BINDING OF HEMIN AND CONGO RED BY ORAL HEMOLYTIC SPIROCHETES

Colony-forming units or cells in suspension of oral anaerobic spiroche tes (Treponema denticola, Treponema vincentii and Treponema socranskii ) bind hemin and Congo red. Hemin or Congo red binds to a hydrophobic polypeptide receptor that is located in the outer membrane of the bact erial cells and it has a relative molecular mass of 47 kDa. These oral spirochetes also lyse sheep erythrocytes to produce beta-hemolytic zo nes around colony-forming units. The oral spirochetes may acquire iron for growth when they lyse erythrocytes and bind heme from which they may sequester and transport iron into the cells.