响应面法优化超声波提取浮萍多糖工艺研究

为优化浮萍多糖的提取工艺,基于单因素试验结果对影响浮萍多糖提取率的三个显著因素及水平：料液比(1∶40、1∶50、1∶60)、超声时间(40 min、60 min、80 min)和超声功率(300 W、350 W、400 W)进行了研究。以浮萍多糖提取率为响应值,运用Design-Expert软件进行响应面设计并开展试验,通过工艺优化确定浮萍多糖的最佳提取条件为料液比1∶40.06、超声时间79.58 min、超声功率341.37 W,此条件下浮萍多糖提取率的理论值可达到1.188%;验证试验的浮萍多糖提取率为1.125%,与理论值仅相差0.063%。优化后的提取工艺条件准确可靠,可用于实际操作。     

Numbers of wintering waterbirds in Great Britain and the Isle of Man (1994/1995-1998/1999): II. Coastal waders (Charadrii)

Great Britain's wintering coastal wader populations have been estimated for the period 1994/1995-1998/1999 from data provided from two sources: the Wetland Bird Survey (WeBS) and the Non-estuarine Coastal Waterfowl Survey (UK-NEWS). New methodology for estimating the number of wintering waders is applied. It imputes (fills in) the value of missing counts before estimating the population size of each species as being the mean of the largest annual count made between November and March over the relevant 5-year period. This methodology has led to an 11% larger estimate of the number of waders present on Great Britain's coasts than the traditional approach based on averaging just January counts over a 5-year period, and it suggests that Great Britain's coastline supports ca. 2.1 million waders. Updated values are presented from which site evaluations based on 1% of the national population can be derived. Great Britain is of considerable international importance for waders. It holds >25 and >50% of the flyway populations of nine and four species of wader, respectively, but for the first time since the start of monitoring in the early 1970s, the historical increase in the number of predominantly coastal waders wintering in Great Britain is coming to an end. Seven of the 14 species that have shown population changes of >5% since the last set of 1987/1988-1991/1992 population estimates have declined in numbers. The possible causes of the fluctuations in wader populations, such as climate change and changing nutrient inputs to coastal waters are discussed. There is an urgent need to identify the causative factors leading to these declines, and to use the new population estimates to identify new sites that should be afforded legal protection, an action that should help Great Britain maintain its internationally important wader populations. The decrease in the updated population estimate of Eurasian oystercatcher, for example, has made it possible to determine that 19 rather than 17 sites in Great Britain are worthy of statutory protection on the basis of holding 1% or more of its national population.     

响应面法优化沙芥叶片总黄酮提取工艺的研究

为了优化沙芥叶片总黄酮的提取工艺条件,以乙醇浓度、料液比、回流温度、回流时间为自变量,以总黄酮提取含量为响应值,应用Box-Behnken中心组合原理建立数学模型,进行响应面分析( RSM ),确定总黄酮的最佳提取工艺。结果表明,沙芥叶片总黄酮的最佳提取工艺为：乙醇浓度85%,料液比1:28,提取温度85℃,回流时间2 h。经验证,沙芥总黄酮提含量实测值26.367 mg·g^-1,与理论值的RSD为0.47%。说明采用响应面法得到的工艺参数可靠, 具有一定的实际价值。     

响应面法优化灵芝AM21菌株液体深层发酵培养基配方

为了提高灵芝(Ganoderma lucidum)AM21菌株菌丝产灵芝三萜的能力,采用响应面法对其液体发酵培养基配方进行优化.首先采用Plackett- Burman设计法对影响菌丝体三萜含量的9个相关因素进行筛选,确定主要影响因子为豆粕粉和山药,然后用最陡爬坡试验逼近2个主要因素的最大响应区域,并通过中心组合设计和响应面分析,确定主要影响因子的最佳浓度.优化后的培养基组成为1.84％豆粕粉,1％玉米粉,1％葡萄糖,0.92％山药,0.5％酵母粉,0.1％麸皮,0.1％ KH2 PO4,0.1％ MgSO4·7H2O,0.01％ VB1.使用该培养基生产的灵芝菌丝体中三萜含量较使用基础发酵培养基生产的高29.13％.     

仙人掌皮黄酮提取工艺优化(简报)

仙人掌皮黄酮提取可提高废弃物的资源利用和活性成分的开发。采用响应面分析法对乙醇体积分数、提取温度、提取时间和剂料比等提取条件进行了优化。结果表明,曲面回归方程拟合性好;优化工艺为乙醇体积分数67%、提取温度76℃、提取时间5.7 h、剂料比21.4 mL/g时,仙人掌皮黄酮得率为6.45 %。经鉴定仙人掌皮中主要黄酮为异鼠李素-3-O-[2-O,6-O-双-?-L-鼠李糖基]-?-L-葡萄糖苷、异鼠李素-3-O-（6?-鼠李糖）葡萄糖苷。     

龙胆中黄酮化合物含量测定的方法学研究

[目的]建立紫外可见分光光度法测定龙胆中总黄酮含量的方法。[方法]通过微波辅助双水相提取龙胆中总黄酮类化合物,采用紫外可见分光光度法,以芦丁作为对照品,测定其含量。[结果]黄酮类化合物浓度在10.4~73.0μg/m L,其吸光度与浓度有良好的线性关系;该方法的精密度、重复性和加样回收率的RSD值分别为0.30%、1.31%、2.27%。[结论]该方法准确、快速、重复性好,可以用于测定龙胆中总黄酮类化合物。     

响应面法优化热带假丝酵母ypy06植酸酶发酵条件的研究

从海南洋浦近海分离到1株产植酸酶的酵母菌株,经鉴定为热带假丝酵母（Candida tropicalis）,利用Plackett-Burman设计对其发酵条件进行了筛选。结果表明,豌豆粉浓度、硫酸铵浓度和初始pH对酶产量具有显著的影响;利用响应面法对3个因子进行了优化,获得了最佳发酵条件：豌豆粉1.0%,葡萄糖2.0%,硫酸铵1.7%,氯化钠1.0%,初始pH 5.2,培养72 h,植酸酶产量达到727.5 U/mL。