Endophytic Bacteria Source Of Physiologically Active Substances Screening

Endophyte is an exceptionally rich, diverse and novel source for bioactive products screening. 1760 samples produced by endophytes reserved by Shanghai Health Creation Center for Biopharmaceutics R&D were tested on several models, and many bioactive samples were selected. The result of second round indepth-screening for these bioactive samples demonstrated that three samples still possecced great inhibitory ability against foam cell formation process of macrophage. The cultural and physiological characters of these strains were studied.The metabolites eliciting inhibition to foam cell formation process of macrophage produced by endophyte HCCB00017 were studied. Several products were isolated through solvent extraction, and silica gel chromatography et al. One compound, HCCB00017-A, showed cytotoxicity; the other two, HCCB00017-C and HCCB00017-E, showed inhibitory activity against foam cell formation process of macrophage. Physical and chemical characteristics and molecular weight of HCCB00017-A were determined by means of MS, UV methods and physical-chemical analysis.An antibiotic synergist model based on drug-resistant strain Pseudomonas Aeruginosa was established. Using optimum ultraviolet radiation treatment, mutatant strain PA9911-C64 was obtained. Antimicrobial agents susceptibility of this strain illustrated that it was resistant to gentamicin, streptomycin, ciprofloxacin, ceftazidime and imipinem. After ten generations growing on drug-free plate, the resistance of PA9911-C64 kept unchanged. 800 broth samples of endophytes were tested on this model, among which several samples showed antimicrobial or synergic activity.