盐生海芦笋内生真菌Salicorn 35的分离鉴定与抗氧化发酵条件优化  

Isolation and Identification of Endophytic Fungal Strain Salicorn 35 from Salicornia bigelovii and Optimization of Its Fermentation Conditions for Production of Antioxidants

作　　者：湛东锐[1] 孟晓露[1] 李连强[1] 曹娜[1] 王惠[1] 刘天行[1] 辛志宏[1] 

机构地区：[1]南京农业大学食品科技学院,江苏南京210095

出　　处：《食品科学》2013年第19期158-165,共8页Food Science

基　　金：国家自然科学基金面上项目(31071586);2011年国家大学生创新训练计划项目(111030739);江苏高校优势学科建设工程资助项目

摘　　要：采用分子生物学与形态学观察相结合的方法,鉴定分离自盐生海芦笋中的内生真菌Salicorn 35。提取基因组DNA后分别对其18S rDNA和ITS1-5.8S-ITS4区域进行PCR扩增并进行单克隆测序分析。将序列提交NCBI进行核酸序列同源性比较,利用MEGA5.0软件对序列进行分析,构建系统发育树。结合形态学与显微镜观察将该菌鉴定为茄病镰刀菌(Fusarium solani)。在此基础上,以抗氧化活性为指标,采用Plackett-Burman试验、最陡爬坡试验和响应曲面法对Salicorn 35菌株的发酵条件进行优化,最大限度地提高其抗氧化活性。优化后的最佳培养基配方为(质量分数):酵母膏1.5%、蛋白胨2.7%、土豆40%、麦芽糖3%、甘露醇1%、葡萄糖1.5%、味精1.0%、氯化钠6.0%,pH5;采用此培养基所得发酵产物对DPPH自由基的清除率为76.75%,比优化前(清除率57.77%)有显著提高。Molecular biological methods and morphology was applied to identify a halophilic endophytic fungal strain named Salicorn 35 isolated from Salicornia bigelovii in this study. The 18S and ITS1-5.8S-ITS4 rDNA were PCR amplified and subjected to monoclonal sequence analysis after the extraction of its DNA genome. By comparison with the sequences obtained in NCBI database, a phylogenetic tree was established using sequence analysis software MEGA5 combined with morphological analysis. The fungus Salicorn35 was identified as Fusarium solani. The fermentation conditions of Salicorn 35 for producing antioxidants with high activity were optimized by using Plackett-Burman （PB） design, steepest ascent path design and response surface methodology. The optimal medium consisted of 1.5% yeast extract, 2.7% peptone, 40% potato, 3% maltose, 1% mannitol, 1.5% glucose, 1.0% monosodium glutamate and 6.0% sodium chloride at pH 5. The maximum DPPH radical scavenging activity of fermentation products produced from the optimal culture medium was 76.75%, which was significantly higher than before the optimization （57.77%）.

关 键 词：内生真菌 分子鉴定 系统发育分析 抗氧化活性 响应曲面法 

分 类 号：TS255.1[轻工技术与工程—农产品加工及贮藏工程]