Bond Chris
National Collection of Yeast Cultures, BBSRC Institute of Food Research, Colney, Norwich, UK.
Methods Mol Biol. 2007;368:99-107. doi: 10.1007/978-1-59745-362-2_6.
A method is described that allows yeast species to be stored using a variation on the standard freeze-drying method, which employs evaporative cooling in a two-stage process. Yeast cultures are placed in glass ampoules after having been mixed with a lyoprotectant. Primary drying is carried out using a centrifuge head connected to a standard freeze-dryer. Once the centrifuge head is running, air is removed and evaporated liquid is captured in the freeze-dryer. Centrifugation continues for 15 min and primary drying for a further 3 h. The ampoules are constricted using a glass blowing torch. They are then placed on the freeze-dryer manifold for secondary drying under vacuum overnight, using phosphorus pentoxide as a desiccant. The ampoules are sealed and removed from the manifold by melting the constricted section. Although the process causes an initial large drop in viability, further losses after storage are minimal. Yeast strains have remained viable for more than 30 yr when stored using this method and sufficient cells are recovered to produce new working stocks. Although survival rates are strain specific, nearly all National Collection of Yeast Cultures strains covering most yeast genera, have been successfully stored with little or no detectable change in strain characteristics.
本文描述了一种方法，该方法允许使用标准冷冻干燥方法的变体来保存酵母菌种，标准冷冻干燥方法在两阶段过程中采用蒸发冷却。酵母培养物在与冻干保护剂混合后放入玻璃安瓿中。初次干燥使用连接到标准冷冻干燥机的离心机转头进行。一旦离心机转头运行，空气被抽出，蒸发的液体被捕获在冷冻干燥机中。离心持续15分钟，初次干燥再持续3小时。使用玻璃吹管收缩安瓿。然后将它们放在冷冻干燥机歧管上，在真空下使用五氧化二磷作为干燥剂进行二次干燥过夜。通过熔化收缩部分将安瓿密封并从歧管中取出。尽管该过程会导致活力最初大幅下降，但储存后的进一步损失很小。使用这种方法储存时，酵母菌株已存活超过30年，并且回收了足够的细胞以制备新的工作菌株。尽管存活率因菌株而异，但几乎所有涵盖大多数酵母属的国家酵母菌种保藏中心的菌株都已成功保存，菌株特征几乎没有或没有可检测到的变化。
