The microorganisms used in study were L. acidophilus NCIMB
8821 (National Collection of Industrial and Marine Bacteria, Aberdeen,
Scotland, UK) and L. plantarum NCIMB 8826, both isolated from
human intestine. In vitro and in vivo studies supporting the probiotic
characteristics of L. plantarum NCIMB 8826 have been previously
reported by Vesa et al. (2000) and Borchers et al. (2009). Black et al.
(1989) and Marteau et al. (1990) have also proved the probiotic
characteristics of L. acidophilus strains similar to the one used in this
work. Thus L. acidophilus NCIMB 8821 could be considered a potentially
probiotic strain though further in vitro and in vivo studies
should be performed to confirm its probiotic properties.
The strains were first sub-cultured three times for 12 h at 37 C in
Man Rogosa Sharp broth (MRS, Merck) from the frozen stock containing
MRS broth and 10% glycerol before using it as an inoculum
and stored at 30 C. The starter culture was obtained by overnight
incubation at 37 C in MRS broth. The culture was centrifuged at
4000 rpm for 7 min (Sigma 6K15, Sigma-Zentrigugen, Germany),
washed in 0.1% sterile NaCl water (Sigma Aldrich, UK) and resuspended
in 10 mL 0.1% sterile NaCl.