Search for and use of enzymes of marine origin for the directed hydrolysis of sulfated polysaccharides

利用仅能水解硫酸酸化多糖的糖苷键的酶，可以生产出广谱的具有生物活性的硫酸寡糖。关于这些酶的报道很少；最近只报道了一组岩藻糖苷酶。这种类型的生物催化剂专门用于从褐藻中提取的含焦多糖，岩藻多糖。岩藻酸苷酶阳性真菌沙棘树突菌TM94（最近分离）可作为酶分析、初始固体底物发酵、批量培养和下游加工的基础研究的起始菌株。此外，必须探索在不损失硫酸盐的情况下降解天然岩藻多糖并生产分子量大于5 kDa的硫酸化低聚物的一般方法。与此同时，必须研究从各种海洋生境中分离出来的其他微生物以内型方式水解天然硫酸酸化多糖的潜力。在生化工程实验和恒化培养中，必须选择最佳的候选物。必须将足够的细胞质量和/或上清转移到下游处理，以分离所需的酶，对其进行表征，并将其用于生产硫酸低聚糖（分子量大于5 kDa）的生物催化。随后，必须对低聚物进行生物活性测试。

By means of enzymes capable to hydrolyse only the glycosidic linkages of sulfated polysaccharides, a broad spectrum of bioactive sulfated oligosaccharides should be produced. Reports on these enzymes are scarce; only one group, that of fucoidanases, was reported recently. This type of biocatalyst is specialized on fucose-containing polysaccharides, fucoidans, from brown algae. The fucoidanase-positive fungus Dendryphiella arenaria TM94 (isolated recently) serves as starting strain for basic studies on enzyme assays, initial solid substrate fermentation, batch cultivations and downstream processing. Additionally, the general methods to degrade natural fucoidans without loss of sulgate and to produce sulfated oligomers with molecular weights of more than 5 kDa have to be explored. In parallel, other microorganisms isolated from various marine habitats, have to be studied for their potential to hydrolyze natural sulfated polysaccharides in an endo-type manner. Best candidates have to be choosen for biochemical engineering experiments in batch and chemostat cultivations. Sufficient cell mass and/or supernatant have to be transferred to the downstream processing for isolation of the desired enzymes, their characterization, and their use in biocatalysis for the production of sulgated oligosaccharides (MW more than 5 kDa). Subsequently, the oligomers have to be tested for bioactivities.