Bacterial strains and growth conditions
Stable L-forms derived from B. subtilis NCIMB 8054,
ATCC 6633 (Allan 1991; Allan et al. 1993) and cell line
BS1 were maintained at 30 C and subcultured weekly on
L-phase medium (LPM; Allan 1991) supplemented with
5% (v/v) inactivated horse serum (Life Technologies,
Paisley, UK; LPMHS). Liquid cultures were initiated by
placing LPMHS agar blocks, containing good surface
growth, into L-phase broth (LPB), as LPM minus the gelling
agent. After a few days incubation at 30
C and 60 rev
min
ÿ1 (Sanyo Gallenkamp, Loughborough, UK) dense
growth was achieved and thereafter subculture was
achieved volumetrically.
Bacillus subtilis cell-walled forms and all other plant/soil
isolates were cultured at 30 C and 100 rev min
ÿ1 in glucose
broth, consisting of 10 g l
ÿ1 glucose and 13 g l
ÿ1
Nutrient Broth