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法夫酵母虾青素提取工艺的优化研究 总被引：12，自引：3，他引：12
从破壁方法、浸提溶剂及提取条件等方面对法夫酵母虾青素提取工艺进行了优化研究。用单因子试验对破壁方法及浸提溶剂进行选择，结果表明二甲亚砜(DMSO)法是法夫酵母破壁提取虾青素的最佳方法，丙酮是理想的提取溶剂。用析因试验对破壁提取的条件进行了分析研究，结果表明破壁的温度、破壁的时间、浸提溶剂的添加量及浸提温度等都会对法夫酵母破壁提取虾青素产生显著影响，但以破壁的温度及丙酮的添加量影响最大。通过最速上升和中心组合设计试验，优化得到适宜的提取条件为：二甲亚砜加量25 mL/g(以干菌体计，下同)、破壁温度75.6℃、破壁时间20 min、丙酮添加量77.4 mL/g、浸提温度为40℃，优化后提取液中虾青素的浓度为3.145 μg/mL，比未优化时增加了27.02%。 相似文献
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离子液体提取山楂绿原酸的工艺优化 总被引：4，自引：3，他引：1
绿原酸是许多植物中的活性成分,因其有显著的药理活性和生物活性而被广泛关注,选择合适的提取溶剂、提取方法和工艺参数是绿原酸得以进一步应用的重要环节。该文以离子液体为溶剂,采用超声辅助方法提取山楂中的绿原酸,首先选择离子液体种类,再通过单因素试验确定离子液体浓度、提取时间和固液比3个主要因素的参数,并用响应面法分析法优化提取工艺参数。结果表明,优化工艺为以离子液体1-乙基咪唑盐酸盐[EIm]Cl的水溶液为提取溶剂,当其浓度为1.19 mol/L,固液比为1∶19.67 g/mL,每次提取时间为42.83 min时,理论的绿原酸提取率为4 179.48μg/g,获得工艺参数的回归模型。验证试验绿原酸提取率为4 128.28μg/g,与模型符合很好。另外,因离子液体的价格昂贵、难降解和不可预知的毒性,进行了离子液体和目标物质的分离操作,在酸性条件下,以乙酸乙酯为反萃取剂萃取出绿原酸,其得率为提取液中质量分数的96.3%;离子液体通过减压蒸馏、在65℃烘干后循环使用,提取率达到第1次的92.96%。此外,试验考察了离子液体与普通溶剂比较,在提取率上和循环使用上具有明显优势,是一种高效、绿色萃取溶剂。 相似文献
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超声波辅助提取文冠果籽油的工艺条件优化 总被引：14，自引：5，他引：14
以文冠果籽为原料,利用超声波辅助提取文冠果籽油。通过单因素试验及二次回归旋转组合试验研究了超声波频率、料液比、提取温度及提取时间等因素对出油率的影响,确定了超声波辅助提取文冠果籽油的最佳工艺条件,建立了提取回归数学模型。结果表明,在试验范围内各影响因素对文冠果出油率作用的大小依次为：超声提取时间〉料液比〉提取温度〉超声波频率,以沸程60～90℃的石油醚为溶剂提取文冠果籽油的最优工艺参数为：料液比1∶10（g/mL）,提取温度60℃,提取时间35 min,超声波频率60 kHz,在该工艺条件下浸提三次总出油率60.18%,提取率达92.47%;所建立的数学回归模型能够较准确预测文冠果油的出油率。 相似文献
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为了提高青稞的附加利用价值,该文以青稞麸皮为研究对象,考察了提取试剂、酸质量分数、萃取pH值、料液比和提取温度对多酚质量分数和 DPPH·自由基清除能力的影响。采用中心组合设计优化其结合酚提取工艺。结果表明,青稞结合酚提取最优工艺条件为：提取试剂为硫酸,酸质量分数为11.10%,水料比为1：17 g/mL,提取温度为75℃,pH值不作处理,此条件下提取得到的结合酚质量分数达224.33 mg/(100 g),DPPH·自由基清除能力达9919.28μmol/(100 g),与预测值多酚质量分数243.80 mg/(100 g),其DPPH·自由基清除能力9087.02μmol/(100 g)基本一致。高效液相色谱法检测到最优工艺下所得青稞结合酚中含有8种酚酸及8种黄酮类物质,总量达325.104 mg/(100 g)。研究结果为全面评价青稞结合酚含量及青稞麸皮的高效利用提供科学依据。 相似文献
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为筛选制定出亚麻叶中五种活性物质的最佳提取工艺,以亚麻叶中提取的荭草素、绿原酸、异荭草素、牡荆素、异牡荆素5种成分的含量作为指标,通过单因素试验研究含醇量、提取时间、固液比、提取次数、提取温度对5种成分提取效果的影响;并利用L9(34)正交试验法方法,优选最佳的提取工艺。确定的最佳提取工艺为乙醇溶液浓度75%、料液比1 ∶ 15(g/mL)、提取次数2次、提取时间1.5 h、温度80 ℃。该提取工艺是一种适合于亚麻叶中有效成分提取的有效方法,可为亚麻叶研究和开发利用提供参考。 相似文献
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速溶牦牛油茶生产工艺及参数研究 总被引：4，自引：1，他引：4
通过L9(34)正交试验选择出最佳膨化工艺参数：进料速率0.9 kg/min，模具预热温度160℃，原料含水率15%；兼顾营养和膨化度确定大豆、青稞的混合膨化比例为15∶85；利用高压提取、减压浓缩技术，提取生长在海拔3 400多米高寒草地牦牛骨髓油，配以混合膨化粉及其他辅料，通过造粒、远红外干燥、自动计量包装等流水线生产，制成含蛋白质152 g/kg，热能17 556 kJ/kg、Ca 15.6 g/kg，P 31 g/kg、Fe 330 mg/kg的营养丰富、冲调性好、极具民族风味特色的新型颗粒状固体油茶。 相似文献
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木荷林凋落物的归还动态及分解特性 总被引：7，自引：0，他引：7
通过对杭州常绿阔叶林中凋落物的定位观测研究表明,该系统中年均凋落物量为5.85t/hm2,其中以叶最多,占总量的79.5%,枝果较少,分别占7.1%和13.4%。归还动态呈双峰型,即4月和9月为2次高峰。凋落物的半分解时间为1.59a,分解动态呈指数衰减规律。凋落物的年养分归还量达223.69kg/hm2。木荷林中凋落物的现存量为7.47t/hm2。平均分解率为45.18%。林分中凋落物量还处于增长阶段。 相似文献
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低共熔溶剂提取核桃青皮多酚工艺优化及其抑菌活性 总被引：3，自引：2，他引：1
为了充分利用核桃副产物,减少环境污染,该研究以核桃青皮为研究对象,分别采用不同pH值(3、7、10)水溶液、50%乙醇溶液和低共熔溶剂(尿素/氯化胆碱:DES-UC,草酸/氯化胆碱:DES-OC)提取多酚。首先在温度80℃、液料比25 mL/g、低共熔溶剂(Deep Eutectic Solvents, DESs)配位剂摩尔比1.0的条件下提取60 min筛选出DES-OC提取效果较好;随后在单因素试验考察的基础上,采用响应面分析法确定了DES-OC提取核桃青皮多酚的优化工艺参数:草酸/氯化胆碱摩尔比1.0、温度85℃、时间62 min、液料比50 mL/g,在此条件下多酚提取量为50.87 mg/g。另外,通过对核桃青皮多酚提取混合溶剂抑菌活性试验的研究,发现DES-OC与核桃青皮多酚混合后对大肠杆菌(E.coli)的抑菌效果较佳,金黄色葡萄球菌(S.aureus)次之,最后为黄青霉(P.chrysogenum)。以上试验结果可为研究开发天然抑菌剂、保鲜剂等提供理论基础,拓宽核桃青皮加工利用途径的同时也为提取农产品副产物中生物活性成分提供新思路。 相似文献
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【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。 相似文献
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Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing. 相似文献
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《中国生态农业学报》2014,(8)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
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M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. 相似文献
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Grete Skrede Berit Karoline Martinsen Anne-Berit Wold Stein-Erik Birkeland Kjersti Aaby 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):193-208
Abstract A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(7):865-877
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils. 相似文献
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Electron donor and pH relationships for biologically enhanced dissolution of chlorinated solvent DNAPL in groundwater 总被引：3，自引：0，他引：3
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells. 相似文献
18.
Aleš Lebeda Ivana Doležalová Eva Křístková Barbora Mieslerová 《Genetic Resources and Crop Evolution》2001,48(2):153-164
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions. 相似文献
19.
Y. Bashan J. J. Bustillos L. A. Leyva J.-P. Hernandez M. Bacilio 《Biology and Fertility of Soils》2006,42(4):279-285
Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several
photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene.
This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments
for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference
in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless
of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots.
Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production
or the positive response of the plants towards A. brasilense Cd inoculation. 相似文献
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Three slow-growing legume trees used for desert reforestation and urban gardening in the Sonoran Desert of Northwestern Mexico
and the Southwestern USA were evaluated whether their growth can be promoted by inoculation with plant growth-promoting bacteria
(Azospirillum brasilense and Bacillus pumilus), unidentified arbuscular mycorrhizal (AM) fungi (mainly Glomus sp.), and supplementation with common compost under regular screenhouse cultivation common to these trees in nurseries. Mesquite
amargo (Prosopis articulata) and yellow palo verde (Parkinsonia microphylla) had different positive responses to several of the parameters tested while blue palo verde (Parkinsonia florida) did not respond. Survival of all tree species was over 80% and survival of mesquite was almost 100% after 10 months of cultivation.
Inoculation with growth-promoting microorganisms induced significant effects on the leaf gas exchange of these trees, measured
as transpiration and diffusive resistance, when these trees were cultivated without water restrictions. 相似文献