ABSTRACT: We aimed to study the growth and toxicity responses of non-toxic (CCMP683) and toxic (CCMP2804) strains of Prorocentrum hoffmannianum under various nitrate and phosphate concentrations. The 2 strains were cultured in L1-Si medium with standard, depleted or 10-fold repleted nitrate or phosphate. CCMP683 cultured in standard L1-Si medium exhibited delayed growth. Nitrate or phosphate depletion decreased the cell density of both strains. Repletion of nitrate slightly increased the cell density of both strains. Repletion of phosphate also slightly increased the cell density of CCMP2804 but surprisingly decreased the cell density of CCMP683. Okadaic acid (OA) and its derivatives were not detected in CCMP683. OA was detected only in CCMP2804. Depletion of nitrate or phosphate increased the cellular concentration of OA, and repletion of nitrate or phosphate had no effect on the cellular concentration of OA. Correlation analysis indicated that the cellular concentration of OA was negatively correlated with cell density. Differences in the growth response to phosphate repletion and in the ability to produce OA suggest that the 2 strains may be good candidates for comparative studies related to phosphate metabolism and OA toxicity.

中文翻译：

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霍夫原菌无毒和有毒菌株的生长和毒性反应比较

摘要：我们旨在研究霍夫曼原肠无毒（CCMP683）和有毒（CCMP2804）菌株的生长和毒性反应在各种硝酸盐和磷酸盐浓度下 将2个菌株在具有标准的，耗尽的或10倍的硝酸盐或磷酸盐的L1-Si培养基中培养。在标准L1-Si培养基中培养的CCMP683表现出延迟生长。硝酸盐或磷酸盐的消耗降低了两种菌株的细胞密度。硝酸盐的补充稍微增加了两个菌株的细胞密度。磷酸盐的补充也略微增加了CCMP2804的细胞密度，但出人意料地降低了CCMP683的细胞密度。在CCMP683中未检测到冈田酸（OA）及其衍生物。仅在CCMP2804中检测到OA。硝酸盐或磷酸盐的消耗增加了OA的细胞浓度，而硝酸盐或磷酸盐的消耗对OA的细胞浓度没有影响。相关分析表明，OA的细胞浓度与细胞密度呈负相关。对磷酸盐补充的生长反应和产生OA的能力的差异表明，这两种菌株可能是与磷酸盐代谢和OA毒性相关的比较研究的良好候选者。