Figure 2.

Binding of Pb and Cd by lactobacilli is consistent over time and independent of cell viability. Overnight cultures of lactobacilli were re-suspended in 50 mM HEPES buffer 0.5 mM (A) Pb and (B) Cd and subsequently monitored over a 48-hour period. Pb and Cd vehicle control groups represent non-inoculated 50 mM HEPES buffer containing 0.5 mM Pb or Cd. Each graph line represents a different biological replicate measured consecutively in triplicate over 48 hours. The binding efficiency between live and dead LGR-1 was compared by heat-inactivating LGR-1 cultures at 80 C for 1 hour. Live and dead LGR-1 were suspended in 50 mM HEPES with 0.5 mg/L (C) Cd and (D) Pb and incubated for 5 mins prior to quantification. Experiments were performed 3 times and analyzed in triplicate. Heat-inactivation experiments were performed in biological triplicate. Pb and Cd were quantified using an inductively coupled plasma atomic emission spectrophotometer. Error bars represent ± standard error. ns = not significant.