926994 Ent enterobactin 66 927136 Ent enterocin 15 927137 Ent enterotoxin 8 927132 ent E. coli siderophore-deficient 1 927133 ent each strand of length l 1 927134 ent enantiomer 1 927135 ent energy-transfer correlation time was theta 1 927138 ent entla 1