Taxonomy and antimicrobial activities of a new Streptomyces sp. TN17 isolated in the soil from an oasis in Tunis

An actinomycete strain referred to as TN17 was screened for its antimicrobial activities. The taxonomic status of this strain was established. The organism was found to have morphological and chemotaxonomic characteristics typical of Streptomycetes. Based on the 16S rRNA nucleotide sequences, Streptomyces sp. TN17 was found to have a relationship with Streptomyces lilaceus, Streptomyces gobitricini and Streptomyces lavendofoliae. Combined analysis of the 16 S rRNA gene sequence (FN687757), phylogenetic analysis, fatty acids profile and physiological tests indicated that there are genotypic and phenotypic differences between TN17 and neighboring Streptomyces species’ neighbors. Therefore, TN17 is a novel species: Streptomyces sp. TN17 (=DSM 42020T=CTM50229T). A cultured extract of this strain inhibits the growth of several Gram positive and Gram negative bacteria and fungi

Streptomyces

Streptomyces is a Gram-positive bacterium, with a high guanine þ cytosine (G þ C) content, belonging to the family Streptomycetaceae and order Actinomycetales. It is found commonly in marine and fresh water, rhizosphere soil, compost, and vermicompost. Streptomyces plays an important role in the plant growth promotion (PGP), plant health promotion (crop protection), degradation of organic residues, and production of byproducts (secondary metabolites) of commercial interest in agriculture and medical fields. Streptomyces, in the rhizosphere and rhizoplane, help crops in enhancing shoot and root growth, grain and stover yield, biologic nitrogen fixation, solubilization of minerals (such as phosphorus and zinc), and biocontrol of insect pests and plant pathogens. There is a growing interest in the use of secondary metabolites produced by Streptomyces such as blasticidin-s, kusagamycin, streptomycin, oxytetracycline, validamycin, polyoxins, natamycin, actinovate, mycostop, abamectin/ avermectins, emamectin benzoate, polynactins and milbemycin for the control of insect pests and plant pathogens as these are highly specific, readily degradable, and less toxic to environment (Aggarwal et al., 2016). The PGP potential of Streptomyces is well documented in tomato, wheat, rice, bean, chickpea, pigeonpea, and pea. This chapter emphasizes the usefulness of Streptomyces in PGP, grain and stover yields, soil fertility, and plant health promotion

Isolation and Identification of Streptomyces from Different Sample of Soils

A total of 36 actinomycetes were isolated and purified from soil samples collected from agricultural soils in Hilla. The isolates were morphologically distinct on the basis of spore mass color, reverse slide color, aerial and substrate mycelia formation and production of diffusible pigment. Only two isolates which were S.A.2 and S.S.10 was selected for further investigation due to its strong antibacterial activity against six pathogenic bacteria which were (Staphylococcus aureus, Escherichia coli, Pseudomonas aeroginosa,Serratiamarcescens, Klebsiella pneumonia, Aeromonashydrophila).These two isolates was identified asStreptomycesorientalisand Streptomyces humidus respectively based on its morphological, cultural, physiological, microscopic features, utilization of carbon sources, biochemical characteristics and  molecular analysis of the 16S rRNA gene primers. Keywords :actinomycetes, spore mass color, 16S rRNA gene primers

Isolamento e seleção de actinobactérias promotoras do crescimento de plantas de solo rizosférico de Araucaria angustifolia

Actinobacteria are capable of playing several different roles in soil ecosystems. These microorganisms affect other organisms by producing secondary metabolites and are responsible for the degradation of different complex and relatively recalcitrant organic compounds. In our survey of actinobacteria isolated from the rhizosphere of Araucaria angustifolia, five culture media (AI, WYE, YCED, MSSC and LNMS) were compared for their effectiveness in isolating these microorganisms. When summing up all the isolates randomly obtained, we got 103 isolates. After isolation, the phosphate-solubilizing ability and the in vitro production of indole-acetic acid and chitinases were evaluated. The AI medium was ineffective for actinobacteria isolation, when it was compared with the other four culture media. Indole-acetic acid and chitinase were produced by respectively 36% and 24% of the strains tested. However, only 2% of the 103 strains presented some phosphate-solubilizing ability. These results demonstrate the biotechnological potential of these microorganisms.Actinobactérias são capazes de desenvolver diferentes funções no ecossistema edáfico. Esses microrganismos, além de interagir com outros grupos de microrganismos e plantas, ao produzir metabólitos secundários, são responsáveis pela degradação de diferentes compostos orgânicos. Com intuito de facilitar os estudos envolvendo actinobactérias encontradas em sistemas florestais, cinco meios de cultura (AI, WYE, YCED, MSSC e LNMS) foram avaliados quanto à eficiência em isolar estes microrganismos. Além disso, foi analisada a capacidade dos diferentes isolados em solubilizar fosfato de cálcio, produzir ácido indol-acético e quitinases. Dos cinco meios de cultura testados, somente o AI foi ineficiente em isolar actinobactérias. A produção de ácido indol-acético e quitinases foi observada em 36% e 24% dos isolados analisados, respectivamente. Contudo, apenas 2% dos 103 isolados foram capazes de solubilizar fosfato de cálcio. Estes resultados comprovam o potencial biotecnológico desses microrganismos

ACTINOMYCIN “D” FROM MARINE SEDIMENT ASSOCIATED STREPTOMYCES CAPILLISPIRALIS MTCC10471

In our screening program for new bio-active metabolites from marine actinomycetes, a cyclic depsipeptide wasfound in the fermentation medium of marine Strepromyces (SS23/4) isolated from sediments collected from Bayoff Bengal, vellampattai,Tamilnadu. It showed strong biological activity against gram-positive / gram negativebacteria by agar overlay technique. It was taxonomically characterized by the basis of morphological andphenotypic characteristics, genotypic data and phylogenetic showing Streptomyces sps. Bio active compoundwas obtained by solvent extraction and purification using column chromatography followed by reverse phaseHPLC. The pure compound had potent activity against Mycobacterium tuberculosis and Multi Drug ResistantMycobacterium tuberculosis strains (437RU) at a concentration of 10 μg/mL, and The minimum inhibitoryconcentration (MIC) against standard test organisms was found to be 1μg/mL against B.subtilis, E.coli andMethicillin resistant Staphylococcus aureus. The compound exhibited potent cytotoxic activity against breastcarcinoma (MCF-7), melanoma cells (A375), prostate carcinoma (DU145) and lung carcinoma (A549) cellswith IC values 20μg/ml. The symbiotic Streptomyces capillispiralis MTCC 10471 produces crude antibiotic30mg/Lt by using nonoptimized fermentation conditions. The structure of the antibiotic was explained by 1D,2D NMR and LC-ESI-MS/MS, MALDI-TOF/MS experiments, revealed that it belongs to cyclic ploy peptideActinomycin D

Mosquito survey and larvicidal activity of actinobacterial isolates against Culex larvae (Diptera: Culicidae)

AbstractThe present study aims to survey and identify the mosquito vector distribution throughout the Bharathidasan University Campus, Tiruchirappalli district, Tamil Nadu, India. Mosquito larvae were collected during October 2012–December 2012 from different breeding habitats. The survey revealed the presence of Aedes sp., Anopheles sp. and Culex sp. mosquito larvae. Among them Culex is dominant, in particularly Culex pipiens followed by Culex quinquifasciatus. Totally 41 actinobacterial isolates were isolated from soil and screened for the production of larvicidal metabolites against the 3rd instar Culex larvae. The obtained data exhibited that the isolated metabolites have lethal effects. Five isolates have shown a most significant mortality rate of the Culex mosquito larvae. In the biolarvicidal assay 1000ppm concentration of the isolate KA13-3 showed 100% mortality and KA25-A showed 90% mortality after 24h of incubation

Occurrence and extracellular enzyme potential of Actinomycetes of a thermoltalerant, northern region of Karanataka, Inida

Occurrence and extracellular enzyme activities of a thermotalerent actinomycetes isolated from thermal spring of compost pit area, hair, feathers dumping places and municipal wastes of Gulbarga and Bellary (Northern part of Karnataka) and tested their degradability against hair and feather. A total of 67 actinomycetes were isolated, out of these 57 actinomycetes screened exhibited amylase, protease, chitinase, cellulase and keratinase activity determined in the petriplate using on starch casein agar (SCA) and nutrient agar media (NA). Out of 57 actinomycetes, 50 isolates showed amylase, 54 protease, 50 chitenase, 52 cellulase and 41 isolates showed keratinase activities respectively. The Maximum keratinase activity shows VSAC-12, this study shows that the isolates were found to be capable using keratin substrates as sole source of carbon and energy for further investigation

Ashbya gossypii beyond industrial riboflavin production: a historical perspective and emerging biotechnological applications

The filamentous fungus Ashbya gossypii has been safely and successfully used for more than two decades in the commercial production of riboflavin (vitamin B2). Its industrial relevance combined with its high genetic similarity with Saccharomyces cerevisiae together promoted the accumulation of fundamental knowledge that has been efficiently converted into a significant molecular and in silico toolbox for its genetic engineering. This synergy has enabled a directed and sustained exploitation of A. gossypii as an industrial riboflavin producer. Although there is still room for optimizing riboflavin production, the recent years have seen an abundant advance in the exploration of A. gossypii for other biotechnological applications, such as the production of recombinant proteins, single cell oil and flavour compounds. Here, we will address the biotechnological potential of A. gossypii beyond riboflavin production by presenting (a) a physiological and metabolic perspective over this fungus; (b) the molecular toolbox available for its manipulation; and (c) commercial and emerging biotechnological applications for this industrially important fungus, together with the approaches adopted for its engineering.The authors thank the financial support from the Fundacao para a Ciencia e a Tecnologia (FCT), Portugal, through the Strategic Project of UID/BIO/04469/2013 unit (Post-Doc fellowship UMINHO/BPD/36/2015 to T. Q. Aguiar), the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes", REF. NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER

NUMERICAL STUDY ON SOME ACTINOMYCETES ISOLATED FROM BURULLOS LAKE IN EGYPT

Twenty nine actinomycetes isolates were isolated from Burullos Lake and characterized taxonomically for 62 phenotypic traits including morphological; biochemical, nutritional, substrate utilization and anti-microbial activities.  The results were analyzed by numerical techniques using the simple matching coefficient (SSM) and UPGMA clustering. At 54% similarity level, the majority of the isolates were grouped into six phena (A, B, C, D, E and F). Only two isolates were grouped separately and formed two single clusters at the same level of similarity. A representative isolate from each phenon was identified. The isolates were found to be Streptoverticillum morookaense, Nocardia brasiliensis, Streptomyces alanosinicus, Streptomyces globosus and Streptomyces gancidicu