A.V. Zhirmunsky Institute of Marine Biology, National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, 690041, Russia.
Mar Biotechnol (NY). 2017 Aug;19(4):410-419. doi: 10.1007/s10126-017-9759-3. Epub 2017 Jul 11.
The water-soluble polysaccharides of brown algae attract the increasing attention of researchers as an important class of polymeric materials of biotechnological interest. The sole source for production of these polysaccharides has been large brown seaweeds such as members of Laminariales and Fucales. A new source of water-soluble polysaccharides is suggested here: it is a filamentous brown alga Streblonema sp., which can be cultivated under controlled conditions in photobioreactors that allow obtaining algal biomass with reproducible content and quality of polysaccharides. The accumulation of water-soluble polysaccharides can be stimulated by macronutrient limitation. In response to nitrogen deficiency, Streblonema sp. accumulated water-soluble polysaccharides (WSPs) rich in laminaran. WSP accumulation started after 3-4 days following nitrate depletion and reached a plateau at around day 7. Polysaccharide accumulation was related to cellular nitrogen content. The critical internal N level that triggered the onset of polysaccharide accumulation was 2.3% dry weight (DW); at a cellular N concentration less than 1.4% DW, the polysaccharide synthesis stopped. Upon nitrate re-supply, mobilization of WSP occurred after 3 days. These results suggest that a two-stage cultivation process could be used to obtain large algal biomass with high water-soluble polysaccharide production: a first cultivation stage using nitrate-supplemented medium to accumulate algal biomass followed by a second cultivation stage in a nitrate-free medium for 3 to 7 days to enhance polysaccharide content in the alga.
褐藻的水溶性多糖作为一类具有生物技术应用潜力的高分子材料，正引起研究人员越来越多的关注。这些多糖的唯一来源是大型褐藻，如巨藻目和墨角藻目成员。本文提出了一种新的水溶性多糖来源：它是一种丝状褐藻 Streblonema sp.，可以在光生物反应器中进行受控培养，从而获得具有可重复多糖含量和质量的藻类生物量。通过大量营养素限制可以刺激水溶性多糖的积累。在氮素缺乏的情况下，Streblonema sp. 积累富含岩藻聚糖的水溶性多糖 (WSP)。在硝酸盐耗尽后 3-4 天开始积累 WSP，并在大约第 7 天达到平台期。多糖积累与细胞氮含量有关。触发多糖积累开始的临界内部氮水平为 2.3%干重 (DW)；当细胞氮浓度低于 1.4% DW 时，多糖合成停止。在硝酸盐再供应后，3 天后发生 WSP 动员。这些结果表明，可以采用两阶段培养工艺来获得具有高水溶性多糖生产的大型藻类生物量：第一阶段使用含硝酸盐的培养基积累藻类生物量，然后在无硝酸盐的培养基中进行第二阶段培养 3 至 7 天，以提高藻类中的多糖含量。
