Why Mycobacteria Are Difficult to Control
The species commonly associated with fish mycobacteriosis include:
* Fish Mycobacteriosis (caused by Mycobacterium marinum, M. fortuitum, M. chelonae, etc.)
These bacteria:
* Form biofilms on tank walls, pipes, and filters.
* Survive inside fish tissues and macrophages.
* Are relatively resistant to many disinfectants.
* Persist in organic-rich culture systems.
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How Ozone Nanobubbles May Help
1. Direct Oxidation of Free-Living Mycobacteria
Ozone is one of the strongest oxidants used in aquaculture.
When ozone nanobubbles collapse, they can:
* Oxidize bacterial cell walls.
* Damage membrane lipids.
* Oxidize proteins and DNA.
Compared with ordinary ozone injection:
* Nanobubbles remain suspended much longer.
* More ozone dissolves into the water.
* Contact time increases significantly.
This increases the likelihood of inactivating:
* Free-floating mycobacteria
* Recently shed bacteria from infected fish
* Bacteria in suspended organic particles
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2. Biofilm Suppression
One of the biggest reservoirs of Mycobacterium is biofilm.
Ozone nanobubbles can:
* Penetrate small crevices in biofilms better than coarse bubbles.
* Oxidize extracellular polymeric substances (EPS).
* Reduce biofilm thickness.
This may lower bacterial reservoirs in:
* Tank walls
* Return piping
* Sumps
* Foam fractionators
* Mechanical filters
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3. Reduction of Organic Matter
Mycobacteria thrive in systems with:
* High DOC (dissolved organic carbon)
* Detritus accumulation
* Uneaten feed
* Fish waste
Ozone nanobubbles:
* Break down dissolved organics.
* Improve protein skimmer performance.
* Reduce bacterial food sources.
This indirectly makes the system less favorable for mycobacterial persistence.
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4. Improved Water Quality and Fish Immunity
Ozone nanobubbles often increase:
* Water clarity
* ORP
* Oxygen availability