2.2. Bacterial strains and growth conditions
A total of 7 oral microorganisms were employed in the study
including 5 Gram positive cariogenic bacteria, Enterobacter faecalis
ATCC 19433 (Ef), Lactobacillus fermentum ATCC 14931 (Lf), Lactobacillus
salivarius ATCC 11741 (Ls), Streptococcus sobrinus ATCC
33478 (Ss) and Streptococcus mutans ATCC 25175 (Sm), and 2 Gram
negative periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans
ATCC 33384 (Aa) and Fusobacterium nucleatum
ATCC 25586 (Fn). Microorganisms were maintained on either brain
heart infusion agar (BHA) with 5% (v/v) blood for facultative bacteria,
and supplemented with 0.5% (w/v) yeast extract, hemin and
vitamin K for anaerobic bacteria. The strains were grown under
aerobic or anaerobic (10% H2, 10% CO2 and 80% N2) conditions as
appropriate.