Scholarlink

<p>Red seaweeds host diverse bacterial communities, including epiphytic and endophytic microbes, which contribute to host defence and offer potential sources of bioactive secondary metabolites. <i>Gelidium pusillum</i> (<i>G. pusillum</i>), a red alga, remains underexplored for its microbial diversity and potential therapeutic applications. This study aimed to isolate and characterize epiphytic and endophytic bacteria from <i>G. pusillum</i>, evaluate their secondary metabolites, and assess their antibacterial, antioxidant, and anti-inflammatory properties. Epiphytic and endophytic bacteria were isolated from fresh <i>G. pusillum</i> collected from Mandapam, India. Morphological, biochemical, and molecular characterization (16S rRNA sequencing) identified the isolates. Secondary metabolite extraction was done using ethyl acetate and tested for antibacterial activity (agar well diffusion), antioxidant capacity (2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Hydrogen peroxide (H₂O₂) assays), and anti-inflammatory potential (egg albumin denaturation assay). Fourier Transform Infrared Spectroscopy (FTIR) analysis identified functional groups, while Gas Chromatography-Mass Spectrometry (GC–MS) characterized the chemical constituents. The epiphytic bacterium was identified as <i>Vibrio harveyi</i> (<i>V. harveyi</i>)<i>,</i> and the endophyte as <i>Sphingomonas leidyi</i> (<i>S. leidyi</i>). Secondary Metabolites (SMs) from both isolates exhibited moderate to significant antibacterial activity against <i>Escherichia coli</i> (<i>E. coli</i>) and <i>Staphylococcus aureus</i> (<i>S. aureus</i>). Antioxidant assays and anti-inflammatory assays revealed concentration-dependent activity, with epiphytic SMs showing lower Half Maximal Inhibitory Concentration (IC₅₀) values than endophytic ones. FTIR confirmed the presence of bioactive functional groups, including phenols, carboxylates, and esters. GC–MS analysis revealed a wide array of structurally diverse compounds in both extracts, including diaziridinone, fluorinated propylamines, heptanoic acid ethyl ester, di-n-decylsulfone, and thiourea derivatives. Epiphytic and endophytic bacteria from <i>G. pusillum</i> produce bioactive metabolites with antibacterial, antioxidant, and anti-inflammatory potential. This highlights their promise as sources of therapeutic agents, warranting further purification and molecular characterization of active compounds.</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

Exploring bioactive potential of epiphytic and endophytic bacteria from Gelidium pusillum: a study on secondary metabolites and therapeutic applications

  • 期刊论文

  • 发表日期：

    2026年1月20日

查看全文
  • Akhila Ann Mathew,
  • Jethendra Kumar Muruganantham,
  • Ramakrishnan Veerabathiran

摘要

Red seaweeds host diverse bacterial communities, including epiphytic and endophytic microbes, which contribute to host defence and offer potential sources of bioactive secondary metabolites. Gelidium pusillum (G. pusillum), a red alga, remains underexplored for its microbial diversity and potential therapeutic applications. This study aimed to isolate and characterize epiphytic and endophytic bacteria from G. pusillum, evaluate their secondary metabolites, and assess their antibacterial, antioxidant, and anti-inflammatory properties. Epiphytic and endophytic bacteria were isolated from fresh G. pusillum collected from Mandapam, India. Morphological, biochemical, and molecular characterization (16S rRNA sequencing) identified the isolates. Secondary metabolite extraction was done using ethyl acetate and tested for antibacterial activity (agar well diffusion), antioxidant capacity (2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Hydrogen peroxide (H₂O₂) assays), and anti-inflammatory potential (egg albumin denaturation assay). Fourier Transform Infrared Spectroscopy (FTIR) analysis identified functional groups, while Gas Chromatography-Mass Spectrometry (GC–MS) characterized the chemical constituents. The epiphytic bacterium was identified as Vibrio harveyi (V. harveyi), and the endophyte as Sphingomonas leidyi (S. leidyi). Secondary Metabolites (SMs) from both isolates exhibited moderate to significant antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Antioxidant assays and anti-inflammatory assays revealed concentration-dependent activity, with epiphytic SMs showing lower Half Maximal Inhibitory Concentration (IC₅₀) values than endophytic ones. FTIR confirmed the presence of bioactive functional groups, including phenols, carboxylates, and esters. GC–MS analysis revealed a wide array of structurally diverse compounds in both extracts, including diaziridinone, fluorinated propylamines, heptanoic acid ethyl ester, di-n-decylsulfone, and thiourea derivatives. Epiphytic and endophytic bacteria from G. pusillum produce bioactive metabolites with antibacterial, antioxidant, and anti-inflammatory potential. This highlights their promise as sources of therapeutic agents, warranting further purification and molecular characterization of active compounds.