黑曲霉XSY0607以纤维素为原料发酵生产柠檬酸培养基优化研究

通过对黑曲霉(Aspergillus niger)XSY0607液体深层发酵柠檬酸的培养基优化实验,得出如下结论:通因实验得出黑曲霉XSY0607发酵柠檬酸的最佳碳源为水稻秸秆、最佳有机氮源为蛋白胨、最佳无机氮源NH4NO3、最佳生长因子为牛肉膏。通过Plackett-Burman实验设计得到黑曲霉XSY0607发酵柠檬素的最佳培养基配方为:水稻秸秆粉6%、蛋白胨4.5%、NH4NO30.5%、牛肉膏0.75%、KH2PO40.15%、Mg SO40.045%和Fe SO4·7H2O 0.0015%。同时通过极差分析还可得出黑曲霉XSY0607发酵培养基中不同成分对柠檬酸发酵的影响顺序为水稻秸秆蛋白胨NH4NO3KH2PO4Mg SO4Fe SO4·7H2O牛肉膏。使用优化后的培养基进行柠檬酸发酵实验,柠檬酸产量为83.6mg/m L,较优化前产量提高了31.83%。     

黑曲霉XSY0607生产柠檬酸培养基优化研究

通过对黑曲霉(Aspergillus niger)XSY0607液体深层发酵柠檬酸的培养基优化试验:通因试验得出黑曲霉XSY0607发酵柠檬酸的最佳碳源为水稻秸秆、最佳有机氮源为蛋白胨、得出如下结论最佳无机氮源NH4NO3、最佳生长因子为牛肉膏。通过Plackett-Burman试验设计得到黑曲霉XSY0607发酵柠檬素的最佳培养基配方为(%):水稻秸秆粉6%、蛋白胨4.5%、NH4NO 30.5%、牛肉膏0.75%、KH2PO4 0.15%、Mg SO44.5×10-3和Fe SO4·7H2O 1.5×10-5。同时通过极差分析还可得出黑曲霉XSY0607发酵培养基中不同成分对柠檬酸发酵的影响顺序为水稻秸秆蛋白胨NH4NO3KH2PO4Mg SO4Fe SO4·7H2O牛肉膏。     

谷氨酰胺转氨酶菌株的筛选及其产酶条件研究

利用蛋白质交联-絮凝沉淀性能测定方法,从土壤中分离得到1株高产谷氨酰胺转氨酶(microbial transglutaminase,MTG)的菌株,命名为HF-82,初步确定为链霉菌属。单因素试验确定最适产酶氮源和碳源分别是蛋白胨和葡萄糖,正交试验确定最适发酵培养基为(g/L):葡萄糖25.0,蛋白胨20.0,酵母提取物5.0,Mg SO4·7 H2O 2.0,K2HPO4·3 H2O 2.0,Na H2PO42.0,Ca CO33.0,p H7.0。此发酵工艺条件下,MTG的酶活可达到0.53 U/m L。     

产海藻糖合酶菌株发酵培养基的研究

在已筛选出产海藻糖合酶菌株———恶臭假单胞杆菌的基础上 ,研究了该菌株最佳发酵培养基。恶臭假单胞杆菌H76的最适碳源为麦芽糖和葡萄糖 ,最适氮源为蛋白胨和酵母粉 ,无机盐为MgSO4 ·7H2 O ;该菌株产酶最佳培养基配方为 :麦芽糖 3 % ,葡萄糖 3 % ,Mg SO4 7H2 O 0 2 % ,蛋白胨 2 % ,酵母粉 0 7%。     

乳酸乳球菌乳酸亚种T0625菌株产Nisin最佳培养条件的研究

对从大白菜叶片上分离得到的一株乳酸乳球菌乳酸亚种T0625产乳酸链球菌素(Nisin)的适宜培养条件进行了研究.采用单因素分析法首先确定了T0625菌株在改良的M17G培养基中产Nisin的最适碳源、氮源、金属离子的种类,即:碳源为葡萄糖;氮源为蛋白胨、酵母膏和牛肉膏组成的混合氮源;金属离子为Mg2 .并确定了各成分的最适浓度.之后确定了装液量、接种量、起始pH和培养温度的最适指标.最终通过正交试验的方法,确定T0625产Nisin的最佳营养条件:葡萄糖2%、蛋白胨4%、酵母膏2%、牛肉膏1%、MgSO4·7H2O 0.003 mol/L、VC0.05%.T0625产Nisin的最佳发酵条件:装液量250 mL(250 mL三角瓶)、接种量7%、起始pH 6.5、35℃下发酵培养12 h.     

基于胞外多糖和菌丝生物量的香菇发酵培养基优化

为研究液体发酵培养基对香菇胞外多糖和菌丝生物量的影响,以秦巴山区香菇808菌株为试材,采用Plackett-Burman设计实验、最陡爬坡实验和响应曲面法对其液体发酵培养基的碳源、氮源和其它营养物质进行优化。结果表明,香菇胞外多糖发酵培养基的最佳组合是(g/500 m L):蔗糖7.18,玉米粉15.00,麦麸14.05,酵母膏0.35,KH2PO40.50,Mg SO4·7H2O 0.50,p H自然,胞外多糖实测值为0.967 g/500 m L;香菇菌丝生物量发酵培养基的最佳组合是(g/500 m L):蔗糖7.18,玉米粉15.00,麦麸14.05,酵母膏0.35,KH2PO40.75,Mg SO4·7H2O 0.50,p H自然,菌丝生物量实测值为28.146 g/500 m L。优化后的香菇胞外多糖产量和菌丝生物量较优化前分别提高12.44%和11.00%。此研究结果可为香菇液体发酵的中试生产提供理论依据。     

嗜碱性类芽孢杆菌产β-环糊精葡萄糖基转移酶发酵条件的优化

以一株Ε-环状糊精葡萄糖基转移酶高产菌株YR为研究对象,对其发酵条件及酶学特性进行初步研究。对该菌株发酵培养基的碳源、氮源和p H进行单因子分析,并对该3个因素进行正交实验确定该菌的最佳发酵培养基配方为:0.3%马铃薯淀粉,0.5%酵母膏,0.13%K2HPO4?3H2O,0.5%Na2CO3,0.02%Mg SO4?7H2O,p H为9.0。在该条件下,菌株YR产Ε-CGTase的酶活由优化前1620.28U/m L提高到4456.34U/m L,比出发菌酶活提高了2.75倍。     

L-精氨酸产生菌发酵培养基及发酵条件优化的初步研究

本文以钝齿棒杆菌诱变菌为实验菌株,采用摇瓶发酵的方式,研究了培养基组分(碳源、有机氮源、无机氮源及无机盐离子)与发酵培养条件(温度、接种量、初始p H及发酵液体积)对菌种产L-精氨酸的产量的影响。结果表明,该菌产L-精氨酸发酵培养基的最佳组分为:葡萄糖12%、硫酸铵4.5%、玉米浆2.5%、KH2PO40.005%、Mg SO4·7H2O0.01%、Fe Cl3·6H2O 0.01%、Mn SO4·H2O 0.05%及碳酸钙3%;最佳发酵条件是:培养温度为30℃、接种量为10%、初始p H为7.0及装液量为15m L/250m L。该菌以最优结果发酵,L-精氨酸的产量较基本培养基提高27.7%,达到了11.23g/L。     

田口方法优化菌株产菊粉酶的培养条件

鉴定一株从菊芋根际土壤中分离出的产外切型菊粉酶活力较高的菌株C-56。通过16S r DNA序列分析构建系统发育树,初步确定菌株的分类地位,利用单因素实验和田口方法优化培养基配方。实验发现菌株C-56属于伯克霍尔德氏菌属(Burkholderia),单因素实验确定菌株产酶的最佳碳源、氮源、无机盐分别为菊粉、酵母膏、Mg SO4·7H2O。应用田口方法优化菌株的培养基,统计学分析发现菊粉对菌株产酶的影响最大,最佳培养基配方为菊粉50 g/L,酵母浸粉20 g/L,Mg SO4·7H2O 6 g/L,p H6.0。在最佳条件下获得的菊粉酶活力为(29.34±1.95)U/m L,比初始菊粉酶酶活力(6.25±0.84)U/m L提高了3.69倍。     

产纤溶酶菌株粪肠球菌EF608液体发酵工艺优化研究

以本实验室筛选到产纤溶酶的粪肠球菌EF608为发酵菌株,通过研究得到该菌株产纤溶酶的最佳工艺条件为:葡萄糖2%,蛋白胨0.75%,牛肉膏0.75%,酵母提取物0.5%,K2HPO4·3H2O1%,NaCl0.2%,MgSO4·7H2O0.02%,初始pH7.5,接种量为6%,装液量为15%,37℃培养10h,发酵液纤溶酶活性达到1833IU/mL。     

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.     

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.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

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 Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.