琼脂糖酶产生菌的筛选和培养基优化

从太岁中筛选得到一株初始产酶较高的琼脂糖酶产生菌,经形态和分子生物学分析方法鉴定之后,认定其属于类芽孢杆菌属(Paenibacillus),命名为Paenibacillus sp. P1(简称为P1)。P1为革兰氏阴性菌,短杆状细胞,对明胶和纤维素都没有水解活性。研究该菌的生长及产酶过程发现,该菌株最适发酵产酶时长是40 h。利用单因素实验对发酵培养基进行优化,最终确定了最适合菌株P1产琼脂糖酶的发酵培养基配方为:Agar 3 g/L、蛋白胨2 g/L、K_2HPO_4·3H_2O 1.0 g/L、NaCl 0.3 g/L、MgSO_4·7H_2O 0.05 g/L、FeSO_4·3H_2O 0.02 g/L、CaCl20.04g/L。菌株P1在优化后的培养基中发酵40 h,琼脂糖酶产量达到了3.47×10~4U/L,是优化前产酶水平的3.4倍。实验结果为非海洋来源的产琼脂糖酶菌株筛选和琼脂糖酶的放大发酵奠定了基础。     

一株碱性低温脂肪酶产生菌发酵条件的优化

通过单因素实验,对SYBC Wu-3菌摇床发酵产脂肪酶的培养基组成和培养条件进行优化,得出较佳的产酶培养基组成配方为:蛋白胨5 g/L,酵母膏 6 g/L,NaH2PO4 3 g/L; 油脂250 mL/L,乳化剂OP 25 mL/L.最优发酵条件为250 mL的摇瓶装液量50 mL,培养温度30 ℃,发酵时间72 h.经过优化后发酵液脂肪酶酶活力最高可达到10.68 U/mL,较优化前提高了2.8倍.     

Penicillium sp.1523产柚苷酶摇瓶发酵培养基优化

采用单因素试验、Plackett-Burman设计和响应面分析相结合的方法,对Penicillium sp.1523产柚苷酶的摇瓶发酵培养基配方进行优化。单因素试验结果显示：发酵培养基中的最优碳源为玉米粉,最优氮源为豆饼粉;Plackett-Burman设计筛选出影响柚苷酶产量的3个重要因素为玉米粉、豆饼粉和柚苷,在此基础上运用最陡爬坡试验逼近最大响应值区域,再利用Box-Behnken试验设计及响应面分析法进行回归分析,获得最佳培养基配方为：玉米粉31.14g/L、豆饼粉31.53g/L、柚苷1.65g/L、K2HPO4 1.00g/L、ZnSO4 0.10g/L、MgSO4 ·7H2O 0.06g/L、CaCl2 0.10g/L。在优化后的条件下摇瓶发酵产柚苷酶酶活力为(891.79±6.33)U/mL,与模型预测值接近,发酵产酶量比优化前提高70.8%。     

嗜酸乳杆菌产细菌素培养基及培养条件的优化

为了提高嗜酸乳杆菌单位体积的活菌数及其产细菌素的产量,通过单因素试验和正交试验优化了培养基配方及培养条件。优化后培养基配方为葡萄糖10g/L,蛋白胨15g/L,牛肉膏15g/L,氯化钠3g/L,碳酸钙1g/L,MgSO4.7H2O 0.4g/L,柠檬酸三铵2g/L,K2HPO4.3H2O 4g/L,MnSO4.H2O 0.2g/L。优化后培养条件为37℃发酵22h,接种量为2%,初始pH值为6.8,摇床转速160r/min。在此条件下,细菌素效价为231.34AU/mL。     

优化陈米糖化液提高细菌纤维素产量的研究

以木醋杆菌（Acetobacter xylinum）为发酵菌种,通过Plackett-Burman试验设计确定了陈米糖化液培养基中酵母膏、KH2PO4、FeSO4、乙醇对木醋杆菌发酵产细菌纤维素具有显著影响,并采用Box-Behnken试验设计对各显著影响因子进行优化,获得最优的陈米糖化液发酵培养基配方为：在陈米糖化液培养基基料中加入酵母膏13.1 g/L、蛋白胨10 g/L、KH2PO4 5.7 g/L、MgSO4 3.1 g/L、FeSO4 0.3 g/L、柠檬酸0.3 g/L、无水乙醇4.0%。在此优化条件下,细菌纤维素的产量为7.08 g/L,是陈米糖化液培养基基料发酵产细菌纤维素（0.38 g/L）的18.6倍,比基础发酵培养基细菌纤维素产量（4.80 g/L）提高了47.5%。     

裂殖壶菌产DHA发酵培养基的优化

从成本控制和发酵罐扩大培养监测控制方面考虑,优化了裂殖壶菌(Schizochytrium sp.FJU-512)产DHA发酵培养基。利用单因素实验和正交实验优化了发酵培养基碳氮源组分,均匀设计实验优化了无机盐组分。最佳产DHA发酵配方为葡萄糖120g/L,酵母浸膏5g/L,谷氨酸钠20g/L,硫酸铵0.25g/L,海水晶25g/L,KH2PO44.0g/L,Mg SO4·7H2O0.5g/L,Ca CO35.0g/L,Na2SO43.0g/L,Fe SO4·7H2O 20mg/L,维生素B10.005g/L,维生素B120.005g/L。优化后,裂殖壶菌DHA产量到达13.83g/L,提高了22%,且培养基成本降低40%左右。     

枯草芽孢杆菌JMUKC2 产肌苷摇瓶发酵培养基的优化

利用单因素试验和正交试验对肌苷生产菌枯草芽孢杆菌JMUKC2的摇瓶发酵培养基进行优化,优化后的最佳发酵培养基配方为葡萄糖140g/L、玉米浆20g/L、酵母膏17g/L、尿素7g/L、硫酸铵20g/L、MgSO4 ·7H2O 1g/L、KH2PO4 7g/L、CaCO3 20g/L。培养基经优化后,生物量比优化前提高了40.67%,肌苷产量比优化前提高了46.57%。     

甲醇蛋白联产木聚糖酶发酵培养基优化

为将实验室诱变选育出的高产甲醇蛋白毕赤酵母菌高效表达木聚糖酶,在100 L发酵罐中,对影响木聚糖酶发酵水平的培养基组分及其质量浓度等因素进行考查,初步确定培养基配方,并设计正交试验优化发酵培养基.结果表明:最优发酵培养基配方为H3PO4质量浓度25 g/L、K2HPO4质量浓度0.5 g/L、NH4 Cl质量浓度0.3...     

红曲霉液态发酵多糖工艺条件的优化

研究了红曲霉产多糖的液态发酵条件,得出优化后的培养基组成为：蔗糖45 g/L,酵母粉4.5 g/L,KH2PO4·3H2O 3.5 g/L,MgSO4·7H2O 0.85 g/L.通过单因素实验和正交试验,得到红曲霉N产多糖的优化发酵工艺条件为：种龄30 h,接种量7.5%,发酵培养基初始pH 5.75,装液量162....     

产胆固醇氧化酶重组大肠杆菌的发酵培养基和诱导条件的优化

在摇瓶中对产胆固醇氧化酶重组大肠杆菌的发酵培养基和诱导条件进行了优化,优化培养基为甘油10 g/L,胰蛋白胨10 g/L,酵母粉5 g/L,KH2PO4 2 g/L,K2HPO4 4 g/L,Na2HPO4·12H2O 7 g/L,(NH4)2SO4 1.2 g/L,NH4Cl 0.2 g/L,MgSO4·7H2O 1 g/L;优化的诱导条件为:对数生长中期诱导,IPTG浓度为0.3 mmol/L.在优化的培养基和优化的诱导条件下,单位菌体产酶量达745.86 U/g,菌体产酶水平达1 625.97 U/L,为优化前的700 U/L的2.3倍.     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press