乙醛在小鼠酒依赖性行为中的作用研究

乙醛为酒精代谢的中间产物,但其在酒依赖中的作用不清楚.通过条件化位置偏好(CPP)和条件化味觉偏好(CTP)试验,分析乙醛对小鼠乙醇依赖性行为的影响,研究乙醛在酒依赖中的作用.研究发现,经0.8%乙醇预处理7d后,小鼠训练8次则表现出对乙醇的条件化位置偏好(n=6,P<0.01),而经乙醛训练的小鼠则对乙醛无明显条件化偏好行为(n=6,P>0.05).当用0.8%乙醇、0.4%乙醛混合训练乙醇依赖性小鼠时,其位置偏好行为减弱(n=6,P<0.01).10%乙醇预处理的小鼠味觉偏好乙醇(n=6,P<0.01),而当乙醇中加入1%乙醛时,其味觉偏好现象减弱(n=6,P<0.01).1%乙醛训练7d后的小鼠不表现对乙醇的味觉偏好,但选择摄入乙醛及乙醇、乙醛混合溶液的量有所增加.结果表明乙醛在小鼠酒依赖行为中可能存在一定促进作用.     

由柑桔落果提取橙皮甙的工艺改进研究

本文提出了一条从柑桔落果提取橙皮甙的改进工艺.先将柑桔落果粉粹到3—4毫米,加入一定量的水,再用生、熟石灰混合粉调节到pH为11至12,搅拌浸提1.5小时,过滤、酸化、收集固体,最后干燥,就可以得到纯度约为90％的橙皮甙,提取率为8.4％左右.     

先进固态发酵技术生产甜高粱乙醇中试研究

先进固态发酵(advanced solid state fermentation,ASSF)生产甜高粱乙醇技术与传统榨汁发酵技术相比,在生产燃料乙醇方面凸显技术优势,近期有望实现大规模商业化.以系列摇瓶实验和10L 固态发酵罐试验为基础,在内蒙巴市五原县就ASSF 法生产甜高粱乙醇中试获得成功:选取醇甜1 号和2 号甜高粱秆(可发酵糖13%~15%,wt)为原料,单批处理量1.0 ～ 1.5t,以专有高产乙醇TS-Sc-1 酵母菌和5m3 转鼓式固态发酵罐为核心,ASSF法生产燃料乙醇,直接固态发酵与蒸馏后获得30% ～ 40%(体积分数)的粗醇溶液,折算可得99.5% 的无水乙醇70 ～ 100kg,0.07 ～ 0.08g 乙醇/g 发酵料(湿基);糟渣粗蛋白含量7%,可替代"黄储"饲料.ASSF 技术外来水消耗很少,几乎无废水产生.中试结果表明:平均13.5 ～ 15.5t 甜高粱秆产1t99.5% 无水乙醇,发酵时间40 ～ 44h,可发酵糖转化率超过95%,最高97% ;无水乙醇实际收率超过90%,最高94%.     

亚硫酸盐甘蔗渣浆酶解液发酵制备乙醇

以亚硫酸盐甘蔗渣浆酶解液作为原料,利用C. shehatae发酵制取燃料乙醇。结果表明：还原糖最适初始质量浓度为葡萄糖140 g/L、木糖60 g/L、酶解液总糖80 g/L。利用初始葡萄糖55.06 g/L、木糖11.18 g/L、纤维二糖4.51 g/L的亚硫酸盐甘蔗渣浆酶解液发酵,经18 h获得乙醇22.98 g/L。乙醇得率为67.23%,葡萄糖利用率为99.27%,木糖利用率为32.96%,C. shehatae适合作为蔗渣为原料的乙醇发酵菌株。     

吸附柱层析法制备纯化茶多酚中EGCG单体

以茶多酚为原料,采用吸附树脂柱层析法制备表没食子儿茶素没食子酸酯(EGCG)单体。考察树脂对儿茶素的吸附容量、吸附率、解吸率及吸附选择因数,选择LX-8树脂初步纯化后采用HP-20树脂二次纯化。经LX-8两步柱层析,1.5 BV/h流速洗脱,25%乙醇洗脱组分上柱后经40%乙醇洗脱5 BV可得到纯度为73.06%的EGCG产品。以20 mg/mL浓度的LX-8柱40%乙醇产品上HP-20柱,1.5 BV/h洗脱,5%乙醇洗3 BV,15%乙醇洗6 BV,80%乙醇洗3 BV后,可制得纯度为93.16%,总收率为49.50%的EGCG产品。     

用基因组改组技术改良发酵木糖酵母Candida tropicalis XY-19的耐乙醇性能

Candida tropicalis XY-19是一株具有优良乙醇发酵性能的发酵木糖酵母,其发酵葡萄糖产乙醇性能与目前酒精工业生产菌种--安琪酒精酵母相近,但XY-19的耐乙醇性能远比安琪酒精酵母差,XY-19在含有超过7%(v/v)乙醇的培养基中不能生长。以XY-19为出发菌株,经紫外线诱变获得了5株能在7.5%(v/v)乙醇的培养基中旺盛生长的突变株,经Co-60诱变获得了8株能在含8%(v/v)乙醇的培养基中旺盛生长的突变株。然后,以紫外线诱变得到的5株菌和Co-60诱变得到的8株菌及耐乙醇性能较好的酿酒酵母(S.cerevisae Angel,S.cerevisae4608和S.cerevisae172)为出发菌株,经过4轮Genome shuffling结合木糖乙醇梯度平板的筛选,获得了4株(G3-13,G3-18,G3-57和G3-60)能够在12%乙醇平板上生长的菌株,其乙醇耐受性比野生菌株XY-19提高了71%,为将XY-19进一步开发成纤维质乙醇发酵的生产菌种奠定基础。本研究结果进一步体现了Genome shuffling技术在改良如乙醇耐受性等多基因控制性状上的突出优势,为工业生产菌种的快速有效改良提供了一种有效的方法。     

大口黑鲈对六种非粮蛋白源的表观消化率

实验以0.1%三氧化二钇(Y₂O₃)为外源指示剂, 用“70%基础饲料+30%待测饲料原料”的方法配制实验饲料。测定初始体重为(19.28±0.10) g的大口黑鲈(Micropterus salmoides)对荚膜甲基球菌蛋白、乙醇梭菌蛋白、黄粉虫粉、酶解大豆、小球藻和棉籽浓缩蛋白的干物质、蛋白质、脂肪、能量和氨基酸的表观消化率。结果显示, 6种实验原料干物质的表观消化率在37.27%—86.43%(荚膜甲基球菌蛋白>乙醇梭菌蛋白>酶解大豆>黄粉虫粉>小球藻>棉籽浓缩蛋白), 其中荚膜甲基球菌蛋白干物质的表观消化率最高, 乙醇梭菌蛋白次之, 黄粉虫粉、酶解大豆和小球藻之间没有显著性差异, 均显著高于棉籽浓缩蛋白(P<0.05); 蛋白质的表观消化率在79.97%—88.45%(荚膜甲基球菌蛋白>乙醇梭菌蛋白>黄粉虫粉>酶解大豆>小球藻>棉籽浓缩蛋白), 其中荚膜甲基球菌蛋白和乙醇梭菌蛋白均显著高于酶解大豆、小球藻和棉籽浓缩蛋白(P<0.05); 脂肪的表观消化率在51....     

甜菜夜蛾核多角体病毒杀虫剂研究进展

一、利用人工半合成饲料批量饲养甜菜夜蛾从 2 8种不同的人工饲料配方中 ,筛选出一种有利于甜菜夜蛾生长发育的人工饲料。经大批量连续饲养表明 ,该饲料具有饲养效率高、产卵量多和历期短等特点。其中孵化率为 85 %、幼虫存活率 93.3%、幼虫历期 9.5± 2 .1ｄ、化蛹率 92 .6 %、雌蛹重 1 2 1 .2± 1 4.3ｍｇ、雄蛹重1 0 8.6± 1 0 .9ｍｇ、羽化率 1 0 0 %、产卵量 1 45 2 .2粒 /雌、成虫期 (寿命 ) :雌 1 2 .2± 2 .3ｄ、雄 1 1 .0± 2 .8ｄ。经多年连续批量饲养 ,已建立了一套较为成熟的饲养技术 ,平均每人每月饲养幼虫达 1 0 - 1 2万条。…     

沙棘果皮多糖清除氧自由基的活性研究

沙棘(Hippophae rhamnosides)果皮经80℃恒温水浴提取, 乙醇沉淀得粗多糖。Sevag法去蛋白,经50%和70%乙醇分级, 得3种级分沙棘多糖H1、H2和H3; 以Fenton 反应, 即H2O2/Fe2+/水杨酸为.OH产生和检测体系; 以邻苯三酚/EDTA/Tris-HCl为O2 -. 产生体系, 对沙棘多糖H1、H2和H3进行抗氧自由基活 性研究。结果表明, 沙棘多糖对.OH和O2 -. 有较显著的清除能力。不同级分多糖H1、H2和H3浓度达200mg.mL-1时, 对.OH的清除率分别为44.9%、49.0%和26.4%, 抗O2-. 活性分别为36.9%,15.4%和23.1%。多糖质量浓度增大时,两种自由基清除率增加, 且呈量效关系。     

三七中三七素的分离纯化与结构分析

以三七(Panaxnotoginseng)为材料,经醇提、水提,得到三七素粗提物,用乙醇沉淀、正丁醇萃取去除皂苷类成分,经阳离子交换树脂柱层析,得到三七素.三七素经初步纯化含量从4.43%提高到13.98%.经过离子交换树脂柱分离后含量提高到96.46%.通过重结晶得到的无色板状晶体三七素的结构经过红外光谱,核磁共振光谱及质谱加以鉴定。     

Ethanol production from lactose by extractive fermentation

Summary The suitability of extractive fermentation as a technique for the production of ethanol from lactose by Candida pseudotropicalis was examined as a potential improvement over conventional methods. A biocompatible solvent was selected through determination of the critical log P (octanol-water distribution coefficient) of the fermentation organism. Using Adol 85 NF, the selected solvent, extractive fed-batch and conventional fed-batch systems were operated for 160 h. The extractive system showed a 60% improvement in lactose consumption and ethanol production, as well as a 75% higher volumetric productivity.     

Optimization of batch alcoholic fermentation of glucose syrup substrate

The quantitative effects of substrate concentration, yeast concentration, and nutrient supplementation on ethanol content, fermentation time, and ethanol productivity were investigated in a Box–Wilson central composite design experiment, consisting of five levels of each variable, High substrate concentration, up to 30° Brix, resulted in higher ethanol content (i.e., up to 15.7% w/v or 19.6% v/v) but longer fermentation time and hence lower ethanol productivity. Increasing yeast concentration, on the other hand, resulted in shorter fermentation time and higher productivity. The highest ethanol productivity of about 21 g EiOH/L h was obtained at low substrate concentration (i.e., 12° Brix), low alcohol content (i.e., 6% by weight), high yeast concentration (i.e., 4.4%), and high supplementation of yeast extract (i.e., 2.8). Productivity of this magnitude is substantially higher that that of the traditional batch fermentation of fed-batch fermentation. It is comparable to the results of continuous fermentation but lower than those of vacuum fermentation but lower than those of vacuum fermentation. Optimal conditions for maximal ethanol productivity can be established by a multiple regression analysis technique and by plotting the contours of constant response to conform to the constraints of individual operations.     

Optimization of pretreatment and saccharification for the production of bioethanol from water hyacinth by Saccharomyces cerevisiae

Alkaline-oxidative (A/O) pretreatment and enzymatic saccharification were optimized for bioethanol fermentation from water hyacinth by Saccharomyces cerevisiae. Water hyacinth was subjected to A/O pretreatment at various NaOH and H(2)O(2) concentrations and reaction temperatures for the optimization of bioethanol fermentation by S. cerevisiae. The most effective condition for A/O pretreatment was 7% (w/v) NaOH at 100 °C and 2% (w/v) H(2)O(2). The carbohydrate content was analyzed after reaction at various enzyme concentrations and enzyme ratios using Celluclast 1.5 L and Viscozyme L to determine the effective conditions for enzymatic saccharification. After ethanol fermentation using S. cerevisiae KCTC 7928, the concentration of glucose, ethanol and glycerol was analyzed by HPLC using a RI detector. The yield of ethanol in batch fermentation was 0.35 g ethanol/g biomass. Continuous fermentation was carried out at a dilution rate of 0.11 (per h) and the ethanol productivity was 0.77 [g/(l h)].     

Ethanol production by thermotolerant yeast and its UV resistant mutants.

Six thermotolerant yeasts were isolated at 37 degrees C from over-ripe grapes by serial dilution technique using glucose yeast extract medium. Purified yeast cultures were screened for ethanol production at 37 degrees C by batch fermentation, using cane molasses containing 20% sugars. Sugar conversion efficiency of these isolates varied from 66.0 to 88.5% and ethanol productivity from 1.11 to 1.73 ml/l/h. The highest ethanol producing isolate was exposed to UV radiations and 13 mutants were picked up from the UV treatment exhibiting 0.1 to 1.0%, survival. The UV mutants varied in cell size from parent as well as among themselves. Determination of ethanol produced by all the mutants revealed that only five mutants resulted in 4.5 to 6.2% increase in sugar conversion and 8.25 to 18.56% increase in ethanol concentration coupled with maximum ethanol productivity of 2.4 ml/l/h in 48 h of batch fermentation of cane molasses (20% sugars) at 37 degrees C temperature.     

固态间歇补料乙醇生料发酵新工艺

浓醪发酵是酒精生产的发展方向。与现行酒精厂普遍采用的热蒸煮工艺相比, 生料发酵技术的发展使得浓醪发酵更容易进行。本研究首次在生料发酵中直接采用固态原料间歇补料, 比较了STARGENTM生淀粉水解酶间歇补料工艺和传统无补料工艺, 并对不同补料方式进行了研究。结果表明: 与传统无补料生料发酵工艺相比, 在相同的干基配料浓度30%、相同的生料酶添加量0.22%(W/W)的条件下, 采用15%的起始配料浓度、发酵15~25 h进行间歇补料的新工艺, 酒精产量从17.06%提高到18.50%。该间歇补料优化工艺的建立, 丰富了生料发酵技术的应用。     

Impacts of main factors on bioethanol fermentation from stalk juice of sweet sorghum by immobilized Saccharomyces cerevisiae (CICC 1308)

In order to attain a higher ethanol yield and faster ethanol fermentation rate, orthogonal experiments of ethanol fermentation with immobilized yeast from stalk juice of sweet sorghum were carried out in the shaking flasks to investigate the effect of main factors, namely, fermentation temperature, agitation rate, particles stuffing rate and pH on ethanol yield and CO(2) weight loss rate. The range analysis and analysis of variance (ANOVA) were applied for the results of orthogonal experiments. Results showed that the optimal condition for bioethanol fermentation should be A(4)B(3)C(3)D(4), namely, fermentation temperature, agitation rate, particles stuffing rate and pH were 37 degrees C, 200rpm, 25% and 5.0, respectively. The verification experiments were carried out in shaking flasks and 5L bioreactor at the corresponding parameters. The results of verification experiments in the shaking flasks showed that ethanol yield and CO(2) weight loss rate were 98.07% and 1.020gh(-1), respectively. The results of ethanol fermentation in the 5L bioreactor showed that ethanol yield and fermentation time were 93.24% and 11h, respectively. As a result, it could be concluded that the determined optimal condition A(4)B(3)C(3)D(4) was suitable and reasonable for the ethanol fermentation by immobilized Saccharomyces cerevisiae. The conclusion in the research would be beneficial for application of ethanol fermentation by immobilized S. cerevisiae from stalk juice of sweet sorghum.     

IN SITU SEPARATION OF ETHANOL WITH AQUEOUS TWO-PHASE SYSTEM AND ASSESSMENT OF KLa FOR YEAST GROWTH IN BATCH CULTIVATION

In the fermentation process, the separation of product and its purification is the most difficult and exigent task in the ground of biochemical engineering. Another major problem that is encountered in the fermentation is product inhibition, which leads to low conversion and low productivities. Extractive fermentation is a technique that helps in the in situ removal of product and better performance of the fermentation. An aqueous two-phase system was employed for in situ ethanol separation since the technique was biofriendly to the Saccharomyces cerevisiae and the ethanol produced. The two-phase system was obtained with polyethylene glycol 4000 (PEG 4000) and ammonium sulfate in water above critical concentrations, with the desire that the ethanol moves to the top phase while cells rest at the bottom. The overall mass transfer coefficient (K_La) was also estimated for the yeast growth at different rpm. The concentration and yield of ethanol were determined for conventional fermentation to be around 81.3% and for extractive fermentation around 87.5% at the end of the fermentation. Based on observation of both processes, extractive fermentation was found to be the best.     

Tyrosinase inhibitory effects and inhibition mechanisms of nobiletin and hesperidin from citrus peel crude extracts

The inhibitory effects of nobiletin and hesperidin from citrus peel crude extracts on tyrosinase diphenolase activity are evaluated. IC50 of nobiletin and hesperidin is 1.49 mM and 16.08mM, respectively and their inhibition mechanism is competitive type with Ki = 2.82 mM and noncompetitive with Ki = 9.16 mM, respectively. Crude extracts from citrus peel (C. unshiu Marc.) were extracted with 95% ethanol and fractionated by petroleum ether (PCPE). The ethanol phase (ECPE) was further desorbed from macroporous adsorption resin (FGRE). Their IC50 values were 8.09 mg/mL, 7.53 mg/mL and 4.80 mg/mL, respectively. Their inhibition on melanogenesis in B16 mouse melanoma cells was also evaluated. FGRE showed a significant inhibition (42.5% at 31.25 microg/mL, p < 0.01) while hesperidin showed almost no inhibition. Nobiletin and PCPE give efficacious antiproliferation effects on B16 mouse melanoma cell with IC50 values 88.6 microM and 62.96 microg/mL, respectively, by the MTT test. Hesperidin and other crude extracts showed very low cytotoxity to the B16 cell.     

Bioconversion of wheat straw cellulose/hemicellulose to ethanol by Saccharomyces uvarum and Pachysolen tannophilus

The information presented in this publication represents current research findings on the production of glucose and xylose from straw and subsequent direct fermentation of both sugars to ethanol. Agricultural straw was subjected to thermal or alkali pulping prior to enzymatic saccharification. When wheat straw (WS) was treated at 170 degrees C for 30-60 min at a water-to-solids ratio of 7:1, the yield of cellulosic pulp was 70-82%. A sodium hydroxide extration yielded a 60% cellulosic pulp and a hemicellulosic fraction available for fermentation to ethanol. The cellulosic pulps were subjected to cellulase hydrolysis at 55 degrees C for production of sugars to support a 6-C fermentation. Hemicellulose was recovered from the liquor filtrates by acid/alcohol precipitation followed by acid hydrolysis to xylose for fermentation. Subsequent experiments have involved the fermentation of cellulosic and hemicelluosic hydrolysates to ethanol. Apparently these fermentations were inhibited by substances introduced by thermal and alkali treatment of the straws, because ethanol efficiencies of only 40-60% were achieved. Xylose from hydrolysis of wheat straw pentosans supported an ethanol fermentation by Pachysolen tannophilus strain NRRL 2460. This unusual yeast is capable of producing ethanol from both glucose and xylose. Ethanol yields were not maximal due to deleterious substances in the WS hydrolysates.     

Highly efficient bioethanol production by a Saccharomyces cerevisiae strain with multiple stress tolerance to high temperature, acid and ethanol

Use of super strains exhibiting tolerance to high temperature, acidity and ethanol is a promising way to make ethanol production economically feasible. We describe here the breeding and performance of such a multiple-tolerant strain of Saccharomyces cerevisiae generated by a spore-to-cell hybridization technique without recombinant DNA technology. A heterothallic strain showing a high-temperature (41°C) tolerant (Htg(+)) phenotype, a derivative from a strain isolated from nature, was crossed with a homothallic strain displaying high-ethanol productivity (Hep(+)), a stock culture at the Thailand Institute of Scientific and Technological Research. The resultant hybrid TJ14 displayed ability to rapidly utilize glucose, and produced ethanol (46.6g/l) from 10% glucose fermentation medium at high temperature (41°C). Not only ethanol productivity at 41°C but also acid tolerance (Acd(+)) was improved in TJ14 as compared with its parental strains, enabling TJ14 to grow in liquid medium even at pH 3. TJ14 maintained high ethanol productivity (46.0g/l) from 10% glucose when fermentation was done under multiple-stress conditions (41°C and pH 3.5). Furthermore, when TJ14 was subjected to a repeated-batch fermentation scheme, the growth and ethanol production of TJ14 were maintained at excellent levels over ten cycles of fermentation. Thus, the multiple-stress (Htg(+) Hep(+) Acd(+)) resistant strain TJ14 should be useful for cost-effective bioethanol production under high-temperature and acidic conditions.