Abstract：
Environmental pollution is considered to lead to Ulva sp. green tides. Nevertheless, nutrients with high concentrations inhibit algae which may be damaged by antibiotics, such as OTC (oxytetracycline). Thus, Ulva sp. algae might pay a physiological cost under nutrient-OTC combined pressures. If this hypothesis is confirmed, Ulva sp. algae cannot easily form green tides, or green tides are difficult to maintain. To test this hypothesis, an uniform design experiment during which OTC, ammonia (NH4-N) and phosphate (PO4-P) were factors was set to simulate nutrient-OTC combined pressures, and Ulva lactuca was exposed to the pressures for 96 h. The TN (total nitrogen, CTN) or TP (total phosphorus, CTP) content in U. lactuca increased with increasing nutrient concentrations, as CTN = 21.206±1.000+ 1.227±0.418NH4-N × PO4-P (R2 = 0.282, p < 0.05) and CTP = 1.886±0.266+ 0.877±0.126PO4-P (R2 = 0.689, p < 0.05), respectively. The increase in dry weight of U. lactuca (Wdry) had a relationship with combined pressures, Wdry = 0.011±0.029 - 0.036±0.014PO4-P (R2 = 0.243, p < 0.05), i.e., the algal growth was inhibited by increasing PO4-P concentration. The SOD (Superoxide dismutase) activity (ASOD) was stimulated by OTC, as ASOD = 127.868±8.741+9.587±4.179 OTC (R2 = 0.193, p < 0.05). The contents of Chl a and b (Ca and Cb) were negatively affected by OTC or PO4-P with high concentration, as Ca = 0.566±0.042 - 0.024±0.022 OTC × PO4-P (R2 = 0.179, p < 0.05) and Cb = 0.512±0.043-0.044±0.020PO4-P (R2 = 0.180, p < 0.05). Thus, too high concentrations of PO4-P or OTC may hinder the formation and maintenance of Ulva sp. green tides.
摘要：
环境污染被认为会导致Ulvasp。绿色潮汐。然而，高浓度的营养物质会抑制可能被抗生素破坏的藻类，如OTC（土霉素）。因此，Ulvasp.在营养-OTC组合压力下，藻类可能会付出生理代价。如果这个假设得到证实,Ulvasp.藻类不容易形成绿潮，或者绿潮难以维持。为了检验这个假设，均匀设计实验，氨(NH4-N)和磷酸盐(PO4-P)是模拟营养-OTC组合压力的因素，和Ulvalacticuca暴露于压力96小时。TN(总氮，CTN)或TP(总磷，CTP)含量随着营养浓度的增加而增加，CTN=21.206±1.000+1.227±0.418NH4-N×PO4-P(R2=0.282,p<0.05),CTP=1.886±0.266+0.877±0.126-P(R2=0.689,p<0.05),分别。U.lactuca（Wdry）干重的增加与综合压力有关，Wdry=0.011±0.029-0.036±0.014PO4-P（R2=0.243，p<0.05），即，增加PO4-P浓度抑制藻类生长。OTC刺激SOD(超氧化物歧化酶)活性(ASOD),ASOD=127.868±8.741+9.587±4.179OTC(R2=0.193,p<0.05)。高浓度的OTC或PO4-P对Chla和b(Ca和Cb)的含量有负面影响，如Ca=0.566±0.042-0.024±0.022OTC×PO4-P（R2=0.179，p<0.05）和Cb=0.512±0.043-0.044±0.020PO4-P（R2=0.180，p<0.05）。因此，过高浓度的PO4-P或OTC可能会阻碍Ulvasp的形成和维持。绿色潮汐。
