ABSTRACT
This study investigated the technical feasibility of using electrogermination to activate dormant cysts as an inoculum for subsequent 14-d photosynthetic astaxanthin production in Haematococcus lacustris. Electrotreatment affected the cell viability, surface charge, and morphology of H. lacustris cysts. At an optimal voltage of 2â¯V for 60â¯min, the cyst germination rate peaked at 44.6â¯% after 1 d, representing a 2.2-fold increase compared with that of the untreated control. Notably, electrogermination significantly enhanced both the astaxanthin content (44.9â¯mg/g cell) and productivity (13.2â¯mg/L/d) after 14 d of photobioreactor cultivation, corresponding to 1.7- and 1.5-fold increases compared with those in control, respectively. However, excessive electrotreatment, particularly at voltages exceeding 2â¯V or for durations beyond 60â¯min, did not enhance the astaxanthin production capability of H. lacustris. Proper optimization of renewable electrogermination can enable sustainable algal biorefinery to produce multiple bioactive products without compromising cell viability and astaxanthin productivity.