Strategy to obtain axenic cultures from field-collected samples of the cyanobacterium Phormidium animalis.
An efficient strategy, based on a combination of procedures, was developed to obtain axenic cultures from field-collected samples of the cyanobacterium Phormidium animalis. Samples were initially cultured in solid ASN-10 medium, and a crude separation of major contaminants from P. animalis filaments was achieved by washing in a series of centrifugations and resuspensions in liquid medium. Then, manageable filament fragments were obtained by probe sonication. Fragmentation was followed by forceful washing, using vacuum-driven filtration through an 8-microm pore size membrane and an excess of water. Washed fragments were cultured and treated with a sequential exposure to four different antibiotics. Finally, axenic cultures were obtained from serial dilutions of treated fragments. Monitoring under microscope examination and by inoculation in Luria-Bertani (LB) agar plates indicated either axenicity or the degree of contamination throughout the strategy.
Centro de Investigaciones de Paludismo, INSP., Tapachula, Chis., Mexico.
Guadalupe
G
Vázquez-Martínez
Mario H
MH
Rodriguez
Fidel
F
Hernández-Hernández
Jorge E
JE
Ibarra
D001431:Bacteriological Techniques / Q000379:methods*; D002498:Centrifugation; D000458:Cyanobacteria / Q000254:growth & development* / Q000302:isolation & purification; D005374:Filtration; D013010:Sonication