黑曲霉Y101菌株的异核体形成性能

经过UV诱变,以孢子颜色互补和传代分离为筛选条件,发现了一株孢子颜色突变为黄色,并具有异核体高形成性和稳定的分离性的菌株黑曲霉,Y101.在察氏(CA)琼脂培养基平皿上,分别点种Y101菌株和其它孢子颜色突变菌株,发现在Y101菌株和其它菌株形成的菌落交界处,可形成大量的黑色孢子的异核体。黑色孢子的体积比亲本大一倍或近一倍,比黑色孢子传代培养可出现亲本孢子颜色的分离.其中,和白色孢子突变株形成的异核体,连续传代培养,保持稳定的黄色、白色、黑色孢子的分离比率.     

紫外线与氯化锂复合诱变选育L-组氨酸产生菌

以一株谷氨酸棒杆菌(Corynebacterium glutamicum)S6为出发菌株,利用氯化锂、紫外线进行诱变,通过实验证明氯化锂诱变剂量在1.2%时致死率达到82.4%,紫外线在照射30 s时致死率达到81.8%.利用氯化锂诱变谷氨酸棒杆菌S6,所得菌株D3的L-组氨酸产量为243 mg/L,比出发菌株提高10.5%;以紫外线做诱变S6,所得高产菌株U1产量256 mg/L,比出发菌株提高8.5%;以紫外线、氯化锂复合诱变S6,所得菌株N1产量为251 mg/L,比出发菌株提高13.6%,结果显示,经紫外线与氯化锂复合诱变后的菌株N1产L-组氨酸的产量最高,比氯化锂诱变后的菌株产L-组氨酸量提高3.1%,比紫外线诱变后的菌株产L-组氨酸量提高5.1%.     

高产谷胱甘肽酵母菌的选育

从自然环境土壤样本中分离筛选出一株谷胱甘肽(GSH)产量为35.4mg/LGSH的酵母菌株Y51;经紫外线诱变、亚硝基胍诱变后,分别用乙硫氨酸、氯化锌和三氮锉三种抗性平板进行抗性筛选,得到一株GSH高产菌株Y51-21-15;对该菌株摇瓶发酵生产GSH的工艺条件进行优化后,菌株Y51-21-15产GSH量达158.4 mg/L,较出发菌株提高3.5倍。     

高菊粉酶活酿酒酵母的诱变选育

以安琪酿酒酵母为出发菌株,采用紫外与微波2种物理诱变方法进行复合诱变.经过初筛与复筛,选育出了高菊粉酶活突变菌株Y05,其酶活达到90.97U/mL,约为出发菌株的8倍.经多次传代证明该菌株遗传稳定性良好.当培养基中菊粉浓度200g/L时,经30℃72h发酵突变菌株Y05发酵液乙醇浓度为71.78g/L,乙醇得率为0.43g/g,分别比出发菌株提高了42.5%和13.2%.     

紫外线和He—Ne激光诱变产植酸酶黑曲霉菌株的研究

采用He—Ne激光（波长632nm,功率10mW）和紫外线对植酸酶产生茵黑曲霉Px的孢子和原生质体进行诱变。结果表明：原生质体对紫外线诱变的耐受能力比孢子强,而对He—Ne激光诱变的耐受能力比孢子弱。经诱变后筛选出一株突变菌株L2—2,植酸酶产量为9274IU／mL,是出发菌株的1．51倍,传代实验表明该菌株植酸酶产量稳定。     

紫外诱变选育米曲霉氨肽酶高产菌株

以米曲霉CICC2066菌株为出发菌株进行紫外诱变,经过多次筛选后得到3株氨肽酶活力显著提高且遗传性较稳定的诱变株UY-15,UY-17和UY-20。将3株诱变株与出发菌株进行发酵实验性能比较,结果表明:米曲霉UY-15,UY-17和UY-20培养42h后制曲中氨肽酶活力分别是出发菌株的1.24,1.38,1.54倍,且UY-20中性蛋白酶活力较出发菌株提高了7%。3株诱变株的孢子量较出发菌株具有优势。     

GABA高产菌株的筛选、鉴定及诱变选育

从火龙果果实表面上筛选出一株发酵产γ-氨基丁酸(GABA)白色菌株,经形态学观察、生理生化试验和18S rDNA测序分析,鉴定为假丝酵母菌菌株(Candida.sp),命名为C2。C2作为出发菌株,分别采用紫外线(UV)和亚硝基胍(NTG)诱变方法选育高产γ-氨基丁酸菌株。与出发菌株相比,紫外诱变菌株γ-氨基丁酸产量增加了40.25%,亚硝基胍诱变菌株γ-氨基丁酸产量增加了62.83%。通过紫外线和亚硝基胍复合诱变,得到正向突变株,其中Y6突变株遗传性状稳定,γ-氨基丁酸产量达2.561 g/L,产量比诱变前提高了3.1倍。     

富硒酵母的诱变及突变株的筛选研究

以实验室冷藏的从馒头酵子中提取的馒头酵母作为出发菌株,把有机硒的含量作为筛选的指标,在诱变过程中,采用紫外线进行物理诱变和硫酸二乙酯(DES)进行化学诱变,诱变的菌种用10倍梯度稀释法稀释至10-5,取10-3,10-4和10-5涂平板,每个梯度涂3个平板,记录平板上的菌落数,并计算致死率。选用物理诱变和化学诱变的最佳致死率作为复合诱变的试验条件。通过初筛,从而选出较强的菌株12株,编号为Y1~Y12,接下来测定烘干的酵母生物量以及有机硒的含量,选育出一株生物量和富硒能力都最高的菌株Y9,该菌株的生物量为12.91 g/L,硒的含量为879μg/g,此菌株硒的含量比原始菌株提高了1.5倍,生物量比原来提高了39%。对Y9菌株连续传代三次,原菌株与三次传代菌株一起发酵培养,用吸光光度法测定有机硒的含量,通过吸光度的比较,得出硒的含量分别为875,869,870和872μg/g,硒的含量没有明显的变化,说明菌株没有发生回复突变,具有一定的稳定性。     

利用离子注入技术选育碱性几丁质酶高产菌种

采用离子注入技术对灰褐链霉菌S1001进行诱变、筛选,选出了突变株EⅢ11.结果表明,突变株EⅢ11产生碱性几丁质酶能力为16.5 U/mL,比出发菌株提高了5倍多;从整体上看,离子注入技术对灰褐链霉菌S1001的诱变效果较好.     

富产琥珀酸米曲霉菌株的诱变选育

以米曲霉AS3.042为出发菌株,经过紫外线诱变后选育出一支琥珀酸产量高的菌株AS-4。以AS-4为出发菌株,采用亚硝基胍诱变后得到一支富产琥珀酸米曲霉诱变菌株ASC-5。该菌株经摇床培养后,琥珀酸产量达到3.60 g/L,相同条件下为出发菌株的371倍,为单用紫外线诱变后的菌株AS-4的13.43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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.