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首页> 外文期刊>Chemosphere >SIGNIFICANCE AND APPLICATION OF MICROBIAL TOXICITY TESTS IN ASSESSING ECOTOXICOLOGICAL RISKS OF CONTAMINANTS IN SOIL AND SEDIMENT [Review]
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SIGNIFICANCE AND APPLICATION OF MICROBIAL TOXICITY TESTS IN ASSESSING ECOTOXICOLOGICAL RISKS OF CONTAMINANTS IN SOIL AND SEDIMENT [Review]

机译：微生物毒性测试在评估土壤和沉积物中污染物的生态毒理学风险中的意义和应用[综述]

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Micro-organisms are vital for soil fertility and for the degradation of organic matter and pollutants in soils and sediments. Due to their function and ubiquitous presence micro-organisms can act as an environmentally very relevant indicator of pollution. Microbial tests should be used discriminatory for the establishment of soil and sediment quality guidelines. This review gives an evaluation of microbial toxicity tests and a novel method to derive quality guidelines. Long term microbial tests are generally less sensitive than short term tests. The toxic effects can be obscured by the activity of a few resistant micro-organisms, when for example soil respiration is used as a sum parameter during a long incubation period. Mineralization tests with high substrate concentrations which enable growth, are less sensitive than similar tests with low concentrations of substrate. The latter tests are more relevant for natural ecosystems. The often applied microbial toxicity tests can be categorized as single species tests, biomass measurements, carbon and nitrogen transformations, enzymatic tests and tests measuring changes in microbial diversity. Comparisons between tests can only be indicative because the relative sensitivity depends on the toxicants and soils used. The respiration rate per unit of biomass is a more sensitive indicator of toxic effects than the respiration rate or the amount of biomass alone. The autotrophic nitrification and acetylene reduction tests can be sensitive when short incubation times are used. The nitrogen mineralization, denitrification and many enzymatic tests are often not very sensitive. The urease activity is a relatively sensitive enzymatic test in many studies. The replacement of sensitive micro-organisms by different resistant species can have serious ecological consequences. Some species become extinct while others appear in bulging numbers. Adaptation of a community to a pollutant must be considered as the very process which disturbs a polluted ecosystem. The resistant micro-organisms often fail to perform specific ecological functions. The occurrence of resistant species can be used as an sensitive and ecologically relevant indicator for deterioration from environmental pollution. Persistent toxic effects on the microflora can be caused by zinc, cadmium and copper at concentration levels lower than European Community limits. Tests with anaerobic sediment processes were orders of magnitude more sensitive for some clorinated aliphatic compounds than aquatic toxicity tests. The addition of a few mg zinc per kg soil can inhibit the more sensitive microbial processes (like chloroform or 4-chlorophenol degradation), whereas soil invertebrates and some plants are less sensitive to zinc. After the evaluation of the tests, a novel method is described to derive soil and sediment quality guidelines using microbial toxicity tests. The results of single species tests with micro-organisms can be incorporated into the contemporary risk assessment method for higher organisms which is based on the extrapolation from single species tests to the protection of 95% of all species in an ecosystem. This method uses the No Observed Effect Concentrations (NOEC) of a number of toxicity tests to calculate a Hazardous Concentration 5% (HC5). The HC5 is calculated from more than 5 NOEC values. In analogy the Effect Concentration 10% (EC10) can be used to calculate the Dangerous Concentration 5% (DC5). The DC5 is calculated from more than 5 EC10 values. The DC5 should give protection to 95% of the microbial processes. The DC5 of a number of pollutants are calculated and compared with the HC5 values from the literature. Microbial toxicity tests can be used for risk assessment because micro-organisms are among the most sensitive organisms for the effects of pollutants. (C) 1997 Elsevier Science Ltd. [References: 197]
机译：微生物对于土壤肥力以及土壤和沉积物中有机物和污染物的降解至关重要。由于它们的功能和普遍存在，微生物可以充当与环境非常相关的污染指标。微生物试验应有区别地用于制定土壤和沉积物质量指南。这项审查提供了微生物毒性测试的评估和一种新的方法来导出质量准则。长期微生物检测通常不如短期检测敏感。当例如在长的温育期中将土壤呼吸用作总参数时，一些抗性微生物的活性可以掩盖毒性作用。具有较高底物浓度的矿化测试可以促进生长，其敏感性低于具有低底物浓度的类似测试。后面的测试与自然生态系统更相关。经常使用的微生物毒性测试可分为单种测试，生物量测量，碳和氮转化，酶促测试和测量微生物多样性变化的测试。测试之间的比较仅是指示性的，因为相对灵敏度取决于所使用的毒物和土壤。与呼吸速率或单独的生物质数量相比，每单位生物质的呼吸速率是毒性影响的更敏感指标。当使用较短的孵育时间时，自养硝化和乙炔还原测试可能很敏感。氮矿化，反硝化和许多酶促测试通常不是很敏感。在许多研究中，脲酶活性是相对敏感的酶促测试。用不同的抗性物种替代敏感微生物会产生严重的生态后果。有些物种已经灭绝，而另一些物种则以不断增加的数量出现。社区适应污染物的过程必须被视为干扰受污染生态系统的过程。抗性微生物通常不能执行特定的生态功能。抗药性菌种的出现可以用作环境污染恶化的敏感且与生态相关的指标。浓度低于欧洲共同体限值的锌，镉和铜可能对微生物区系产生持久的毒性作用。与某些水生毒性试验相比，厌氧沉积过程的测试对某些氯代脂族化合物的敏感性要高几个数量级。每公斤土壤添加几毫克锌可以抑制更敏感的微生物过程（如氯仿或4-氯苯酚降解），而无脊椎动物和某些植物对锌的敏感性较低。在对测试进行评估之后，描述了一种使用微生物毒性测试得出土壤和沉积物质量指南的新方法。可以对微生物进行单物种测试的结果纳入当代高等生物风险评估方法，该方法基于从单物种测试到生态系统中所有物种95％的保护的推断。此方法使用许多毒性测试的“未观察到的浓度”（NOEC）来计算5％的危险浓度（HC5）。 HC5是根据5个以上的NOEC值计算得出的。以此类推，可将效应浓度10％（EC10）用于计算5％危险浓度（DC5）。从5个以上的EC10值中计算出DC5。 DC5应该为95％的微生物过程提供保护。计算了许多污染物的DC5并将其与文献中的HC5值进行比较。微生物毒性测试可用于风险评估，因为微生物是对污染物影响最敏感的生物之一。 （C）1997 Elsevier Science Ltd. [参考：197]

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