The implications of exoenzyme activity on microbial carbon and nitrogen limitation in soil: a theoretical model

分解 化学 动力学 外酶 呼吸速率 反应速率常数 呼吸 有机质 环境化学 有机化学 植物 生物 量子力学 物理
作者
Joshua P. Schimel
出处
期刊:Soil Biology & Biochemistry [Elsevier BV]
卷期号:35 (4): 549-563 被引量:1471
标识
DOI:10.1016/s0038-0717(03)00015-4
摘要

Traditional models of soil organic matter (SOM) decomposition are all based on first order kinetics in which the decomposition rate of a particular C pool is proportional to the size of the pool and a simple decomposition constant (dC/dt=kC). In fact, SOM decomposition is catalyzed by extracellular enzymes that are produced by microorganisms. We built a simple theoretical model to explore the behavior of the decomposition–microbial growth system when the fundamental kinetic assumption is changed from first order kinetics to exoenzymes catalyzed decomposition (dC/dt=KC×Enzymes). An analysis of the enzyme kinetics showed that there must be some mechanism to produce a non-linear response of decomposition rates to enzyme concentration—the most likely is competition for enzyme binding on solid substrates as predicted by Langmuir adsorption isotherm theory. This non-linearity also induces C limitation, regardless of the potential supply of C. The linked C and N version of the model showed that actual polymer breakdown and microbial use of the released monomers can be disconnected, and that it requires relatively little N to maintain the maximal rate of decomposition, regardless of the microbial biomass’ ability to use the breakdown products. In this model, adding a pulse of C to an N limited system increases respiration, while adding N actually decreases respiration (as C is redirected from waste respiration to microbial growth). For many years, researchers have argued that the lack of a respiratory response by soil microbes to added N indicates that they are not N limited. This model suggests that conclusion may be wrong. While total C flow may be limited by the functioning of the exoenzyme system, actual microbial growth may be N limited.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
明芬完成签到,获得积分10
2秒前
3秒前
123456完成签到,获得积分10
6秒前
结实的慕凝完成签到,获得积分10
8秒前
苗条小土豆完成签到,获得积分10
8秒前
flance完成签到 ,获得积分10
10秒前
11秒前
fanfan完成签到 ,获得积分10
13秒前
SkyTsai完成签到,获得积分10
13秒前
16秒前
17秒前
轻松的惜芹应助诚心谷南采纳,获得10
17秒前
天天快乐应助sml采纳,获得10
18秒前
20秒前
21秒前
21秒前
华仔应助sxx采纳,获得10
24秒前
YJ888发布了新的文献求助10
25秒前
26秒前
哼哼唧唧发布了新的文献求助10
26秒前
石大大发布了新的文献求助10
28秒前
huoguo完成签到,获得积分10
29秒前
小二郎应助完美芒果采纳,获得10
29秒前
Liufgui应助紫竹魔笛采纳,获得10
31秒前
32秒前
34秒前
Liufgui应助YJ888采纳,获得10
35秒前
赘婿应助麦子采纳,获得10
35秒前
36秒前
KK发布了新的文献求助10
36秒前
娟姐完成签到,获得积分10
37秒前
ding应助李朝富采纳,获得10
38秒前
桐桐应助学术蝗虫采纳,获得10
39秒前
杨桃发布了新的文献求助10
39秒前
40秒前
biubiudididi发布了新的文献求助10
40秒前
YUMI发布了新的文献求助10
41秒前
科研通AI5应助slx采纳,获得10
41秒前
搜集达人应助娟姐采纳,获得10
43秒前
完美芒果发布了新的文献求助10
44秒前
高分求助中
A new approach to the extrapolation of accelerated life test data 1000
ACSM’s Guidelines for Exercise Testing and Prescription, 12th edition 500
‘Unruly’ Children: Historical Fieldnotes and Learning Morality in a Taiwan Village (New Departures in Anthropology) 400
Indomethacinのヒトにおける経皮吸収 400
Phylogenetic study of the order Polydesmida (Myriapoda: Diplopoda) 370
基于可调谐半导体激光吸收光谱技术泄漏气体检测系统的研究 350
Robot-supported joining of reinforcement textiles with one-sided sewing heads 320
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 3989550
求助须知:如何正确求助?哪些是违规求助? 3531774
关于积分的说明 11254747
捐赠科研通 3270278
什么是DOI,文献DOI怎么找? 1804966
邀请新用户注册赠送积分活动 882125
科研通“疑难数据库(出版商)”最低求助积分说明 809176