Abdelghani Zitouni - Academia.edu (original) (raw)

Papers by Abdelghani Zitouni

Advanced Research in Life Sciences, 2021

An actinobacterial strain named LG10 was isolated from a Saharan Atlas soil (Laghouat, Algeria). ... more An actinobacterial strain named LG10 was isolated from a Saharan Atlas soil (Laghouat, Algeria). The aerial hyphae were yellowish-white on all culture media with rectiflexibiles spore chains, suggested that this bacterium attached to Streptomyces. Furthermore, LG10 contained chemical characteristics that were diagnostic for the genus Streptomyces, such as the presence of LL-diaminopimelic acid isomer (LL-DAP) and glycine amino acid. The hydrolysates of whole-cell included non-characteristic sugars. Comparative analysis of the 16S rDNA sequence displayed a similarity level of 100% with Streptomyces puniceus NRRL ISP-5058T. The antimicrobial activity of the LG10 strain was better in the culture medium MB5. Streptomyces strains are good sources of bioactive compounds with multiple biological activities.

Geomicrobiology Journal, 2020

The Sahara, one of the most extreme environments on Earth, constitutes an unexplored source of al... more The Sahara, one of the most extreme environments on Earth, constitutes an unexplored source of alkalitolerant actinobacteria. ln this worl<, we studied the diversity of alkalitolerant actinobacteria in various soils collected from different regions of the Algerian Sahara. A total of 29 alkalitolerant actinobacterial strains were isolated by using a complex agar medium. The diversity of these acti nobacteria was evaluated using a polyphasic approach, which included morphological, chemotaxo nomic, physiological (numerical taxonomy) and 16S rRNA gene analyses. The isolates which were assigned to the genus Nocardiopsis, shared relatively low 16S rRNA gene sequences similarities compared to closely related species suggesting that they belonged to putatively new species. Ali of the strains were tested for antibiotic activity against a broad range of microorganisms and screened for genes encoding polyketide synthases and non-ribosomal peptide synthetases and found to have the potential to produce secondary metabolites. Consequently, the study supports the view that extrerne environments contain many nove! actinobacteria, which represent an unex plored source for the discovery of biologically active compounds.

Archives of Microbiology, 2020

Saccharothrix algeriensis NRRL B-24137 is an actinobacterium isolated from Algerian Saharan soil.... more Saccharothrix algeriensis NRRL B-24137 is an actinobacterium isolated from Algerian Saharan soil. This strain has the ability to produce several dithiolopyrrolone antibiotic derivatives depending on the precursors added to the culture medium. This group of antibiotics is known for their potent antimicrobial and anticancer activities. Holomycin is a member of the dithiolopyrrolone group of antibiotics, and has already been isolated from several species of actinobacteria belonging to the genus Streptomyces and also from some Gram-negative bacteria. In this study, holomycin was produced for the first time in the culture broth of a non-Streptomyces actinobacteria. This antibiotic was induced by adding 5 mM of L-cystine as precursor to the semi-synthetic fermentation broth of Sa. algeriensis NRRL B-24137 and then fully identified after HPLC purification. The minimum inhibitory concentrations (MIC) of holomycin were determined against several pathogenic microorganisms, including Escherichia coli ATCC 10536 Klebsiella pneumoniae CIP 82.91, Listeria monocytogenes CIP 82110, Staphylococcus aureus CIP 7625, Aspergillus carbonarius M333, Fusarium culmorum FC1, Candida albicans IPA 200. This antibiotic showed a broad-spectrum antimicrobial activity, inhibiting a variety of Gram-positive and Gram-negative bacteria, and micro-fungi.

Biocontrol Science and Technology, 2018

Biocontrol and plant-growthpromoting capacities of actinobacterial strains from the Algerian Saha... more Biocontrol and plant-growthpromoting capacities of actinobacterial strains from the Algerian Sahara and characterisation of Streptosporangium becharense SG1 as a promising biocontrol agent. (2018) Biocontrol Science and Technology, 28 (9). 858-873.

Letters in Applied Microbiology, 2018

Significance and Impact of the Study: Dithiolopyrrolone antibiotics, known for their strong antim... more Significance and Impact of the Study: Dithiolopyrrolone antibiotics, known for their strong antimicrobial activities, gained greater interest after the discovery of their antitumor properties. Depending on precursors added, Saccharothrix algeriensis NRRL B-24137 has the ability to produce several dithiolopyrrolones derivatives. Since biological activities of dithiolopyrrolones are related to their variable structure, discover of new natural analogues to be therapeutically explored remains a significant framework of research. In this study, a new dithiolopyrrolone derivative was purified from the fermentation broth of S. algeriensis NRRL B-24137. This new antibiotic, characterized as benzoyl-pyrrothine dithiolopyrrolone, was induced by adding cinnamic acid, as precursor, to a semi-synthetic medium.

Biocontrol Science and Technology, 2016

OATAO is an open access repository that collects the work of some Toulouse researchers and makes ... more OATAO is an open access repository that collects the work of some Toulouse researchers and makes it freely available over the web where possible.

South African Journal of Botany, 2016

International Journal of Systematic and Evolutionary Microbiology, 2016

The taxonomic position of a novel actinobacterium, strain SG1 T , isolated from a Saharan soil sa... more The taxonomic position of a novel actinobacterium, strain SG1 T , isolated from a Saharan soil sample collected from B eni-Abb es, B echar (south-west Algeria), was established by using a polyphasic approach. The microorganism had morphological and chemical features that were consistent with its classification in the genus Streptosporangium. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained ribose and glucose, but not madurose. The predominant menaquinones were MK-9(H 2) and MK-9(H 4). The polar lipid profile contained diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylhydroxymethylethanolamine, phosphatidylhydroxyethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. The predominant cellular fatty acids were C 17 : 1 !8c, iso-C 16 : 0 , 10-methyl C 17 : 0 , C 18 : 1 !9c and C 17 : 0. 16S rRNA gene sequence similarity analysis supported the classification of the isolate in the genus Streptosporangium and indicated that it was related most closely to 'Streptosporangium subfuscum' DSM 46724 (99.7 % similarity), Streptosporangium pseudovulgare DSM 43181 T (98.7 %), Streptosporangium fragile DSM 43847 T (98.6 %) and Streptosporangium sandarakinum DSM 45763 T (98.5 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SG1 T formed a cluster with its closest relative 'S. subfuscum' DSM 46724. However, DNA-DNA relatedness as well as physiological and chemotaxonomical analyses showed that strain SG1 T could be differentiated from its closest phylogenetic relatives. Therefore, it is proposed that strain SG1 T should be classified as representing a novel species in the genus Streptosporangium, for which the name Streptosporangium becharense sp. nov. is proposed. The type strain is SG1 T (=DSM 46887 T =CECT 8961 T). The GenBank /EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain 33 SG1 T is KU593506. Two supplementary figures and one supplementary table are available with the online Supplementary Material.

Antonie van Leeuwenhoek, 2014

A halophilic actinomycete strain, designated H27(T), was isolated from a soil sample collected fr... more A halophilic actinomycete strain, designated H27(T), was isolated from a soil sample collected from a hypersaline habitat in Djelfa Province (North-Central Algeria), and then investigated using a polyphasic taxonomic approach. The strain was observed to produce poor aerial mycelium, which formed short chains of oval to cylindrical-shaped spores at maturity, and non fragmented substrate mycelium. The optimum NaCl concentration for growth was found to be 10-15 % (w/v) and the optimum growth temperature and pH were found to be 28-37 °C and 6-7, respectively. The diagnostic diamino acid in the cell-wall peptidoglycan was identified as meso-diaminopimelic acid. The predominant menaquinones of strain H27(T) were identified as MK-11 (H4) and MK-10 (H6). The major fatty acids were found to be iso-C16:0, anteiso-C17:0, 10 methyl C17:0 and 10 methyl C16:0. The diagnostic phospholipids detected were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and...

International journal of systematic and evolutionary microbiology, Jan 30, 2015

A moderately halophilic actinomycete strain, designated AH97T, was isolated from Saharan soil in ... more A moderately halophilic actinomycete strain, designated AH97T, was isolated from Saharan soil in the Hoggar region (south Algeria) and was subjected to polyphasic taxonomic characterization. The morphological and chemotaxonomic characteristics of the strain were consistent with those of the genus Actinoalloteichus. Results of 16S rRNA gene sequence comparison revealed that strain AH97T shared the highest degree of 16S rRNA gene sequence similarity with Actinoalloteichus hymeniacidonis DSM 45092T (99.3 %) and Actinoalloteichus nanshanensis DSM 45655T (98.7 %). However, DNA-DNA hybridization studies showed only 26.5 % relatedness with A. hymeniacidonis DSM 45092T and 28.0 % with A. nanshanensis. The genotypic and phenotypic data showed that the strain AH97T represents a novel species of the genus Actinoalloteichus, for which the name Actinoalloteichus hoggarensis sp. nov. is proposed, with AH97T (=DSM 45943T =CECT 8639T) as the type strain.

Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology], 2011

A moderately halophilic actinomycete strain designated AH97 was isolated from a saline Saharan so... more A moderately halophilic actinomycete strain designated AH97 was isolated from a saline Saharan soil, and selected for its antimicrobial activities against bacteria and fungi. The AH97 strain was identified by morphological, chemotaxonomic and phylogenetic analyses to the genus Actinoalloteichus. Analysis of the 16S rDNA sequence of strain AH97 showed a similarity level ranging between 95.8% and 98.4% within Actinoalloteichus species, with A. hymeniacidonis the most closely related. The comparison of the physiological characteristics of AH97 with those of known species of Actinoalloteichus showed significant differences. Strain AH97 showed an antibacterial and antifungal activity against broad spectrum of microorganisms known to be human and plant pathogens. The bioactive compounds were extracted from the filtrate culture with n-butanol and purified using thin layer chromatography and high pressure liquid chromatography procedures. Two active products were isolated, one hydrophilic f...

Journal of Basic Microbiology, 2014

An actinomycete strain named IA1, which produced an antimicrobial compound, was isolated from a S... more An actinomycete strain named IA1, which produced an antimicrobial compound, was isolated from a Saharan soil in In Amenas, Algeria. The study of the 16S rDNA sequence of this strain permitted to relate it to Streptomyces mutabilis NBRC 12800 T (99.93% of similarity). Strain IA1 exhibited strong activity against a wide range of plant pathogenic fungi. One bioactive compound produced in large amounts (46.7 mg L À1 day À1), named YA, was isolated and purified by TLC and reverse phase HPLC. The structure elucidation of the pure substance, using combined data from UV visible, NMR spectra, and mass spectrometry, permitted to identify it as actinomycin D, and was thus found for the first time in S. mutabilis related species. The biocontrol abilities of the strain IA1 and compound YA were evaluated through two diseases, i.e., chocolate spot of field bean and Fusarium wilt of flax. The occurrence of the two fungal diseases was effectively reduced. The reduction of chocolate spot disease symptoms reached 80 and 91.7% with IA1 and YA seedlings pretreatments, respectively. Soil pretreatment with IA1 or YA also allowed to reduce Fusarium wilt disease impact by almost 60%.

International Journal of Systematic and Evolutionary Microbiology, 2015

Actinomycete strain SA198T, isolated from a Saharan soil sample of Algeria, was characterized tax... more Actinomycete strain SA198T, isolated from a Saharan soil sample of Algeria, was characterized taxonomically by using a polyphasic approach. Chemotaxonomic and morphological characteristics observed suggested that it was a member of the genus Saccharothrix . The 16S rRNA gene sequence analysis confirmed that strain SA198T was a member of the genus Saccharothrix and showed a similarity level ranging between 97.5 and 98.9 % within species of the genus Saccharothrix , Saccharothrix australiensis being the most closely related. However, DNA–DNA hybridization values between strain SA198T and its closest phylogenetic neighbours, the type strains of S. australiensis , Saccharothrix xinjiangensis , Saccharothrix algeriensis and Saccharothrix espanaensis , were clearly below the 70 % threshold. Based upon genotypic and phenotypic differences from other members of the genus, a novel species, Saccharothrix tamanrassetensis sp. nov., is proposed, with SA198T ( = DSM 45947T = CECT 8640T) as the t...

Annals of Microbiology, 2014

An actinomycete strain designated G60 was isolated from a Saharan soil sample in Ghardaïa, Algeri... more An actinomycete strain designated G60 was isolated from a Saharan soil sample in Ghardaïa, Algeria, by a dilution agar plating method using chitin-vitamin agar medium supplemented with penicillin. Morphological and chemical studies indicated that this strain belonged to the genus Streptomyces. Analysis of the 16S rDNA sequence showed an identity level within Streptomyces species, with S. coerulescens ISP 5146 T and S. bellus ISP 5185 T the most closely related (100 % for each). However, the comparison of the morphological and physiological characteristics of the strain with those of the two nearest species showed significant differences. Strain G60 had a very strong activity against pathogenic staphylococci, including methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300, other clinical isolates of MRSA and vancomycin resistant S. aureus (VRSA) S1. One antimicrobial compound was extracted by n-hexane from the ISP2 culture medium at 5 days of fermentation culture and purified by HPLC. The chemical structure of the compound was determined after spectroscopic (1 H NMR, 13 C NMR, 1 H-1 H COSY and 1 H-13 C HMBC spectra), and spectrometric (mass spectrum) analyses. The bioactive compound was identified as di-(2-ethylhexyl) phthalate.

World Journal of Microbiology and Biotechnology, 2013

Twenty-seven endophytic actinomycete strains were isolated from five spontaneous plants well adap... more Twenty-seven endophytic actinomycete strains were isolated from five spontaneous plants well adapted to the poor sandy soil and arid climatic conditions of the Algerian Sahara. Morphological and chemotaxonomical analysis indicated that twenty-two isolates belonged to the Streptomyces genus and the remaining five were non-Streptomyces. All endophytic strains were screened for their ability to produce indole-3-acetic acid (IAA) in vitro on a chemically defined medium. Eighteen strains were able to produce IAA and the maximum production occurred with the Streptomyces sp. PT2 strain. The IAA produced was further extracted, partially purified and confirmed by thin layer chromatography (TLC) analysis. The 16S rDNA sequence analysis and phylogenetic studies indicated that strain PT2 was closely related to Streptomyces enissocaecilis NRRL B 16365 T , Streptomyces rochei NBRC 12908 T and Streptomyces plicatus NBRC 13071 T , with 99.52 % similarity. The production of IAA was affected by cultural conditions such as temperature, pH, incubation period and L-tryptophan concentration. The highest level of IAA production (127 lg/ml) was obtained by cultivating the Streptomyces sp. PT2 strain in yeast extract-tryptone broth supplemented with 5 mg L-tryptophan/ml at pH 7 and incubated on a rotary shaker (200 rpm) at 30°C for 5 days. Twenty-four-hour treatment of tomato cv. Marmande seeds with the supernatant culture of Streptomyces sp. PT2 that contained the crude IAA showed the maximum effect in promoting seed germination and root elongation.

Research in Microbiology, 2005

Microbiological Research, 2006

A new actinomycete strain designated Sg 10, producing antimicrobial substances was isolated from ... more A new actinomycete strain designated Sg 10, producing antimicrobial substances was isolated from an Algerian soil. Morphological and chemical studies indicated that strain Sg 10 belonged to the genus Streptosporangium. The comparison of its physiological characteristics with those of known species of Streptosporangium showed significant differences with the nearest species Streptosporangium carneum. Analysis of the 16S rDNA sequence of strain Sg 10 showed a similarity level ranging between 96.3% and 97.8% within Streptosporangium species, with S. carneum the most closely related. However, the phylogenetic analysis indicated that strain Sg 10 represent a distinct phyletic line suggesting a new genomic species. The antimicrobial activity of strain Sg 10 showed an antibacterial activity against Gram-positive bacteria as well as an antifungal one. Four active products were isolated from the culture broth using various separation procedures. On the basis of UV-VIS spectrometry, infrared spectroscopy and chemical revelations, the antibiotics were classified in the group of glycosylated aromatics.

Microbiological Research, 2014

Letters in Applied Microbiology, 2012

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

The Journal of Antibiotics, 2010