为提高海洋来源成团泛菌(Pantoea agglomerans)Y-03产低温甾醇酯酶的酶活力,该研究首先通过单因素试验及Plackett-Burman(PB)试验确定成团泛菌Y-03产低温甾醇酯酶酶活的显著影响因素,然后运用Box-Behnken(BB)响应面试验对其发酵工艺进...为提高海洋来源成团泛菌(Pantoea agglomerans)Y-03产低温甾醇酯酶的酶活力,该研究首先通过单因素试验及Plackett-Burman(PB)试验确定成团泛菌Y-03产低温甾醇酯酶酶活的显著影响因素,然后运用Box-Behnken(BB)响应面试验对其发酵工艺进行优化。结果表明,成团泛菌Y-03产低温甾醇酯酶的最适发酵工艺为葡萄糖添加量3.7%、胰蛋白胨添加量1.3%、K_(2)HPO_(4)添加量0.4%、初始p H值8、转速180 r/min、接种量4%、装液量44 m L/250 m L、发酵温度27℃。在此优化条件下,甾醇酯酶活力为484.24 U/L,相比于优化前酶活力提高143.89%。该研究为提高成团泛菌的甾醇酯酶产量及酶活力和未来放大生产研究奠定了基础。展开更多
Unlike most plants, members of the genus Solanum produce cholesterol and use this as a precursor for steroidal glycoalkaloids. The production of the compounds begins as a branch from brassinosteroid biosynthesis, whic...Unlike most plants, members of the genus Solanum produce cholesterol and use this as a precursor for steroidal glycoalkaloids. The production of the compounds begins as a branch from brassinosteroid biosynthesis, which produces cholesterol that is further modified to produce steroidal glycoalkaloids. During the cholesterol biosynthesis pathway, genetic engineering could alter the formation of cholesterol from provitamin D3(7-dehydrocholesterol) and produce vitamin D3. Cholesterol is a precursor for many steroidal glycoalkaloids, including a-tomatine and esculeoside A. Alpha-tomatine is consumed by mammals and it can reduce cholesterol content and improve LDL:HDL ratio. When there is a high a-tomatine content, the fruit will have a bitter flavor, which together with other steroidal glycoalkaloids serving as protective and defensive compounds for tomato against insect, fungal, and bacterial pests. These compounds also affect the rhizosphere bacteria by recruiting beneficial bacteria. One of the steroidal glycoalkaloids, esculeoside A increases while fruit ripening. This review focuses on recent studies that uncovered key reactions of the production of cholesterol and steroidal glycoalkaloids in tomato connecting to human health, fruit flavor, and plant defense and the potential application for tomato crop improvement.展开更多
文摘为提高海洋来源成团泛菌(Pantoea agglomerans)Y-03产低温甾醇酯酶的酶活力,该研究首先通过单因素试验及Plackett-Burman(PB)试验确定成团泛菌Y-03产低温甾醇酯酶酶活的显著影响因素,然后运用Box-Behnken(BB)响应面试验对其发酵工艺进行优化。结果表明,成团泛菌Y-03产低温甾醇酯酶的最适发酵工艺为葡萄糖添加量3.7%、胰蛋白胨添加量1.3%、K_(2)HPO_(4)添加量0.4%、初始p H值8、转速180 r/min、接种量4%、装液量44 m L/250 m L、发酵温度27℃。在此优化条件下,甾醇酯酶活力为484.24 U/L,相比于优化前酶活力提高143.89%。该研究为提高成团泛菌的甾醇酯酶产量及酶活力和未来放大生产研究奠定了基础。
文摘Unlike most plants, members of the genus Solanum produce cholesterol and use this as a precursor for steroidal glycoalkaloids. The production of the compounds begins as a branch from brassinosteroid biosynthesis, which produces cholesterol that is further modified to produce steroidal glycoalkaloids. During the cholesterol biosynthesis pathway, genetic engineering could alter the formation of cholesterol from provitamin D3(7-dehydrocholesterol) and produce vitamin D3. Cholesterol is a precursor for many steroidal glycoalkaloids, including a-tomatine and esculeoside A. Alpha-tomatine is consumed by mammals and it can reduce cholesterol content and improve LDL:HDL ratio. When there is a high a-tomatine content, the fruit will have a bitter flavor, which together with other steroidal glycoalkaloids serving as protective and defensive compounds for tomato against insect, fungal, and bacterial pests. These compounds also affect the rhizosphere bacteria by recruiting beneficial bacteria. One of the steroidal glycoalkaloids, esculeoside A increases while fruit ripening. This review focuses on recent studies that uncovered key reactions of the production of cholesterol and steroidal glycoalkaloids in tomato connecting to human health, fruit flavor, and plant defense and the potential application for tomato crop improvement.
