微生物植酸酶及其对土壤植酸的矿化作用综述  

Microbial phytase and its role in phytate mineralization in soils:A review

作　　者：苏奇倩 丁豪杰 李晓锋 李林[1] RENSING Christopher 刘雪 SU Qiqian;DING Haojie;LI Xiaofeng;LI Lin;RENSING Christopher;LIU Xue(Institute of Ecology and Environment,Southwest Forestry University,Kunming,650224,China;Institute of Resources and Environment,Fujian Agriculture&Forestry University,Fuzhou,350002,China)

机构地区：[1]西南林业大学生态与环境学院,昆明650224 [2]福建农林大学资源与环境学院,福州350002

出　　处：《环境化学》2023年第4期1366-1380,共15页Environmental Chemistry

基　　金：国家重点研发计划项目(2018YFC1800504);国家自然科学基金(41867066,41907129);云南省自然科学基金(2019FB032);云南省高端外国专家项目(YNQR-GDWG-2018-017)资助.

摘　　要：有机磷是土壤磷的主要存在形式,占比40%—90%,是作物磷营养的重要来源和储备库,亦是引起水体富营养化的潜在因子.磷作为植物生长发育的必需大量营养元素,通常以无机磷肥形式施用于土壤,易吸附于土壤表面或与钙、镁、铝、铁等金属阳离子形成难溶性络合物,导致其生物可利用性降低,其中20%—80%磷肥转化为有机磷,不易被植物吸收利用.矿化作用是在土壤微生物作用下,土壤中有机态化合物转化为无机态化合物的总称.土壤中有机磷主要以植酸及其盐类形式存在(占比50%—70%),植酸(盐)可被专一性酶(植酸酶)矿化水解为肌醇和磷酸(盐),并释放出无机磷,以供植物的根系直接吸收和利用.前期研究发现,缺磷胁迫下微生物可大量分泌植酸酶分解植酸,释放磷酸根,促使土壤有机磷水解矿化为无机磷,提高了土壤有机磷的生物可利用率.目前关于微生物植酸酶矿化植酸的研究多集中于谷类作物和动物营养,对土壤植酸矿化与土壤有机磷利用的综述性报道较少.因此,本文主要关注微生物植酸酶对土壤植酸的矿化作用与土壤有机磷利用,重点阐述其过程、机制和效率,包括微生物植酸酶的种类来源、酶学性质、作用机理和实际应用等方面的研究进展,可为提高土壤有机磷的生物利用效率、减少农业磷肥施用量、降低土壤磷流失及水体污染风险提供理论依据和技术支撑,为深入探究植酸酶功能并应用于农业生产实践及保障生态环境安全提供基础信息和参考.Soil organic phosphorus(Po)is the predominant form of phosphorus(P)in soils which accounts for 40%—90%of soil total P(Pt).Therefore,it is an important P source for crop nutrition and also a potential factor for water eutrophication.Phosphorus is an essential element for plant growth,which is often applied to land as inorganic phosphate(Pi)fertilizers.Once into soils,P is readily sorbed on soils or bound with metal cations such as calcium,magnesium,aluminum,and iron,thereby being less bioaccessible.20%—80%of P fertilizer can be transformed to Po,rendering it reluctant to be utilized by plants.Mineralization is the transformation of soil organic compounds into inorganic compounds with the help of microbes.Phytate is the predominant fraction of Po(50%—70%),which can be mineralized or hydrolyzed to inositol and P by the specific enzyme—phytase,releasing P for root uptake and plant growth.Microbes can secret phytase to hydrolyze phytate to release phosphate under P-deficiency stresses,thereby improves the bioaccessibility and bioavailability of soil phytate.At present,studies on microbial phytate mineralization by phytase mainly focus on cereal and poultry nutritional aspects,limited review papers on soil phytate mineralization and its P utilization by plants.Therefore,this paper reviews microbial phytase and its roles in soil phytate mineralization,with the emphasis on mineralization processes,mechanisms and efficiencies.These include the research progress on phytase’s species,sources,enzymatic properties,functional mechanisms,and its practical application efficiencies.The information provides theoretical foundation and technical support for improving soil Po utilization efficiency and reducing P fertilizer consumption and risk of P runoff and water eutrophication.In addition,this paper provides basic information and reference for further investigating microbial phytase to better its practical application in agricultural production and ecological environment safety protection.

关 键 词：磷 微生物 植酸酶 植酸 矿化 农业生产 

分 类 号：S153.6[农业科学—土壤学]