite the large capacity to produce secondary metabolites, such as polyketide compounds. To explore this potential, we constructed a terpenoid-biosynthetic platform in Streptomyces reveromyceticus SN-593. This strain is unique in that it harbors the mevalonate gene cluster enabling the production of furaquinocin, which can be controlled by the pathway specific regulator Fur22. We simultaneously expressed the mevalonate gene cluster and subsequent terpenoid-biosynthetic genes under the control of Fur22. To achieve improved fur22 gene expression, we screened promoters from S. reveromyceticus SN-593. Our results showed that the promoter associated with rvr2030 gene enabled production of 212 ± 20 mg/L botryococcene to levels comparable to those previously reported for other microbial hosts. Given that the rvr2030 gene encodes for an enzyme involved in the primary metabolism, these results suggest that optimized expression of terpenoid-biosynthetic genes with primary and secondary metabolism might be as important for high yields of terpenoid compounds as is the absolute expression level of a target gene(s).

  20. Density functional theory based study of chlorine doped WS2-metal interface

    International Nuclear Information System (INIS)

    Chanana, Anuja; Mahapatra, Santanu

    2016-01-01

    Investigation of a transition metal dichalcogenide (TMD)-metal interface is essential for the effective functioning of monolayer TMD based field effect transistors. In this work, we employ the Density Functional Theory calculations to analyze the modulation of the electronic structure of monolayer WS 2 with chlorine doping and the relative changes in the contact properties when interfaced with gold and palladium. We initially examine the atomic and electronic structures of pure and doped monolayer WS 2 supercell and explore the formation of midgap states with band splitting near the conduction band edge. Further, we analyze the contact nature of the pure supercell with Au and Pd. We find that while Au is physiosorbed and forms n-type contact, Pd is chemisorped and forms p-type contact with a higher valence electron density. Next, we study the interface formed between the Cl-doped supercell and metals and observe a reduction in the Schottky barrier height (SBH) in comparison to the pure supercell. This reduction found is higher for Pd in comparison to Au, which is further validated by examining the charge transfer occurring at the interface. Our study confirms that Cl doping is an efficient mechanism to reduce the n-SBH for both Au and Pd, which form different types of contact with WS 2 .

  1. Control of Bean Rust using Antibiotics Produced by Bacillus and ...

    African Journals Online (AJOL)

    Antibiotic culture filtrates produced by Bacillus (CA5) and Streptomyces spp. were tested for translocation and persistence when applied on snap beans inoculated with rust (Uromyces appendiculatus) in greenhouse pot experiments. The antibiotics were applied on the first trifoliate leaves and translocation was assessed as ...

  2. TOF-SIMS investigation of Streptomyces coelicolor, a mycelial bacterium

    International Nuclear Information System (INIS)

    Vaidyanathan, Seetharaman; Fletcher, John S.; Lockyer, Nicholas P.; Vickerman, John C.

    2008-01-01

    Streptomyces coelicolor is a mycelial microorganism that produces several secondary metabolites, including antibiotics. The physiology of the organism has largely been investigated in liquid cultures due to ease of monitoring different physiological parameters and more homogeneous culture conditions. However, solid cultures reflect the natural physiology of the microorganism better, given that in its natural state it grows in the soil. Imaging mass spectrometry with TOF-SIMS and C 60 + primary ion beams offers a potential route to studying chemical changes at the molecular level, both intracellular and extracellular that can help in understanding the natural physiology of the microorganism. Here, we report the application of the technique for studying the lateral distribution of the chemical species detected in a population, grown in both liquid and solid cultures. The capability of the technique for studying biological systems with minimal system intervention is demonstrated.

  3. TOF-SIMS investigation of Streptomyces coelicolor, a mycelial bacterium

    Science.gov (United States)

    Vaidyanathan, Seetharaman; Fletcher, John S.; Lockyer, Nicholas P.; Vickerman, John C.

    2008-12-01

    Streptomyces coelicolor is a mycelial microorganism that produces several secondary metabolites, including antibiotics. The physiology of the organism has largely been investigated in liquid cultures due to ease of monitoring different physiological parameters and more homogeneous culture conditions. However, solid cultures reflect the natural physiology of the microorganism better, given that in its natural state it grows in the soil. Imaging mass spectrometry with TOF-SIMS and C 60+ primary ion beams offers a potential route to studying chemical changes at the molecular level, both intracellular and extracellular that can help in understanding the natural physiology of the microorganism. Here, we report the application of the technique for studying the lateral distribution of the chemical species detected in a population, grown in both liquid and solid cultures. The capability of the technique for studying biological systems with minimal system intervention is demonstrated.

  4. Crystallization and preliminary crystallographic analysis of nosiheptide-resistance methyltransferase from Streptomyces actuosus in complex with SAM

    International Nuclear Information System (INIS)

    Yang, Huirong; Wang, Ping; Dong, Zhenghong; Li, Xueyuan; Gong, Rui; Yang, Ying; Li, Ze; Xu, Youwei; Xu, Yanhui

    2010-01-01

    The expression, purification and crystallization of nosiheptide-resistance methyltransferase (NSR) from Streptomyces actuosus is described. Nosiheptide-resistance methyltransferase (NSR) methylates 23S rRNA at the nucleotide adenosine 1067 in Escherichia coli and thus contributes to resistance against nosiheptide, a sulfur-containing peptide antibiotic. Here, the expression, purification and crystallization of NSR from Streptomyces actuosus are reported. Diffracting crystals were grown by the hanging-drop vapour-diffusion method in reservoir solution consisting of 0.35 M ammonium chloride, 24%(w/v) PEG 3350, 0.1 M MES pH 5.7 at 293 K. Native data have been collected from the apo enzyme and a SAM complex, as well as apo SeMet SAD data. The diffraction patterns of the apo form of NSR, of NSR complexed with SAM and of SeMet-labelled NSR crystals extended to 1.90, 1.95 and 2.25 Å resolution, respectively, using synchrotron radiation. All crystals belonged to space group P2 1 , with approximate unit-cell parameters a = 64.6, b = 69.6, c = 64.9 Å, β = 117.8°

  5. Antibiotic Properties of the endophytic Streptomyces Spp. Isolated from the Leaves of Myanmar Medicinal Plants

    International Nuclear Information System (INIS)

    Aye Pe; Mar Mar Nyein; Win Maung

    2002-02-01

    Three medicinal plants of Myanmar are selected in the study of endophytic microorganisms and are taxonomically classified and identified to be Sa-ba-lin (Cymbopogon citratus Stapf.), Shazaungtinga- neah (Euphorbia splendens Bojer. ex Hooker) and Ma-shaw (Sauropus grandifolius Pax. and Hoffm.). The screening of endophytic microorganisms is performed according to the ISP method (International Streptomyces Projects 1993). The morphological and physicochemical properties of isolated strains are studied and identified to be the Genus Streptomyces. The test of apparent antimicrobial activity of isolated Streptomyces is done on 18 strains of pathogenic bacteria. It is found that the isolated endophytic Sireptomyces showed the significant antibacterial activity on most of the test organisms. (author)

  6. Manumycin from a new Streptomyces strain shows antagonistic ...

    African Journals Online (AJOL)

    Manumycin from a new Streptomyces strain shows antagonistic effect against methicillin-resistant Staphylococcus aureus (MRSA)/vancomycin-resistant enterococci (VRE) strains from Korean Hospitals. Yun Hee Choi, Seung Sik Cho, Jaya Ram Simkhada, Chi Nam Seong, Hyo Jeong Lee, Hong Seop Moon, Jin Cheol Yoo ...

  7. Physicochemcial characteristic of CdS-anchored porous WS2 hybrid in the photocatalytic degradation of crystal violet under UV and visible light irradiation

    Science.gov (United States)

    Vattikuti, S. V. Prabhakar; Ngo, Ich-Long; Byon, Chan

    2016-11-01

    In this work, we report the synthesis of CdS-incorporated porous WS2 by a simple hydrothermal method. The structural, morphological, and optical properties of the samples were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), high resolution X-ray photoelectron spectroscopy (XPS) and UV-visible spectrometry. The photocatalytic activities were established for degradation of crystal violet (CV) under UV and visible light irradiation. The CdS-incorporated porous WS2 hybrid demonstrated high photocatalytic activity for degradation of CV pollutant compared to pure CdS nanoparticles and porous WS2 sheets. This result implies that the CdS-incorporated porous WS2 promoted more electron-hole pair transformation under UV and visible light irradiation. This significant enhancement of photocatalytic efficiency of CdS-incorporated porous WS2 photocatalyst under visible light can be ascribed to the presence of CdS nanospheres on the meshed-like WS2 sheets which potentially improves absorption in the visible range enabled by surface plasmon resonance effect of CdS nanospheres. The photostability and reusability of the CdS-porous WS2 were examined through recycling experiments.

  8. Correlating microstructure and activity for polysulfide reduction and oxidation at WS2 electrocatalysts

    DEFF Research Database (Denmark)

    Stephens, Ifan E.L.; Ducati, Caterina; Fray, Derek J.

    2013-01-01

    The polysulfide reduction and oxidation activity of WS2 electrocatalysts was studied. This was undertaken with a specific view to improve the efficiency of the polysulfide-bromine redox flow battery, for large scale energy storage. Using data from the literature, it is estimated that the catalysts.......47 and 1 M NaOH, simulating the operating conditions of a half-charged polysulfide-bromine redox flow battery. The catalyst activity increased in the following order: IF-WS2

  9. Systems biology and biotechnology of Streptomyces species for the production of secondary metabolites

    DEFF Research Database (Denmark)

    Hwang, Kyu-Sang; Kim, Hyun Uk; Charusanti, Pep

    2014-01-01

    Streptomyces species continue to attract attention as a source of novel medicinal compounds. Despite a long history of studies on these microorganisms, they still have many biochemical mysteries to be elucidated. Investigations of novel secondary metabolites and their biosynthetic gene clusters...... collected in the form of databases and knowledgebases, providing predictive information and enabling one to explore experimentally unrecognized biological spaces of secondary metabolism. Herein, we review recent trends in the systems biology and biotechnology of Streptomyces species....

  10. Systematics of Plant-Pathogenic and Related Streptomyces Species Based on Phylogenetic Analyses of Multiple Gene Loci

    Science.gov (United States)

    The 10 species of Streptomyces implicated as the etiological agents in scab disease of potatoes or soft rot disease of sweet potatoes are distributed among 7 different phylogenetic clades in analyses based on 16S rRNA gene sequences, but high sequence similarity of this gene among Streptomyces speci...

  11. Isolation and partial characterization of antimicrobial compounds from a new strain Streptomyces sp. CN207

    International Nuclear Information System (INIS)

    Slama, Nedra; Lazim, Hadeer; Barkallah, Insaf; Limam, Ferid

    2008-01-01

    A distinct streptomyces strains were isolated from Tunisian soil. the isolate designed CN207, was assigned to the genus streptomyces on the basis of morphological and chemotaxonomic criteria. A 16S rDNA sequence of the isolate was determined. Streptomyces sp CN207 secreted large amount antibiotic against gram positive bacteria, gram negative bacteria, yeast and fungi on his barley (HB) medium. (HB) medium was found to be suitable substrate of the medium for CN207 production. Maximum yield of CN207 product (700 mg/ml) after optimize fermentation process. Bioactive molecules from strain CN207 were extracted with ethyl acetate and analyzed by PTLC using silica gel plates.The separated compounds were visualiszed under UV at 254 nm and the active spots were detected by bioautography on silica gel plates using salmonella thyphimurium NRRL B4420 and Staphylococcus aureus CDC 103 as indicator microorganisms. The crude extract (8.36 g) was fractionated on Sep-pack column (C18 cartridge) and elution was performed using a discontinue gradient of methanol-water. Two active fractions eluted by 20% and 40% of methanol were obtained. The bioactive compounds were separated by preparative high performance liquid chromatography (HPLC) on a C18 reversed phase column and eluted with a linear gradient of acetonitrile -water in presence of 0.1% formic acid. The peaks were collected separately, concentrated and bioassayed against the routine indicator microorganisms. The absorption spectrum of the active molecules was determined with a shimadzu UV-160 a spectrophotometer. Determination of the chemical structure of these compounds on the basis on their IR, COSY and H 1: C13 is in progress

  12. Genomic characterization of a new endophytic Streptomyces kebangsaanensis identifies biosynthetic pathway gene clusters for novel phenazine antibiotic production

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    Juwairiah Remali

    2017-11-01

    Full Text Available Background Streptomyces are well known for their capability to produce many bioactive secondary metabolites with medical and industrial importance. Here we report a novel bioactive phenazine compound, 6-((2-hydroxy-4-methoxyphenoxy carbonyl phenazine-1-carboxylic acid (HCPCA extracted from Streptomyces kebangsaanensis, an endophyte isolated from the ethnomedicinal Portulaca oleracea. Methods The HCPCA chemical structure was determined using nuclear magnetic resonance spectroscopy. We conducted whole genome sequencing for the identification of the gene cluster(s believed to be responsible for phenazine biosynthesis in order to map its corresponding pathway, in addition to bioinformatics analysis to assess the potential of S. kebangsaanensis in producing other useful secondary metabolites. Results The S. kebangsaanensis genome comprises an 8,328,719 bp linear chromosome with high GC content (71.35% consisting of 12 rRNA operons, 81 tRNA, and 7,558 protein coding genes. We identified 24 gene clusters involved in polyketide, nonribosomal peptide, terpene, bacteriocin, and siderophore biosynthesis, as well as a gene cluster predicted to be responsible for phenazine biosynthesis. Discussion The HCPCA phenazine structure was hypothesized to derive from the combination of two biosynthetic pathways, phenazine-1,6-dicarboxylic acid and 4-methoxybenzene-1,2-diol, originated from the shikimic acid pathway. The identification of a biosynthesis pathway gene cluster for phenazine antibiotics might facilitate future genetic engineering design of new synthetic phenazine antibiotics. Additionally, these findings confirm the potential of S. kebangsaanensis for producing various antibiotics and secondary metabolites.

  13. Streptomyces humi sp. nov., an actinobacterium isolated from soil of a mangrove forest.

    Science.gov (United States)

    Zainal, Nurullhudda; Ser, Hooi-Leng; Yin, Wai-Fong; Tee, Kok-Keng; Lee, Learn-Han; Chan, Kok-Gan

    2016-03-01

    A novel Streptomyces strain, MUSC 119(T), was isolated from a soil collected from a mangrove forest. Cells of MUSC 119(T) stained Gram-positive and formed light brownish grey aerial mycelium and grayish yellowish brown substrate mycelium on ISP 2 medium. A polyphasic approach was used to determine the taxonomic status of strain MUSC 119(T), which shows a range of phylogenetic and chemotaxonomic properties consistent with those of the genus Streptomyces. The cell wall peptidoglycan consisted of LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9(H8), MK-9(H6) and MK-9(H4). The polar lipid profile consisted of phosphatidylinositol, phosphatidylethanolamine, glycolipids, diphosphatidylglycerol and four phospholipids. The predominant cellular fatty acids were anteiso-C15:0, iso-C16:0, and anteiso-C17:0. The cell wall sugars were glucose, mannose, ribose and rhamnose. The phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain MUSC119(T) to be closely related to Streptomyces rhizophilus JR-41(T) (99.0 % sequence similarity), S. panaciradicis 1MR-8(T) (98.9 %), S. gramineus JR-43(T) (98.8 %) and S. graminisoli JR-19(T) (98.7 %). These results suggest that MUSC 119(T) should be placed within the genus Streptomyces. DNA-DNA relatedness values between MUSC 119(T) to closely related strains ranged from 14.5 ± 1.3 to 27.5 ± 0.7 %. The G+C content was determined to be 72.6 mol %. The polyphasic study of MUSC 119(T) showed that this strain represents a novel species, for which the name Streptomyces humi sp. nov. is proposed. The type strain of S. humi is MUSC 119(T) (=DSM 42174(T) = MCCC 1K00505(T)).

  14. Coral pathogens identified for White Syndrome (WS epizootics in the Indo-Pacific.

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    Meir Sussman

    Full Text Available BACKGROUND: White Syndrome (WS, a general term for scleractinian coral diseases with acute signs of advancing tissue lesions often resulting in total colony mortality, has been reported from numerous locations throughout the Indo-Pacific, constituting a growing threat to coral reef ecosystems. METHODOLOGY/PRINCIPAL FINDINGS: Bacterial isolates were obtained from corals displaying disease signs at three ws outbreak sites: Nikko Bay in the Republic of Palau, Nelly Bay in the central Great Barrier Reef (GBR and Majuro Atoll in the Republic of the Marshall Islands, and used in laboratory-based infection trials to satisfy Henle-Koch's postulates, Evan's rules and Hill's criteria for establishing causality. Infected colonies produced similar signs to those observed in the field following exposure to bacterial concentrations of 1x10(6 cells ml(-1. Phylogenetic 16S rRNA gene analysis demonstrated that all six pathogens identified in this study were members of the gamma-Proteobacteria family Vibrionacae, each with greater than 98% sequence identity with the previously characterized coral bleaching pathogen Vibrio coralliilyticus. Screening for proteolytic activity of more than 150 coral derived bacterial isolates by a biochemical assay and specific primers for a Vibrio family zinc-metalloprotease demonstrated a significant association between the presence of isolates capable of proteolytic activity and observed disease signs. CONCLUSION/SIGNIFICANCE: This is the first study to provide evidence for the involvement of a unique taxonomic group of bacterial pathogens in the aetiology of Indo-Pacific coral diseases affecting multiple coral species at multiple locations. Results from this study strongly suggest the need for further investigation of bacterial proteolytic enzymes as possible virulence factors involved in Vibrio associated acute coral infections.

  15. Plasma modified PLA electrospun membranes for actinorhodin production intensification in Streptomyces coelicolor immobilized-cell cultivations.

    Science.gov (United States)

    Scaffaro, Roberto; Lopresti, Francesco; Sutera, Alberto; Botta, Luigi; Fontana, Rosa Maria; Gallo, Giuseppe

    2017-09-01

    Most of industrially relevant bioproducts are produced by submerged cultivations of actinomycetes. The immobilization of these Gram-positive filamentous bacteria on suitable porous supports may prevent mycelial cell-cell aggregation and pellet formation which usually negatively affect actinomycete submerged cultivations, thus, resulting in an improved biosynthetic capability. In this work, electrospun polylactic acid (PLA) membranes, subjected or not to O 2 -plasma treatment (PLA-plasma), were used as support for immobilized-cell submerged cultivations of Streptomyces coelicolor M145. This strain produces different bioactive compounds, including the blue-pigmented actinorhodin (ACT) and red-pigmented undecylprodigiosin (RED), and constitutes a model for the study of antibiotic-producing actinomycetes. Wet contact angles and X-ray photoelectron spectroscopy analysis confirmed the increased wettability of PLA-plasma due to the formation of polar functional groups such as carboxyl and hydroxyl moieties. Scanning electron microscope observations, carried out at different incubation times, revealed that S. coelicolor immobilized-cells created a dense "biofilm-like" mycelial network on both kinds of PLA membranes. Cultures of S. coelicolor immobilized-cells on PLA or PLA-plasma membranes produced higher biomass (between 1.5 and 2 fold) as well as higher levels of RED and ACT than planktonic cultures. In particular, cultures of immobilized-cells on PLA and PLA-plasma produced comparable levels of RED that were approximatively 4 and 5 fold higher than those produced by planktonic cultures, respectively. In contrast, levels of ACT produced by immobilized-cell cultures on PLA and PLA-plasma were different, being 5 and 10 fold higher than those of planktonic cultures, respectively. Therefore, this is study demonstrated the positive influence of PLA membrane on growth and secondary metabolite production in S. coelicolor and also revealed that O 2 -plasma treated PLA membranes

  16. Characterization of Streptomyces spp. isolated from the rhizosphere of oil palm and evaluation of their ability to suppress basal stem rot disease in oil palm seedlings when applied as powder formulations in a glasshouse trial.

    Science.gov (United States)

    Shariffah-Muzaimah, S A; Idris, A S; Madihah, A Z; Dzolkhifli, O; Kamaruzzaman, S; Maizatul-Suriza, M

    2017-12-18

    Ganoderma boninense, the main causal agent of oil palm (Elaeis guineensis) basal stem rot (BSR), severely reduces oil palm yields around the world. To reduce reliance on fungicide applications to control BSR, we are investigating the efficacy of alternative control methods, such as the application of biological control agents. In this study, we used four Streptomyces-like actinomycetes (isolates AGA43, AGA48, AGA347 and AGA506) that had been isolated from the oil palm rhizosphere and screened for antagonism towards G. boninense in a previous study. The aim of this study was to characterize these four isolates and then to assess their ability to suppress BSR in oil palm seedlings when applied individually to the soil in a vermiculite powder formulation. Analysis of partial 16S rRNA gene sequences (512 bp) revealed that the isolates exhibited a very high level of sequence similarity (> 98%) with GenBank reference sequences. Isolates AGA347 and AGA506 showed 99% similarity with Streptomyces hygroscopicus subsp. hygroscopicus and Streptomyces ahygroscopicus, respectively. Isolates AGA43 and AGA48 also belonged to the Streptomyces genus. The most effective formulation, AGA347, reduced BSR in seedlings by 73.1%. Formulations using the known antifungal producer Streptomyces noursei, AGA043, AGA048 or AGA506 reduced BSR by 47.4, 30.1, 54.8 and 44.1%, respectively. This glasshouse trial indicates that these Streptomyces spp. show promise as potential biological control agents against Ganoderma in oil palm. Further investigations are needed to determine the mechanism of antagonism and to increase the shelf life of Streptomyces formulations.

  17. VIABILITY AND ANTIMICROBIAL ACTIVITY OF STREPTOMYCES STRAINS FROM NCNM AFTER LYOPHILIZATION

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    Oleg CHISELIŢA

    2016-05-01

    Full Text Available The article deals with the aspects related to lyophilization of streptomycetes strains, preserved in the National Collection of Nonpathogenic Microorganisms (NCNM. Was determined that lyophilization do not significantly modify the antimicrobial activity of streptomycetes. Maximum viability of strains of genus Streptomyces (83,2-90,2% is ensured after lyophilization at initial titer by 9-11 log10UFC ml-1 in protective medium (gelatin 2,5% + glucose 7,5% by rehydra­tion with distillate water.VIABILITATEA ŞI ACTIVITATEA ANTIMICROBIANĂ A TULPINELOR DE STREPTOMYCES DIN CNMN DUPĂ LIOFILIZAREAcest articol prezintă aspecte legate de liofilizarea tulpinilor de streptomicete, depozitate în Colecţia Naţională de Microorganisme Nepatogene (CNMN. A fost stabilit că liofilizarea nu modifică esenţial activitatea antimicrobiană a streptomicetelor. Viabilitatea maximă a tulpinilor genului Streptomyces (83,2-90,2% este asigurată după liofilizarea la titrul iniţial 9-11 log10UFC ml-1 în mediu protectiv (gelatină 2,5% + glucosă 7,5% şi la rehidratarea cu apă distilată. 

  18. Streptomyces asenjonii sp. nov., isolated from arid Atacama Desert soils and emended description of Streptomyces viridosporus Pridham et al. 1958

    Science.gov (United States)

    A polyphasic study was undertaken to establish the taxonomic status of Streptomyces strains isolated from arid Atacama Desert soils. Analysis of the 16S rRNA gene sequences of the isolates showed that they formed a well-defined lineage that was loosely associated with the type strains of several Str...

  19. WS2 as an excellent high-temperature thermoelectric material

    KAUST Repository

    Gandi, Appala; Schwingenschlö gl, Udo

    2014-01-01

    The potential of WS2 as a thermoelectric material is assessed. The electronic contribution to the thermoelectric properties is calculated within the constant relaxation time approximation from the electronic band structure, whereas the lattice contribution is evaluated using self-consistently calculated phonon lifetimes. In addition, the dependence of the lattice thermal conductivity on the mean free path of the phonons is determined.

  20. WS2 as an excellent high-temperature thermoelectric material

    KAUST Repository

    Gandi, Appala

    2014-11-25

    The potential of WS2 as a thermoelectric material is assessed. The electronic contribution to the thermoelectric properties is calculated within the constant relaxation time approximation from the electronic band structure, whereas the lattice contribution is evaluated using self-consistently calculated phonon lifetimes. In addition, the dependence of the lattice thermal conductivity on the mean free path of the phonons is determined.