Evaluation Of Antimicrobial Activity And Optimization Of Two Strains Of Endophytic Fungi From South China Sea

In this paper, 84 strains of symbiotic fungi were isolated from the South China Sea gorgonian. After screening the 84 strains, two strains exhibited high antibacterial activity. The two strains were identified, and the biological characteristics, the fermentation conditions and fermentation properties were studied.The results are shown below:(1) 2 strains of symbiotic fungi were isolated from the South China Sea gorgonian.Strain P1 was identified as a species of Penicillium and Strain P11 was identified as a species of Alternaria by morphological observation and ITS-r DNA sequence alignment.(2) The fermentation conditions of the two strains were optimized on the base of GYP medium by single-factor experiment and orthogonal tests.(3) To study the stability and polarity of active substances secreted by the two Marine fungi we selected, The effect of p H, temperature, light, ultraviolet on the stability of active substances was analyzed, and to study the polarity and the hydrophobic nature of the antibacterial substances. The result indicates that penicillium chrysogenum and Alternaria sp. exhibited different effect on four bacteria.The antibacterial substances was soluble in ethyl acetate,n-butyl alcohol and petroleum ether. Alternaria sp. is more stable than penicillium chrysogenum. The antibacterial substances of penicillium chrysogenum has strong hydrophily. It provide potential for further research on isolation of bio-active secondary metabolites.