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A total of 192 different Streptomyces isolates were recovered from 34 soil samples collected from different localities in Egypt. The cytotoxic activities of culture supernatant of each of the recovered isolate were investigated against Caco-2 cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The Streptomyces isolate coded S19, that showed the highest cytotoxic activity against Caco-2 cell line (CD50 of 26.4 µg/mL), was identified using 16S rRNA gene sequence analysis as Streptomyces variabilis isolate MW091521. The influence of cultural parameters affecting the cytotoxic activity of the respective isolate including the different culture media, initial pH value, temperature and rotation speed was investigated. A maximum cytotoxic activity (CD50 of 13.4 µg/mL) was obtained using the culture medium of soybean meal at an initial pH of 7.0, incubation temperature 28°C and 200 rpm. Thereafter, the fermentation was conducted in a 14 L laboratory fermenter under the previously stated optimum conditions with the aim of extraction, and purification of cytotoxic metabolite(s). Fractionation of the ethyl acetate extract followed by advanced spectroscopic analysis using LC/ESI/MS as well as 1D and 2D NMR experiments yielded the cytotoxic metabolite heliomycin. To the best of our knowledge, this is the first report on the production of heliomycin by Streptomyces variabilis isolate MW091521.

To date, endophytic actinomycetes have been well-documented as great producers of novel antibiotics and important pharmaceutical leads. The present study aimed to evaluate potent bioactivities of metabolites synthesized by the strain LCP18 residing in the Vietnamese medicinal plant Litsea cubeba (Lour.) Pers towards human pathogenic bacteria and human cancer cell lines. Endophytic actinomycete strain LCP18 showed considerable inhibition against seven bacterial pathogens and three human tumor cell lines and was identified as species Streptomyces variabilis. Strain S. variabilis LCP18 was phenotypically resistant to fosfomycin, trimethoprim-sulfamethoxazole, dalacin, cefoxitin, rifampicin, and fusidic acid and harbored the two antibiotic biosynthetic genes such as PKS-II and NRPS. Further purification and structural elucidation of metabolites from the LCP18 extract revealed five plant-derived bioactive compounds including isopcrunetin, genistein, daidzein, syringic acid, and daucosterol. Among those, isoprunetin, genistein, and daidzein exhibited antibacterial activity against Salmonella typhimurium ATCC 14,028 and methicillin-resistant Staphylococcus epidermidis ATCC 35,984 with the MIC values ranging from 16 to 128 µg/ml. These plant-derived compounds also exhibited cytotoxic effects against human lung cancer cell line A549 with IC(50) values of less than 46 μM. These findings indicated that endophytic S. variabilis LCP18 can be an alternative producer of plant-derived compounds which significantly show potential applications in combating bacterial infections and inhibition against lung cancer cell lines.

The present study was undertaken to evaluate the saccharification, followed by bioethanol production by an actinobacterium Streptomyces variabilis (MAB3) isolated from the sediment sample of mangrove environment using Modified Yeast extract—Peptone medium substituted with different concentrations of xylanase (50 to 400 IU) pretreated various agro-residues like vegetable, banana, mango, sugarcane bagasse and sugarcane juice through fermentation process. Among the tested residues, sugarcane juice substituted medium pretreated with 200.0 IU concentration of xylanase exhibited maximum level of reducing sugar (50.19 mg/g), degree of saccharification (59.49%) as well as bioethanol (4.69 g/L) production. Further the organism expressed highest saccharification yield and bioethanol production at the optimized cultural conditions of pH 6, temperature 30 °C, inoculum size 2.5% and incubation time 72 h substituted with 2.5% dextrose and 2.0% urea, respectively as carbon and nitrogen sources. The concentration of produced bioethanol (82.26%) from the optimized medium was determined through HPLC analysis. Finally the bioethanol was evaluated through FT-IR and GC-MS analysis. The basic functional ethanol groups (O–H and C–O) from the optimized medium were denoted in both FT-IR and GC-MS analysis at the wavenumber of 3272.22 and 1077.15 cm−1 with the retention time of 2.60 min, respectively. Based on the results, it could be confirmed that the selected isolate is a potent strain and it can able to hydrolyze the pretreated agro-residues and also it can able to convert the pretreated agro residues into economically important byproduct like bioethanol.

The present study aimed to investigate the potential of plant growth-promoting rhizobacteria (PGPR) to improve the salt stress and alleviate its impact on Stevia crop plant under different levels of salt concentration. Two Streptomyces spp. isolated from the rhizosphere of halophytic plants (Cucumis sativus L. and Salicornia europaea L.) have shown potential for plant growth promotion in Stevia plant. The streptomycetes isolates were identified by classical microbiological techniques and partial sequencing of 16S rRNA gene as Streptomyces variabilis (4NC) and S. fradiae (8PK). The results have shown that inoculation of Stevia plant by these isolates has enhanced plant growth parameters under applied salt stress. Moreover, total cellular proteins were extracted from the two Streptomyces isolates and SDS-PAGE technique was conducted. Mass spectrometric analysis has identified unique polypeptide of the elongation factor thermos unstable (EF-Tu) indicating the elevation of ribosomal RNA and ribosomal protein genes transcription. On the same context, alleviation of salt stress in Stevia plants inoculated with the two Streptomyces isolates has potentially promoted the accumulation of the major pronounced RuBisCO large subunit protein band detected approximately at 53 kDa. These results may give novel insights and accretion our understanding of salinity tolerance mechanisms using PGP streptomycetes to develop resistant sugar crops of highly important economic value. This study has presented the integration of microbiological, biochemical, and molecular techniques to evaluate the effect of salt stress and to assess the level of stress amelioration using PGPR on proteostasis of sugar crops in Egypt.

Arterial/venous thrombosis is the major cardiovascular disorder accountable for substantial mortality; and the current demand for antithrombotic agents is extensive. Heparinases depolymerize unfractionated heparin (UFH) for the production of low molecular-weight heparins (LMWHs; used as anticoagulants against thrombosis). A microbial strain of Streptomyces sp. showing antithrombotic activity was isolated from the soil sample collected from north India. The strain was characterized by using 16S rRNA homology technique and identified as Streptomyces variabilis MTCC 12266 capable of producing heparinase enzyme. This is the very first communication reporting Streptomyces genus as the producer of heparinase. It was observed that the production of intracellular heparinase was [63.8 U/mg protein (specific activity)] 1.58 folds higher compared to extracellular heparinase [40.28 U/mg protein]. DEAE-Sephadex A-50 column followed by Sepharose-6B column purification of the crude protein resulted 19.18 folds purified heparinase. SDS-PAGE analysis of heparinase resulted an estimated molecular-weight of 42 kDa. It was also found that intracellular heparinase has the ability to depolymerize heparin to generate LMWHs. Further studies related to the mechanistic action, structural details, and genomics involved in heparinase production from Streptomyces variabilis are warranted for large scale production/purification optimization of heparinase for antithrombotic applications.

The present study was undertaken to evaluate the biosynthesis, molecular modeling and statistical optimization of xylanase production through Box-Behnken design by a mangrove associated actinobacterium Streptomyces variabilis (MAB3). Initially, the production of xylanase by the selected strain was carried through submerged fermentation using birchwood xylan as substrate. Further the xylanase production was statistically optimized through Box-Behnken design. It showed 5.30 fold increase of xylanase production by the isolate compared to ‘one factor at a time approach’ in the presence of the basal medium containing birchwood xylan (2.0% w/v) at pH 8.2, temperature 46.5 °C, inoculum size of 2% for 68 h. The analysis of variance (ANOVA) revealed high coefficient of determination (R2 = 0.9490) for the respective responses at significant level (P

Heterologous expression of bacterial artificial chromosome (BAC) clones from the genomic library of Streptomyces variabilis Snt24 in Streptomyces lividans SBT5 which carried a truncated undecylprodigiosin biosynthetic gene cluster led to the identification of hybrubins A-C. The hybrubins represent a new carbon skeleton in which a tetramic acid moiety is fused to a 2,2'-dipyrrole building block. Gene knockout experiments confirmed that hybrubins are derived from two convergent biosynthetic pathways including the remaining genomic red genes of S. lividans SBT5 as well as the BAC encoded hbn genes for the production of 5-ethylidenetetramic acid. A possible biosynthetic pathway was also proposed.

Three isolates ofStreptomyces variabilis(AB5, F and K1A) and one isolate ofStreptomyces sp.(C2) were isolated of acidic cultures from mineral ores and concentrates from mines of the Peruvian highlands. The isolates were identified molecular and phenotypically and characterized by growth at different conditions as pH tolerance, temperature, and sodium chloride and heavy metals resistance.Streptomyces sp. (C2) was able to grow until 200 ppm of mercury andS. variabilis(AB5) grows in the presence of 100 ppm of mercury. The isolates AB5 and K1A ofS. variabiliswere able to grow only until 50 ppm of mercury.All strains were tested by their ability to induce germination ofLactuca sativa,Medicago sativaandPhaseolus vulgarisseeds exposed to different mercury concentrations. It was shown a significative improvement inL.sativaandP. vulgaris. InL. sativaexposed to 50 ppm of mercury, all strains were able to improve germination, root length and number of leaves. Without Streptomyces addition, they only growth until 10 ppm of mercury.Streptomyces sp.isolatehad better results in germination, root length and number of leaves ofL. sativa.The results found in this work indicate the potential of these isolates for restoration of soils polluted with mercury.

Bacterial secondary metabolites possess a wide range of biologically active compounds including antibacterial and antioxidants. In this study, a Gram-positive novel marine Actinobacteria was isolated from sea sediment which showed 84% 16S rRNA gene sequence (KT588655) similarity with Streptomyces variabilis (EU841661) and designated as Streptomyces variabilis RD-5. The genus Streptomyces is considered as a promising source of bioactive secondary metabolites. The isolated novel bacterial strain was characterized by antibacterial characteristics and antioxidant activities. The BIOLOG based analysis suggested that S. variabilis RD-5 utilized a wide range of substrates compared to the reference strain. The result is further supported by statistical analysis such as AWCD (average well color development), heat-map and PCA (principal component analysis). The whole cell fatty acid profiling showed the dominance of iso/anteiso branched C15–C17 long chain fatty acids. The identified strain S. variabilis RD-5 exhibited a broad spectrum of antibacterial activities for the Gram-negative bacteria (Escherichia coli NCIM 2065, Shigella boydii NCIM, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas sp. NCIM 2200 and Salmonella enteritidis NCIM), and Gram-positive bacteria (Bacillus subtilis NCIM 2920 and Staphylococcus aureus MTCC 96). Extract of S. variabilis strain RD-5 showed 82.86 and 89% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and metal chelating activity, respectively, at 5.0 mg/mL. While H2O2 scavenging activity was 74.5% at 0.05 mg/mL concentration. Furthermore, polyketide synthases (PKSs types I and II), an enzyme complex that produces polyketides, the encoding gene(s) detected in the strain RD-5 which may probably involve for the synthesis of antibacterial compound(s). In conclusion, a novel bacterial strain of Actinobacteria, isolated from the unexplored sea sediment of Alang, Gulf of Khambhat (Gujarat), India showed promising antibacterial activities. However, fractionation and further characterization of active compounds from S. variabilis RD-5 are needed for their optimum utilization toward antibacterial purposes.

Made available in DSpace on 2015-02-02T12:39:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-09-01Bitstream added on 2015-02-02T13:08:32Z : No. of bitstreams: 1 S1517-83822014000300022.pdf: 1163361 bytes, checksum: f6578eb61c12ca4b15b58b2bb5a98706 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) 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. Universidade Federal Rural de Pernambuco Departamento de Morfologia e Fisiologia Animal Universidade Estadual Paulista Júlio de Mesquita Filho Escola de Ciências Farmacêuticas Departamento de Bioprocessos e Biotecnologia Universidade Federal de Pernambuco Department of Antibiotics Universidade Federal de Pernambuco Laboratorio de Biotecnologia University of Genoa Department of Civil, Chemical and Environmental Engineering Universidade de São Paulo Departamento de Bioquimica e Tecnologia Farmacêutica Universidade Estadual Paulista Júlio de Mesquita Filho Escola de Ciências Farmacêuticas Departamento de Bioprocessos e Biotecnologia

INTRODUCTION Among various ecological habitats, soil is one of the richest reservoirs supporting a variety of organisms including microorganisms. Rhizosphere is the region of soil present in vicinity to plant roots and is influenced by secretions of plant roots called root exudates. This region is thought to be of great importance to plant health and soil fertility. The exudates from plant roots stimulate the growth of microbial populations in soil and thus, the microbial activity is greatest in rhizosphere region. Actinomycetes forms a key part of soil microorganisms. The species of the genus Streptomyces are saprophytic and are commonly associated with soils. It has been found that about 90 % of soil actinomycetes are reported to be Streptomyces species. In soil, Streptomyces species significantly contribute to the turnover of complex biopolymers such as cellulose, pectin, lignin etc. They are noteworthy as they are the prolific producers to a range of bioactive metabolites including antibiotics. Western Ghats of India covers an area of 1, 80, 000 km and represent just under 6 % of the land area of India. The area represents > 30 % of all plant, fish, herpeto-fauna, birds and mammal species found in India which include some of the globally threatened species. Agumbe, a region of Western Ghats of Shivamogga district, Karnataka, India is shown to be a rich reservoir for Streptomyces species having potent industrial and agricultural significance in terms of production of bioactive metabolites. Streptomyces species from Agumbe region of Western Ghats have shown to antimicrobial, antioxidant, enzyme inhibitory, insecticidal, cytotoxic, anthelmintic, analgesic, antiinflammatory, CNS depressant and antipyretic activities. Streptomyces variabilis strain PO-178 (Figure 1) of this study was isolated from a rhizosphere soil of Agumbe, Karnataka, India. The extract from this strain was shown to possess antimicrobial, insecticidal, cytotoxic, analgesic, antiinflammatory, antipyretic and CNS depressant activity. In continuation part of our previous study, the present study was conducted with an aim of determining antioxidant, anthelmintic and enzyme inhibitory activity of butanol extract of S.variabilis PO-178 isolated from rhizosphere soil of Agumbe, Karnataka, India.

Marine microorganism was emerging as the great source for the discovery of novel enzyme. The search and discovery of new enzymes derived from actinomycetes have received much attention nowadays due to a growing need for applications in various industries including food industry. Endo-β-1,4-xylanases is considered one of critical enzyme involves in the degradation of xylan that is able to cleave the β-1,4-glycosidic linkages in the xylan backbone resulting in various xylooligosaccharides and xylose. Screening and characterization of novel actinomycetes that is capable of producing high xylanase are necessary to produce xylooligosaccharides from hemicellulose hydrolysis process. The objective of this research is screening and characterizing of novel marine actinomycetes from working culture of Research Center for Biotechnology, Biotechnology Culture Collection (BTCC) that are capable of producing high-level hemicellulase-degrading enzymes, especially endo-xylanase enzyme. Approximately, 70 strains from Indonesia marine Actinomycetes have been screened by using congo red, SDS-PAGE and zymogram methods. Of these 70 strains, 3 strains were successfully identified that is capable in producing high level of xylanase enzymes based on the diameter of clear zone more than 1.5 cm on xylan plate medium pH 5.0 and 6.0. Three strains from marine Actinomycetes were identified based on analysis a 16S rRNA gene sequence revealed that all of strains belonging to the genus Streptomyces. Strain 47 is closely related with Streptomyces variabilis (98%). All strains had ability to produce xylanase at optimum pH 5.0 and temperature range between 50-60 °C with range activity from 2.5 – 4.3 U/mL. Each isolate had a molecular weight from 20-50 kDa based on SDS-PAGE and zymogram analysis. Based on TLC analysis using beechwood xylan, each isolate had ability to produce xylooligosaccharides. These characterizations showed that these isolates are potentially used for xylooligosaccharides productions. Strain 47 was selected for the next analysis for molecular cloning based on the pattern and results of TLC clearer then strain 41 and strain 42.

A novel actinomycete strain designated CN-207(T) was isolated from northern Tunisian soil. This strain exhibited potent broad spectrum antibacterial activity against clinical isolates of methicillin-resistant Staphylococcus species and several other Gram-positive and Gram-negative bacteria. Strain CN-207(T) developed greyish aerial mycelium and pale grey substrate mycelium on yeast extract/malt agar. The isolate produced branching vegetative mycelia with sporangiophores bearing sporangia developing at a late stage of growth. The sporangia contained smooth, non-motile spores. Chemotaxonomic characteristics of strain CN-207(T) were typical of the Streptomyces genus. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CN-207(T) belonged to the genus Streptomyces, and was most closely related to Streptomyces griseoincarnatus DSM 40274(T), Streptomyces variabilis DSM 40179(T), Streptomyces labedae DSM 41446(T) and Streptomyces erythrogriseus DSM 40116(T). Low DNA-DNA relatedness values were recorded between strain CN-207(T) and its closest phylogenetic neighbours. Strain CN-207(T) was also distinguished from the nearest phylogenetic neighbours using a combination of morphological and phenotypic characteristics. On the basis of its phenotypic and molecular properties, strain CN-207(T) is considered as a novel species of the Streptomyces genus, for which the name Streptomyces tunisiensis sp. nov. is proposed. The type strain is CN-207(T) (=JCM 17589(T) = DSM 42037(T)).

Out of 210 actinomycetes isolates belonged to the genus Streptomyces recovered from rhizospheric soil of Triticum vulgaris, Zea mays and Vicia faba cultivated in Assuit and New Valley Governorates of Egypt, ten isolates were capable of producing high amounts of L-glutaminase enzyme. The most potent L-glutaminase producer isolate was Streptomyces sp. ASU319 recovered from rhizosphere of Triticum vulgaris. The higher producer actinomycete isolate was identified by sequencing of 16S rRNA as Streptomyces variabilis ASU319 and was deposited in the GenBank nucleotide sequence database under accession number KC145278. Factors affecting L-glutaminase production by the Streptomyces variabilis ASU319(KC145278) were examined and the results revealed that the maximum L-glutaminase value was obtained when the isolate cultivated in the production broth medium supplemented by glutamine 8 mg/ml, adjusted at pH 4 and incubated at 35 °C. These results suggest that L-glutaminase-producing Streptomyces variabilis ASU319 could be used as a plant growth promoting rhizobacteria by increasing the ammonia content in the rhizosphere soil across degradation of the agricultural wastes. Also this isolate can be used in both pharmaceutical and food industrial application for L-glutaminase production on commercial scale.

Ammosamides E-F (1-2), are amidine analogs of the ammosamide family of alkaloids isolated from a marine-derived Streptomyces variabilis. Further studies with S. variabilis revealed a variety of aryl and alkyl amines added into the fermentation media could be efficiently incorporated into the ammosamide framework to generate a library of precursor-directed amidine analogs, ammosamides G-P (9 - 18). We demonstrate that the amines are introduced via non-enzymatic addition to the iminium ion of ammosamide C. Biological evaluation of the amidine analogs against quinone reductase 2 (QR2) showed low nM potency for a number of analogs. When tested for in vivo activity against a panel of non-small cell lung cancer (NSCLC) cell-lines there was a clear increase in potency by incorporation of lipophilic alkylamines, with the most potent compounds having sub μM IC(50) values (0.4 to 0.8 μM).

The search for novel bioactive compounds from the natural environment has been rapidly increased with the increase in multi-drug resistant (MDR) pathogens. In the present study, the antimicrobial potential of novel actinomycetes has been evaluated by initial screening of six soil samples. Primary and secondary screening was performed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans, Candida tropicalis, Trichophyton rubrum, and other MDR bacterial and fungal test strains, and at the end thirteen active isolates were selected for further study. Microbial strains were identified on the basis of growth conditions and other biochemical characters. Five most active microbial strains were identified using 16S rRNA sequence homology and designated as Streptomyces xanthophaeus MTCC 11938, Streptomyces variabilis MTCC 12266, Streptomyces xanthochromogenes MTCC 11937, Streptomyces levis EU 124569 and Streptomyces sp. NCIM 5500. Four antibacterial and three antifungal compounds isolated from the above five isolates were purified and partially characterized using UV absorption and IR spectra. Two antibacterial metabolites, belong to chromone and peptide antibiotic, respectively. The antifungal compounds were found to be of non-polyene nature. In conclusion, we study the isolation of novel bacterial strains of actinomycetes for producing novel compounds having antibacterial and antifungal activities from the unexplored agro-ecological niches of India. Also, this study paves the way for further characterization of these isolates of Streptomyces sp. for their optimum utilization for antimicrobial purposes.

Most immunosuppressive agents were initially developed as antibiotics produced by the genus Streptomyces. This investigation was devoted to explore the bioactive metabolite of the Streptomyces variabilis ASU319 extract and testing the purified active compound of this extract as an immunosuppressive agent in rats blood. Elucidation of the chemical structure and optimization of the active compound were studied as well. Antimicrobial activity was conducted using agar-well diffusion and disc diffusion assays. The antimicrobial metabolite was extracted from the fermentation broth by ethyl acetate and purified by TLC and silica gel column chromatography. The pure active compound was then subjected to spectroscopic analyses: 1H NMR, Elemental analysis, IR and Mass spectra. The active antimicrobial compound was tested as an immunosuppressive agent by injection in the rat blood and the complete blood count (CBC) was determined. The crude extracts of the selected active antagonistic five isolates weretested to prevent the inflammation and proliferation of lymphocytes of the rats blood. The active antimicrobial compound of Streptomyces ASU319 was purified and proven as an immunosuppressive agent. The tested compound decreased each of the neutrophils, lymphocytes and monocytes than the positive control. The compound was of molecular weight 458 g/mol and had given the proposed chemical formula C24H46O8. The most potent bacterial isolate was identified by 16SrRNA sequencing as Streptomyces variabilis ASU319 with accession number [GenBank: KC145278]. These results revealed that Streptomyces variabilis ASU319 is potential microbial for production of active antimicrobial compound that has the ability to decrease the proliferation of the lymphocytes cells in the blood and may be a good immunosuppressive agent. &nbsp

A Gram-positive, aerobic, non-motile actinomycete (strain MS 3/20T) 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(H8) and MK-9(H6). Diagnostic polar lipids were glycolipid, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, unidentified phospholipid and unidentified amino lipid. The major fatty acids were anteiso-C15:0 (17.53%), iso-C16:0 (23.89%) and anteiso-C17:0 (10.29%). The strain showed 100% 16S ribosomal RNA (rRNA) gene sequence similarity with Streptomyces variabilis NBRC 12825T, Streptomyces erythrogriseus LMG 19406T, Streptomyces griseoincarnatus LMG 19316T and Streptomyces labedae NBRC 15864T. However, strain MS 3/20T 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 3/20T in comparison with its phylogenetic relatives. Disparate morphological, physiological and chemotaxonomic features, principally growth in NaCl, further corroborated the distinction of strain MS 3/20T from other phylogenetic relatives. Strain MS 3/20T 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 3/20T (=CICC 11032T=DSM 103378T).

Ammosamide D (1), an oxidized analog of the ammosamide family, was isolated from a marine-derived Streptomyces variabilis. Pyrroloquinoline containing alkaloids are a growing class of natural products, with 1 being the first example of an oxidized analog resulting in a 5,6-dioxo-5,6-dihydroquinoline ring system. Attempts at chemical conversion of ammosamide B to ammosamide D revealed that a strong chemical oxidant is required. Ammosamide D has modest cytotoxicity to the MIA PaCa-2 pancreatic cancer cell line.

Irrigation of farm field with water mixed with pulp and paper mill effluent from Century pulp and paper mill in Uttrakhand state of India for over last 25 years in succession increased streptomycetes population (120 × 105) compared to the fresh water irrigated fields (48 × 103 in WIF). Denaturing gradient gel electrophoresis, amplified ribosomal DNA restriction analysis, 16S rRNA gene sequencing, BIOLOG™ substrate usage, production of extracellular enzymes (xylanase and cellulase) and plant growth promoting attributes were applied to monitor changes in genetic and metabolic diversity of streptomycetes. Significant variation was observed for production of extracellular enzymes, Indolic compounds, siderophore and P-solubilisation among isolates. Metabolic substrate usage of Streptomyces isolates was evaluated using the BIOLOG™ GP2 plates and unique carbon substrate usage profiles were observed. Based on 16S rRNA gene sequencing, the isolates were identified as Streptomyces variabilis, Streptomyces spp. S. glaucescens, S. viridochromogenes, S. cinnabarinus, S. aburaviensis, S. viridis, S. xylophagus, S. macrosporeus, S. thermocarboxydus, and S. albogriseolus. The diversity index parameters like Shannon index, reciprocal of Simpson’s index (1/D), and Pielou index of evenness based on ARDRA revealed that streptomycetes community in effluent irrigated field (EIF) was more diverse. DGGE profiles of Streptomyces specific 16S rRNA gene fragments (16S-DGGE) amplified directly from soil samples were highly similar in both soils.

The study was carried out to determine the grease stain removing ability of lipase from an Actinomycete strain (Streptomyces variabilis NGP 3 (JX843530)) recovered from marine sediment of South Indian coastal region. The strain was identified using 16SrRNAgene sequence analysis. The efficiency of lipase produced by Streptomyces variabilis NGP3 in combination with various commercially available detergents (Ariel, Tide, Henko, Rin and Surf excel) was studied. Among them, lipase with Surf excel treated knitted fabric removed 77.27% grease from the fabric. Abrasion resistance test was carried out to analyze the capability of the knitted fabric against abrasion surface. Minimum abrasion of knitted fabric (1.50%) was observed when treated with S. variabilis NGP 3 lipase and surf excel. Perspiration test for the colour fastness of the knitted fabric on treatment with lipase and detergents (Rin and Surf excel) revealed a rating of 5 (ideal) in the Grey scale reader, in both acidic and alkali treatment

Objective: This study was focused on an evaluation of antimicrobial activity of actinobacterial isolated from Kanyakumari marine sediments.Methods: This study includes sample collection from Kanyakumari beach, followed by isolation of marine actinobacteria, screening for antibacterial activity and antifungal activity. Finally, the most active isolate was identified using 16S rRNA sequencing. Results: Marine actinobacteria are one of the leading microbes of the ocean known for producing excellent secondary metabolites and having a broad spectrum of anti-microbial activity, hence they are very important from an industrial point of view. The marine sediment sample used was collected from Kanyakumari beach, in the month of July, falling in the latitudinal range of 8.5074°N and in the longitude of 76.9730°E. A total of 8 actinobacterial colonies were isolated by spread plate technique on Actinomycetes isolation agar, Kuster's agar and Starch casein agar. The isolate cultures were designated as UST1- UST8. Among them, UST3 showed a maximum zone of inhibition against clinical pathogens Salmonella typhi and Aspergillus niger with a zone of inhibition of 22mm and 20mm respectively. In solvent extraction study ethyl acetate and hexane was found as best solvents for extraction. Potential isolate UST3 was identified as Streptomyces variabilis using morphological studies and 16S rRNA sequencing. Potential strain was submitted as Streptomyces variabilis- VITUMVB03Conclusion: Results obtained in this study concluded that marine actinobacteria have broad-spectrum antimicrobial activity and can be used in the pharmaceutical industry.Keywords: Anti-fungal activity, Anti-bacterial activity, Salmonella typhi, Aspergillus niger, Streptomyces variabilis

Since the marine environmental conditions are extremely different from the other ones, marine actinomycetes might produce novel bioactive compounds. Therefore, actinomycete strains were screened from marine water and sediment samples collected from the coastal areas of Northern Vietnam. Ninety-nine actinomycete strains were obtained on starch-casein agar media by dilution technique, only seven strains, named HP112, HP12, HP411, HPN11, HP 11, HPT13 and HPX12, showed significant antibacterial activity against both gram-positive and gram-negative bacteria (Bacillus subtilis ATCC 6633, Staphylococcus epidemidis ATCC 12228, Escherichia coli ATCC 11105). Further studies were carried out with the most active HP411 strain against Candida albicans ATCC 10231. This strain could grow rapidly on starch casein agar and other media with high salt containing 7-10% NaCl at 28-30oC. Spore-chain of HP411 showed an elongated and circular shape with 10 to 30 spores/chain. Identification of the strain was carried out by employing the taxonomical studies including the 16S rRNA sequence. Based on phylogenetic and phenotypic evidence it is proposed that HP411 to be belongs to species Streptomyces variabilis. The potent of the crude extract of fermentation broth of HP411 that are effective against wide range of pathogens: both grampositive, gram-negative and fungi. Further studies revealed that the crude extract HP411 could obtain the anticancer activity for cancer cell lines: Hep-G2 (liver cancer cell line); RD (cardiac and skeletal muscle letters cell line); FL (membrane of the uterus cancer cell line). However, the actinomycetes from marine ecosystem will be useful for the discovery of new drugs in the future.

A novel actinomycete, strain FX61T, was isolated from a saline sample collected from the Inner Mongolian Autonomous Region in China and subjected to a taxonomic study using a polyphasic approach. The predominant menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The major fatty acids were iso-C16 : 0, anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 1 H, C16 : 0, iso-C14 : 0 and anteiso-C17 : 0. The phospholipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, two phosphatidylinositol mannosides and an unidentified phospholipid. The G+C content of the genomic DNA was 72 mol%. The 16S rRNA gene sequence of the isolate had greater than 98 % similarity with those of Streptomyces griseoincarnatus ATCC 23623T (98.2 %), Streptomyces labedae DSM 41446T (98.2 %), Streptomyces variabilis ATCC 19815T (98.2 %), Streptomyces erythrogriseus ATCC 27427T (98.2 %), Streptomyces matensis ATCC 23935T (98.2 %), Streptomyces althioticus ATCC 19724T (98.2 %) and Streptomyces luteosporeus ATCC 33049T (98.0 %), showing that the novel strain should be assigned to the genus Streptomyces . DNA–DNA hybridizations with the seven above-mentioned members of the genus Streptomyces showed 29.8, 28.5, 27.0, 25.5, 25.0, 23.5 and 22.0 % relatedness, respectively. On the basis of the phenotypic characteristics and genotypic distinctiveness, strain FX61T should be classified as a novel species of the genus Streptomyces , for which the name Streptomyces wuyuanensis sp. nov. is proposed. The type strain is FX61T ( = CGMCC 4.7042T = KCTC 29112T).

Objective: This study was aimed to evaluate the bioactive potential (antimicrobial and antioxidant) of marine actinobacteria isolated from Thottadamarine sediment, Kannur, Kerala.Methods: The study involved isolation of marine actinobacteria from Thottada marine sediments, followed by antimicrobial and antioxidant activityof the crude extract. Finally, identification of potential isolates.Results: In this study, a total of 6 actinobacterial colonies were isolated, out of which only one isolate DV-35 showed maximum anti-microbial andanti-oxidant activity. The isolate DV-35 showed maximum inhibitory activity against Gram-negative bacterial pathogens Pseudomonas aeruginosa(18 mm) followed by Salmonella typhi (17 mm) and Klebsiella sp. (13 mm) at a dose of 100 μg/ml. In antifungal activity, extract showed maximumactivity against Aspergillus niger (19 mm) followed Aspergillus flavus (17 mm) at a dose of 100 μg/ml. Simultaneously the extract was evaluated for itsantioxidant activity. The potential isolate DV-35 also showed moderately higher antioxidant activity in various screening assay, viz., 2,2-diphenyl-1-picrylhydrazyl scavenging assay (80.12%), metal chelating assay and reducing power assay (76%) at a concentration of 100 μg/ml. Potential isolateDV-35 was identified as Streptomyces variabilis DV-35 using molecular 16S rRNA sequencing.Conclusion: The results obtained suggest that the extract is having bioactive metabolites that can be considered as a potential source for antimicrobialand anti-oxidant drug development.Keywords: Marine actinomycetes, Anti-microbial activity, Anti-oxidant activity, Pseudomonas aeruginosa, Aspergillus niger, Streptomyces variabilis.

A culture similar to Streptomyces variabilis was found to produce a novel cyclic hexadepsipeptide antibiotic named variapeptin. Variapeptin is structurally related to azinothricin, A83586C, and citropeptin. The antibiotic was active against Gram-positive bacteria and showed cytotoxic activity against mammalian cells.

In the present study, characterization and antibacterial activity of a glycoside antibiotic from fermentation broth of bioactive Streptomyces variabilis PO-178 recovered previously from Western Ghat soil of Agumbe, Karnataka, India was investigated. Mass cultivation of the strain PO-178 was carried out in Starch casein nitrate broth. The fermentation broth was extracted using butanol solvent in a separation funnel. The concentrated butanol extract was subjected to chromatographic techniques viz., thin layer and silica gel column chromatography for purification of bioactive components. Out of 3 fractions (A, B and C) obtained, only one fraction (C) displayed inhibitory activity against Staphylococcus aureus and Pseudomonas aeruginosa. The bioactive fraction C was subjected to spectral analysis (LC-MS, IR, 1 H-NMR and 13 C-NMR) in order to determine the structure. On the basis result of spectral analysis, the purified fraction was predicted as a glycoside antibiotic with molecular weight 514 and molecular formula C 24 H 34 O 12 . The antibiotic displayed marked inhibitory activity against S. aureus as revealed by wider zones of inhibition and low minimum inhibitory concentration value.

Variapeptin and citropeptin were found as novel hexadepsipeptide antibiotics produced by Streptomyces variabilis and Streptomyces flavidovirens, respectively. Their structures were elucidated by NMR spectral analysis including a variety of 2D techniques. Variapeptin and citropeptin are structurally related to azinothricin and A83586C, respectively.

espanolEl presente trabajo tiene como objetivos evaluar actinomicetos aislados de Argopecten purpuratus y su capacidad de producir enzimas extracelulares (EEC), asi como determinar su actividad antagonista frente a patogenos de importancia en acuicultura. Se aislaron 27 cepas de actinomicetos a partir de la masa visceral de especimenes adultos de A. purpuratus colectados en la localidad de Pisco y Pucusana (Lima) - Peru. El 81,5 y 59,2% de los aislados mostraron actividad proteolitica y lipolitica, respectivamente. Asimismo, las cepas senaladas como ARG 9-II, ARG 10-II, ARG 12-II y ARG 14-II mostraron mayor actividad antimicrobiana contra los patogenos Vibrio anguillarum, V. vulnificus, V. alginolitycus, Lactococcus garvieae, Streptococcus iniae, Carnobacterium piscicola y Yersinia ruckeri. La cepa ARG 4-II exhibio la mayor actividad inhibitoria. La Concentracion Minima Inhibitoria (CMI) del extracto diclorometanico de la cepa ARG 12-II frente a V. anguillarum y V. alginolyticus fue calculada en 250 y 500 µg ml-1 respectivamente. Las cepas ARG 9-II, ARG 12-II y ARG 14-II sobre la base del analisis de su ARNr 16S fueron identificadas como Streptomyces variabilis, St. labedae y St. rochei, respectivamente. Los resultados senalan a A. purpuratus como una fuente promisoria de aislamiento de nuevas cepas de Streptomyces con alta capacidad bioactiva y antagonista contra patogenos de importancia en acuicultura y con posibilidades de ser desarrolladas como potenciales agentes probioticos en el futuro. EnglishThe present study was aimed at isolating Argopecten purpuratus-associated actinomycetes strains, and evaluating their capacity of production of extracellular enzymes (ECE), as well as inhibitory compounds against relevant pathogens in commercial aquaculture. Twenty seven strains were isolated from the gut of A. purpuratus adult specimens that were collected in the city of Pisco and Pucusana (Lima) _ Peru; 81.5 and 59.2% of the isolates showed proteolytic and lipolytic activity, respectively. In addition, the strains ARG 9-II, ARG 10-II, ARG 12-II and ARG14-II evidenced broad-spectrum antimicrobial activity against the pathogens Vibrio anguillarum, V. vulnificus, V. alginolitycus, Lactococcus garvieae, Streptococcus iniae, Carnobacterium piscicola, and Yersinia ruckeri. The strain ARG 4-II produced the highest inhibitory effect against S. iniae. The Minimum Inhibitory Concentration (MIC) of the dichloromethane extract obtained from the strain ARG 12-II supernatant was 250 and 500 µg ml-1 against V. anguillarum and V. alginolyticus, respectively. Based on 16S rRNA sequence analysis, strains ARG 9-II, ARG 12-II and ARG 14-II were identified as Streptomyces variabilis, St. labedae and St. rochei, respectively. Results indicate that A. purpuratus is a promissory source for the isolation of new strains of Streptomyces with high bioactivity and antagonistic capacity against relevant pathogens in aquaculture. These strains have high potential for being developed as probiotic agents in the future.