Leahy J G, Colwell R R
Department of Microbiology, University of Maryland, College Park 20742.
Microbiol Rev. 1990 Sep;54(3):305-15. doi: 10.1128/mr.54.3.305-315.1990.
The ecology of hydrocarbon degradation by microbial populations in the natural environment is reviewed, emphasizing the physical, chemical, and biological factors that contribute to the biodegradation of petroleum and individual hydrocarbons. Rates of biodegradation depend greatly on the composition, state, and concentration of the oil or hydrocarbons, with dispersion and emulsification enhancing rates in aquatic systems and absorption by soil particulates being the key feature of terrestrial ecosystems. Temperature and oxygen and nutrient concentrations are important variables in both types of environments. Salinity and pressure may also affect biodegradation rates in some aquatic environments, and moisture and pH may limit biodegradation in soils. Hydrocarbons are degraded primarily by bacteria and fungi. Adaptation by prior exposure of microbial communities to hydrocarbons increases hydrocarbon degradation rates. Adaptation is brought about by selective enrichment of hydrocarbon-utilizing microorganisms and amplification of the pool of hydrocarbon-catabolizing genes. The latter phenomenon can now be monitored through the use of DNA probes. Increases in plasmid frequency may also be associated with genetic adaptation. Seeding to accelerate rates of biodegradation has been shown to be effective in some cases, particularly when used under controlled conditions, such as in fermentors or chemostats.
本文综述了自然环境中微生物种群对碳氢化合物降解的生态学，重点阐述了有助于石油和单个碳氢化合物生物降解的物理、化学和生物因素。生物降解速率在很大程度上取决于石油或碳氢化合物的组成、状态和浓度，在水生系统中，分散和乳化会提高降解速率，而土壤颗粒的吸附是陆地生态系统的关键特征。温度、氧气和养分浓度在这两种环境中都是重要的变量。盐度和压力在某些水生环境中也可能影响生物降解速率，而湿度和pH值可能会限制土壤中的生物降解。碳氢化合物主要由细菌和真菌降解。微生物群落预先接触碳氢化合物后的适应性会提高碳氢化合物的降解速率。适应性是通过选择性富集利用碳氢化合物的微生物和扩大碳氢化合物分解代谢基因库来实现的。现在可以通过使用DNA探针来监测后一种现象。质粒频率的增加也可能与遗传适应性有关。在某些情况下，特别是在受控条件下使用，如在发酵罐或恒化器中，接种以加速生物降解速率已被证明是有效的。
