CONTEXT

• Antimicrobial resistance (AMR) is a growing global health threat. WHO projects AMR may cost $1 trillion in healthcare by 2050.
• The search for new antibiotics is critical as existing ones lose effectiveness; discovery of natural antibiotic producers is vital.
• Hot springs, due to their extreme conditions, host thermophilic bacteria — potential sources of novel antibiotics.
• Indian hot springs remain underexplored microbiologically compared to other global sites.

CONCEPT

• Thermophiles are heat-loving bacteria surviving 45–70°C, where most organisms perish.
• In nutrient-rich but competitive habitats like hot springs, thermophiles often produce antibiotics to suppress rival microbes.
• Actinobacteria, a group of such bacteria, are renowned antibiotic producers (e.g., streptomycin, tetracycline).
• 16S rRNA metagenomics is used to identify bacterial diversity by analyzing a conserved gene common across species.
• Gas Chromatography-Mass Spectrometry (GC-MS) helps isolate and identify bioactive compounds.

CURRENT (RAJGIR HOT SPRING STUDY)

• Conducted by: Vellore Institute of Technology (VIT), Tamil Nadu.
• Location: Rajgir hot spring lake, Nalanda district, Bihar.
• Temperature: 43–45°C soil; ~45°C water.
• Findings:
  • Identified diverse thermophilic microbes; Actinobacteria constituted 40–43% of the microbial population — unusually high.
  • Seven Actinobacteria strains found to produce antimicrobials effective against E. coli, Salmonella, Klebsiella, Pseudomonas, and Staphylococcus.
  • Diethyl phthalate, an antibacterial compound, was isolated — shown to inhibit Listeria monocytogenes, a deadly foodborne pathogen.
• Applications:
  • Medical: New antibiotic possibilities.
  • Industrial: Enzymes from thermophiles used in PCR tests (e.g., Thermus aquaticus).
  • Agricultural: Soil microbes from hot springs promote plant growth; useful in sustainable farming.