A new peer-reviewed study published in Applied Microbiology and Biotechnology evaluated the effectiveness of visible light in the 400-420 nm range for the inactivation of Mycobacterium tuberculosis (Mtb), the bacterium responsible for tuberculosis.

The research, conducted under BSL-3 biosafety conditions by the University of Rome Tor Vergata and IRCCS San Raffaele, tested UV-free visible LED exposure without external photosensitizers.

Biovitae LED technology was directly used as the light source during testing.

The challenge: environmental persistence and resistance

Mtb is characterized by:

  • high environmental resilience
  • prolonged surface survival
  • increasing antibiotic resistance

These factors require continuous, safe, and deployable disinfection strategies.

The results

Samples exposed to visible light (400–420 nm) showed:

  • significant reduction in bacterial viability
  • 99% (>2-log) decrease in Mtb load
  • clear dose-response relationship
  • no chemicals or UV required

Inactivation occurred through photodynamic mechanisms, activating endogenous chromophores and generating reactive oxygen species (ROS).

Why it matters

Unlike UV-C or chemical disinfectants, visible light:

  • can operate in occupied environments
  • enables continuous use
  • avoids toxicological risks
  • integrates into standard lighting systems

Conclusions

The findings indicate that visible LED light may serve as a continuous, non-chemical, and safe environmental sanitization strategy, supporting infection control in healthcare settings and reducing the risk of tuberculosis transmission.

 

Source: D’Agostini et al., 2026. Photodynamic inactivation of Mycobacterium tuberculosis by broad‑spectrum visible light. Applied Microbiology and Biotechnology (peer-reviewed). https://doi.org/10.1007/s00253-026-13709-0