Turnover of carbon and phosphorus in the microbial biomass depending on phosphorus availability
Turnover of carbon and phosphorus in the microbial biomass depending on phosphorus availability
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DOI：
10.1016/j.soilbio.2017.05.017
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发表时间：
2017-10-01
影响因子：
9.7
通讯作者：
Widdig, Meike
中科院分区：
文献类型：
--
作者：
Spohn, Marie;Widdig, Meike
土壤微生物生物量中元素平均停留时间（MRT）的调整可能是微生物群落适应营养贫乏环境并维持其元素生物量比例的重要过程。然而，人们对SMB中碳（C）和磷（P）等元素的周转知之甚少，这部分是由于方法上的挑战。这是第一个研究，以确定在SMB中的C和P的MRT的基础上标记的微生物DNA与C-14和P-33。我们研究了C和P在SMB从温带，中质草原施肥与5个不同的P量。为此，土壤标记与C-14-葡萄糖和P-33-磷酸盐，培养24 h，然后，C-14和P-33在土壤微生物DNA测定。根据土壤微生物DNA中C、P含量计算C、P的MRT值，并观察到土壤微生物生物量C与微生物DNA呈线性相关。土壤微生物群落中的微生物碳和微生物碳的MRT不受磷有效性的影响，而微生物群落中的微生物碳的MRT随着磷有效性的降低而显著增加，从18.1天增加到39.0天。我们的研究结果表明，在SMB中的单个元素的MRT的调整是一个重要的过程，微生物适应营养不良的环境，并能够保持其生物量元素的比例分解时，具有非常高的C-营养比的基板。(C)2017爱思唯尔有限公司版权所有。
Adjustment of the mean residence time (MRT) of elements in the soil microbial biomass (SMB) might be an important process by which microbial communities adapt to nutrient-poor environments and maintain their element biomass ratio. Yet, little is known about the turnover of elements such as carbon (C) and phosphorus (P) in the SMB, which is partly due to methodological challenges. This is the first study to determine the MRT of C and P in SMB based on labeling of microbial DNA with C-14 and P-33. We studied the MRT of C and P in the SMB of topsoil from a temperate, mesic grassland fertilized with five different amounts of P. For this purpose, soil was labeled with C-14-glucose and P-33-phosphate and incubated for 24 h, and then, C-14 and P-33 in the soil microbial DNA were determined. The MRT of C and P was calculated based on the C and P content of DNA, and the observation that soil microbial biomass C and microbial DNA are linearly correlated. The SMB-C and the MRT of C in the SMB were not affected by P availability, whereas the microbial community significantly increased the MRT of P in its biomass from 18.1 to 39.0 days with decreasing P availability. Our results indicate that the adjustment of the MRT of individual elements in the SMB is an important process by which microbes adapt to nutrient poor environments and are able to maintain their biomass element ratio when decomposing substrate with a very high C-to-nutrient ratio. (C) 2017 Elsevier Ltd. All rights reserved.