[Effect of redox potential on culture parameters of Trypanosoma cruzi developed in liquid stirred media].

The redox potential (Eh) is a physico-chemical property presented by solutes able to interchange electrons with an inert electrode. The redox potential influences bacterial growth in an independent way from dissolved oxygen. The available information about protozoans in vitro grown is scarce, being Trypanosoma cruzi main example. T. cruzi Tulahuén 0 strain, developed in CIEN liquid stirred media, was used to determine the Eh effect on growth parameters. Eh values between 310 mV (reference) and 110 mV were measured in 11 different samples and by duplicate. pH, m, Eh, rH, consume glucose rate and efficiency were determined. Results show that specific rate of development (mu) varies in a direct way with Eh. A high correlation (r = 0.93; P < 0.01) between rH (rH = Eh(V) + 0.06 pH) and mu was established, even when dissolved oxygen concentration remained constant. Other parameters in the growing medium showed no significant variations. It is concluded that changes on Eh in the medium significantly affect of T. cruzis growth being a variable to take into account when potential trypanocide substances are analyzed.