Study on preservation of functions of biological consortia responsible for maintenance of sound balance of global environment.

微藻和植物是维持全球环境健康平衡的生物群落的主要成员。然而，近年来，诸如温室效应和酸雨等环境问题变得越来越严重。在这种情况下，许多藻类和植物物种濒临灭绝。本研究采用海藻酸钙微球包埋-脱水法，在超低温保存过程中保持了藻体各组成成分之间的功能和结构相互作用，对7株海洋微藻中的6株，6株淡水绿色藻中的1株，用0.5M蔗糖作为脱水诱导剂，成功地将7株淡水蓝藻中的4株在液氮中进行了超低温保存。这些结果表明，这种方法是特别有用的海洋微藻的超低温保存。本研究首次采用冷冻-脱水法对微藻进行超低温保存，将该方法应用于辣根毛状根培养物诱导的芽原基，获得了约50%的存活率。此外，通过加入1.0 M甘油与0.5 M蔗糖的组合，存活率提高到90%以上。用0.5M甘油和0.3M蔗糖对毛状根培养物的根尖进行了超低温保存，成活率为60%。这也是首次利用该方法对植物根系进行超低温保存的研究，表明该方法是一种很有前途的植物资源超低温保存方法。

Microalgae and plants are the main members of biological consortia responsible for maintenance of sound balance of global environment. Recently, however, environmental problems, such as greenhouse effect and acid rain are becoming serious. Under those conditions, many species of those algae and plants are on the point of extermination. The aim of this research is to establish a general, simple, and long term cryopreservation method of them.Encapsulation-dehydration method in which materials were encapsulated in Ca-alginate beads and desiccated, was employed in this study, because functional and structural interactions among constituents of the consortia could be maintained during cryopreservation process.Six of the 7 marine microalgal strains, 1 of the 6 freshwater green algae, and 4 of the 7 freshwater cyanobacteria were successfully cryopreserved in liquid nitrogen by using 0.5 M sucrose as an additives for induction of desiccation tolerance. These results suggest that this method is specifically useful for cryopreservation of marine microalgae. This is the first research about the cryopreservation of microalgae by the encapsulation-dehydration method.When the method was applied to shoot primordia induced from hairy root cultures of horseradish, about 50% of survival was obtained. Furthermore, the survival was increased to more than 90% by addition of 1.0 M glycerol combined with 0.5 M sucrose. Root tips of the hairy root cultures also successfully cryopreserved by using 0.5 M glycerol and 0.3 M sucrose, and the survival was about 60%. This is also the first research about the cryopreservation of plant roots by this method.It is indicated that the method presented here is promising as a practical procedure for cryopreservation of useful plant resources.