Context
Phage infection of Lactococcus lactis (commercially important bacterium used to make fermented dairy products) during fermentation of milk is a troublesome and persistent economic problem in factories where fermented dairy products are produced such as in cheese factories.
In this study, the concentration of the lactococcal 936-species bacteriophages was evaluated in aerosols collected in a cheese factory with different sampling techniques: either filters (polycarbonate and Teflon) or liquid sampling (Coriolis® and BioSampler).
Materials
- Coriolis®µ, sterile cones.
- BioSampler (SKC).
- Liquid: Sterile water+ 0.01%Tween20.
- PC (Polycarbonate) filter on 37 mm cassette.
- PTFE (Teflon) filter on 37 mm cassette.
- Real time PCR.
Protocol
- Coriolis®µ (n=5): 3 x 10 minutes; 300 L/min.
- BioSampler (n=6): 20 min, 12.5 L/min.
- PC and PTFE filters (n=6): 12 hours; 2 L/min.
- Real time PCR (SYBR Green) : number of phage genomes per cubic meter of air.
Results
Coriolis®µ: Conclusive result with a fast sampling (30 minutes) and a limit of detection 8 to 113 times better than other samplers.
PC et PTFE filters: Conclusive results (above the limit of detection); the time of sampling (12 hours) is still a restrictive step.
BioSampler: Inconclusive results (limit of detection)
Customer
