Information on microbial biomass carbon (MBC) is crucial to assess their stocks and role for plant nutrient release in soil. Next to fumigation-extraction, molecular methods are routinely used to estimate the contribution of fungi, bacteria, and archaea to the soil microbial community. However, more information on the links between these different indices would deepen the understanding of microbial processes. The current study is based on 11 datasets, which contain MBC and MBN data obtained by fumigation-extraction and information on bacterial, archaeal, and fungal gene abundance, totalling 765 data points from agricultural, forest, and rangeland soils. Some of these datasets additionally provide information on double-stranded deoxyribonucleic acid (dsDNA) and fungal ergosterol. MBC varied around the median of 206 µg g⁻¹ soil. MBN followed with a median MB-C/N ratio of 4.1. Median microbial gene abundance declined from bacteria (96 × 10⁸) to archaea (4.4 × 10⁸) to fungi (1.8 × 10⁸). The median ratio of MBC/dsDNA was 15.8 and that of bacteria/dsDNA was 5.8 × 10⁸ µg⁻¹. The relationships between MBC and dsDNA as well as between bacterial gene abundance and dsDNA were both negatively affected by soil pH and positively by clay content. The median ergosterol/MBC and fungi/ergosterol ratios were 0.20% and 4.7 (n × 10⁸ µg⁻¹), respectively. The relationship between fungal gene abundance and ergosterol was negatively affected by soil pH and clay content. Our study suggests that combining fumigation-extraction with molecular tools allows more precise insights on the physiological interactions of soil microorganisms with their surrounding environment.

有关微生物生物量碳 (MBC) 的信息对于评估其储量及其在土壤中植物养分释放的作用至关重要。除了熏蒸提取之外，分子方法通常用于估计真菌、细菌和古细菌对土壤微生物群落的贡献。然而，有关这些不同指数之间联系的更多信息将加深对微生物过程的理解。目前的研究基于 11 个数据集，其中包含通过熏蒸提取获得的 MBC 和 MBN 数据以及细菌、古菌和真菌基因丰度信息，总计来自农业、森林和牧场土壤的 765 个数据点。其中一些数据集还提供有关双链脱氧核糖核酸 (dsDNA) 和真菌麦角甾醇的信息。 MBC 在 206 µg g ⁻¹土壤的中位数附近变化。 MBN 紧随其后，MB-C/N 比率中位数为 4.1。微生物基因丰度中位数从细菌（96 × 10 ⁸）下降到古细菌（4.4 × 10 ⁸）再到真菌（1.8 × 10 ⁸）。 MBC/dsDNA的中位比为15.8，细菌/dsDNA的中位比为5.8×10 ⁸  µg ^-1。 MBC 和 dsDNA 之间以及细菌基因丰度和 dsDNA 之间的关系均受到土壤 pH 值的负面影响和粘土含量的正面影响。麦角甾醇/MBC和真菌/麦角甾醇比率的中值分别为0.20%和4.7 (n × 10 ⁸  µg ^-1 )。真菌基因丰度与麦角甾醇之间的关系受到土壤 pH 值和粘土含量的负面影响。我们的研究表明，将熏蒸提取与分子工具相结合可以更精确地了解土壤微生物与其周围环境的生理相互作用。