Synergistic Effect\nof Polyglycerol and DMSO for Long-Term\nCryopreservation of <i>Stichococcus</i> Species

Herein, we present a significant advancement in long-term\ncryopreservation\ntechniques for microalgae <i>Stichococcus</i> species using\na combination of linear polyglycerol (<i>lin</i>PG) and\ndimethyl sulfoxide (DMSO). The technique was tested on three <i>Stichococcus</i> species: Stichococcus bacillaris, Stichococcus deasonii, and Stichococcus minor, which showed long-term viability\nand recovery rates superior to those when treated with a traditional\ncryoprotectant only. While DMSO alone enabled high cell recovery rates\nfor all species after 1 week of cryopreservation, the rates for some\nof them dropped below 50% after 26 weeks of cryopreservation. Treating\nthe cells with a combination of <i>lin</i>PG and DMSO raised\nthe recovery rates for all three <i>Stichococcus</i> species\nto above 92% after long-term cryopreservation. Our findings indicate\nthat <i>lin</i>PG in combination with DMSO offers a synergistic\nand effective solution for maintaining cell integrity and functionality\nduring long-term cryopreservation of microalgae.