Abstract: Using tissue separation and grinding coated method, the endophytes were screened out to study the active substances in the leaves of wild jujube endophytic microbes and species identification, and the filter method was used to test the antibacterial activities. The fermented product extraction of strain C-22-1 was extracted again and again to gain the antimicrobial substances. The single fermentation conditions of strain C-22-1, including carbon source, nitrogen source and time, were optimized according to the size of inhibition zone. The antibacterial activities of fermented liquid of C-22-1 and the antimicrobial substances were detected to seven human common pathogenic bacteria; the strain C-22-1’s antibacterial circle diameter reached 29 mm to Staphylococcus albus. Qualitative test showed the strain C-22-1 produce saponins. Single factor optimization results showed that best carbon, nitrogen source and time was glucose, yeast extract and 8 d, respectively. Strain C-22-1 produce antimicrobial substances, which was initially identified as triterpenoid saponins.

Key words: wild Zizyphus jujube, endophytes, tissue separation method, grinding coated method, antimicrobial activity