The effect of starter LAB on pathogens (those used as indicator
organisms in the experiments described above) during the process
of fermentation was determined as follows. Cassava tubers were
obtained from a local market in East London and peeled, cut into
cylindrical pieces of approximately 10 g and sterilised by irradiation
(18.8 kGY, Isotron, Swindon, UK). Approximately 100 g of sterile
cassava were steeped in 250 ml sterile distilled water in “fermentation”
jars (Kilner). Cultures (10%: v/v inocula) of indicator bacteria
were prepared in NB incubated aerobically for 24 h. The starter
LAB in MRS broth were incubated anaerobically for 48 h at 37 C.
These constituted the stock inocula. A starter inoculum of
L. plantarum Z and CL06 (2.5 ml) to effect fermentation was mixed
in the steeped cassava together with an inoculum (2.5 ml) of each
pathogen. All cassava samples were incubated (fermented) at 37 C
aerobically for 5 days. To follow the inactivation of the pathogens,
sampling was carried out every 24 h by spread plating decimal
dilutions of the cassava on the relevant selective medium. This