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1.
产中性蛋白酶菌株发酵条件的研究   总被引:1,自引:0,他引:1  
对一株产中性蛋白酶的枯草芽孢杆菌的发酵条件进行了优化,确定其最适培养基配方为豆饼粉3%、玉米粉3%、麸皮2,5%、KH2PO4 0.05%、Na2HPO4 0.4%,最适摇瓶培养条件为种龄8h、接种量2%、装液量50mL/250mL、摇床转速180r/min、32℃培养33h,中性蛋白酶的摇瓶发酵单位最高可达4830U/mL。  相似文献   

2.
重组甲醇毕赤酵母(Pichia methanolica)工程菌PMADl6/pMETA-Lccl能分泌表达杂色云芝重组漆酶。本文通过对其发酵条件的研究,找出摇瓶发酵表达漆酶的最适培养条件:在BMMY培养基中添加0.2mmol/L的Cu^2+.装液量为25mL/250mL三角瓶,接种量体积之比为45:25,0.5%甲醇诱导,20℃条件下摇瓶培养5d,漆酶最高酶活力达1192U/L。  相似文献   

3.
棒曲霉GM-69深层发酵生产木聚糖酶的研究   总被引:1,自引:0,他引:1  
报道了发酵条件对棒曲霉GM-69产木聚糖酶的影响,并用50L发酵罐进行了深层发酵试验。确定产酶摇瓶培养的最佳条件:培养时间为72h,温度为28℃,培养基起始pH为3.8,接种量为5%(V/V),转速为250r/min,装液量为90mL/500mL三角瓶。其酶活力最高362IU/mL,平均为343IU/mL,比培养条件优化前增加了55.6%。50L发酵罐发酵最佳条件:转速为400r/min,通风量为1:0.6~1,罐压为0.08Mpa,装量为700,发酵周期为72h,温度28℃,培养基起始pH3.8,接种量5%(V/V),酶活力平均为351IU/mL。  相似文献   

4.
对摇瓶发酵生产富含S-腺苷甲硫氨酸的面包酵母的培养条件和培养基成分进行了优化,单因子实验结果表明,发酵最适pH值为5.0,最适装液量为70/250mL,最佳接种量为2%。正交优化实验结果表明,最佳培养基成分为12°Brix糖蜜,另加酵母粉6.667g/L,(NH4)2SO4 2.829g/L,MgS040.2g/L,ZnSO4 0.1g/L,KH2P041g/L,在该条件下,S-腺苷甲硫氨酸产量为14.26mg/L,含量为1.64mg/g,分别提高了76.5%和84.3%。  相似文献   

5.
基因工程菌Pichia Pastoris高密度培养条件的摇瓶研究   总被引:7,自引:0,他引:7  
对基因工程茵Pichia pastoris高密度培养的培养基进行了研究,选取了价廉易得的培养基,对此培养基各组分进行了优化,并对其它发酵条件进行了优化试验,得到了最优培养基配方及培养条件。结果表明,培养基最佳配方为:葡萄糖为5%,氨水单次补料量为20μL(250mL摇瓶装液量为20mL),KH2PO4浓度为0.7%,培养基其它组分为:K2HPO40.1%、MgSO4.7H2O0.03%、FeSO4.7H2O0.05%、MnSO4.H2O0.05%。种子液最佳培养时间为40h,接种量为10%,250mL三角瓶装液量为20mL,摇床转速为220r/m,发酵培养基最佳初始pH5.5,发酵温度为30℃,发酵结束时间64h。在此优化的培养基及培养条件下,茵体密度达到最高,OD600达到64.3,细胞干重20.2g/L。  相似文献   

6.
嗜酸乳杆菌高密度培养及发酵剂的研究   总被引:2,自引:0,他引:2  
研究了嗜酸乳杆菌的高密度培养条件,并使用喷雾干燥法对嗜酸乳杆菌粉末发酵剂进行了制备。实验表明,嗜酸乳杆菌6012的最佳增菌培养基为:乳清培养基+0.6%(w/v)低聚异麦芽糖+0.6%(w/v)黄豆粉+10%(v/v)胡萝卜汁+0.5%(w/v)CaCO3,在培养过程中伤脑筋20%柠檬酸钠调节培养基pH值为6.2,37℃静置培养18h,活菌数可达1.0×10^9 cfu/mL。以0.5%甘油+0.5%葡萄精+3%大豆分离蛋白+2%海藻酸钠作为抗热保护剂,菌体经过喷雾干燥,其发酵剂活菌数为8.0×10^9 cfu/g。  相似文献   

7.
以从红树林底泥中分离筛选的施氏假单胞(Pseudomonas stutzeri)为对象,采用单因素和正交实验方法,通过摇瓶发酵方式对其产卡拉胶酶发酵条件进行了研究。得到最佳培养基配方和培养条件分别如下:卡拉胶0.3‰,酵母浸粉0.1‰,NaNO30.3‰,乳糖0.04%,吐温-800.2‰;起始pH值6.0,温度32℃,装样量90mL/250mL,接种量13%,摇床转速160r/min。在最佳条件下,发酵液的酶活力为26.5U/mL,比优化前的活力提高了80%。  相似文献   

8.
Brevibacterium sp.可以发酵生产胆固醇氧化酶,实验中对该菌种进行了底物诱导及发酵条件的优化, 确定其最适培养基为(%):蔗糖0.3,酵母膏0.2,蛋白胨0.3,牛内膏0.3,K_2PO_4 0.1,MgSO_4 0.05,pH6.8。最适培养条件为:接种量5%,24℃培养20h,通气量为50mL 培养基/250mL 三角瓶,200r/min。在最适培养基及最适条件下,胆固醇氧化酶的酶活力可达到24.01U/mg,比未优化前1.71U/mg 提高了14倍。该酶具有较强的酸碱稳定性和热稳定性,最适 pH 为6.5,最适温度为54℃。在最适 pH 和温度条件下测得该酶 km 值为7.1 ×10~(-5)mol/L。  相似文献   

9.
重组大肠杆菌产β-胡萝卜素的发酵条件   总被引:3,自引:0,他引:3       下载免费PDF全文
对重组大肠杆菌产β-胡萝卜素发酵条件进行了研究.在M9培养基中添加Span-200.7g/L有利于细胞生长和β-胡萝卜素表达,初始pH值6.0、接种体积分数5%、发酵温度28℃、抗生素氨苄青霉素质量浓度80μg/mL和氯霉素质量浓度40μg/mL为最佳发酵条件,在7L发酵罐进行发酵动力学试验表明,重组菌最适发酵周期为22h,细胞干重最高可达1.55g/L,β-胡萝卜素表达量可达0.75μg/mL。  相似文献   

10.
利用响应面法对Cl/top/1uspasseckerianus进行发酵培养条件优化。首先通过Plackett-Burman设计两水平实验对8种发酵条件进行筛选,得列葡萄糖和大豆油含量为主要影响因素。再根据中心复合实验设计,对葡萄糖含量和火豆油含量进行响应面优化,得到最优培养条件为葡萄糖5.0%、大豆油0.33%、酵母粉0.6%、玉米浆3.0%、MgS040.035%、CaCO30.05%、初始pH6.9、装量50mL/500mL△,产量为24.75mg/mL,在原培养基基础上提高53.7%。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

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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.  相似文献   

18.
<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  相似文献   

19.
《印刷工业》2014,(11):95-95
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%.  相似文献   

20.
《印刷工业》2014,(8):103-103
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  相似文献   

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