A comparison of the growth and starvation responses of Acanthamoeba castellanii and Hartmannella vermiformis in the presence of suspended and attached Escherichia coli K12

摘要: The growth and starvation responses of Acanthamoeba castellanii Hartmannella vermiformis were investigated in the presence absence Escherichia coli on an agar surface or within shaken suspensions. amoebae perceived all suspended systems to be unfavourable for growth, despite being challenged with high levels prey, as a consequence they exhibited response. However, response differed between species, A. producing characteristic cysts H. round bodies. These amoebic forms reactivated into feeding trophozoites bacterial aggregates, which formed after 68 h incubation. In contrast, both species grew well attached E. at concentration 1 x 10(6) cells cm(-2) yielded specific rates c. 0.04 h(-1). Starvation induced end phase, these equivalent those recorded systems. We conclude that, when suspended, 'floating form' cannot feed effectively hence is initiated. Thus majority via trophozoite grazing prey.