甘油对湛江等鞭金藻生长及细胞内多糖累积的影响

摘要

采用单因素试验方法研究富氮及限氮两种培养体系下甘油浓度（41、110、206 mmol／L ）对湛江等鞭金藻生长及细胞内多糖累积的影响。试验结果显示，当甘油浓度为41 mmol／L时湛江等鞭金藻的细胞密度、细胞内多糖含量及产量均比其他两种甘油浓度时的值高，其中富氮培养体系的细胞密度、细胞内多糖含量及产量分别为7．73×107个／m L、16．21％和0．32 g／L ，限氮培养体系的细胞密度、细胞内多糖含量及产量依次为5．29×107个／m L、54．43％和1．02 g／L。表明培养体系中甘油浓度低而氮含量高时有利于细胞生长（前者是后者的1．46倍），而甘油和氮含量均少时利于细胞积累多糖（后者的多糖含量和产量分别是前者的3．36倍和3．19倍）。在两种培养体系下，随着甘油浓度的增加，湛江等鞭金藻的细胞密度及藻细胞内累积的多糖呈降低趋势，说明高浓度甘油抑制湛江等鞭金藻细胞生长和细胞内多糖的累积。因此，为提高湛江等鞭金藻细胞内的多糖产量，应在接种时添加低浓度甘油的限氮培养体系中培养湛江等鞭金藻，这些结果可为高值天然产物的生产提供参考。%Effects of glycerol concentration (41 mmol/L ,110 mmol/L and 206 mmol/L ) on grow th and polysaccharides accumulation of alga Isochrysis zhanjiangensis were investigated in rich - nitrogen and limited-nitrogen culture systems by means of single factor experiments .The results showed that the cell density ,content and yield of polysaccharides were higher in 41mmol/L glycerol than those in the other glycerol concentrations . T he cell density , content and yield of polysaccharides in rich‐nitrogen culture system were 7 .73 × 107 cells/mL ,16 .21% and 0 .32 g/L ,respectively ,while those in limited‐nitrogen culture system were 5 .29 × 107 cells/mL ,54 .43% and 1 .02 g/L ,respectively .These data explained that lower glycerol concentration and higher nitrogen concentration were advantageous to the growth of I . zhanjiangensis (the biomass in the former was 1 .46 times as that in the later) ,however ,when glycerol concentration and nitrogen concentration were lower at the same time , the cell accumulated more polysaccharides (the content and the yield of polysaccharides of the later were 3 .36 times and 3 .19 times as the former ,respectively ) .No matter the difference in nitrogen supply ,with the increasing concentration of glycerol ,the cell density and polysaccharides content of I .zhanjiang‐ensis showed a decreasing trend . It indicated that high concentration of glycerol inhibited the growth of I .zhangjiangensis and the accumulation of polysaccharides .So ,I .zhangjiangensis should be cultured in the limited‐nitrogen culture system with low concentration of glycerol at inoculation to promote the accumulation of polysaccharides . The findings will provide reference with producing natural products of high value .