大洋纵列海鞘共附生链霉菌Streptomyces sp. FDZ35-2的化学成分

Secondary metabolites of Streptomyces sp. FDZ35-2 associated with Symplegma oceania

海鞘共附生微生物是尚待关注的海洋微生物资源重要来源之一。本文研究了大洋纵列海鞘（Symplegma oceania）的一株共附生链霉菌Streptomyces sp. FDZ35-2的代谢产物,以探讨其主要代谢产物的结构类型和菌株的潜在药用价值。运用多种柱层析和HPLC等分离技术,从菌株甲醇提取物中分离鉴定2个主要的单体化合物;经LC-MS、1H-和13C-NMR等波谱学方法和文献数据对照,鉴定化合物结构分别为：9-甲基-β-咔啉-3-羧酸甲酯（1）和放线菌素D（2）。考虑放线菌素D生物合成可能利用培养基氮源中的氨基酸,本文还利用磷虾蛋白水解产物代替商品蛋白胨作为培养基氮源,对Streptomyces sp. FDZ35-2的发酵条件进行了初步研究,结果显示能产出更多种放线菌素D的结构类似物的发酵培养基为：磷虾蛋白水解产物2.0 g、葡萄糖2.0 g、硫酸铵1.0 g、碳酸钙0.5 g、氯化钠0.05 g、磷酸二氢钾0.05 g、海水1.0 L,p H 7.8~8.0。对比实验结果表明：与商品蛋白胨组相比,南极磷虾蛋白水解产物作为发酵培养基氮源所发酵产生的放线菌素D的结构类似物多样性更好,二者产生总放线菌素含量相当。这为开发南极磷虾蛋白在微生物发酵工业中的新用途提供了依据。

Ascidian-derived microbes are important marine microorganism resources that need more attention. Investigation on secondary metabolites of Streptomyces sp. FDZ35 - 2, associated with ascidian Symplegma oceania, has been carried out to understand its chemical constituent types and its potential in medicinal development. Two compounds were obtained by various column chromatography and preparative HPLC, and their structures were identified as 9-methyl-β-earboline-3-earboxylate （1） and actinomyein D （2） by comparison of LC-MS, 1 H- and 13C-NMR data with those reported. The amino acids of N-sources in culture medium may be applied in biosynthesis of actinomycin D. Therefore, Antarctic krill protein hydrolysate was used as N-sources in culture medium, and the fermentation conditions of Streptomyces sp. FDZ35 - 2 were optimized by analysis of its metabolites compared with commercially obtained peptones. To yield more actinomyein D derivatives, better fermentation medium for this strain in 1.0 L sea water should contain krill protein hydrolysate 2.0 g, glucose 2.0 g, ammonium sulfate 1.0 g, calcium carbonate 0. 5 g, sodium chloride 0.05 g, and potassium dihydrogen phosphate 0. 05 g. The pH value should be 7.8 - 8.0. The results of comparative experiments showed that the Antarctic krill protein hydrolysate was better than some peptones in the market as N-sources in fermentation mediums to produce various actinomycin D derivatives, and the total actinomycins yields were close. This research may be a good basis for developing a new application of Antarctic krin protein as peptone material in the microorganisms fermentation industry.