整合生物学期刊网

应用天然产物 ›› 2024, Vol. 14 ›› Issue (5): 40-40.DOI: 10.1007/s13659-024-00460-0

• ORIGINAL ARTICLES • 上一篇    下一篇

Hibiscus acid and hydroxycitric acid dimethyl esters from Hibiscus flowers induce production of dithiolopyrrolone antibiotics by Streptomyces Strain MBN2-2

Felaine Anne Sumang1, Alan Ward2, Jeff Errington1,3, Yousef Dashti1,3   

  1. 1. Faculty of Medicine and Health, University of Sydney, Sydney, NSW, 2015, Australia;
    2. School of Biology, Newcastle University, Newcastle Upon Tyne, UK;
    3. Sydney Infectious Diseases Institute, University of Sydney, Sydney, NSW, 2015, Australia
  • 收稿日期:2024-05-24 出版日期:2024-10-24 发布日期:2024-10-14
  • 通讯作者: Yousef Dashti,E-mail:yousef.dashti@sydney.edu.au
  • 基金资助:
    This work was funded by an ARC Australian Laureate Fellowship (grant number FL210100071) to JE. FAS is supported by DOST-SEI Foreign Graduate Scholarship Program.

Hibiscus acid and hydroxycitric acid dimethyl esters from Hibiscus flowers induce production of dithiolopyrrolone antibiotics by Streptomyces Strain MBN2-2

Felaine Anne Sumang1, Alan Ward2, Jeff Errington1,3, Yousef Dashti1,3   

  1. 1. Faculty of Medicine and Health, University of Sydney, Sydney, NSW, 2015, Australia;
    2. School of Biology, Newcastle University, Newcastle Upon Tyne, UK;
    3. Sydney Infectious Diseases Institute, University of Sydney, Sydney, NSW, 2015, Australia
  • Received:2024-05-24 Online:2024-10-24 Published:2024-10-14
  • Contact: Yousef Dashti,E-mail:yousef.dashti@sydney.edu.au
  • Supported by:
    This work was funded by an ARC Australian Laureate Fellowship (grant number FL210100071) to JE. FAS is supported by DOST-SEI Foreign Graduate Scholarship Program.

摘要: Plants and microbes are closely associated with each other in their ecological niches. Much has been studied about plant-microbe interactions, but little is known about the effect of phytochemicals on microbes at the molecular level. To access the products of cryptic biosynthetic gene clusters in bacteria, we incorporated an organic extract of hibiscus flowers into the culture media of different Actinobacteria isolated from plant rhizospheres. This approach led to the production of broad-spectrum dithiolopyrrolone (DTP) antibiotics, thiolutin (1) and aureothricin (2), by Streptomyces sp. MBN2-2. The compounds from the hibiscus extract responsible for triggering the production of these two DTPs were found to be hibiscus acid dimethyl ester (3) and hydroxycitric acid 1,3-dimethyl ester (4). It was subsequently found that the addition of either Fe2+ or Fe3+ to culture media induced the production of 1 and 2. The Chrome Azurol S (CAS) assay revealed that 3 and 4 can chelate iron, and therefore, the mechanism leading to the production of thiolutin and aureothricin appears to be related to changes in iron concentration levels. This work supports the idea that phytochemicals can be used to activate the production of cryptic microbial biosynthetic gene clusters and further understand plant-microbe interactions.

关键词: Plant–microbe interactions, Cryptic biosynthetic gene cluster, Streptomyces, Microbial natural products

Abstract: Plants and microbes are closely associated with each other in their ecological niches. Much has been studied about plant-microbe interactions, but little is known about the effect of phytochemicals on microbes at the molecular level. To access the products of cryptic biosynthetic gene clusters in bacteria, we incorporated an organic extract of hibiscus flowers into the culture media of different Actinobacteria isolated from plant rhizospheres. This approach led to the production of broad-spectrum dithiolopyrrolone (DTP) antibiotics, thiolutin (1) and aureothricin (2), by Streptomyces sp. MBN2-2. The compounds from the hibiscus extract responsible for triggering the production of these two DTPs were found to be hibiscus acid dimethyl ester (3) and hydroxycitric acid 1,3-dimethyl ester (4). It was subsequently found that the addition of either Fe2+ or Fe3+ to culture media induced the production of 1 and 2. The Chrome Azurol S (CAS) assay revealed that 3 and 4 can chelate iron, and therefore, the mechanism leading to the production of thiolutin and aureothricin appears to be related to changes in iron concentration levels. This work supports the idea that phytochemicals can be used to activate the production of cryptic microbial biosynthetic gene clusters and further understand plant-microbe interactions.

Key words: Plant–microbe interactions, Cryptic biosynthetic gene cluster, Streptomyces, Microbial natural products