海洋菌对对硫磷的积累与降解  

Accumulation and Degradation of ^(14)C-labeled parathion in some Marine Bacteria

作　　者：杨杏[1] 

机构地区：[1]中山大学生命科学学院,2001硕广州510275

出　　处：《中山大学研究生学刊（自然科学与医学版）》2002年第3期87-95,共9页Journal of the Graduates Sun YAT-SEN University(Natural Sciences.Medicine)

摘　　要：本文研究了3株海洋菌对对硫磷的积累与降解,结果发现,对硫磷在三株菌中标记率由高到低分别是菌株4307、菌株4320、菌株5621。菌株4307的标记率普遍在70%以上,菌株4320则表现了明显的时间变化,随着时间的增长标记率不断减少,由0.5小时到24小时的标记率分别为:68.63%、56.47%、53.06%、31.96%、17.17%、8.98%。菌株5621的标记率远远低于上述两株菌,平均值在8小时内才30%左右;对硫磷在菌株中的结合态比率比较低,在菌株4307中平均值只有4%左右,在菌株4320中表现出时间变化,随时间的增长,结合态不断增加,由0.5小时到24小时的结合态比率分别为:6.19%、6.90%、12.25%、14.15%、26.94%、28.27%,菌株5621也表现出时间变化,但是增幅没有菌株4320明显;在降解方面,在菌株4307中,随着时间的推移,其母体对硫磷由开始时的100%,逐渐降到24小时的82.6%,降解物对氧磷,也由开始的0增长到后来的11.8%。在菌株4320中,可以明显的看出对硫磷的降解情况,在4个小时内,60%的母体就已经发生了降解,到了24小时,母体只剩下3.9%。菌株5621对对硫磷的降解情况也比较明显,24小时内母体就只剩下56.5%%,原点未知物增加到32.8%。同时在实验中我们发现降解率、标记率这两个指标进行着同步变化。标记率越大,降解程度就越完全,并推测在这些海洋菌含有能降解对硫磷的胞内酶。Three strains of marine bacteria,isolated from South China Sea,were treated with ^(14)C-labeled parathion after cultured to OD=0.8.Samples were collected in 0.5,1,2, 4,8,24 hour,and after centrifugalized,one part of the supermaterial was used to measure the radioativity and the other was adsorpted by active-carbon to analysis its degradation cont- ent.The sediment was extracted to determine its radioativity as the ratio of bound residues. By measuring the label rate,ratio of bound residues and metabolism,it had been found that the ratio of label in strain 4307 and 4320 was higher than that in strain 5621,and it could be clearly observed in 4320 that the label rate was gradually dropped from 68.6% in 0.5h to 9.0% in 24h.The ratio of bound residues of the three bacteria were quite low as the average of 4307 was only around 4% while the other two were no more than 29% after 24h, and the ratio of bound residues could be observed raising from 6.2% (0.5h) to 28.3% (24h)in strain 4320.Different degradation level could be noted from the three strains of bacteria,for example,in strain 4320,60% of parathion have been degradated into paraoxon within 4h and,after 24h,there are only 3.9% parathion left.From these facts we draw a conclusion that there may be some enzyme which can degrade parathion in the cell.

关 键 词：对硫磷 海洋菌 积累 降解 有机磷农药 标记率 结合态比率 海洋污染 农药残留 

分 类 号：X592[环境科学与工程—环境工程] X172