细菌作用下球状碳酸盐矿物形成的新途径： 以柠檬酸杆菌GW-M菌株为例

为了探讨细菌作用下碳酸盐矿物的形成机理，本文对分离自土壤的一株柠檬酸杆菌GW-M菌株进行了为期165d的培养 实验。利用X-射线衍射技术对沉淀物的矿物成分进行了测定，利用扫描电子显微镜对沉淀物的形态进行了系统的观察。结果 表明，GW-M菌株诱导形成的碳酸盐矿物（方解石和单水碳钙石）具有多种形态共存并以球状为主的特点，而无菌对照实验产 物中的矿物形态则比较单一。在GW-M菌株的作用下，通过以下三条途径均可能形成球状矿物：（1）单个哑铃→两端生长→ 球；（2）两个交叉的哑铃→两个哑铃的两端各自生长→球；（3）三个交叉的哑铃→三个哑铃的两端各自生长→球。
Inordertounderstandtheformationmechanismofcarbonatemineralsinducedbymicrobes,cultureexperimentswitha durationof165dayswereperformedunderthemediationofstrainGW-Misolatedfromsoil.MineralspeciesweredeterminedbyX-ray diffraction,andthemorphologiesofprecipitatedcarbonateswereobservedusingscanningelectronmicroscopy.Theresultsshowedthat the carbonate minerals (calcite and monohydrocalcite) induced by strain GW-M featured various morphologies, mainly spherical morphology.Incontrast,morphologiesofcarbonatemineralsformedintheasepticexperimentswererelativelysimple.Threeways mightleadtotheformationofsphericalmineralsundertheactionofstrainGW-M.(1)Thefirstwaywassingledumbbell-shaped mineralswithfinecrystalsgatheredfasteronbothendsthanthemiddlepartofthedumbbell,changingdumbbell-shapedmineralsinto sphericalones.(2)Thesecondwaywastwocrosseddumbbell-shapedmineralswithfinecrystalsgatheredfasteronbothendsthanthe middlepartofthetwodumbbells,resultinginsphericalminerals.(3)Thefinalwaywasthreecrosseddumbbell-shapedmineralswith finecrystalsgatheredfasteronbothendsthanthemiddlepartofthethreedumbbells,eventuallyevolvingintosphericalminerals.