Zhu Honghui

Isolating Tomato Rhizobacteria Using Root Exuding Pectin

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.