毕业论文移动版

摘要1-脱氧野尻霉素（DNJ）为哌啶生物碱。它能够对葡萄糖苷酶产生阻遏作用，进 而阻遏糖的汲取，达到减少餐后血糖浓度作用，同时也具有抗病毒、抗肿瘤迁移等 作用。当前，DNJ 主要的出处大多是桑树提取物，但是它的提取产量并不是很高，并 且一般的合成工艺不能合成获取。因此我们采用从微生物中提取 DNJ 的方法。这是

因为微生物的分散较宽泛，且根源富足，因而其在一般工业生产中被使用的最多。 当前找到的可用于产 DNJ 的微生物菌株，除了链霉菌之外，还有芽孢杆菌属、藤黄 微球菌等。而桑树是目前已知的 DNJ 含量最多的一种植物，所以研究目的就是从桑 树园中的土壤来进行产 DNJ 菌株的筛选。

从桑园泥土中筛选产 DNJ 菌株的方法包括琼脂平板法和反相高效液相色谱法， 最终从 78 株菌株筛选出一株微生物菌株可以产 DNJ，其产量最高约为 29。48mg/L， 称之为 XY-1。

通过控制单因素变化进行实验确定菌株 XY-1 产 DNJ 能力达到最大时的发酵条 件，得出菌株的发酵条件如下：发酵温度为 37℃，发酵液起始 pH 为 7。50，恒温摇 床转速为 180rpm，发酵时间 24h。

对筛选出的菌株 XY-1 进行了常规鉴定。发现菌株属于好氧菌，没有运动性，能 进行淀粉的水解反应，可以不利用葡萄糖为单一碳源，为革兰氏阳性菌。利用 PCR 法扩增了 DNA 部分片段，序列测定后从 Genebank 中搜索与其类似的序列所属菌属， 发现序列与球形赖氨酸芽孢杆菌 （ Lysinibacillus sphaericus）的序列相似度很高， 所以确定分离出的菌株 XY-1 为芽孢杆菌。 通过实验做出菌株的生长曲线图，得出菌 株 XY-1 的各个生长阶段分别为： 0-3h 处于调整期， 3-15h 处于对数期，15-30h 处 于稳定期，30 h  以后进入衰亡期。82343

毕业论文关键词： 1-脱氧野尻霉素（ DNJ）； 芽孢杆菌； 筛选； 鉴定；

Abstract 1- deoxynojirimycin (DNJ) is a piperidine alkaloid,it is capable of glucosidase inhibition produced thereby which inhibit the absorption of sugar, reducing postprandial blood glucose levels, anti-viral, anti-metastatic effects。 Currently, the main source of DNJ mostly extract from mulberry, but production is not high, and chemical synthesis   process is complex。 Therefore, we use production DNJ from microorganisms。 This is because the bacteria is widely distributed, abundant source which is used in the fermentation industry, mostly fermented with bacteria。 The bacterial strain can be  used for the  production  of DNJ ,has now been found in Bacillus spp,Micrococcus luteus, expect for Streptomyces。 The Mulberry is known as containing most DNJ content of a plant, so the aim of our study is from the mulberry garden soil to screen DNJ yield strains。

Using agar plate method and HPLC to screen from soil mulberry DNJ yield strains, 78 strains producing DNJ screened a strain of bacteria, which produces about 29。48mg/L, named it as XY -1。

Through the change control of a single factor experiment to determine the strain

capacity of DNJ XY - 1 when the maximum conditions of fermentation,and the fermentation conditions were as follows: fermentation temperature 37 ℃, initial fermentation pH 7。50, rotation speed of 180rpm,fermentation time 24h。

Screening of bacterial strains XY-1 carried out physiological and biochemical and molecular biological identification 。 Strains belong to aerobic bacteria, no motion, able to use starch hydrolysis, can not utilize glucose as sole carbon source, gelatin liquefaction, phenylalanine deaminase and methyl red test were negative。 16srDNA was amplified by PCR fragments after sequencing retrieval NCBI database, the sequence of was close to Bacillus spherical lysine (Lysinibacillus sphaericus), determining the strains we isolated XY-1 is lysine Bacillus。 The growth curve of strain were measured, drawn its  various stages of growth and XY-1 strains various stages of growth was: 0-3h in lag phase, 3-15h in log phase, 15-30h is stable period, 30 h after entering the decline phase。 (责任编辑：qin)