Enhancing protein extraction from heterotrophic Auxenochlorella protothecoides microalgae through emerging cell disruption technologies combined with incubation

This study evaluated pulsed electric fields (PEF) and ultrasonication (US) combined with incubation to enhance cell disruption and protein extraction from Auxenochlorella protothecoides, comparing them to conventional high-pressure homogenization (HPH). A 5 h incubation enhanced protein yield by 79.4 % for PEF- and 27.2 % for US-treated samples. Extending the incubation to 24 h resulted in a total yield increase of 122 % for PEF (0.25 ± 0.03 kgEP kgTP−1) and 51.9 % for US (0.20 ± 0.02 kgEP−1 kgTP−1). Autofermentation in untreated cells after 24 h resulted in protein release with lower yields than all other treated and incubated samples. While HPH had the highest protein yield (0.58 ± 0.04 kgEP kgTP−1), PEF-incubation after 5 h (56.6 ± 5.3 MJ kgEP−1) and 24 h (49.5 ± 3.7 MJ kgEP−1) were 1.5 and 1.7-times more energy-efficient than HPH (82.9 ± 7.8 MJ kgEP−1). PEF combined incubation is an energy-efficient and targeted protein extraction method in heterotrophic A. protothecoides biorefinery.