产紫红色素红曲霉菌的筛选及生物学特性研究

通过对获得的5株红曲霉菌株的生物学特性进行研究,选出了一株生长速度快、产桔霉素低、产色能力强且为紫红色的优良菌株M2。并进一步应用单因素试验对其研究发现,该菌株最适生长条件为:温度35℃,初始pH值为4.0,而产色素的最适温度为30℃,初始pH值为5.0。该试验结果还表明,培养基中有乙醇的存在对红曲霉菌M2的生长和产色素能力均有很强的抑制作用。     

耐高温α-淀粉酶产生菌的选育研究

从土壤中分离到1株能在55℃生长并分泌耐高温α-淀粉酶的菌株,其最适生长pH值为7．0-8．0,最适生长温度50℃。该菌株经初步鉴定为芽孢杆菌,疑似微地衣芽孢杆菌,命名为DG-1。对该菌株分泌的耐高温α-淀粉酶的性质研究表明,最适作用pH值为7．0,在pH6．0-7．5的范围内有较高酶活。最适反应温度为95℃,95℃保温60min处理后酶活仅损失4．73％。经紫外线诱变处理,得到菌株DG-4,酶活较出发菌株提高了104．6％。     

一株产酸性α-淀粉酶产生菌的分离鉴定及所产酶学特性的初步研究

从食醋厂内土壤中分离得到一株产酸性α-淀粉酶能力较强的菌株,通过形态学和ITS区基因序列分析的手段对其进行鉴定,对其生长温度及发酵液初始p H值等生物学特性进行分析,并对其所产酶的特性进行研究,研究结果表明:通过形态学及分子生物学鉴定为黑曲霉,并命名为Aspergillus niger ZTL;菌株最适生长温度为35℃;最适产酶温度为40℃;最适生长p H值为6.0,最适产酶p H值为5.0;所产α-淀粉酶在p H值4.5~7.0时酶活性保持在80%以上;该酶的最适作用温度范围是40~50℃;通过测定该酶的热稳定性表明,在40~50℃时酶较稳定,但在60℃时保温一段时间后,酶稳定性显著下降;Ca2+对该酶有一定的激活作用,Na+对该酶的活性作用不明显,而Mg2+、Fe2+和Cu2+对酶的活性均有比较明显的抑制作用;该酶的Km值为4.52×10-3g/L。从而确定该菌株所产的α-淀粉酶具有具有很大的开发价值。     

中度嗜盐菌产α-淀粉酶发酵条件优化和酶活性质研究

实验室从新疆盐湖分离得到1株产α-淀粉酶中度嗜盐菌Bacillus sp.XJ1-05,对该菌株进行发酵条件优化和酶活性质研究,发现该菌株适宜的液态发酵工艺条件为:培养摹碳源为酵母浸粉,氮源为大豆分离蛋白,两者比例1:1,培养温度33~C,发酵时间72h,初始pH值7.0.最大酶活为98U,最佳反应温度为75℃,pH值为6.0～9.0.     

一株α-淀粉酶产生菌的分离、鉴定及产酶条件研究

为获得具有高产α-淀粉酶能力的菌株,从不同土壤环境中分离产酶菌株,对其进行分类鉴定和产酶条件研究。通过透明圈法初筛、3,5-二硝基水杨酸(3,5-dinitrosalicylic acid,DNS)法复筛分离得到产α-淀粉酶能力较强的菌株,利用形态学和生理生化反应特征,结合16S rDNA序列分析,对其进行分类鉴定;通过单因素试验和正交试验确定该菌株的最佳产酶条件。结果表明:从土壤环境中分离得到一株产α-淀粉酶菌株MF04,初步鉴定为蜡状芽胞杆菌(Bacillus cereus),其初始产酶活力为32.5 U/mL;产酶条件试验结果显示其最适培养温度为37℃,初始pH值为6.0,培养时间为72 h,经优化后液体发酵得到的粗酶液酶活力为60.2 U/mL,是优化前的85.2%。因此分离得到菌株MF04在工业生产中具备潜在开发价值。     

酸性α-淀粉酶生产菌株的筛选及酶学性质研究

从土壤中筛选到一株产酸性α-淀粉酶的野生菌株N7,此菌株具有较高的产酶活性。通过菌落形态、菌体特征观察和16SrDNA序列比对,鉴定该菌株为枯草芽孢杆菌。其酶学性质研究表明,菌株代谢产酶的反应最适温度为53℃,最适作用pH值为4．6,在pH3．0～10．0之间,具有较好的酸稳定性。     

酒曲中产香霉菌的筛选及其培养条件优化

通过初筛、复筛对从大曲、小曲及麸曲等酒曲中筛选得到的25株霉菌进行产香能力研究,筛选出产香能力强的菌株并对其生长条件进行优化。研究结果发现,霉菌M23产香能力最强,总酯含量达到1.765 g/L;霉菌M23的最佳生长条件为温度30℃、初始p H值6.0、耗氧量150 r/min,此条件下菌丝体干重达到6.25 g/L,其中,培养温度和耗氧量对霉菌M23的生长具有显著性影响(P<0.05),初始pH值对其生长具有极显著性影响(P<0.01)。     

耐高温α-淀粉酶产生菌的分离鉴定及发酵条件与酶性质研究

从西藏八宿温泉附近土壤中 ,分离到一株能在 5 .5℃生长并分泌高温α- 淀粉酶的菌株 ,其生长pH 5 . 0～11. 0 ,最适生长pH 7. 0～ 8. 0。该菌株经初步鉴定为地衣芽孢杆菌 ,命名为BacilluslicheniformisZ - 8。在 4 5℃ ,10 %装液量 ,16. 0r/min条件下振荡培养 4 8h后 ,发酵液酶活可达 2 1. 2× 10 .4UV/mL。发酵培养基的组成成分为黄豆粉 0 . 5 %、麸皮 1%、可溶性淀粉 0 . 2 5 %、pH 8. 8。对该酶的性质研究表明 ,其最适作用pH为 6 . 0 ,最适反应温度为 95℃ ,95℃下保温 6 0min处理后酶活仅损失 5 . 4 % ,对Ca2 + 没有依赖性。     

泡菜汁中乳酸菌优良菌株筛选及生长与发酵特性研究

从自然发酵泡菜汁中分离筛选乳酸菌优良菌株,并对其生长与发酵特性进行研究.从分离到的13株乳杆菌中筛选出11株产乳酸菌株,通过测定菌液OD值、pH值和亚硝酸盐降解率,筛选出2株生长速度快、发酵活力高、亚硝酸盐降解能力强的优良菌株;通过测定不同初始pH、不同培养温度、不同盐浓度下的菌液OD值和总酸度,得2株优良菌株最佳生长和产酸条件.试验可为纯菌种泡菜发酵剂的研究奠定理论基础.     

耐酸性α-淀粉酶产生菌株的筛选及其液态发酵条件研究

从富含淀粉质的土壤中筛选到1株耐酸性α-淀粉酶的产生菌株ZY8,经初步鉴定为黑曲霉。并对其液态发酵条件进行了研究,产酶适宜培养基为可溶性淀粉50g/L,柠檬酸氢二铵20g/L,KH2PO43g/L,CaCl20.1g/LF,eSO4.7H2O0.01g/L,MgSO4.7H2O1g/L。以2%的接种量在30℃、120r/min、初始pH4.0的条件下培养72h,酶活力达到19.86U/mL。酶学特性研究表明,该耐酸性-α淀粉酶最适反应温度为70℃,最适反应pH值为2.0～5.0,在90℃高温处理20min酶活力仍然保持在80%以上。     

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.