Microbiome analyses of soils and microcosm experiments depend on conditions that include sterilization in order to perform experimental manipulation of microbial communities. Still, they should represent conditions close to nature. When using metal contaminated soils, sterilization methods might alter metal availability. Here, four typical metal contaminated substrates were analyzed, representing different contamination histories and soil types. They included two very poor substrates, as they are often found at metal contaminated sites. The low contents in organic carbon and nitrogen as well as two substrates with slightly higher nutrient availability were used to perform a comprehesive study for element availability changes induced by sterilization. Autoclaving, dry heat or gamma raγ sterilization were applied and compared to a non-treated control. The sterile substrates were analyzed using sequential extraction to account for different associations of the elements. Metals forming specific (hydro)oxide layers were specifically analyzed since they in turn may also impact other metals or ions. In addition, (heavy) metals and (micro)nutrients were analyzed for changes in speciation. The effects of autoclaving (wet heat) was found acceptable, while γ-ray irradiation did show unexpected changes in metal associations, especially for one substrate. Dry heat changed metal availability to the highest degree.

中文翻译：

---

消毒在重金属污染的基质中诱导的元素利用率变化：一项全面的研究。

土壤的微生物组分析和微观实验取决于包括灭菌在内的条件，以便进行微生物群落的实验操作。尽管如此，它们仍应代表接近自然的条件。当使用金属污染的土壤时，灭菌方法可能会改变金属的利用率。在这里，分析了四种典型的金属污染基质，分别代表了不同的污染历史和土壤类型。它们包括两种非常差的基材，因为它们经常在金属污染的地点发现。利用有机碳和氮的低含量以及两种养分利用率稍高的底物，对灭菌引起的元素利用率变化进行了综合研究。高压灭菌 进行干热或伽马射线灭菌，并与未处理的对照进行比较。使用顺序提取分析无菌底物，以说明元素的不同关联。对形成特定（氢）氧化物层的金属进行了专门分析，因为它们反过来也可能会影响其他金属或离子。此外，分析了（重）金属和（微量）营养素的形态变化。发现高压灭菌（湿热）的效果是可以接受的，而γ射线辐照的确显示出金属缔合的出乎意料的变化，尤其是对于一种基材。干热最大程度地改变了金属的可用性。对形成特定（氢）氧化物层的金属进行了专门分析，因为它们反过来也可能会影响其他金属或离子。此外，分析了（重）金属和（微量）营养素的形态变化。发现高压灭菌（湿热）的效果是可以接受的，而γ射线辐照的确显示出金属缔合的出乎意料的变化，尤其是对于一种基材。干热最大程度地改变了金属的可用性。对形成特定（氢）氧化物层的金属进行了专门分析，因为它们反过来也可能会影响其他金属或离子。此外，分析了（重）金属和（微量）营养素的形态变化。发现高压灭菌（湿热）的效果是可以接受的，而γ射线辐照的确显示出金属缔合的出乎意料的变化，尤其是对于一种基材。干热最大程度地改变了金属的可用性。