Environ Technol. 2014 Mar-Apr;35(5-8):773-80. doi: 10.1080/09593330.2013.850520.
We investigated microbiota in surface and subsurface soil from a site, above steam-treated deep sub-soil originally contaminated with chlorinated solvents. During the steam treatment, the surface soil reached temperatures c. 30 degrees C higher than the temperature in untreated soil; whereas the subsurface soil, at a depth of about 40 cm, reached a temperature c. 45 degrees C higher than untreated soil. The soil was examined prior to, during, and 6, 12, 14, 20 and 31 months after treatment. Numbers of bacteria cultivable at 42 degrees C increased significantly in subsurface soil. Similarly, substrate utilization in ECOLOG plates, incubated at 42 degrees C, increased from less than 10% of available carbon sources in the untreated soil to more than 60% of the available carbon sources in the steam-treated soil. Aspergillus fumigatus was quantified as an example ofheat-tolerant fungi normally found in compost. These organisms are rarely detected in Danish soils but high numbers (c. 10(5) hyphal forming units g(-1)) occurred in the treated soil up to 31 months after the steam-treatment. We conclude that steam-treatment leads to changes of the microbial communities. Some changes are temporary while others can last for years after termination of the steam-treatment; reflecting different strategies that soil microorganisms follow.
我们研究了蒸汽处理过的深层污染场地的表层和亚表层土壤中的微生物区系。在蒸汽处理过程中，表层土壤的温度比未处理土壤高约 30 摄氏度；而在大约 40 厘米深的亚表层土壤中，温度比未处理土壤高约 45 摄氏度。在处理前、处理期间以及处理后 6、12、14、20 和 31 个月对土壤进行了检查。42°C 下可培养细菌的数量在亚表层土壤中显著增加。同样，在 42°C 下培养的 ECOLOG 平板的底物利用度从未处理土壤中不到 10%的可用碳源增加到蒸汽处理土壤中超过 60%的可用碳源。以烟曲霉为例，它是耐热真菌，通常存在于堆肥中。这些生物在丹麦土壤中很少被检测到，但在蒸汽处理后的土壤中数量很高（约 10(5)个菌丝形成单位 g(-1))，直到 31 个月后仍有大量存在。我们得出结论，蒸汽处理会导致微生物群落发生变化。一些变化是暂时的，而另一些变化则可以在蒸汽处理结束后持续多年；反映了土壤微生物遵循的不同策略。
