南瓜籽蛋白Pw-1的抑菌活性和稳定性研究

通过抑菌试验和稳定性试验,研究了南瓜籽蛋白Pw-1对9种常见植物病原真菌和常见病原细菌的抑制作用,探讨热处理、pH、紫外照射及储存时间对Pw-1抑菌稳定性的影响。抑菌试验表明,Pw-1对9种供试菌均有抑制作用,其中对黄瓜枯萎病菌、白色葡萄球菌、枯草芽孢杆菌和金黄色葡萄球菌4个菌株抑制作用显著,抑菌圈直径均在10 mm以上;稳定性试验表明:60℃以下Pw-1热稳定性良好;最适宜pH范围7~9;紫外照射对Pw-1抑菌活性有明显影响,10 min以上抑菌活性即逐渐减弱;长时间储存于-18℃冰箱内,Pw-1抑菌活性稳定。     

芝麻菜种子抗菌蛋白的纯化及其抗菌活性

本文旨在从芝麻菜种子中分离纯化得到一种具有抗菌活性的蛋白,并对其抗菌活性进行研究。通过SP-Sepharose离子交换色谱、Mono STM 5/50GL和SuperdexTM 75 10/300GL快速蛋白液相色谱进行分离纯化,经Tricine-SDS-PAGE电泳分析;采用纸片扩散法、荧光染色法,对其抗菌活性和稳定性进行研究。结果表明,从芝麻菜种子中纯化一种抗菌蛋白ZSU2,经Tricine-SDS-PAGE电泳鉴定达到电泳纯,相对分子质量约为12 kDa;ZSU2蛋白对小白菜炭疽病菌等12种真菌具有较强的抑制作用,抗菌活性在pH1~13、温度0~100℃稳定,且具有较强的金属阳离子耐受能力;此外,ZSU2蛋白能引起菌丝尖端几丁质积累和细胞膜选择透过性的改变。     

黑豆胰蛋白酶抑制剂的纯化及性质研究

目的:分离、纯化一种黑豆胰蛋白酶抑制剂,并进行酶学性质及其生物学性质研究,为其生物活性蛋白的研究提供依据。方法:采用硫酸铵分级沉降、弱阳交换色谱CM-Sephadex C-50、亲和色谱Affi-gel和SDS-PAGE等方法分离、纯化和鉴定;以BANPA为底物,检测BSTI对胰蛋白酶的抑制活性。结果:从黑豆种子中分离到一种胰蛋白酶抑制剂,命名为BSTI。SDS-PAGE和阴离子高效液相色谱鉴定表明该蛋白具有相当高的纯度。其相对分子质量为20 kD,等电点为5.6。当抑制剂与酶的物质的量比达到1时,使酶完全失活。在温度65℃以下以及经pH 2～10处理后,BSTI活性几乎不受影响。BSTI对植物致病菌苹果轮纹病菌、瓜果腐霉病菌和白菜黑斑病菌具有较强的抑制作用,而对甜瓜枯萎病菌和葡萄灰霉病菌无抑制作用。结论:本文分离、表征到一种具有抗菌活性的新型胰蛋白酶抑制剂,可以使用离子交换层析柱进行分离、纯化。     

海洋假单胞菌GY-1菌株的抗菌作用及其胞外抗菌蛋白的分离纯化

采用对峙培养法和牛津杯法测定海洋假单胞杆菌(Pseudomonas) GY-1菌株和发酵液的抑菌作用。结果表明：GY-1菌株和发酵液对小麦根腐病菌(Bipolaris sorokiniana)、禾谷镰刀病菌(Fusarium graminearum)、菠菜早疫病菌(Alternaria solania)、斑点落叶病菌(Alternaria alternata)、油菜菌核病菌(Sclerotinia sclerotiorum)和小麦叶枯病菌(Alternaria tenuis Nees)等植物病原真菌有较强的抑制作用。发酵液采用硫酸铵分级沉淀、DEAE Sepharose Fast Flow柱层析、Sephadex G-75凝胶层析,以小麦根腐病菌为指示菌进行活性追踪和SDS-PAGE电泳纯度跟踪检测,纯化出一种对小麦根腐病菌具有明显抗菌作用的抗菌蛋白,其分子质量约为70.9kD。     

小红豆抗菌蛋白的分离纯化及其功能活性

研究旨在从小红豆中分离纯化得到一种具有抗菌活性的蛋白,对其部分生物活性进行表征和研究。通过缓冲液抽提(NaAc-HAc,20 mmol/L,pH5.4)、硫酸铵分级沉降、Affi-gel blue gel亲和色谱、Sephadex SP C-25离子交换色谱及Sephadex G-50凝胶过滤色谱进行分离纯化,经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)分析鉴定其相对分子质量,并对其抗真菌活性进行表征。结果表明,从小红豆中分离纯化出的一种抗菌蛋白,经SDS-PAGE鉴定达到电泳纯,且其相对分子质量约为4 kDa,通过纯化的抗菌蛋白对来自茄子、甜瓜及苦瓜的尖孢镰刀菌的抑制实验,证明此抗菌蛋白具有较强的抗真菌活性。从小红豆中分离纯化出的一种分子质量约为4 kDa的抗菌蛋白,其对真菌具有抑制作用,且其抑制率对浓度的依赖性较高。     

海洋多黏类芽孢杆菌L1-9 菌株抗菌蛋白的分离纯化及其抗菌作用

通过硫酸铵分级沉淀、DEAE Sepharose Fast Flow 柱层析、Sephadex G-200 柱层析,以小麦蠕孢病菌和金黄色葡萄球菌为指示菌采用抑菌活性追踪和SDS-PAGE 跟踪检测,从分离自连云港海域、对多种病原真菌具有抑菌作用的多黏类芽孢杆菌L1-9 菌株发酵液中分离纯化得到一种对金黄色葡萄球菌和小麦蠕孢病菌的菌丝生长及孢子萌发具有抑制作用的抗菌蛋白,分子质量约31kD。     

枯草芽孢杆菌SH7 抑菌蛋白产生的最佳发酵条件及温室防效

枯草芽孢杆菌SH7可抑制烟草青枯病菌的生长,利用硫酸铵沉淀法从发酵液中提取抑菌蛋白质,测定其对烟草青 枯病菌抑菌活性,从而确定抑菌蛋白产生的最佳培养基和培养条件。本实验产生抗菌蛋白的最佳培养基为NA液体培养基, 最佳发酵条件为：pH 6.0,26 ℃,装液量100 mL,170 r/min振荡培养96 h。粗抑菌蛋白在pH为9.0和10.0时,其抑菌活性仍 保持为86%, 88%,对碱稳定;在100 ℃和121 ℃处理20 min,其抑菌活性仍保持为83.1%, 68.0%,具有良好的热稳定性。在 温室内,抗菌蛋白粗提液对烟草青枯病可取得70.8%的防效。     

解淀粉芽胞杆菌NCPSJ7对采后苹果轮纹病的生物防治作用

为了解解淀粉芽孢杆菌NCPSJ7及其抗菌蛋白对苹果轮纹病菌的抑制以及对采后苹果轮纹病的防治作用,以NCPSJ7发酵液、菌悬液及无菌胞外抗菌蛋白为试验材料,分别采用牛津杯法和果实打孔法试验对苹果轮纹病菌LW182的平板抑制效果和果体抑制效果进行检验。采用果实喷洒防腐试验,检验对采后苹果的防腐效果。结果显示,试验材料对轮纹病菌LW182均有不同程度的抑制作用。菌悬液和发酵液对轮纹病菌LW182的平皿抑制效果比胞外抗菌蛋白粗提液好。胞外抗菌蛋白粗提液对苹果轮纹病菌LW182的果体抑制作用非常明显,主要表现为减轻苹果的腐烂和变色程度,以及抑制轮纹病菌LW182菌丝的生长。果实防腐试验显示,胞外抗菌蛋白粗提液对采后苹果轮纹病具有良好的防治作用,防治效果与纳他霉素相当,而发酵液的效果不明显。解淀粉芽胞杆菌NCPSJ7及其抗菌蛋白对苹果轮纹病菌具有抑制作用,同时,NCPSJ7产抗菌蛋白对于采后苹果轮纹病的生物防治具有良好的实际应用价值。     

腊肉拮抗菌分离及抗真菌脂肽特性分析

从传统腊肉中筛选拮抗菌株,纯化鉴定新型抗菌物质并对其抗菌特性研究,为抗菌脂肽在食品防腐中的应用提供理论依据。采用抑菌圈法筛选拮抗菌株;通过酸沉淀、硅胶柱层析和半制备反相高效液相色谱分离纯化抗菌脂肽;通过傅里叶红外光谱、基质辅助激光解吸电离飞行时间质谱对脂肽鉴定。结果表明,筛选得到12?株拮抗细菌,其中菌株XLP27对革兰氏阳性菌、革兰氏阴性菌以及对1?株酵母菌和4?株霉菌有明显抑菌作用。拮抗菌株XLP27鉴定为短小芽孢杆菌,其抗菌物质主要在稳定期合成,并在发酵60?h时达到最大产量。分离纯化得到单一组分抗菌物质,并鉴定为环状脂肽Iturin?A,其由m/z?1?046.182、1?060.213、1?074.198、1?088.201和1?102.175的5?个同系物组成,对应脂肪酸链长度C14～C18。脂肽具有极高的热稳定性,在40～100?℃下保温30?min活性基本保持不变,在较宽的pH值范围（4～10）内稳定性好,且对所有蛋白水解酶不敏感。菌株XLP27所产抗菌物质主要是脂肽Iturin?A,具有广谱抑菌活性,稳定性良好,有潜力在食品保鲜和农业生物防治领域替代传统抗菌剂使用。     

白骨壤抗菌蛋白对香蕉炭疽病菌的抑制作用

本文以红树植物白骨壤叶为材料,以硫酸铵分级沉淀分离不同的抗菌蛋白,采用抑制菌丝生长速率和孢子萌发的方法测定白骨壤抗菌蛋白对香蕉炭疽病菌的抗菌活性,显微观察分析抗菌作用方式机理,进行白骨壤抗菌蛋白对感病香蕉的贮藏防病实验。结果表明:35%、75%、85%硫酸铵沉淀分离的抗菌蛋白(抗菌蛋白Ⅰ、Ⅱ、Ⅲ)具有明显抗菌活性,其抑制菌丝生长的半效应浓度(EC_(50))分别为:7.93±0.29、6.80±0.28、16.21±0.13μg/m L。100μg/m L的抗菌蛋白(Ⅰ、Ⅱ、Ⅲ)溶液对香蕉炭疽分生孢子的萌发抑制率分别达到95.5%±0.01%、97.5%±0.03%、92.5%±0.01%。显微观察发现三种抗菌蛋白处理的菌丝分别出现了扭曲、断裂、畸形以及原生质外渗现象。经抗菌蛋白处理后的采后感病香蕉果实具有明显降低发病率的效果。抗菌蛋白Ⅰ、Ⅱ、Ⅲ对香蕉炭疽病的防治效果分别达到74.48%±0.68%、77.24%±0.53%、75.87%±0.24%。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.