氮元素对发菜生长及多糖含量的影响

为优化培养条件，研究含氮(BG11)和无氮(BG110)培养基对发菜(Nostoc flagelliforme)的色素、藻胆蛋白及胞内多糖和胞外多糖(EPS)含量的影响。结果显示：含氮组发菜的叶绿素a(Chl a)、类胡萝卜素(Carotenoids)、藻蓝蛋白(PC)、别藻蓝蛋白(APC)、藻红蛋白(PE)的含量均显著高于无氮组；胞内及胞外多糖含量无氮组高于含氮组，两者胞内多糖含量最大分别为1.03mg/mL 和0.78mg/mL，EPS 含量最大分别为243.8μg/mL 和74.9μg/mL。表明氮元素的缺乏对发菜的色素合成有抑制作用，但在一定程度上能够促进胞内及胞外多糖的合成和分泌。

Effect of Nitrogen on the Growth and Polysaccharide Content of Nostoc flagelliforme

Cultivation of Nostoc flagelliforme in nitrogen-containing (BG11) and non-nitrogen-containing (BG110) media was conducted for figuring out the effects of nitrogen on the growth and the contents of phycobiliprotein (PC), allophycocyanin (APC), phycoerythrin (PE) and endo- and exopolysaccharides of Nostoc flagelliforme were investigated. The results showed that after 20 d cultivation, compared to BG110 medium, N. flagelliforme cultured in BG11 medium had much higher contents of Chl a, carotenoides, PE, APC and PC, but much lower contents of endo- and exo polysaccharides. The maximum content of endopolysaccharides was 1.03 mg/mL in BG110 and 0.78 mg/mL in BG11, while that of exopolysaccharides was 243.8μg/mL in BG110 and 74.9μg/mL in BG11. These results indicate that nitrogen deficiency may inhibit the growth of N.flagelliforme, but promote the synthesis of endo- and exopolysaccharides to a certain extent.