University of California, (UCD), Davis, US.
Queens College, City University of New York (CUNY), The CUNY Graduate Center.
Ecol Lett. 2012 Nov;15(11):1257-1265. doi: 10.1111/j.1461-0248.2012.01848.x. Epub 2012 Aug 16.
The source of microbial C is thought to impact its stability in soil due to variations in cellular biochemistry. It has been hypothesised that a fungal-dominated community stabilises more C than a bacterial-dominated community, in part due to chemical recalcitrance of their non-living biomass, particularly cell wall components and pigments. We compared the turnover of (13)C-labelled (99.9 atom %) temperate and tropical microbial isolates [i.e. fungi, Gram-positive bacteria (including actinobacteria) and Gram-negative bacteria] in temperate (California) and tropical (Puerto Rico) forest soils. While significant differences in (13)C recovery and mean residence times occurred among some microbial additions, similar turnover rates were observed, and in general, results do not support the view that microbial biochemistry affects soil C maintenance. Different effects by microbial necromass additions in California and Puerto Rico suggest that ecosystem-specific effects may be as important to microbial C stabilisation as its macromolecular composition and recalcitrance.
由于细胞生物化学的差异，微生物 C 的来源被认为会影响其在土壤中的稳定性。有人假设，真菌占主导地位的群落比细菌占主导地位的群落更能稳定更多的 C，部分原因是它们的无生命生物量（特别是细胞壁成分和色素）具有化学抗性。我们比较了（13）C 标记的（99.9 原子%）温带和热带微生物分离物[即真菌、革兰氏阳性菌（包括放线菌）和革兰氏阴性菌]在温带（加利福尼亚州）和热带（波多黎各）森林土壤中的周转情况。虽然一些微生物添加物中（13）C 的回收率和平均停留时间存在显著差异，但观察到了相似的周转速率，一般来说，结果不支持微生物生物化学影响土壤 C 维持的观点。加利福尼亚和波多黎各微生物残体添加物的不同影响表明，生态系统特有的影响可能与微生物 C 的稳定性与其高分子组成和抗性一样重要。
