Аннотация:The nuclear wavepacket formed by 20-fs excitation on the P* potential energy surface in native and mutant (YM210W and YM210L) reaction centers of Rhodobacter (Rb.) sphaeroides and Chloroflexus (C) aurantiacus RCs was found to be reversibly transferred to the P+BA- surface at 120, 380, and 640-fs delays (monitored by measurements of B-A(-) absorption at 1020-1028 nm). The reaction centers of YM210W(L) mutant show the most simple pattern of fs oscillations with a period of 230 fs in stimulated emission from P* and in the product P+BA-. The mechanisms of the electron transfer pathway between P* and B-A and of the stabilization of the state P+BA- in bacterial reaction centers are discussed.