Soil ecological stoichiometry provides powerful theories to integrate the complex interplay of element cycling and microbial communities into biogeochemical models. One essential assumption is that microbes maintain stable C:N:P (carbon:nitrogen:phosphorus) ratios independent of resource supply, although such homeostatic regulations have rarely been assessed in individual microorganisms. Here, we report an unexpected high flexibility in C:N and C:P values of saprobic fungi along nutrient supply gradients, overall ranging between 7‐126 and 20‐1488, respectively, questioning microbial homeostasis. Fungal N:P varied comparatively less due to simultaneous reductions in mycelial N and P contents. As a mechanism, internal recycling processes during mycelial growth and an overall reduced N and P uptake appear more relevant than element storage. The relationships among fungal stoichiometry and growth disappeared in more complex media. These findings affect our interpretation of stoichiometric imbalances among microbes and soils and are highly relevant for developing microbial soil organic carbon and nitrogen models.

中文翻译：

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土壤真菌菌丝体的化学计量比C：N和C：P出乎意料地灵活

土壤生态化学计量学提供了强有力的理论，可将元素循环和微生物群落之间的复杂相互作用整合到生物地球化学模型中。一个基本的假设是微生物保持稳定的C：N：P（碳：氮：磷）比率，而与资源供应无关，尽管很少有人对单个微生物中的这种体内平衡进行评估。在这里，我们报告了沿营养供应梯度的腐生真菌的C：N和C：P值出乎意料的高灵活性，总体范围分别在7-126和20-1488之间，对微生物的体内平衡提出了质疑。由于菌丝体N和P含量的同时减少，真菌N：P的变化相对较小。作为一种机制，菌丝生长过程中的内部再循环过程以及总体上减少的N和P吸收比元素存储更为重要。真菌化学计量与生长之间的关系在更复杂的培养基中消失了。这些发现影响了我们对微生物与土壤之间化学计量失衡的解释，并且与开发微生物土壤有机碳和氮模型高度相关。