Study On Bacterium B25W Isolated From The Marine Sponge Hymeniacidon Perleve And Its Antifungal Antibiotic

Many unique compounds, which were able to be anti-tumour, anti-virus, anti-fungi and anti-bacteria, had been obtained from sponges. Recently, many studies proved that marine sponge-microorganisms are the real producer of those bioactive substances. Therefore, more and more interests have been focused on sponge-microorganism as an important development trend of the bioactive compounds.The strain B25W that was isolated from the marine sponge Hymeniacidon perleve in Dalian, exhibited inhibitory effects on Trichometasphaeria turcica, Nisikado et Miyake, Magnaporthe grisea, Fusarium graminearum Schw, Colletotrichunspp. and Botryophaeria berengeriana(Moug exfr). This paper investigated morphological, cultural and physiological characteristics and 16SrDNA sequences of the strain B25W. It was identified to be Paenibacillus amyloliquefaciens according to the above characteristics. Acute oral toxicity on mouse and acute dermal toxicity experimentation on rabbits indicated that B25W-antibiotic was innoxious.By Unifactor and Uniform Design Experiments, the fermentation medium for strain B25W was optimized, which was as follow: 0.34% of corn flour, 0.1% of glucose, 1.66% of soybean powder, 0.04% of ZnSO₄, 0.02 % of MgSO₄, pH6.0. The 2.5ml seed culture (12h) was transferred into 250ml Erlenmeyer flask containing 25ml of medium and incubated with rotary shaking for 20h at 28℃. The relative valence of the optimum fermentation liquid on Candida albicans achieved 13680u/ml, which was increased by 62% compared with the original.