发酵木糖酵母菌株的选育

本文介绍了发酵木糖产酒精酵母菌种的筛选方法并利用该方法筛选出一株性能优良的发酵木糖产酒精酵母菌株Zs。该菌株性能测试结果为：发酵木糖产乙醇能力相当于理论产量的60．0％；发酵葡萄糖浓度为8％的发酵液，乙醇转化率为0.388g/g；最低乙醇抑制浓度14％（v/v)；在温度高达42℃的条件下仍能正常生长。并初步鉴定该菌株为奥默毕赤氏酵母（Pichia ahmeri)。     

TTC在发酵木糖高产乙醇的休哈塔假丝酵母选育中的应用

TTC可以作为筛选发酵葡萄糖产酒精能力强的酵母茵的显色剂,但发酵木糖产乙醇的酵母茵的代谢和发酵途径与之相比都有所不同,本实验用TTC作为初筛显色剂筛选发酵木糖产酒精能力较强的休哈塔假丝酵母.紫外诱变后从TTC平板上挑取显红色菌株150株进行摇瓶发酵测定乙醇产量,得到的正突变率为29%,负突变率为10%;挑取显白色菌株100株,得到的正突变率为0,负突变率为56%.将紫外诱变后产量已经有所提高的突变株S28进行氮离子注入诱变,从TTC平板上挑取显红色菌株100株进行摇瓶发酵测定乙醇产量,得到的正突变率为20.05%,负突变率为10.14%,其中的部分突变株的产量相比S28又有所提高.可见TTC能将乙醇产量较低的菌株淘汰,筛选出乙醇产量高的休哈塔假丝酵母菌.     

Candida shehatae 的纯化及其利用木糖和葡萄糖发酵的特性研究

通过对休哈塔假丝酵母TZ1 分离纯化以获取高产乙醇菌株,并对木糖、葡萄糖以及不同比例的混合糖发酵产乙醇进行实验研究。结果显示,筛选出的TZ8-13 对木糖和葡萄糖都有良好的发酵性能,糖浓度为60g/L 时的乙醇产量分别达到了21.6g/L 和24.2g/L,糖利用率分别为97.81%(72h)和99.13%(36h),较初始菌株TZ1 发酵木糖乙醇产量提高了55.38%、木糖利用率提高了19.54%;混合糖发酵存在糖的二次利用关系,TZ8-13 首先利用葡萄糖。木糖和葡萄糖比为1:1 时乙醇产量为22.8g/L。     

多耐性酒精酵母菌的选育及特性研究

以酿酒酵母spc1,Y14,S16为出发菌株,经紫外线诱变和筛选,获得了3株对温度、乙醇浓度、pH耐性有所提高的正向突变株UVs,UV14,UV16;以这些菌株为出发菌株,进行三轮原生质体融合,最终获得了能耐受48℃,19%vol乙醇浓度和耐酸(pH 2.6)的酵母菌TY33.该突变株对温度和耐酒精能力分别提高了17.1%和58.3%.该菌株在35℃下发酵72h酒精产量为101.58g/L,比出发菌株spc1在35℃发酵液中最高乙醇浓度83.82g/L提高了21.1%.     

多样品耐高温产乙醇酵母的筛选及生长特性研究

从未经蒸煮的压滤酒糟、蒸煮酒糟、菜园土壤以及家用面头等4种样品中,经菌种富集、纯化、耐酒精和耐高温的驯化以及发酵产气和产乙醇能力的比较,选育出一株耐性优良的高产菌株LZ2.该菌株的最低乙醇致死浓度为22%(v/v),37～40℃生长良好,在10°麦汁的初步发酵研究中,40℃条件下发酵5d,最终乙醇浓度为5.21%(v/v),发酵液中残还原糖和总糖浓度分别为12.751mg/mL和32.758mg/mL.该菌的成功选育为酵母菌实际利用稻草粉的同步糖化发酵提供了菌种来源.     

耐高温酵母的筛选鉴定及发酵性能的初步研究

为获得耐高温酵母菌,从白酒糟醅中分离筛选出1株在45℃生长良好且产乙醇能力较高的酵母菌株.经ITS和26S rDNAD1/D2区域序列分析比对,结合菌落菌体形态鉴定其为库德毕赤酵母.其最适生长温度为30℃,与安琪酵母相比较,高温条件下生长优势明显.以浓度为10％ (w/v)的葡萄糖为底物,在45℃进行静置发酵,其产乙醇浓度为18.74g/L,安琪酵母产乙醇浓度为11.40g/L,该菌株较安琪酵母表现出明显的优势.     

发酵木糖高产乙醇休哈塔假丝酵母突变株的选育

木糖的乙醇发酵是利用木质纤维原料生产乙醇的关键环节。休哈塔假丝酵母是木糖发酵性能较好的天然酵母之一。研究中对Candida shehatae CICC1766进行了紫外诱变和离子注入诱变,力求选育出发酵木糖产乙醇能力强的假丝酵母。先将其进行紫外诱变,得到的突变株S28在木糖添加量为60g/L的条件下乙醇产量为2364g/L,相比原始菌株提高1498%,乙醇得率达到0394g/g(乙醇/木糖)。再对S28进行氮离子注入诱变,得到的突变株SY58乙醇产量为2508g/L,相比S28提高609%,乙醇得率为0418g/g(乙醇/木糖),达到理论得率的908%。进而对SY58菌株进行了5L罐发酵实验,乙醇产量达到2504g/L,得率为0417g/g(乙醇/木糖),同摇瓶发酵结果基本相同,并且发酵时间由原来的72h缩短到52h。     

青海东部野生酵母菌株抗性及发酵特性研究

以分离自青海的97株野生酵母菌株为材料,通过杜氏管发酵法初筛出35株发酵力强、有香味的酵母菌株,对其抗性和发酵特性进行研究.结果表明,35株酵母菌对SO2具有高度的抗性,大部分菌株在SO2浓度为600 mg/L时仍可正常生长并发酵;有7株耐NaCl高达120.0g/L,菌株QXN2在160.0 g/L的浓度下仍可正常生长并发酵;但大多数菌株的酒精耐受力弱,仅有6株可耐12%vol的乙醇,但已不能发酵产气;部分酵母菌株的耐温性较高,如菌株QHL4、QXS1、QJD12可耐受55℃高温;pH耐受范围在2.5～12.0之间,大部分菌株可在600 g/L的葡萄糖溶液中生长,其中9株仍可发酵产气.这9株发酵力较好且产香酵母的酒精发酵结果表明,4株产酒精度为0,具有浓郁的芳香;4株产酒度在2.1%vol～2.4%vol之间,且残糖较低,有浓郁果香.优良酵母菌株有望应用于面包生产、无醇饮料的开发、工业废水处理等领域.     

发酵木糖产酒精酵母菌的初步研究

采用稀释平板法及划线分离法从自然环境中筛选获得120株形态特征不尽相同的酵母菌,然后通过发酵木糖、葡萄糖试验获得6株能利用木糖为唯一碳源生长的酵母菌株,其中有1株分解木糖产乙醇能力较佳,其发酵条件为:96r/min摇瓶发酵、温度为30℃、木糖浓度为3.0%时木糖转化率最高达7.1%。     

黑麦草纤维发酵产乙醇菌种的筛选及特性研究

从酒渣、土壤和酵母粉3种样品中筛选出可利用黑麦草纤维发酵生产乙醇的菌种。试验利用梯度法和划线分离法从3种样品中筛选出18株酵母菌,其中有3菌株可高效利用木糖,通过理化分析及预发酵试验,确定其中的Rr菌株最适合黑麦草纤维的发酵;并对其耐受性的研究表明,其pH值耐受范围为3.3~5.2、最佳木糖浓度为0.02g/mL、耐受NaCl浓度范围为0.00~0.04g/mL、耐受乙醇浓度为0%vol~4%vol。     

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.