原油污染土壤是一个严重的生态问题,可能对公共卫生产生不利影响。这项研究使用鼠精子异常测定法评估了生物修复前后来自原油污染土壤的模拟渗滤液的生殖细胞毒性,精子计数,和睾丸组织病理学。总睾酮(TT)水平,卵泡刺激素(FSH),和促黄体生成素(LH);和过氧化氢酶(CAT)的活性,碱性磷酸酶(ALP),超氧化物歧化酶(SOD),天冬氨酸转氨酶(AST),测定丙氨酸转氨酶(ALT)。物理化学,石油总烃(TPH),并对渗滤液进行了重金属分析。将雄性小鼠连续五天暴露于50、25、10、5和1%(v/v;渗滤液:蒸馏水)的渗滤液样品中,35天后被处死.结果显示有统计学意义(p<0.05),暴露小鼠异常精子细胞的浓度依赖性增加,像折叠的精子,无定形封头,尾部附件错误,远端液滴,没有钩子,和环形尾巴。数据进一步显示暴露小鼠中平均精子计数的浓度依赖性显著降低。具有不同病变和ALT活性的生精小管的改变,AST,ALP,FSH,LH,还记录了TT。高水平的选定重金属(As,Cr,Cd,Cu,和Pb)和TPH被认为有助于观察到的生殖毒性和调节的酶活性。因此可以得出结论,对原油污染土壤的微生物修复产生了土壤中重金属和TPH水平的降低,减少生殖毒性,和酶活性的调节。然而,生物介导土壤的生殖毒性仍然显著,因此,可以做进一步的工作来使用细菌的联合体,并延长生物修复过程的时间,以确保完全去除污染物。
Contamination of soil with crude oil is a serious ecological problem with potential adverse public health effects. This study assessed the germ cell toxicity of simulated leachates from crude oil-contaminated soil before and after bioremediation using the murine sperm abnormality assay, sperm count, and testes histopathology. The levels of Total Testosterone (TT), Follicle Stimulating Hormone (FSH), and Luteinizing Hormone (LH); and activities of catalase (CAT), alkaline phosphatase (ALP), superoxide dismutase (SOD), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were determined. The physicochemical, Total Petroleum Hydrocarbon (TPH), and heavy metal analyses of the leachates were also carried out. Male mice were exposed to 50, 25, 10, 5, and 1% (v/v; leachate:distilled water) of the leachate samples for five consecutive days, and were sacrificed after 35 days. The result showed a statistically significant (p < 0.05), concentration-dependent increase in abnormal sperm cells in exposed mice, with aberrations such as folded sperm, amorphous head, wrong tail attachment, distal droplet, no hook, and looped tail. Data further showed a concentration-dependent significant reduction in mean sperm count in the exposed mice. Alterations of seminiferous tubules with different lesions and activities of ALT, AST, ALP, FSH, LH, and TT were also recorded. The high level of selected heavy metals (As, Cr, Cd, Cu, and Pb) and TPH was believed to contribute to the observed reproductive toxicity and modulated enzyme activities in the treated mice. It is therefore concluded that the microbial remediation of the crude oil contaminated soil produced a reduction in the levels of heavy metals and TPH in the soil, reduced reproductive toxicity, and modulation of enzyme activities. However, the induced reproductive toxicity by the bioremediated soil is still significant, hence, further work could be done to employ a consortium of bacteria and extend the period of the bioremediation process to ensure complete removal of the contaminants.