【摘要】 采集了鄂南不同母质和利用现状的6个红壤样,用2%PEG+6%Dextran两相分离技术(Aque-ous two-phase partitioningtechnique,简写为A2PP)纯化细菌,测定细菌生物量,研究两相分离技术在土壤微生物研究领域的可应用性。结果表明:(1)采用0.1%胆酸钠、钠型离子交换树脂、玻璃珠与土壤一起在4℃下振荡2h,能较好地分散土壤细菌。供试土样细菌分离率介于0.41~0.60之间,不同母质发育的红壤相比,细菌分离率高低依次为:砂页岩>花岗岩>第四纪红色粘土;(2)A2PP技术能较好地纯化土壤中的细菌。6个供试原样的细菌多与土壤颗粒及有机质结合在一起,而两相分离技术能够得到较为纯净的细菌个体,土样细菌大多被分离存在于PEG相中,纯化率为63%~78%;细菌提取率介于0.31~0.48,不同母质发育土壤细菌提取率顺序与细菌分离率顺序相同;(3)供试土样的细菌形态都以小球状、小杆状细菌为主。更多还原

【Abstract】 The aqueous two-phase partitioning(A2PP)technique,considered as a useful tool to separate and purify cells,virus,macromolecule,has found extensive application in biochemistry,cytobiology and other relevant fields.However,few reports are so far available on its application in the field of soil microbiology.This experiment was designed to study components of microbes in red soils with the PEG/Dextran A2PP technique.Results show that soil bacteria were well dispersed after the Dowex resin,sodium cholate,glass beads and soils were mixed into suspension,which was then shaken for 2h at the temperature of 4℃.The separation rate of bacteria ranged between 0.41～0.60 and varied with parent material in the order of sandstone>granite>Q2 deposits.The experiments demonstrated that A2PP could separate and purify soil bacteria quite well.With the two-phase technique,about 63%～78% of the bacteria in the soil samples were separated and stored in the PEG phase.With the fluorescence microscope technique,most soil bacteria were closely tied with soil clays and organic matter,whereas with the A2PP technique purer bacteria could be obtained.The bacteria extraction rate was in the range of 0.31 ～ 0.48,and varied with parent material in the same order of sandstone>granite>Q2 deposits as was with the separation rate.For the six red soil samples examined,micrococcus and microbacilli were dominant in terms of forms of soil bacteria.更多还原