该文以云南产的紫蓝草为原料,研究紫蓝草紫色素的提取工艺,并研究紫蓝草紫色素对糯米染色前后表观性能。在单因素试验基础上,以吸光度为响应值,采用响应面法对紫蓝草紫色素提取工艺进行优化;并将优化提取的色素对糯米进行染色,通过扫描...该文以云南产的紫蓝草为原料,研究紫蓝草紫色素的提取工艺,并研究紫蓝草紫色素对糯米染色前后表观性能。在单因素试验基础上,以吸光度为响应值,采用响应面法对紫蓝草紫色素提取工艺进行优化;并将优化提取的色素对糯米进行染色,通过扫描电子显微镜(scanning electron microscope,SEM)对糯米染色前后的表观性能进行研究。结果表明,紫蓝草紫色素的最佳提取工艺为:提取时间20 min,提取温度45℃,提取料液比1∶30(g∶mL),在此条件下进行6次重复试验,吸光度为1.412;SEM分析表明,紫蓝草紫色素颗粒呈碎片状;糯米淀粉粒与色素发生相互作用,经染色后,糯米淀粉粒表面由光滑状态变为皱缩、粗糙不均匀状态;紫蓝草紫色素与淀粉粒的吸附作用影响了淀粉的糊化。该研究为紫蓝草开发利用和功能性彩色米的产业化生产提供了一定的技术支持。展开更多
[Objective] The paper was to optimize ultrasound-assisted extraction of proacyanidins from purple cabbage. [Method] The ultrasound-assisted extraction technology was used to study the extraction of proacyanidins from ...[Objective] The paper was to optimize ultrasound-assisted extraction of proacyanidins from purple cabbage. [Method] The ultrasound-assisted extraction technology was used to study the extraction of proacyanidins from purple cabbage. The effect of ethanol concentration, temperature, time, material-solution ratio and the power of ultrasound on extracting efficiency were studied by single-factor experiment. Based on this, L16（4%orthogonal test were conducted to determine the optimal condi- tion for extraction of proacyanidins from purple cabbage. [Result] The optimal condi- tion for extraction of proacyanidins from purple cabbage was as follows： ethanol concentration 50%, extraction temperature 50℃, extraction time 1 h, extraction power 540 W, material-liquid ratio 1：20. The extraction rate of procyanidins under this condition reached 104.8 mg/g. [Conclusion] The study provided a theoretical basis for scientific and reasonable utilization of procyanidins in purple cabbage.展开更多
otrA resembles elongation factor G （EF-G） and is considered to be an oxytetracycline （OTC）-resistance determinant in Streptomyces rimosus. In order to determine whether otrA also conferred resistance to OTC and ot...otrA resembles elongation factor G （EF-G） and is considered to be an oxytetracycline （OTC）-resistance determinant in Streptomyces rimosus. In order to determine whether otrA also conferred resistance to OTC and other aminoglycosides to Streptomyces coelicolor, the otrA gene from S. rimosus M527 was cloned under the control of the strong ermE promoter. The resulting plasmid, pIB139-otrA, was introduced into S. coeficolor M145 by intergenedc conjugation, yielding the recombinant strain S. coelicolor M145-OA. As expected S. coelicolor M145-OA exhibited higher resistance levels specifically to OTC and aminoglycosides gentamycin, hygromycin, streptomycin, and spectinomycin. However, unexpectedly, S. coelicolor M14-~OA on solid medium showed an accelerated aerial mycelia formation, a precocious sporulation, and an enhanced actinorhodin （Act） production. Upon growth in 5-L fermentor, the amount of intra- and extracellular Act production was 6-fold and 2-fold higher, respectively, than that of the original strain. Consistently, reverse transcription polymerase chain reaction （RT-PCR） analysis revealed that the transcrip- tional level of pathway-specific regulatory gene acUl-orf4 was significantly enhanced in S. coelicolor M145-OA compared with in S. coelicolor M145.展开更多
文摘该文以云南产的紫蓝草为原料,研究紫蓝草紫色素的提取工艺,并研究紫蓝草紫色素对糯米染色前后表观性能。在单因素试验基础上,以吸光度为响应值,采用响应面法对紫蓝草紫色素提取工艺进行优化;并将优化提取的色素对糯米进行染色,通过扫描电子显微镜(scanning electron microscope,SEM)对糯米染色前后的表观性能进行研究。结果表明,紫蓝草紫色素的最佳提取工艺为:提取时间20 min,提取温度45℃,提取料液比1∶30(g∶mL),在此条件下进行6次重复试验,吸光度为1.412;SEM分析表明,紫蓝草紫色素颗粒呈碎片状;糯米淀粉粒与色素发生相互作用,经染色后,糯米淀粉粒表面由光滑状态变为皱缩、粗糙不均匀状态;紫蓝草紫色素与淀粉粒的吸附作用影响了淀粉的糊化。该研究为紫蓝草开发利用和功能性彩色米的产业化生产提供了一定的技术支持。
基金Supported by Science and Technology Project of Beijing Education Commission (KM200811417002)~~
文摘[Objective] The paper was to optimize ultrasound-assisted extraction of proacyanidins from purple cabbage. [Method] The ultrasound-assisted extraction technology was used to study the extraction of proacyanidins from purple cabbage. The effect of ethanol concentration, temperature, time, material-solution ratio and the power of ultrasound on extracting efficiency were studied by single-factor experiment. Based on this, L16（4%orthogonal test were conducted to determine the optimal condi- tion for extraction of proacyanidins from purple cabbage. [Result] The optimal condi- tion for extraction of proacyanidins from purple cabbage was as follows： ethanol concentration 50%, extraction temperature 50℃, extraction time 1 h, extraction power 540 W, material-liquid ratio 1：20. The extraction rate of procyanidins under this condition reached 104.8 mg/g. [Conclusion] The study provided a theoretical basis for scientific and reasonable utilization of procyanidins in purple cabbage.
基金Project supported by the National Natural Science Foundation of China(No.31772213)the Excellent Youth Fund of Zhejiang Province,China(No.LR17C140002)
文摘otrA resembles elongation factor G （EF-G） and is considered to be an oxytetracycline （OTC）-resistance determinant in Streptomyces rimosus. In order to determine whether otrA also conferred resistance to OTC and other aminoglycosides to Streptomyces coelicolor, the otrA gene from S. rimosus M527 was cloned under the control of the strong ermE promoter. The resulting plasmid, pIB139-otrA, was introduced into S. coeficolor M145 by intergenedc conjugation, yielding the recombinant strain S. coelicolor M145-OA. As expected S. coelicolor M145-OA exhibited higher resistance levels specifically to OTC and aminoglycosides gentamycin, hygromycin, streptomycin, and spectinomycin. However, unexpectedly, S. coelicolor M14-~OA on solid medium showed an accelerated aerial mycelia formation, a precocious sporulation, and an enhanced actinorhodin （Act） production. Upon growth in 5-L fermentor, the amount of intra- and extracellular Act production was 6-fold and 2-fold higher, respectively, than that of the original strain. Consistently, reverse transcription polymerase chain reaction （RT-PCR） analysis revealed that the transcrip- tional level of pathway-specific regulatory gene acUl-orf4 was significantly enhanced in S. coelicolor M145-OA compared with in S. coelicolor M145.
