两种喂食方式下微囊藻毒素-LR在罗非鱼肝脏和肌肉中动态变化的比较

试验以尼罗罗非鱼作为受试动物,通过直接投喂未经处理的新鲜藻细胞和喂食相同量经超声波破碎过的藻细胞,比较了罗非鱼在摄食完整蓝藻细胞与摄食破碎的蓝藻细胞时微囊藻毒素-LR(MC-LR)在其体内的动态变化规律及代谢差异.结果表明,无论是喂食破碎蓝藻细胞还是未破碎的蓝藻细胞均可在罗非鱼肝脏和肌肉中检出MC-LR,细胞破碎组肝脏和肌肉的富集能力高于未破碎组.富集第3d,即可在肝脏和肌肉中检出不同程度的MC-LR,肝脏中MC-LR的含量显著高于肌肉,随着富集时间的延长,MC-LR的含量总体呈上升趋势,破碎组肝脏和肌肉分别在染毒的16d和11d达到最大值(分别为2.021μg·g-1和0.071μg·g-1);未破碎组则分别在染毒的24d和21d达到最大值(分别为1.856μg·g-1和0.036μg·g-1).整个富集阶段破碎组肝脏MC-LR的平均值为1.171μg·g-1,略高于未破碎组的1.029μg·g-1;破碎组肌肉含量的平均值0.051μg·g-1,高于未破碎组的0.029μg·g-1.将细胞未破碎组的罗非鱼进行释放阶段的试验.结果表明,罗非鱼的肝脏能快速清除MC-LR,释放13d时达到释放阶段的最低值(为0.241μg·g-1),与肝脏相比,肌肉对毒素的清除要缓慢得多.

Dynamical Response of Microcystins-LR in Liver and Muscle of Tilapia (Oreochromis niloticus)in Two Feeding Conditions of Cyanobacteria

Two feeding conditions of cyanobacteria to tilapia fish(Oreochromis niloticus)have been carried out to investigate the dynamical response of microcystins-LR in liver and muscle of tilapia fish.In the first group,fish were fed naturally with fresh cyanobacteria(Microcystis aeruginosa)cells throughout the experiment,while in the second group,the cell wall of cyanobacteria were broken by Ultrasonic wave.The results show that the MC-LR accumulated in tilapia in both two groups.The cell-broken group shows high accumulation rate than non-broken group.The maximum MC-LR in the liver and muscle of the fish in cell-broken group were 1.856μg·g-1 and 0.036μg·g-1,respectively,while in non-broken group,the values were 2.021μg·g-1 and 0.071μg·g-1,respectively.During the accumulation period,the average MC-LR concentration of liver and muscle in non-broken were 1.029μg·g-1 and 0.028μg·g-1,respectively,lower than the cell-broken group(1.171μg·g-1 and 0.051μg·g-1).The depuration of MC-LR to tilapia in non-broken was observed in the following 20d,and the results of liver show high depuration rate than those of muscle.The grazing ability of tilapia on toxic cyanobacteria suggests an applicability of using phytoplanktivorous fish to counteract cyanotoxin contamination in entropic waters.This experiment focus on the quality safety and minus content standard of tilapia fish exposued in microcystins farmed in eutrophication water.