营养条件对水华蓝藻铜绿微囊藻的胞外多糖产生的影响  

Effects of Nutrient Conditions on Exopolysaccharide Production in Water-bloom Forming Cyanobacteria,Microcystis aeruginosa

作　　者：雷腊梅[1] 宋立荣[2] 欧丹云[2] 韩博平[1] 

机构地区：[1]暨南大学水生生物研究中心,广东广州510632 [2]中国科学院水生生物研究所,湖北武汉430072

出　　处：《中山大学学报（自然科学版）》2007年第3期84-87,共4页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：国家重点基础研究计划973计划资助项目(2002CB412306)

摘　　要：当自然条件下的群体微囊藻转入实验室培养后,它们的胶被多糖往往急剧下降,形态由群体解聚为单细胞。M icrocystis aeruginosaDCA(群体)和M.aeruginosaDCS(单细胞)是同源而形态不同的两株微囊藻,对它们的研究在一定程度上可展示微囊藻群体解聚机制。研究显示两株微囊藻在正常培养基中的生长和EPS产量差异很大,单细胞微囊藻生长快但EPS产量少,群体微囊藻正相反。以单细胞微囊藻为材料研究N,P,S,Fe和EDTA等营养元素对EPS产生的影响,实验浓度为正常培养基中营养元素的5倍和1/5。结果显示,在N缺乏条件下,单细胞微囊藻生长很慢,大约在第6天停止生长,其他营养条件的改变对单细胞微囊藻的生长没有明显的影响,在N缺乏条件下单细胞微囊藻的EPS含量在第3天达到最高,然后急剧下降;5倍的N条件显著刺激EPS的产生,P丰富的条件也轻微刺激EPS的产生。其他营养条件的改变对生长和EPS产生的影响都不明显。我们的结果与一般规律显著不同,即在某些产生EPS的微藻,N缺乏刺激多糖合成。After transfer into laboratory culture, colonial Microcystis dramatically decreased mucilage production and became single-celled. We used two strains of the same origin, M. aeruginosa DCA （colony） and M. aeruginosa DCS （single-cell）, and were able to display a mechanism for colony disaggregation. The growth and EPS production of two strains in routine medium showed great differences. The EPS content of M. aeruginosa was estimated by the anthrone method using glucose as the standard. Compared with colonial Microcystis DCA cultured in routine medium, single-celled Microcystis grew faster but produced much less EPS. The single-celled M. aeruginosa DCS was used to examine the influence of various nutrient elements, such as N, P, S, Fe and EDTA, on the EPS production. Each treatment was set at 5 times and 1/5 time normal concentration, samples were taken every three days and the A66s and EPS in the medium were assayed. The growth curves didn＇t show obvious differences except for the N-deficient condition, where the growth was slow and tended to cease after six days and EPS content reached its highest point and then sharply decreased after three days. N-enrichment Condition strikingly stimulated the EPS production and P-enrichment Condition slightly promoted the EPS production but the stage for EPS release was different. Other nutrient changes did not affect either the growth or EPS yield. Our results are in sharp contrast to the ordinary regulation rule which has been shown that N deficiency stimulates polysaccharide synthesis in some EPS- producing microalgae.

关 键 词：多糖 微囊藻 营养 群体 单细胞 

分 类 号：Q946.3[生物学—植物学]