盐度和营养限制对盐田底栖硅藻披针舟形藻生长及胞外多糖产率的影响

EFFECTS OF SALINITY AND NUTRIENT LIMITATION ON THE GROWTH AND EXOPOLYSACCHARIDE PRODUCTION OF THE SALTERN BENTHIC DIATOM NAVICULA LANCEOLATA

从台南盐场藻垫中分离得到底栖硅藻披针舟形藻(Navicula lanceolata),该藻生长的最适盐度是1.6%NaCl。在最适盐度之上,随着盐度增大,藻细胞生长受到轻微抑制。氮磷营养限制条件下披针舟形藻生长受到严重抑制,氮营养限制比磷营养限制对藻生长的抑制作用更显著。高盐度和氮磷营养限制条件下,披针舟形藻胞外多糖(EPS)产率都明显增加,氮营养限制比磷营养限制对EPS产率的促进作用更显著。这表明在盐田高盐和氮磷营养限制条件下披针舟形藻产生更多的EPS,有利于藻垫的形成和稳定。

The benthic diatom Navicula lanceolata was isolated from the algal mat in Tainan Saltworks. The optimum salinity for the growth of Navicula lanceolata was 1.6 % NaCl. Above the optimum salinity, the growth of the alga was inhibited slightly with the increasing salinity. The growth of the alga was inhibited severely under nitrogen or phosphorous limitation conditions. The inhibitory effect of nitrogen limitation on growth was stronger than phosphorous limitation. The exopolysaccharide （EPS） production was enhanced under high salinity, nitrogen limitation or phosphorous limitation. The alga produced more EPS under nitrogen limitation than phosphorous limitation. The data suggested the alga could produce abundant EPS under high salinity or nutrient limitation in saltworks, and benefited the formation and stabilization of algal mats.