A series of in vitro experiments were conducted to investigate
the impact of two tea extracts on the growth of two strains of lactic
acid bacteria. Pure cultures of Lactobacillus rhamnosus and Bifidobacterium
breve were obtained from the culture collection held
by Environmental Science and Research (ESR), New Zealand. These
strains were grown to stationary phase in Mann-Rogosa-Sharpe
(MRS) medium and then 1% (v/v) inoculums from these cultures
were introduced into 2 ml of fresh MRS broth containing different
concentrations of the tea extracts. The extracts were added to MRS
broths at 10% and 25% (v/v). The tubes were incubated at 37 C for
48 h and at the end of the incubation period, the broths from control
and extract-containing incubations were serially diluted 10-
fold in fresh MRS broth and then 100 ll aliquot of each dilution