check papers of Johan de Jonckheere e.g. 1. "De Jonckheere JF: Molecular definition and the ubiquity of species in the genus Naegleria. Protist 2004, 155(1):89-103."
naegleria fowleri has several life-cycle stages - I assume you trying to grow a flagellated organism? The media is different for each life-cycle stage - especially to induce flagella, which requires a low salt media.
Not that I want to sound like some pedantic stickler but you know N. fowleri should be grown in containment level 2 facilities? Obviously by properly trained personnel as there is no treatment against infection...
Ditto what Mark can der Giezen said. The simplest method for cultivation is on non-nutrient agar plates (water agar) coated with washed E.coli. They form plaques as they multiply and consume the bacteria. If you want to grow large numbers of them, you would need to get them in a liquid medium. I recommend Mix medium (John and Howard, 1995), but they can be grown in a minimal salts medium (Page's Saline) with the washed E. coli as well. Please work in a biocontainment hood (NOT laminar flow). Best!