【作者】 周荣丽；

【导师】 穆军；

【作者基本信息】 大连交通大学 ， 环境科学， 2008， 硕士

【摘要】 随着抗生素及其他抗菌药物的广泛应用,病原微生物的耐药问题日趋严重,因此开发新型抗生素迫在眉睫。陆地微生物曾是寻找抗生素的主要来源,但近年来从陆地微生物中发现新抗生素的几率越来越低,人们必须寻找新的药源。海洋环境的特殊性使海洋微生物具有独特的遗传背景与代谢途径,可能产生结构新颖、作用独特的代谢产物,成为筛选新型抗生素的重要来源。本论文对分离自大连黑石礁海域海水样品的一株具有抗菌活性的硫酸盐还原细菌SRB-22菌株进行了研究,考察了SRB-22菌株的最佳发酵条件和活性代谢产物的稳定性,提取分离了2个紫外吸收明显的代谢产物并进行了光谱分析和结构解析。主要研究结果如下:对SRB-22菌株产活性物质的最佳培养条件进行了考察,确定最佳培养条件为:初始pH为7.2,培养温度25℃～30℃,接种量10%,培养时间28d。对SRB-22菌株代谢产物稳定性进行了初步考察,结果表明代谢产物有较强的光稳定性和热稳定性,4℃长时间放置也较稳定,但强酸强碱条件下不稳定。经过正相硅胶柱层析、凝胶柱层析、反相硅胶柱层析及反相HPLC制备层析,得到两个较纯化合物,其中化合物D-1通过对其核磁共振谱、质谱的解析,再与有关文献报道的数据进行比较,确定该化合物为胸腺嘧啶。化合物D-2由于纯度不够,主要成分的质谱、一维、二维核磁共振谱给出有用信息较少,最终未能鉴定其结构。更多还原

【Abstract】 With the wide use of antibiotics and other antibacterial agents, the problem of drug resistance became more and more serious, so it is crucial to seek new antibiotics. Terrestrial microorganisms, as the main source of new antibiotics in the early ages, seemed to be almost exhausted now and new drug source were in great demand. For their special living environment, marine microorganisms have unique genetic background and metabolic pathways, and were found to be potential to synthesize some structurally distinct antibiotics. Therefore they have become a significant source for new antibiotics of screening.In this thesis, an antimicrobial sulfate-reducing bacterium SRB-22, isolated from the sea water sample of Heishijiao sea area in Dalian, was studied on its fermentation conditions, the stability of antimicrobial activity metabolities and purification and identification of compounds. Two compounds that had stronger ultraviolet aborption were isolated and their spectral and structures were analyzed. Main results are as follows:The fermentation conditions suitable for the bioactive substance production were studied. The optimal culture condition was determined to be that the liquid medium with 10% inoculation amount was cutured at 25℃～30℃with the initial pH value of 7.2 for 28 d.The stability of the antibacterial metabolites was investigated. The results showed the bioactive substance was heat-resistant and optically stable. It was more stable if saved at 4°C for long time. But it was not stable under strong acidic or strong alkaline conditions.Two compounds were obtained by comprehesive use of column chromatographies on silica gel, Sephadex LH-20 and reverse phase silica gel as well as reverse phase high performance liquid chromatography. One of them, compound D-1 was indentified as thymidineby spectral analysis of ¹H-NMR, ¹³C-NMR and MS as well as by comparison with data reported in reference. D-2 was not ultimately identified because of its worse purity and less useful information provided by MS, one-dimensional, two-dimensional NMR of the main component.更多还原