不同硝酸钾浓度对蔷薇藻生长及生理特性的影响

Effect of KNO_3 Concentrations on the Growth and Physiological Characteristics of Rhodella reticulata

蔷薇藻(Rhodella reticulata)是属于红藻门的一种海洋单细胞微藻,其生长过程中产生藻胆蛋白、胞外多糖等生物活性物质。研究了不同硝酸钾浓度对蔷薇藻生长代谢的影响,分析测定蔷薇藻比生长速率、胞外多糖产量、藻蓝蛋白含量、色素含量、硝酸还原酶活性和SOD活性等参数。结果表明,与无氮培养基相比,蔷薇藻在以硝酸钾为氮源,浓度为0.75g/L的条件下生长最好,硝酸还原酶活性最大,分别得到最大的藻蓝蛋白产量(24mg/L)和类胡萝卜素含量(1.42mg/L);当KNO3浓度为7.5g/L时,获得最高叶绿素a含量为1.91mg/L;高氮源有利于产糖,当KNO3浓度为30g/L时,得到最高胞外多糖产量为1.633g/L;SOD活性随硝酸钾浓度增加而增大。

The unicellular red alga, Rhodella reticulata, can synthesize some bioactive substances such as phycobiliprotein and exopolysaccharides. In this paper, the growth and physiological of Rh. reticulata under different KNO3 concentrations were studied. The parameters, such as growth rate, exopolysaccharide, phycocyanin, pigments, nitrate reductase and SOD, were used in the assays. The result showed that Rh. reticulata grew the best under 0. 75 g/L nitrate condition compared with nitrogen free medium, the alga also produced the highest activity of nitrate reductase, phycocyanin content （24 mg/L ）, and caroteneid （ 1.42 mg/L）. While at the concentration 7.5 g/L nitrate, Rh. reticulata produced the most content of chlorophyll a （1.91 mg/L）. Higher nitrogen promoted the accumulation of Rh. reticulata exopolysaccharides. We got 1. 633 g/L of exopolysaccharides when the concentration of nitrate was 30 g/L. With the increasing of KNO3 concentration, the activity of SOD enhanced.