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作 者 ：葛体达;宋世威;黄丹枫

期 刊 ：应用生态学报 2010年 21卷 3期 页码：694-700

关键词：氨基酸；多肽；温度；可溶性有机氮；矿化；吸收动力学；

Keywords:amino acid, peptide, temperature, dissolved organic nitrogen, mineralization, adsorption,

摘 要 ：

研究了不同温度（1 ℃、15 ℃和25 ℃）对3种园艺生产系统（有机生产系统OS、转换期生产系统TS、常规生产系统CS）土壤中外源添加氨基酸、多肽的矿化及其吸收动力学特性的影响.结果表明：随着温度的升高，外源添加的氨基酸和多肽在土壤中的矿化速度加快.在1 ℃、15 ℃和25 ℃下，3种供试土壤中谷氨酸（Glu）的平均半衰期分别为13.3、6.8和5.5 h；而谷氨酰苯丙氨酸（Glu-Phe）的平均半衰期则分别为29.7、7.5和4.4 h.土壤的氨基酸、多肽的吸收动力学试验表明，土壤对氨基酸、多肽的吸收速率随着外源添加氨基酸和多肽浓度及温度的增加而提高.土壤对氨基酸的最大吸收速率(V_max)和亲和力（K_m）及对多肽的吸收速率（V_h）均随温度的升高而增大.在0～2.5 mmol·L^-1浓度范围内，土壤对氨基酸的吸收动力学曲线遵循经典的米氏动力学曲线，而多肽则表现为线性模式.3种园艺生产系统土壤的氨基酸和多肽的周转速率、吸收动力学参数（V_max、K_m和V_h）均表现为OS>TS>CS.总之，温度显著影响了氨基酸、多肽在土壤中的矿化及其吸收动力学特性.

Abstract:

An incubation test was conducted to study the effects of different temperature (1 ℃, 15 ℃, and 25 ℃) on the mineralization and adsorption of exogenous amino acid and peptide in the soils of horticultural production systems, including organic farming system (OS), transitional farming system (TS), and conventional farming system (CS). With the increase of incubation temperature, the mineralization of exogenous amino acids and peptides in test soils quickened. The mean half-life (D₅₀) of Glu at 1 ℃, 15 ℃, and 25 ℃ was 13.3, 6.8, and 5.5 h, while the D₅₀ of Glu-Phe was 29.7, 7.5, and 4.4h, respectively. The adsorption rate of the exogenous amino acids and peptides was dependent on their concentrations and incubation temperature. The maximum adsorption rate (V_max) and affinity (K_m) of amino acids and the adsorption rate (V_h) of peptides were all increased with incubation temperature. In the range of 0-2.5 mmol·L^-1, the adsorption of amino acids conformed to classical Michaelis-Menten equation, while that of peptides conformed to linear equation. The turnover rate and the V_max,K_m, and V_h values of exogenous amino acids and peptides generally followed the series OS>TS>CS. In summary, temperature had significant effects on the mineralization and adsorption of exogenous amino acids and peptides in test soils.

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