The cultures were stored on slopes with media
specific for their growth (Table 1). Inocula for the
growth studies were developed in specific liquid media (200 ml) (Table 1) in conical flasks (250 ml).
After an asceptic inoculation, these flasks were incubated
on an orbital shaker (105 +2 rpm) at 28 + I°C
for 3 days.
Culture MC1 was an unidentified mixed culture
which had been isolated by staff at Viridian Bioprocessing
Ltd from grease-trap residues obtained
from a fast-food restaurant. It was used by Viridian
Bioprocessing Ltd as a culture for treating fat-rich
wastewaters and was donated to Birmingham as a
culture in treated wastewater. The activated sludge
was obtained from the aeration tank at a local
sewage-treatment works, where the raw wastewater
contained an element of greasy material.
Culture MC1 (100 ml) and activated sludge were
initially centrifuged (2355 g) for 30 s, and the individual
supernatants were removed. The pellets of
biological solids were then resuspended to their
original volumes in quarter-strength Ringer's solution.
This procedure was repeated two more times,
in order to remove all traces of residual substrate
carbon from the inocula.