Streptomyces tunisialbus sp. nov., a novel Streptomyces species with antimicrobial activity

• Published in: Antonie van Leeuwenhoek Vol. 111; no. 9; pp. 1571 - 1581
• Main Authors: Ayed, Ameni, Slama, Nedra, Mankai, Houda, Bachkouel, Sarra, ElKahoui, Salem, Tabbene, Olfa, Limam, Ferid
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.09.2018; Springer Nature B.V
• Subjects: Anti-Infective Agents - isolation & purification; Anti-Infective Agents - pharmacology; Antibacterial activity; Antifungal activity; Antimicrobial activity; Antimicrobial agents; Bacteria - drug effects; Base Composition; Biomedical and Life Sciences; Deoxyribonucleic acid; Diaminopimelic Acid - chemistry; Diphosphatidylglycerol; DNA; DNA topoisomerase; DNA, Bacterial - genetics; Fatty acids; Fatty Acids - chemistry; Fungi; Fungi - drug effects; Fungicides; Gene sequencing; Genes, Bacterial - genetics; Genome, Bacterial; Gram-negative bacteria; Hydrolysates; Lavandula - microbiology; Life Sciences; Lipids; Medical Microbiology; Menaquinones; Microbiology; Morphology; New species; Nucleic Acid Hybridization; Original Paper; Phenotype; Phosphatidylethanolamine; Phosphatidylglycerol; Phosphatidylinositol; Phospholipids - chemistry; Phylogenetics; Phylogeny; Physical characteristics; Plant Sciences; RecA protein; Rhizosphere; RNA, Ribosomal, 16S - genetics; RpoB protein; rRNA 16S; Soil Microbiology; Soil Science & Conservation; Streptococcus infections; Streptomyces; Streptomyces - chemistry; Streptomyces - classification; Streptomyces - genetics; Streptomyces - physiology; Tunisia; Vitamin K 2 - chemistry; Yeast; DNA–DNA relatedness; Rhizosphere; MLSA; Antimicrobial activity; Polyphasic taxonomy; Lavandula officinalis; Streptomyces
• ISSN: 0003-6072; 1572-9699
• DOI: 10.1007/s10482-018-1046-4

A novel actinomycete strain designated S2 T was isolated from Tunisian rhizosphere soil of Lavandula officinalis . This isolate exhibited broad spectrum antibacterial activity against several Gram-positive and Gram-negative bacteria and also antifungal activity against yeast and filamentous fungi. The isolate S2 T presents morphological and chemotaxonomic characteristics typical of the members of the genus Streptomyces . Whole cell hydrolysates of S2 T were found to contain LL-diaminopimelic acid. The major fatty acids were identified as C16:0, anteiso-C15:0 and iso-C16:0 whereas the predominant menaquinones were found to be MK-9(H6) and MK-9(H8). The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and three unidentified compounds. The G+C content of the genomic DNA was determined to be 71.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S2 T belongs to the genus Streptomyces and is closely related to Streptomyces netropsis DSM 40259 T with 99.86% sequence similarity. Multi-locus sequence analysis (MLSA) based on four house-keeping gene alleles ( gyrB , recA , trpB , rpoB ) showed that isolate S2 T is closely related to S. netropsis, with an MLSA distance greater than 0.007. The DNA–DNA relatedness between strain S2 T and its near phylogenetic neighbour was 63.6 ± 2.3%, which is lower than the 70% threshold value for delineation of genomic prokaryotic species. This isolate was also distinguished from the type strain S. netropsis DSM 40259 T , using a combination of morphological and physiological features. Based on its phenotypic and molecular properties, strain S2 T is considered to represent a novel species of the genus Streptomyces , for which the name Streptomyces tunisialbus sp. nov. is proposed. The type strain is S2 T (= JCM 32165 T  = DSM 105760 T ).