Figure 4: FeNPs-PEG supports the cellular growth of S. pneumoniae. Bacteria were cultivated using different iron sources end the cellular growth was determined each h for 10 h. by spectrophotometry at 600 nm. Cellular growth of ATCC 49619, R6 y TIGR4 with different sources of iron: squares; untreated, empty diamonds; +FeCl3, filled circle; +FeNPs-PEG, filled stars; iron starvation.