两种硝酸盐浓度下威氏海链藻和盐生杜氏藻硝酸还原酶活力研究  

Comparative Studies on Nitrate Reductase Activity of Thalassiosira weissflogii and Dunaliella salina Cultured in Two Nitrate Concentrations

作　　者：吕嘉扬[1] 王大志[1] 洪华生[1] 黄邦钦[1] 

机构地区：[1]厦门大学海洋环境科学教育部重点实验室环境科学研究中心,福建厦门361005

出　　处：《集美大学学报（自然科学版）》2004年第1期6-10,共5页Journal of Jimei University：Natural Science

基　　金：国家重点基础研究发展规划资助项目(2001CB409700)

摘　　要：把盐生杜氏藻(Dunaliellasalina)和威氏海链藻(Thalassiosiraweissflogii)培养在两种硝酸盐浓度下(800μmol/L和200μmol/L),比较研究了它们在培养液中硝酸盐及亚硝酸盐的变化及细胞硝酸还原酶活力变动情况.结果表明,在两种硝酸盐浓度下,两种微藻培养液中硝酸盐及亚硝酸盐的变化基本相同.在高硝酸盐浓度下,两种微藻培养液中的硝酸盐减少并维持较高的浓度,且细胞叶绿素a含量较高;而在低硝酸盐浓度下,培养液中的硝酸盐在培养的第二天即被耗尽,且细胞叶绿素a含量很低.培养液中亚硝酸盐的变化在高浓度呈现逐渐增加的趋势,而在低浓度则呈现先增加后减少的趋势;两种微藻的硝酸还原酶活力在培养的第二天即达到最大值,随后迅速下降并维持一低值,但威氏海链藻的硝酸还原酶活力要略高于盐生杜氏藻.本研究结果表明,在不同硝酸盐浓度下藻类细胞内部的硝酸盐的吸收同化机制不同,从而导致营养盐的变化也各不相同.Two microalgae, Thalassiosira weissflogii and Dunaliella salina were grown in modified K-medium with two nitrate concentrations,800μmol/L and 200μmol/L,variations of nitrate and nitrite in the culture mediums and nitrate reductase activity of cells were investigated comparatively.The results showed that variations of nitrate and nitrite in the culture mediums of two algaes under two nitrate concentration were almost same:nitrate concentration in the culture mediums of two algaes decreased slowly in the culture with high nitrate concentration,and chlorophyll a contents of cells were very high;however,nitrates in the culture mediums were exhausted within the second growth day in the culture with low nitrate concentrations and chlorophyll a contents were very low.Nitrite concentration in the culture mediums increased slowly in the culture with high nitrate concentration while it increased within the first two days then decreased in the culture with low nitrate concentration.Nitrate reductase activity of two microalgaes peaked in the second growth day and decreased sharply and maintained a relatively low stable level,however NR of T.weissflogii was higher than that of D. salina. The results indicat that the uptake and assimilation mechanisms of nitrate in cells are different in the culture with different nitrate concentrations,which result in nutrient varied greatly.

关 键 词：亚硝酸盐 硝酸还原酶 威氏海链藻 盐生杜氏藻 浮游植物 

分 类 号：Q949.2[生物学—植物学] Q945.1