葡萄叶中总黄酮的提取工艺研究

目的：从葡萄叶中提取总黄酮。方法：采用正交试验法研究葡萄叶总黄酮的最佳提取工艺条件,考察了乙醇浓度、回流温度、回流时间及料液比四因素对葡萄叶总黄酮提取率的影响。结果：确立了葡萄叶总黄酮最佳提取条件为：45％的乙醇为溶剂、液料比为1：40、提取温度为60％、提取时间2h,在最佳工艺条件下葡萄叶总黄酮含量为5．329mg／g。     

Hair Cells – Beyond the Transducer

Overview This review considers the “tween twixt and twain” of hair cell physiology, specifically the signaling elements and membrane conductances which underpin forward and reverse transduction at the input stage of hair cell function and neurotransmitter release at the output stage. Other sections of this review series outline the advances which have been made in understanding the molecular physiology of mechanoelectrical transduction and outer hair cell electromotility. Here we outline the contributions of a considerable array of ion channels and receptor signaling pathways that define the biophysical status of the sensory hair cells, contributing to hair cell development and subsequently defining the operational condition of the hair cells across the broad dynamic range of physiological function.     

一株高产Monacolin K紫红曲霉菌株筛选、鉴定及发酵条件优化

为从天然发酵红曲米中分离的30株红曲霉菌株中筛选高产MonacolinK的菌株,并对其产MonacolinK的发酵条件进行优化。实验采用高效液相色谱法(HPLC)筛选到9株具有产MonacolinK能力的红曲霉菌株,其中以编号ZX26的菌株产MonacolinK能力最高,发酵液中Monacolin K产量达到107.6mg/L,并且产MonacolinK能力具有良好的稳定性。微生物形态学结合ITS基因同源性分析结果表明,编号ZX26菌株为紫红曲霉。进一步采用单因素试验和正交试验法优化紫红曲霉ZX26产MonacolinK的发酵条件,结果表明在培养基组分为葡萄糖70g/L,牛肉膏15g/L,NaNO32g/L,MgSO4·7H2O0.5g/L,KH2PO41.5g/L时,其最优发酵条件为:发酵初始pH4.0,接种量为7%,培养温度30℃,发酵10天,在此条件下,紫红曲霉ZX26发酵液中MonacolinK产量达到271.36mg/L,相对于培养条件优化前MonacolinK产量提高152.19%,经验证此培养条件下MonacolinK产量最佳。     

决明子营养价值分析及蛋白提取工艺研究

以大决明子为原材料,基于氨基酸比值系数法,对决明子的营养价值进行了分析;并以碱性缓冲液为提取剂,进行决明子蛋白提取工艺研究,探讨了缓冲液浓度及pH值、料液比、浸泡时间对蛋白提取率的影响,最后用正交试验确定大决明子蛋白的最佳提取工艺。结果表明决明子的营养价值高于大豆和紫花苜蓿,与南瓜接近略低于鸡蛋;提取工艺条件最佳为50 mmol/L、pH值=8.0的KH2PO4-NaOH缓冲液,料液比1 g：50 mL,浸泡提取时间12h。此条件下决明子蛋白的提取率为93.3%。     

荧光素酶基因luc在大肠杆菌中表达条件优化

对重组荧光素酶大肠杆菌菌株M15／pQE30-luc进行了表达条件的优化研究。单因素结果表明：在初始pH值7．0,装液量为20％,2％的接种量,终浓度为0．5mmol／L的IPTG,添加10—30mmol／L的Mg^2＋,摇床转速为200r／min,37℃诱导3．5h酶的表达量最高。正交试验结果表明：初始pH值为7．0,添加40mmol／LMg^2=,接种量2％,装液量为20％时表达量最高,比酶活达1．63×10^8RFU／mg蛋白。     

STATISTICAL APPROACH FOR THE ENHANCED PRODUCTION OF COLD-ACTIVE β-GALACTOSIDASE FROM Thalassospira frigidphilosprofundus: A NOVEL MARINE PSYCHROPHILE FROM DEEP WATERS OF BAY OF BENGAL

In the present investigation Thalassospira frigidphilosprofundus, a novel species from the deep waters of the Bay of Bengal, was explored for the production of cold-active β-galactosidase by submerged fermentation using marine broth medium as the basal medium. Effects of various medium constituents, namely, carbon, nitrogen source, pH, and temperature, were investigated using a conventional one-factor-at-a-time method. It was found that lactose, yeast extract, and bactopeptones are the most influential components for β-galactosidase production. Under optimal conditions, the production of β-galactosidase was found to be 3,864 U/mL at 20 ± 2°C, pH 6.5 ± 0.2, after 48 hr of incubation. β-Galactosidase production was further optimized by the Taguchi orthogonal array design of experiments and the central composite rotatable design (CCRD) of response surface methodology. Under optimal experimental conditions the cold-active β-galactosidase enzyme production from Thalassospira frigidphilosprofundus was enhanced from 3,864 U/mL to 10,657 U/mL, which is almost three times higher than the cold-active β-galactosidase production from the well-reported psychrophile Pseudoalteromonas haloplanktis.     

正交设计优化微波辅助测定延胡索叶总生物碱含量

通过微波辅助提取的方式,以延胡索叶总生物碱含量为考察指标,通过单因素试验和正交试验对总生物碱提取方法进行优化。重点考察了微波提取温度、时间、料液比、提取缓冲液pH值等因素对延胡索叶总生物碱得率的影响。各因素对延胡索叶总生物碱提取量的影响大小依次为:提取缓冲液pH值料液比提取温度。其最佳的提取方法为:提取缓冲液pH值为1. 0,料液比1∶100,提取温度60℃,提取时间20 min。在此条件下,叶总生物碱含量为25. 910 mg/g。利用微波辅助提取延胡索叶中总生物碱,不仅耗时短,效率高,而且操作简单、稳定,为延胡索叶总生物碱含量测定提供一定的技术支持。     

鸭毛梗制备复合氨基酸工艺条件的研究

采用正交试验方法 ,研究了鸭毛梗水解制备复合氨基酸的工艺条件 ,结果表明 :温度 /压力是影响氨基酸转化率最主要的因素。鸭毛梗水解制备的复合氨基酸转化率盐酸法最高 (82 .36 % ) ,氢氧化钠法最低 (5 8.4 6 % ) ,硫酸法与盐酸法接近(79.4 4 % )。硫酸法产率较高 ,操作方便 ,环境污染和设备腐蚀均小 ,适合大量生产 ,确定为水解制备复合氨基酸介质 ,其最佳工艺条件为 :水解时间 8.0h ,硫酸浓度 3.0mol·L-1,水解温度 12 5℃。氨基酸分析表明 ,水解液中均含有 18种以上氨基酸。     

菌核多孔菌培养特性及驯化栽培

为了充分开发利用菌核多孔菌Polyporus tuberaster资源,对采自吉林省露水河东升林场的野生菌核多孔菌进行分离纯化获取纯菌株作为实验材料,采用十字划线法研究固体培养条件下不同碳源、氮源、pH和温度对其菌丝生长的影响,从以上4个单因素实验中选出3个最优水平进行正交实验。结果表明,菌核多孔菌P. tuberaster的最适培养条件为：碳源糊精粉（20mg/mL）、氮源酵母浸粉（2mg/mL）、pH 5.0、温度25℃。在最适培养条件下采用试剂盒测定液体培养条件下菌株的产酶活力,结果表明,菌核多孔菌产漆酶能力较强,酶活力最高可达386.96U/L;木质素过氧化物酶活力仅为5.23U/L;未检测到锰过氧化物酶。出菇实验中,二级种选用麦粒菌种,500mL罐头瓶装干料160g,每瓶接种蚕豆大小菌块3-4块,25℃培养,菌丝满瓶时间为20d;栽培种配方为阔叶树木屑78%、麦麸20%、石灰粉1%、石膏1%、含水量65%左右,17cm×33cm×0.05cm栽培袋装干料520g,每袋接种蚕豆大小二级种3-4块,菌丝发菌时间为26d;在92%-95%空气湿度、一定散射光和20-21℃低温刺激下培养13d后原基分化形成菇蕾,此后加大空气湿度至97%-98%并保持温度24-25℃培养32d后子实体成熟。     

稻曲病菌厚垣孢子壁黑色素提取方法研究

探究稻曲病菌（Ustiloginoidea virens（Cooke） Takahashi）厚垣孢子壁黑色素的最佳提取方法,采用以HCl为提取剂的酸提法和以NaOH为提取剂的碱提法,对该病菌黑色和黄色2种厚垣孢子壁的黑色素进行提取,用3因素3水平进行正交设计试验,结果表明以NaOH作提取剂为佳,其提取黑色素效果最佳的组合条件为3 mol/L NaOH、2 mol/L HC l、水浴温度80℃、水浴时间120 min。