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

微藻和植物是负责维持全球环境良好平衡的生物联盟的主要成员。然而，最近，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，这些藻类和植物中的许多物种都濒临灭绝。本研究的目的是建立一种通用、简单、长期的超低温保存方法。由于在超低温保存过程中可以保持藻酸钙组分之间的功能和结构上的相互作用，因此本研究采用了将材料包裹在海藻酸钙珠中并进行脱水的包埋-脱水方法。用0.5M蔗糖作为诱导脱水耐性的添加剂，成功地将7个海洋微藻中的6个菌株、6个淡水绿藻中的1个和7个淡水蓝藻中的4个在液氮中超低温保存。这些结果表明，该方法特别适用于海洋微藻的超低温保存。这是首次采用包埋-脱水法对微藻进行超低温保存的研究，将该方法应用于辣根毛状根培养物诱导的茎原基，可获得约50%的存活率。添加1.0M甘油和0.5M蔗糖可使成活率提高到90%以上。毛状根培养物的根尖用0.5M甘油和0.3M蔗糖超低温保存也很成功，存活率约为60%。这也是首次利用该方法对植物根部进行超低温保存的研究，表明该方法是一种实用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.