Li B Q, Tian S P
Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
Lett Appl Microbiol. 2007 Apr;44(4):437-42. doi: 10.1111/j.1472-765X.2006.02080.x.
To improve viability and biocontrol efficacy of Cryptococcus laurentii after freeze drying and in subsequent storage.
Viability of C. laurentii was improved after freeze drying and in subsequent storage at 4 or 25 degrees C by using skimmed milk (SM) and sugars (glucose, galactose, sucrose and trehalose) as protectants. Sugars and SM mixed together showed better protection than when they were used separately. Citric acid used as carbon source could induce accumulation of intracellular trehalose in the yeast. The yeast cells with high trehalose level (HT cells) had higher viability than those with low trehalose level (LT cells) after freeze drying and storage for 90 days. After storage for 90 days at 4 degrees C, the HT cells plus SM and sugars as protectant showed a similar biocontrol effect against blue mould rot in apple fruit caused by Penicillium expansum as fresh cells.
Increasing intracellular trehalose content of C. laurentii and adding exogenous protectant (sugars + SM) could improve its viability and maintain its biocontrol efficacy.
The results have a potential value for commercial application of C. laurentii.
提高罗伦隐球酵母冻干后及后续储存过程中的活力和生物防治效果。
通过使用脱脂牛奶（SM）和糖类（葡萄糖、半乳糖、蔗糖和海藻糖）作为保护剂，罗伦隐球酵母在冻干后及随后4℃或25℃储存时活力得到提高。糖类和SM混合使用比单独使用时具有更好的保护效果。用作碳源的柠檬酸可诱导酵母细胞内海藻糖的积累。在冻干并储存90天后，海藻糖水平高的酵母细胞（HT细胞）比海藻糖水平低的酵母细胞（LT细胞）具有更高的活力。在4℃储存90天后，添加SM和糖类作为保护剂的HT细胞对扩展青霉引起的苹果果实青霉腐烂病具有与新鲜细胞相似的生物防治效果。
增加罗伦隐球酵母细胞内海藻糖含量并添加外源保护剂（糖类+SM）可提高其活力并维持其生物防治效果。
该结果对罗伦隐球酵母的商业应用具有潜在价值。
