本研究探討自四草野生動物保護區純種分離附著性矽藻的方法，並進行純種矽藻對重金屬銅與鎘之耐污性研究。結果顯示:以Marine enrinchment medium f/2 修正培養基在光照100μmol．photons．m-2．S-1，溫度30℃，pH值8.0的培養條件，可分離出四草野生動物保護區內之附著性矽藻，以進行純種培養。分離之矽藻經進一步以光學顯微鏡及掃瞄式電子顯微鏡鑑定結果顯示:已分離出之矽藻包括羽紋矽藻目(Pennales)的雙眉藻屬(Amphora)、舟形藻屬(Navicula)及菱形藻屬(Nitzschia)等三屬六種，及一種圓心矽藻目(Centrales)的矽藻。分別編號為STSP1(雙眉藻屬Amphora sp1)、STSP2(雙眉藻屬Amphora sp2)、STSP3(圓心矽藻目矽藻)、STSP4(舟形藻屬Navicula sp1)、STSP5(舟形藻屬Navicula sp2)、STSP6(舟形藻屬Navicula sp3)、STSP7(菱形藻屬Nitzschia sp1)等七種。
進一步以分離純化之品系STSP1及STSP2，探討重金屬銅與鎘對附著性矽藻-雙眉藻屬(Amphora)之細胞分裂生長的影響，發現STSP1與STSP2可在培養57小時之後，分別適應培養液中加入的0.6ppm及0.9ppm的銅離子濃度。然而，STSP1與STSP2對鎘離子之適應濃度則相當高，在6ppm的鎘離子濃度，細胞仍可分裂生長，但在8ppm以上則完全無法存活。此外，回復培養研究中發現STSP1與STSP2對於銅離子之耐污性亦極高，可自0.9至9ppm銅離子濃度污染後回復培養。此結果顯示STSP1與STSP2可做為重金屬銅與鎘污染的指標生物。 This study focused on the isolation of attached diatoms taken from Szu-Tsao Wildlife Reserve and their tolerance of the heavy metals copper and cadmium. The results showed that the attached diatoms could be isolated from the nature and pure culture by the Marine enrichment medium f/2 medium under conditions of 30℃, pH8 and light intensity 100μmol．photons．m-2．S-1. Seven species were identified under the light microscope (LM) and scanning electric microscope(SEM). Three genera with six species were under order Pennales and one species was under order Centrals. The isolated diatoms were strain STSP1(Amphora sp1), STSP2(Amphora sp2), STSP3(order Centrales), STSP4(Navicula sp1)、STSP5(Navicula sp2)、STSP6(Navicula sp3) and STSP7(Nitzschia sp1).
Furthermore, the heavy metal copper and cadmium were added to the pure culture diatoms of strain STSP1 and STSP2 separately and cell growth of the diatoms were observed. We found that after 57 hours, strain STSP1 and STSP2 would grow in 0.6ppm and 0.9ppm concentration of copper separately. On contrast, strain STSP1 and STSP2 could grow as well in solution containing cadmium in concentration as high as 6ppm, however, a concentration of 8ppm cadmium ions could damage of them.
In addition, growing recovery culture revealed that strain STSP1 and STSP2 could tolerate very high concentration of copper. Both of them could survive in copper ion solution with a concentration of 0.9 to 9ppm. In conclusion, we believe that strain STSP1 and STSP2 could act as bioindicators in environment polluted by the heavy metals copper and cadmium。
