Scholarlink

<p>Thiolutin and 2,2-dioxidothiolutin are sulfur-containing antibiotics discovered through a targeted high-throughput screening strategy designed to identify compounds with antimicrobial activity. The producing strain, JHD1<sup>T</sup>, is an actinomycete isolated from marine sediment collected in Chonburi Province, Thailand. Chemotaxonomic characteristics and 16S rRNA gene sequence analysis indicated that strain JHD1<sup>T</sup> belongs to the genus <i>Streptomyces</i>. Taxonomic analysis using a polyphasic approach further supported its placement within the genus <i>Streptomyces</i>. The strain exhibited low similarity to its closest known relatives, <i>Streptomyces alkaliterrae</i> OF1<sup>T</sup> and <i>Streptomyces chumphonensis</i> KK1-2<sup>T</sup>, with average nucleotide identity based on MuMmer ultra-rapid aligning tool (ANIm) values of 85.7–86.2%, average amino acid identity (AAI) values of 71.8–78.1%, and digital DNA–DNA hybridization (dDDH) values of 23.4–25.0%, all well below the established thresholds for species delineation. These results reveal that strain JHD1<sup>T</sup> represents a novel species within the genus <i>Streptomyces</i>, for which the name <i>Streptomyces marinisediminis</i> sp. nov. is proposed. The crude extract obtained from the culture broth of strain JHD1<sup>T</sup> exhibited strong antimicrobial activity against Gram-positive bacteria and led to the discovery of two promising secondary metabolites, thiolutin and 2,2-dioxidothiolutin, along with 8-amino-2<i>H</i>-benz[<i>e</i>][1,3]oxazine-2,4(3<i>H</i>)-dione, benadrostin, 2,3-dihydroxybenzamide, and 2-hydroxy-3-methoxybenzamide. In this study, 2,2-dioxidothiolutin was structurally confirmed for the first time by X-ray crystallographic analysis. Interestingly, thiolutin demonstrated strong anti-human small cell lung cancer (NCI-H187) activity, with an IC₅₀ value of 0.35&#xa0;µg/mL, and also showed cytotoxicity against human breast cancer (MCF-7) cells, with an IC₅₀ value of 5.61&#xa0;µg/mL.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Discovery of Streptomyces marinisediminis sp. nov., a new thiolutin producing actinomycete isolated from Thai marine sediment

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年8月11日

查看全文
  • Rawirat Pansomsuay,
  • Poowadon Fukasem,
  • Pattama Pittayakhajonwut,
  • Chakapong Intaraudom,
  • Chanwit Suriyachadkun,
  • Montri Yasawong,
  • Ya-Wen He,
  • Somboon Tanasupawat,
  • Yang Qian,
  • Chitti Thawai

摘要

Thiolutin and 2,2-dioxidothiolutin are sulfur-containing antibiotics discovered through a targeted high-throughput screening strategy designed to identify compounds with antimicrobial activity. The producing strain, JHD1T, is an actinomycete isolated from marine sediment collected in Chonburi Province, Thailand. Chemotaxonomic characteristics and 16S rRNA gene sequence analysis indicated that strain JHD1T belongs to the genus Streptomyces. Taxonomic analysis using a polyphasic approach further supported its placement within the genus Streptomyces. The strain exhibited low similarity to its closest known relatives, Streptomyces alkaliterrae OF1T and Streptomyces chumphonensis KK1-2T, with average nucleotide identity based on MuMmer ultra-rapid aligning tool (ANIm) values of 85.7–86.2%, average amino acid identity (AAI) values of 71.8–78.1%, and digital DNA–DNA hybridization (dDDH) values of 23.4–25.0%, all well below the established thresholds for species delineation. These results reveal that strain JHD1T represents a novel species within the genus Streptomyces, for which the name Streptomyces marinisediminis sp. nov. is proposed. The crude extract obtained from the culture broth of strain JHD1T exhibited strong antimicrobial activity against Gram-positive bacteria and led to the discovery of two promising secondary metabolites, thiolutin and 2,2-dioxidothiolutin, along with 8-amino-2H-benz[e][1,3]oxazine-2,4(3H)-dione, benadrostin, 2,3-dihydroxybenzamide, and 2-hydroxy-3-methoxybenzamide. In this study, 2,2-dioxidothiolutin was structurally confirmed for the first time by X-ray crystallographic analysis. Interestingly, thiolutin demonstrated strong anti-human small cell lung cancer (NCI-H187) activity, with an IC₅₀ value of 0.35 µg/mL, and also showed cytotoxicity against human breast cancer (MCF-7) cells, with an IC₅₀ value of 5.61 µg/mL.