卵孢金孢藻对不同磷化合物的利用及生长响应

为了解水华蓝藻卵孢金孢藻对水体不同磷化合物的利用能力,试验以磷酸氢二钾为对照,通过室内模拟的方法探究不同磷基质条件下卵孢金孢藻的生长响应.结果表明: 卵孢金孢藻能直接利用三聚磷酸钠和十水焦磷酸钠,且对三聚磷酸钠有极高的利用率.15天后,三聚磷酸钠处理组的藻细胞生物量和叶绿素a浓度最高,分别达到(426.96±47.42) mg·L^-1和(1852.34±116.60) μg·L^-1.2-氨基乙基膦酸和五水β-甘油磷酸钠处理组生物量与对照无明显差异,可溶性无机磷变化特征响应了碱性磷酸酶活性大小,表明卵孢金孢藻能通过酶水解利用这两种有机磷.而整个培养过程中,草甘膦处理组可溶性无机磷浓度趋近于0 mg·L^-1,藻细胞生物量、比生长速率、叶绿素a浓度及光合活力均显著低于对照,表明草甘膦不仅不利于藻细胞摄取磷,还对其生长产生抑制作用.本研究结果为了解卵孢金孢藻向不同水生态系统的扩散机理提供了新的思路,对我国新型蓝藻水华的防治具有一定的理论参考价值.

Utilization and growth response of Chrysosporum ovalisporum to different phosphorus compounds

To explore the ability of bloom-forming cyanobacterium Chrysosporum ovalisporum to utilize different kinds of phosphorus compounds in the water column, we examined the growth response of C. ovalisporum in the laboratory by taking dipotassium hydrogen phosphate as the control and set different treatments of phosphorus substrates. The results showed that C. ovalisporum could utilize sodium tripolyphosphate and terasodium pyrophosphate decahydrate, with better utilization of sodium tripolyphosphate. After 15 days, it had the highest biomass and chlorophyll a concentrations under the treatment of sodium tripolyphosphate, with a value of (426.96±47.42) mg·L^-1 and (1852.34±116.60) μg·L^-1, respectively. Compared with the control, there was no significant difference in biomass of C. ovalisporum under both the (2-aminoethyl)-phosphonic acid and disodium β-glycerol phosphate pentahydrate treatments. The change characteristics of dissolved inorganic phosphate were related to the alkaline phosphatase activity, indicating that C. ovalisporum was able to utilize these two organophosphorus compounds via enzyme hydrolysis. The concentration of dissolved inorganic phosphate reached 0 mg·L^-1 during the whole experiment when the C. ovalisporum were fed with glyphosate. Biomass, specific growth rate, chlorophyll a concentration and photosynthetic activity of algal cells were significantly lower than those of the control, indicating that C. ova-lisporum could not uptake phosphorus compounds in the glyphosate substrate and thus their growth being inhibited. Our results present new insights to understand the diffusion mechanism of C. ovalisporum into different aquatic ecosystems and had theoretical reference value for the prevention and control of new cyanobacterial blooms.