Increasing experimental evidence and modeling efforts have found that microbial necromass is highly associated with mineral-associated organic matter (MAOM). However, recent studies found that MAOM is predominantly derived from plant litter materials, challenging the notion that microbial necromass is preferentially occluded in MAOM. Here, we compiled 245 observations of glucosamine, galactosamine, mannosamine and muramic acid (specific biomarker for microbial necromass) in MAOM and particle organic matter (POM) from current experiments conducted in croplands, forests and grasslands. We evaluated the influence of climatic and edaphic factors on the partitioning of amino sugars in MAOM and POM. Total amino sugars are predominantly occluded within MAOM (3.23 ± 0.53 mg/g soil) rather than POM (1.73 ± 0.26 mg/g soil) on a global scale, and this preference varies among ecosystem types. Specifically, there are no significant differences in the concentrations of total amino sugars between MAOM and POM in croplands and grasslands. However, forests have significantly higher concentrations of total amino sugars in MAOM (3.88 ± 0.85 mg/g soil) compared to POM (2.23 ± 0.57 mg/g soil). Our results corroborate a consistent preponderance of glucosamine over muramic acid in MAOM and POM across diverse ecosystems. Altitude and MAT were key factors in explaining the occlusion of total amino sugars in MAOM, but those in POM decreased with increasing soil bulk density. Our synthesis across different ecosystems suggests that microbial necromass is predominantly preserved in MAOM, which is driven by climatic factors.

中文翻译：

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生物标志物证据表明，微生物坏死物质优先闭塞在矿物相关有机物中，而不是颗粒有机物中


越来越多的实验证据和建模工作发现，微生物坏死量与矿物相关有机物 （MAOM） 高度相关。然而，最近的研究发现，MAOM 主要来源于植物凋落物材料，挑战了微生物坏死团优先被 MAOM 封闭的观点。在这里，我们汇编了 MAOM 中葡萄糖胺、半乳糖胺、甘露糖胺和胞壁酸（微生物坏死质量的特异性生物标志物）和颗粒有机物 （POM） 的 245 次观察结果，这些观察来自当前在农田、森林和草原进行的实验。我们评估了气候和 edaphic 因素对 MAOM 和 POM 中氨基糖分配的影响。在全球范围内，总氨基糖主要被封闭在 MAOM（3.23 ± 0.53 mg/g 土壤）而不是 POM（1.73 ± 0.26 mg/g 土壤）中，并且这种偏好因生态系统类型而异。具体而言，MAOM 和 POM 在农田和草原中总氨基糖浓度无显著差异。然而，与 POM（2.23 ± 0.57 mg/g 土壤）相比，MAOM（3.88 ± 0.85 mg/g 土壤）中森林的总氨基糖浓度明显更高。我们的结果证实了在不同生态系统中 MAOM 和 POM 中葡萄糖胺始终优于胞壁酸。海拔和 MAT 是解释 MAOM 中总氨基糖闭塞的关键因素，但 POM 中的氨基糖随着土壤容重的增加而降低。我们对不同生态系统的综合表明，微生物坏死量主要保存在 MAOM 中，这是由气候因素驱动的。