Marine microorganisms are gaining increased global importance owing to their richness in various bioactive compounds. The thraustochytrid Aurantiochytrium limacinum produces high amounts of the omega-3 fatty acid, DHA, and thus is of biotechnological importance. Aurantiochytrium limacinum cultures are usually maintained by continuous sub-culturing or plating, which is labour and resource-intensive. Having a cryopreservation technique will be useful for the preservation of A. limacinum cultures. Hence, we explored and developed a cryopreservation technique to preserve A. limacinum. Cryopreservation was done at two different temperatures by using a mechanical freezer (− 80 °C) and liquid nitrogen (− 196 °C). In the mechanical freezer, the cells were preserved in glycerol, while in liquid nitrogen four widely used cryoprotectants namely ethylene glycol, glycerol, methanol and dimethyl sulfoxide were used. The cells stored in a mechanical freezer had a relatively constant growth rate up to 12 months of storage. For liquid nitrogen storage, glycerol, methanol and dimethyl sulfoxide showed promising cryoprotectant activity with viability as high as 80% even after 12 months of storage. However, ethylene glycol did not exhibit any cryoprotective effect evidenced by marginal viability. Post-thaw assessment is crucial for judging the success of cryopreservation protocol and therefore, the study also looked into the functionality of cells on revival. On reviving no significant difference in the fatty acid profile and cell morphology among treatments was observed. The cryopreservation technique thus developed for preserving A. limacinum will help save human efforts and time and also conserve the organism’s genetic integrity.

海洋微生物由于富含各种生物活性化合物，因此在全球范围内变得越来越重要。破囊壶菌金黄色葡萄球菌产生大量的ω-3脂肪酸DHA，因此具有重要的生物技术意义。通常通过连续的继代培养或接种来维持金黄色葡萄球菌的培养，这是劳力和资源密集的。具有冷冻保存技术将对保存A. limacinum培养物有用。因此，我们探索并开发了一种冷冻保存技术来保存青霉菌。。通过使用机械冷冻机（-80°C）和液氮（-196°C）在两个不同的温度下进行低温保存。在机械冷冻机中，细胞被保存在甘油中，而在液氮中，使用了四种广泛使用的冷冻保护剂，即乙二醇，甘油，甲醇和二甲基亚砜。储存在机械冰箱中的细胞在储存12个月后具有相对恒定的生长速率。对于液氮储存，甘油，甲醇和二甲基亚砜显示出极好的冷冻保护活性，即使在储存12个月后仍具有高达80％的活力。但是，乙二醇没有表现出任何边际生存能力所证明的冷冻保护作用。解冻后评估对于判断冷冻保存方案的成功至关重要，因此，该研究还研究了细胞在复兴时的功能。复活后，各处理之间的脂肪酸谱和细胞形态均无显着差异。因此开发的用于保存的低温保存技术A. limacinum将有助于节省人类的精力和时间，还可以保护生物体的遗传完整性。