利用果胶培养基分离番茄根际细菌

Isolating Tomato Rhizobacteria Using Root Exuding Pectin

采用平板稀释和PCR-DGGE相结合的方法,比较了4种培养基(果胶富营养培养基PM,只含果胶一种营养的培养基PA,添加果胶的寡营养培养基YPP以及与YPP营养成分一致但不添加果胶的寡营养培养基YPG)分离番茄根际细菌的能力.结果显示:PA培养基能够分离到42种形态的细菌;YPP培养基可以分离到最高的细菌菌落数,分离获得的种类比PA少;YPP培养基分离获得细菌的种类和菌落数量比YPG培养基要多.聚类分析也显示只有果胶一种营养的PA培养基能分离到最多种类,分离获得的菌群与自然环境中微生物群落最相似.研究结果表明添加番茄根际主要分泌物——果胶到培养基中可以提高培养基分离细菌的能力.

Pectin is the major secretions of tomato rhizosphere.Four different kinds of pectin media（PM nutrient medium,PA medium with only a single pectin carbon source,oligotrophic medium YPP with pectin,and oligotrophic medium YPG without pectin） were applied to compare the ability in isolating tomato rhizosphere bacteria by plate technique and denaturing gradient gel electrophoresis（DGGE）.The results showed that PA medium isolated up to 42 types of soil bacteria;YPP medium isolated the highest numbers of colonies among the four media,and lower types of bacteria than that by PA medium;YPG medium isolated lower quantities and species of bacteria than those by YPP medium.Clustering analysis also revealed that PA medium with pectin as the nutrition could isolate more bacteria than other media,and the bacteria community isolated by PA medium was most similar to that in natural environment.Therefore,adding pectin from tomato rhizosphere into the culture medium could increase the separative capacity of the medium.