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

Purification and structure elucidation of three naturally bioactive molecules from the new terrestrial Streptomyces sp. TN17 strain

Thirty litres of fermentation broth was extracted from the newly isolated Streptomyces sp. strain TN17 and various separation and purification steps led to the isolation of three pure bioactive compounds (1–3). Compound 1: cyclo (L-Leu-L-Arg), a diketopiperazine ‘DKP’ derivative; 2: di-(2-ethylhexyl) phthalate, a phthalate derivative; and 3: cyclo 1-[2-(cyclopentanecarbonyl-3-phenyl-propionyl]-pyrrolidine-2-carboxylic acid (1-carbamoyl-propyl)-amide, a cyclic tetrapeptide derivative. The chemical structure of these three active compounds was established on the basis of spectroscopic studies (MS and NMR) and by comparison with data from the literature. According to our biological studies, the pure compounds (1–3) possess antibacterial and antifungal activities

Taxonomy, purification and chemical characterization of four bioactive compounds from new Streptomyces sp. TN256 strain

A new actinomycete strain designated TN256, producing antimicrobial activity against pathogenic bacteria and fungi, was isolated from a Tunisian Saharan soil. Morphological and chemical studies indicated that strain TN256 belonged to the genus Streptomyces. Analysis of the 16S rDNA sequence of strain TN256 showed a similarity level ranging between 99.79 and 97.8% within Streptomyces microflavus DSM 40331T and Streptomyces griseorubiginosus DSM 40469T respectively. The comparison of its physiological characteristics showed significant differences with the nearest species. Combined analysis of the 16 S rRNA gene sequences (FN687758), fatty acids profile, and results of physiological and biochemical tests indicated that there were genotypic and phenotypic differentiations of that isolate from other Streptomyces species neighbours. These date strongly suggest that strain TN256 represents a novel species with the type strain Streptomyces TN256 (=CTM50228T). Experimental validation by DNA–DNA hybridization would be required for conclusive confirmation. Four active products (1–4) were isolated from the culture broth of Streptomyces TN256 using various separation and purification steps and procedures. 1: N-[2-(1H-indol-3-yl)-2 oxo-ethyl] acetamide ‘alkaloid’ derivative; 2: di-(2-ethylhexyl) phthalate, a phthalate derivative; 3: 1-Nonadecene and 4: Cyclo (l-Pro-l-Tyr) a diketopiperazine ‘DKP’ derivative. The chemical structure of these four active compounds was established on the basis of spectroscopic studies NMR and by comparing with data from the literature. According to our biological studies, we showed in this work that the pure compounds (1–4) possess antibacterial and antifungal activities

Ruta montana L. leaf essential oil and extracts

The aims of this study were to assess the antimicrobial efficacy of the leaf essential oil and the leaf extracts of R. montana against Botrytis cinerea, Fusarium oxysporum, Verticillium dahliae, Aspergillus oryzae and Fusarium solani. The oil (1.000 µg/disk) and the extracts (1.500 µg/disk) revealed a remarkable antifungal effect against the tested plant pathogenic fungi with a radial growth inhibition percentage of 40.0–80.0 % and 5.0–58.0 %, respectively along with their respective MIC values ranging from 100 to 1100 µg/mL and 250 to 3000 µg/mL. The oil had a strong detrimental effect on spore germination of all the tested plant pathogens along with the concentration as well as time-dependent kinetic inhibition of Fusarium oxysporum. Also, the oil exhibited a potent in vivo antifungal effect against Botrytis cinerea on tomato plants. Experiments carried out in plant revealed that the essential oil was slightly effective in suppression of gall formation induced by Agrobacterium tumefaciens on bitter almond. The results of this study indicate that the oil and extracts of R. montana leaves could become natural alternatives to synthetic fungicides to control certain important plant microbial diseases. The GC–MS analysis determined that 28 compounds, which represented 89.03 % of total oil, were present in the oil containing mainly 1-butene, methylcyclopropane, 2-butene and caryophyllene oxide

Purification et Caractérisation de Biomolécules à partir de microorganismes nouvellement isolés et identifiés

Au cours de ce travail de thèse, nous nous sommes intéressés aux études taxonomiques des deux souches TN17 et Fr10 qui sont deux nouvelles espèces du genre Streptomyces dont nous avons proposé les nomenclatures suivantes : Streptomyces lilaceus sp. TN17 et Streptomyces microflavus sp. Fr10. A partir de la souche Streptomyces lilaceus sp. TN17, trois molécules on été purifiées et identifiées par le biais de plusieurs techniques spectroscopiques, il s’agit d’un dérivé de DKP (L-Leu, L-Arg), un dérivé de phtalate le di-(2-éthylhexyl) phtalate et un tértrapeptide cyclique : le 1 - [2 -(cyclopentanecarbonyl-3-phenylpropionyl] – pyrrolidine-2-carboxylique (1-carbamoyl-propyl)-amide. Ces trois molécules présentent des activités antibactériennes et antifongiques. Suite au criblage des souches de bactéries lactiques productrices de bactériocines de la collection de notre laboratoire et leurs caractérisations, nous avons identifié une nouvelle souche de Lactobacillus nommée Lactobacillus plantarum sp.TN635 qui produit une bactériocine « BacTN635 » de 3,8 KDa. Cette dernière a été purifiée à homogénéité, elle possède un spectre d’action très large contre les bactéries à Gram+, à Gram- et contre les champignons filamenteux et unicellulaires. BacTN635 a un effet bactéricide contre Listeria ivanovii BUG 496 et fongistatique contre Candida tropicalis R2 CIP203

Purification et Caractérisation de Biomolécules à partir de microorganismes nouvellement isolés et identifiés

Au cours de ce travail de thèse, nous nous sommes intéressés aux études taxonomiques des deux souches TN17 et Fr10 qui sont deux nouvelles espèces du genre Streptomyces dont nous avons proposé les nomenclatures suivantes : Streptomyces lilaceus sp. TN17 et Streptomyces microflavus sp. Fr10. A partir de la souche Streptomyces lilaceus sp. TN17, trois molécules on été purifiées et identifiées par le biais de plusieurs techniques spectroscopiques, il s’agit d’un dérivé de DKP (L-Leu, L-Arg), un dérivé de phtalate le di-(2-éthylhexyl) phtalate et un tértrapeptide cyclique : le 1 - [2 -(cyclopentanecarbonyl-3-phenylpropionyl] – pyrrolidine-2-carboxylique (1-carbamoyl-propyl)-amide. Ces trois molécules présentent des activités antibactériennes et antifongiques. Suite au criblage des souches de bactéries lactiques productrices de bactériocines de la collection de notre laboratoire et leurs caractérisations, nous avons identifié une nouvelle souche de Lactobacillus nommée Lactobacillus plantarum sp.TN635 qui produit une bactériocine « BacTN635 » de 3,8 KDa. Cette dernière a été purifiée à homogénéité, elle possède un spectre d’action très large contre les bactéries à Gram+, à Gram- et contre les champignons filamenteux et unicellulaires. BacTN635 a un effet bactéricide contre Listeria ivanovii BUG 496 et fongistatique contre Candida tropicalis R2 CIP203. ABSTRACT : In This Thesis, we are interested in taxonomic studies of two strains TN17 and Fr10 which are two new species of the genus Streptomyces, and we have proposed the following names: Streptomyces lilaceus sp. TN17 and Streptomyces microflavus sp. Fr10. From Streptomyces lilaceus strain sp. TN17, three molecules have been purified and identified by means of several spectroscopic techniques, it is a derivative of DKP (L-Leu, Larg), a derivative of phthalate di-(2-ethylhexyl) phthalate and cyclic peptide 1 - [2 - (cyclopentanecarbonyl-3-phenylpropionyl] - pyrrolidine-2-carboxylic acid (1-carbamoylpropyl)- amide. All three molecules exhibit antibacterial and antifungal activities. A novel strain of lactic acid bacteria was isolated and characterized from a collection of our laboratory. It’s identified as a new strain of Lactobacillus, named Lactobacillus plantarum sp.TN635 producing a new bacteriocin "BacTN635" of 3.8 kDa, purified to homogeneity and spectrum with a very broad action against Gram + and Gram-, filamentous and unicellular fungi. BacTN635 has a bactericidal effect against Listeria ivanovii BUG 496 and fungistatic against Candida tropicalis R2 CIP203

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

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

Sickle cell disease: current drug treatments and functional foods with therapeutic potential

Miguel Brito gratefully acknowledges the FCT/MCTES national support through the projects H&TRC UIDB/05608/2020, UIDP/05608/2020, and IPL/IDI&CA2023/Ipasthma_ESTeSL. J.M. Oliveira acknowledges the financial support of CICECO–Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC). Ana Paula Arez would like to acknowledge Fundação para a Ciência e a Tecnologia for funds to GHTM—UID/04413/2020 and LA-REAL LA/P/0117/2020.Sickle cell anemia (SCA), the most common form of sickle cell disease (SCD), is a genetic blood disorder. Red blood cells break down prematurely, causing anemia and often blocking blood vessels, leading to chronic pain, organ damage, and increased infection risk. SCD arises from a single-nucleotide mutation in the β-globin gene, substituting glutamic acid with valine in the β-globin chain. This review examines treatments evaluated through randomized controlled trials for managing SCD, analyzes the potential of functional foods (dietary components with health benefits) as a complementary strategy, and explores the use of bioactive compounds as functional food ingredients. While randomized trials show promise for certain drugs, functional foods enriched with bioactive compounds also hold therapeutic potential. Further research is needed to confirm clinical efficacy, optimal dosages, and specific effects of these compounds on SCD, potentially offering a cost-effective and accessible approach to managing the disease.info:eu-repo/semantics/publishedVersio

Inhibition of Fungi and Gram-Negative Bacteria by Bacteriocin BacTN635 Produced by Lactobacillus plantarum sp. TN635

The aim of this study was to evaluate 54 lactic acid bacteria (LAB) strains isolated from meat, fermented vegetables and dairy products for their capacity to produce antimicrobial activities against several bacteria and fungi. The strain designed TN635 has been selected for advanced studies. The supernatant culture of this strain inhibits the growth of all tested pathogenic including the four Gram-negative bacteria (Salmonella enterica ATCC43972, Pseudomonas aeruginosa ATCC 49189, Hafnia sp. and Serratia sp.) and the pathogenic fungus Candida tropicalis R2 CIP203. Based on the nucleotide sequence of the 16S rRNA gene of the strain TN635 (1,540 pb accession no FN252881) and the phylogenetic analysis, we propose the assignment of our new isolate bacterium as Lactobacillus plantarum sp. TN635 strain. Its antimicrobial compound was determined as a proteinaceous substance, stable to heat and to treatment with surfactants and organic solvents. Highest antimicrobial activity was found between pH 3 and 11 with an optimum at pH = 7. The BacTN635 was purified to homogeneity by a four-step protocol involving ammonium sulfate precipitation, centrifugal microconcentrators with a 10-kDa membrane cutoff, gel filtration Sephadex G-25, and C18 reverse-phase HPLC. SDS-PAGE analysis of the purified BacTN635, revealed a single band with an estimated molecular mass of approximately 4 kDa. The maximum bacteriocin production (5,000 AU/ml) was recorded after a 16-h incubation in Man, Rogosa, and Sharpe (MRS) medium at 30 °C. The mode of action of the partial purified BacTN635 was identified as bactericidal against Listeria ivanovii BUG 496 and as fungistatic against C. tropicalis R2 CIP203

Natural antioxidants from agro-industrial by-products and applications in foods

With about one-third of foods produced around the globe is wasted and never consumed, the issue of food waste and loss continues to be one of the major challenges to food sustainability and food security. This chapter will first look at recent literature on various natural antioxidants that can be extracted from agro-industrial by-products, such as fruits and vegetable by-products (skin, peels, pomace, seeds, husk, etc.), grains and oilseeds by-products (bran, press cakes, meal, etc.), and dairy, meat, and poultry by-products (whey, skin, viscera, etc.). Then, traditional and emerging techniques used to recover these natural antioxidants from agro-industrial waste and by-products will be discussed, and examples of their applications in various food categories will be presented. Finally, limitations, future prospects, and conclusions will be described. © 2024 Elsevier Inc. All rights reserved