Low doses of the quaternary ammonium salt Cetyltrimethylammonium bromide can be used as a pesticide to control grazers in microalgal cultures

Effective removal of the rotifer Brachionus calyciflorus from a Chlorella vulgaris microalgal culture by homogeneous solar photo-Fenton at neutral pH

“…The performance achieved was comparable to other known chemical methods such as botanical pesticides, surfactants, or disinfectants, but without the associated disinfection by-products (Farinelli et al, 2021). For example, a complete inactivation of 5 rotifers mL − 1 was achieved with 3 µM of cetyltrimethylammonium bromide in C. vulgaris cultures (biomass dry weight: 160 mg L − 1 ) (Deruyck et al, 2019a), and with 1.8 µg L − 1 of toosendanin in Chlorella sp. cultures (cell density 2⋅10 − 7 cells mL − 1 ) (Huang et al, 2014a).…”

“…Effective approaches for the removal of rotifers from microalgae cultures remain relatively unexplored, even if some innovative methods have been investigated and successfully applied so far, such as the use of hydrodynamic cavitation, surfactants, or botanical pesticides (Deruyck et al, 2019a;Huang et al, 2014aHuang et al, , 2014bKim et al, 2017;Zhang et al, 2021). Sodium hypochlorite (0.45 to 0.6 mg Cl L − 1 ) was also successfully applied to inactivate rotifers in microalgae cultures, and to the best of our knowledge, this is the only study where a (plain) oxidative treatment was used for an in-situ inactivation of rotifers (Park et al, 2016).…”