Abstract: The extraction methods of microorganisms from the bean’s leaves were investigated and the efficiency of different methods was compared. Results showed that different extraction methods and solvents led to quite different results. By ultrasonic cleaner method, the number of microorganisms increased to a maximum with the time prolonging and then decrease, the most effective treatment time is about four minates. There are no significant difference between sterile water and phosphate buffer. Comparing with ultrasonic cleaner method, extraction efficiency of homogenate method was much higher. The maximum yield of the former was about 7.67×106 cfu/g fresh leaves while the latter was up to 1.12×10⁷ cfu/g. The optimal weight of the leaves sample was four to five g. Leaf age influenced the abundance of microbial population significantly, but the leaf age of a sample for a specific purpose still depends on the other factors.

Key words: phyllosphere, microorganism, extraction method