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酒糟中超高温耐高酒精度酵母菌株的选育 总被引:8,自引:1,他引:7
从酒糟中选育耐高温及高酒精度的乙醇酵母,对于提高发酵效率、降低生产成本、提升酵母产乙醇的潜力具有重大的工业实用价值.经富集、分离纯化后得到6株具有典型特征的酵母菌,再经紫外诱变及耐高温和耐高浓度乙醇选育得到2株优良酵母P1,5min和P2,10min,两菌株最大耐受酒精度为16%vol,在52℃高温下24h内均出现较好的生长特性,72h内菌落直径达2.3mm,产乙醇能力分别为5.95%和5.83%.较之诱变前和常温发酵相比,两菌株乙醇生产能力均有不同程度的下降,说明酵母酒精耐受能力与乙醇生产能力之间没有严格的相关性. 相似文献
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膜生物反应器用于乙醇连续发酵菌株的适应性培养 总被引:1,自引:1,他引:1
将一种耐高温酿酒干酵母在体积为5L、膜而积为0.08m2的硅橡胶膜生物反应器乙醇连续发酵系统中进行适应性培养,选育出适应该环境的优势菌种.三轮乙醇连续发酵实验的结果表明,糖的转化率差别不大,但单位酵母细胞代谢产生乙醇的能力有了提高,说明酵母细胞在长期封闭循环发酵环境条件下,原种菌经过几百代繁殖后其后代遗传特征发生了改变,能逐渐适应所处的不利环境.表明通过膜生物反应器长期封闭循环发酵对酵母细胞进行适应性培养,可以获得具有某种遗传优势的新菌株. 相似文献
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酵母耐乙醇性状及提高其乙醇耐性的途径 总被引:1,自引:0,他引:1
乙醇是酿酒酵母厌氧发酵的重要工业产物,但对酵母细胞本身在又是毒素和抑制剂,为了进一步提高酒精和啤酒等生产效率和经济效益,浓醪高乙醇发酵是大家是感兴趣并在深入研究的一个生物工程课题,本文仅就其中酵母的乙醇耐受性定义和检测,酵母乙醇耐受性生理基础及提高酵母乙醇耐受性途径作一些介绍和论述。 相似文献
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采用平板分离法,从29 份新鲜采集的土样中分离获得64 株耐高温酵母菌株,并对其在高温条件下的乙醇发酵性能进行了分析比较。26S rDNA D1/D2区域序列测定和生理特征分析结果表明,这些酵母菌株在亲缘关系上可归类于6 个属7 个种,分别为热带假丝酵母(Candida tropicalis)(占总分离株的39.1%)、马克斯克鲁维酵母(Kluyveromyces marxianus)(占23.4%)、东方伊萨酵母(Issatchenkia orientalis)(占29.7%)、季也蒙毕赤酵母(M. guilliermondii)(占1.6%)、Kazachstania bovina(占1.6%)、Candida palmioleophila(占1.6%)和酿酒酵母(Saccharomyces cerevisiae)(占3.1%)。其中,马克斯克鲁维酵母的耐高温能力和乙醇发酵能力最强;40 ℃条件下发酵72 h后,发酵液中乙醇体积分数最高可达6.56%,显著高于相同条件下其他耐高温酵母的乙醇产量。上述结果表明,马克斯克鲁维酵母在高温乙醇发酵过程中具有明显优势,可作为利用生物质发酵生产乙醇的优良候选菌株。 相似文献
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利用选育的耐酸耐高温酵母Q-10,采用甜高粱秸秆固态发酵生产燃料乙醇.当接种量为5%,发酵温度34℃,发酵起始pH4.0,糖化酶和纤维素酶用量分别为50U/g原料和20U/g原料,发酵周期4d时,乙醇体积分数达到6.5%.小试试验乙醇体积分数达到6.4%.工业试验乙醇体积分数达到6.0%. 相似文献
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Raphaël Ducommun Marie‐France Favre Delphine Carrard Fabian Fischer 《Yeast (Chichester, England)》2010,27(3):139-148
A Janus head‐like bi‐cathodic microbial fuel cell was constructed to monitor the electron transfer from Saccharomyces cerevisiae to a woven carbon anode. The experiments were conducted during an ethanol cultivation of 170 g/l glucose in the presence and absence of yeast‐peptone medium. First, using a basic fuel‐cell type activity sensor, it was shown that yeast‐peptone medium contains electroactive compounds. For this purpose, 1% solutions of soy peptone and yeast extract were subjected to oxidative conditions, using a microbial fuel cell set‐up corresponding to a typical galvanic cell, consisting of culture medium in the anodic half‐cell and 0.5 M K3Fe(CN)6 in the cathodic half‐cell. Second, using a bi‐cathodic microbial fuel cell, it was shown that electrons were transferred from yeast cells to the carbon anode. The participation of electroactive compounds in the electron transport was separated as background current. This result was verified by applying medium‐free conditions, where only glucose was fed, confirming that electrons are transferred from yeast cells to the woven carbon anode. Knowledge about the electron transfer through the cell membrane is of importance in amperometric online monitoring of yeast fermentations and for electricity production with microbial fuel cells. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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低能N~+离子注入谷氨酸产生菌诱变选育初步研究 总被引:13,自引:0,他引:13
离子束生物工程技术作为一种全新的诱变育种技术广泛地应用于生物育种方面。文中采用低能N+ 离子注入技术 ,进行了诱变选育高产谷氨酸菌种的试验研究。通过研究已经初筛到 2株高产菌株D52 2 1 和B32 6 3,比出发菌产酸分别提高 3 5 48%和 2 5 %。D52 2 1 的摇瓶最高产酸可以达到 8 8%。它们的一级种子生长曲线和发酵过程的pH值比原出发菌有明显变化。注入后的筛选菌株发酵对数期平均提前 2~ 3h ,代谢活力大大增强 ,倍增时间缩短 ,对缩短发酵周期有促进作用 相似文献
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甘蔗生产燃料乙醇的发展现状及前景展望 总被引:1,自引:0,他引:1
甘蔗是C4作物,其光能转换效率、光合速率、单位面积生物产量显著高于其他作物,其净能比最高。用甘蔗生产燃料乙醇,成本低。甘蔗是最有潜力的生物能源作物,但是我国发展生物能源必须重视能源甘蔗品种的选育,加强甘蔗燃料乙醇生产工艺的研究与开发。利用甘蔗发展燃料乙醇产业具有广阔的前景。分析了我国利用甘蔗发展可再生生物能源的必要性及可行性。 相似文献
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<正> 花生四烯酸简介 1.什么是花生四烯酸 花生四烯酸(Arachidonic acid,简称AA),属n-6系列多不饱和脂肪酸(PUFAs),其化学结构为5,8,11,14-二十碳四烯酸,是哺乳动物体内含量最丰富、分布最广的一种多不饱和脂肪酸。AA主要存在于哺乳动物的器官、肌肉和血液中,尤其是在脑和神经组织中,AA含量一般占总PUFAs的40%-50%。在视网膜中AA和DHA是含量最丰富的两种长链多不饱和脂肪酸,如缺乏则会使动物的视网膜和视觉功能受损。 相似文献
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Kenneth A. Leiper Cornelia Schlee Ian Tebble Graham G. Stewart 《Journal of the Institute of Brewing》2006,112(2):122-133
Fermentation of sugar or starch‐containing substrates by yeast to produce ethanol for use as a liquid fuel has been an accepted technology for many years. Currently, the most popular substrates are sugar cane molasses and starch from maize or wheat. Interest in renewable liquid fuels is growing and other substrates are now being considered, choice of these depends on local conditions. This paper presents findings from work carried out on syrup from sugar beet, an ideal crop for cultivation in the United Kingdom and parts of Europe. Fermentation of this substrate was found to be successful. The process of backsetting was investigated as a way of reducing water usage and effluent disposal. This was found to have no effect on ethanol production provided compensation was made for increases in gravity caused by glycerol levels. Backsetting was also found to be beneficial to yeast growth. As yeast remain in the fermented substrate, the effect of distillation on yeast cells was also investigated. It was found that dead yeast cells are present in backset and thus persist into subsequent fermentations. This can cause difficulties in viability measurement if the methylene blue method is used. 相似文献