[An automatic gas scanning device, technical improvement for obtaining a favourable atmosphere for in vitro culture of anaerobic bacteria].
All methods for growth of anaerobic bacteria on solid media depend on the elimination of atmospheric O2 through use of a palladium catalyst (Deoxo-Catalyst), active in presence of at least 5% H2 with resultant formation of water. Anaerobic chambers and jars are the two conventional methods employed. Both are based on the elimination of air by means of a pump and its replacement with gas from a cylinder (evacuation-replacement technique). An alternative chemical technique for use in anaerobic jars consists of adding internal gas-generating sachets. The former techniques are more efficient but the trend, particularly in the clinical laboratories, is to use the simpler chemical system that has two inconveniences: a slow establishment of anaerobiosis, and a high cost. We propose a new system that does not require a vacuum pump and consists in flushing anaerobic jars with a convenient gas mixture (H2, CO2, N2: 4.5; 5; 90.5 v/v) by means of an automaton regulating both time and gas flow. Gas-liquid chromatography analysis of the gas inside the jar shows a rapid elimination of gaseous O2, whose residual concentration is low enough to permit growth of all anaerobes of clinical interest, including those which are more O2-sensitive. Comparative qualitative and quantitative data obtained with all available techniques demonstrate the advantages of the new system.
Willemot
J M
JM
Taema, Antony, France.
Su
W J
WJ
Briend
R
R
Sebald
M
M
D000693:Anaerobiosis; D001331:Automation; D001421:Bacteria, Anaerobic / Q000166:cytology*; D001431:Bacteriological Techniques; D003470:Culture Media; D066298:In Vitro Techniques; D010100:Oxygen / Q000378:metabolism
D003470:Culture Media; D010100:Oxygen
Balayage gazeux à l'aide d'un automate, une amélioration technique d'obtention d'une atmosphère propice à la culture en jarre des bactéries anaérobies.