不同pH糖液中发酵产品的积累情况

苏联酒精厂采用单流加法，双流加法或经过改进的其它连续发酵方法，从糖蜜的精液中制取酒精。研究证明：用单流加发酵法制成的发酵成熟醪中，含有的挥发酸、酯类、醛类、甘油和未发酵的糖都比采用双流加发酵法的多，从而使单流连续发酵法的每吨淀粉，糖蜜生成的粗酒精得率降低1.0—1.5％。本文将介绍糖液pH值影响发酵产品的积累、酵母细胞数量和质量，以及糖酵解酶活性的科研成果。     

固定化活酵母连续发酵生产糖蜜酒精

固定化活酵母连续发酵生产糖蜜酒精李起斌广西平南糖厂（５３７３００）关键词酒精，固定化酵母，连续发酵，糖蜜酒精我厂是日榨甘蔗２０００吨的碳酸法中型糖厂，附设日产酒精２万升的酒精车间。酒精车间发酵工段有发酵罐１１个，１～２＃罐每个容量６０ｍ￣３，３～１１...     

高浓度糖蜜快速热澄清发酵酒精技术的研究

酒精高浓度发酵能够提高发酵醪液含酒分,可以节省酒精蒸馏蒸汽消耗量,减少酒精废醪液排放量,提高设备利用率,日益受到酒精生产企业的重视。目前糖蜜酒精生产发酵含酒分普遍偏低,糖蜜高浓度发酵面临很大困难,笔者认为主要原因是糖蜜中的灰分和胶体等杂质含量不断增高,会抑制酵母的繁殖和发酵,影响糖蜜高浓度发酵酒精。对糖蜜进行澄清处理是实现糖蜜酒精浓醪发酵的快捷途径,通过对糖蜜快速热澄清处理,得到糖蜜高浓度发酵酒精,与传统糖蜜酸化后发酵酒精相比,发酵含酒分明显提高,发酵成熟醪锤度降低。     

糖蜜酒精残液生物发酵效果及水培试验分析

通过糖蜜酒精残液的自然搅拌发酵和添加水解菌剂的生物发酵以及糖蜜酒精残液水培试验,研究了添加1%水解菌剂对糖蜜酒精残液DO值(溶解氧)、p H值和EC值的影响。结果表明,添加生物发酵水解菌剂对糖蜜酒精残液DO值和EC值影响不显著,但可提高糖蜜酒精残液的p H值,同时植物水培试验效果观察发现,和添加新鲜糖蜜酒精残液比较,添加一定比例发酵的糖蜜酒精残液可减轻对植物的毒害作用。上述研究结果可对糖蜜酒精残液的进一步开发研究生产生态型有机液体肥料提供理论支撑。     

酒精生产及蒸馏废液处理新技术

据悉，在传统上，亚洲几乎所有酒厂都采用间歇发酵。大约于１９８５年至１９８６年度，糖蜜连续发酵制酒精这种技术引进印度，后来亚洲其他国家也采用这种技术。现在，光在印度就有５０多家酒厂采用这种技术。 在连续发酵中，用泵把进料连续泵入发酵罐，通过蒸馏，得到酒精。在发酵周期的初始阶段投入酵母，长期连续发酵不用停顿。采用由３～７个发酵罐串联的连续发酵系统，这种系统的第一个罐的酒精浓度约５％～６％（Ｖ／Ｖ），而最后一个罐的酒精浓度较高，约７％～９％（Ｖ／Ｖ）。在这种系统中，若采用粒状酵母，当发酵结束时，可简单…     

不同原料配比制备燃料乙醇的研究

通过用糖蜜按不同比例取代木薯液化醪混合酒精发酵,并与纯木薯液化醪发酵进行对比试验,确定混合发酵的优势以及最佳混合比例,降低酒精发酵生产成本,以期实现燃料乙醇原料结构优化、降低成本的目的。经研究,添加糖蜜混合发酵可促进酒精发酵,在添加量为10%时产酒量最高,比不添加糖蜜酒分增加1.3%左右,但是提高酒精产量的同时,COD也随之升高,提高了污水处理的难度。     

活性干酵母在糖蜜酒精生产中的应用

采用酿酒活性干酵母代替传统方法培养酵母，进行连续发酵生产糖蜜酒精，节省生产工序和汽、电、提高了发酵率。较详细地介绍了酿酒活性干酵母的活化及大生产的情况。生产结果表明，发酵率提高1．04％。     

活性干酵母在糖蜜酒精生产中的应用

采用ＡＡＤＹ代替传统方法培养酵母进行连续发酵生产糖蜜酒精，节省了生产工序和汽、电，提高了发酵率。文章较详细地介绍了ＡＡＤＹ活化及大生产的情况，结果表明，发酵率提高１．０４个百分点。     

活性干酵母在糖蜜酒精生产中的应用

采用酿酒活性干酵母（以下简称AADY）代替传统方法培养酵母进行连续发酵生产糖蜜酒精，节省生产工序和汽、电，提高了发酵率。文章较详细地介绍了AADY活化及大生产的情况，结果表明，发酵率提高1．04％。     

活性干酵母在糖蜜酒精的应用

采用ＡＡＤＹ代替传统方法培养酵母进行连续发酵生产糖蜜酒精节省生产工序和汽、电，提高了发酵率。文章较详细地介绍了ＡＡＤＹ活化及大生产的情况，结果表明，发酵率提高１．０４％。     

糖蜜酒精发酵中专用高效消泡剂的研究

介绍了糖蜜酒精发酵中泡沫产生的原因和常用的消泡剂产品,对自主研发的专用高效消泡剂与其它几种消泡剂在实验室进行了性能对比,并在工厂进行现场应用试验,结果表明该高效消泡剂消、抑泡性能优越,适合在糖蜜酒精发酵过程中使用。     

回用糖蜜酒精废液中砷、铅对酒精发酵的影响

采用双浓度流程利用酵母菌发酵酒精 ,以甘蔗亚硫酸法、碳酸法的糖蜜为原料 ,对其酒精废液中主要的两种有毒元素 Pb、As在发酵过程中的影响进行单因素试验。采用原子吸收分光法测定了糖蜜的 Pb、As含量 ,在此基础上对发酵原料添加不同量的 Pb、As元素 ,考察各元素对发酵产酒的抑制点 ,初步得出各元素对发酵的抑制点为 As3+3mg/L、Pb2 +2 1m g/L。     

甘蔗糖蜜高浓发酵中有机酸对产酒的影响极值研究

以甘蔗糖蜜为原料,利用酵母菌高浓发酵酒精,探索发酵液中的代谢副产物有机酸含量对发酵产酒的影响.在发酵醪液中添加不同量的非氮有机酸,考察其对发酵产酒的影响.初步得出甲酸、乙酸、乳酸添加量对发酵的抑制点为0.15%、0.3%、2.5%,琥珀酸在添加量为3.0%时轻微抑制,添加酒石酸未见有抑制点.     

甘蔗制糖业副产物的综合利用

针对甘蔗制糖过程中副产物的产生及其特点 ,综述了国内外有关蔗渣、滤泥、糖蜜等糖厂副产物综合利用的最新研究进展和研究成果 ,以及糖蜜发酵乙醇后废醪液的治理工艺。     

ISOLATION AND SELECTION OF ETHANOL-RESISTANT AND OSMOTOLERANT YEASTS FROM REGIONAL AGRICULTURAL SOURCES IN MEXICO

In Mexican alcohol distilleries using sugarcane molasses, one reason for low alcoholic fermentation efficiency is the use of inferior yeast cultures. The objective of the present study was to isolate and select yeast strains from alcoholic fermentations of natural sources (sugarcane molasses, grape juice, cane juice and pineapple) from Veracruz city market and Mexican distilleries, and to evaluate their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Ethanol production, glucose composition, growth rate, "Killer" activity, ethanol and glucose tolerance of the most promising strains were monitored on synthetic and molasses media. A total of 112 yeast strains were isolated by their capacity to produce ethanol, and from these, only 58 were selected on the basis of best ethanol theoretical yields (88–96%). These strains were exposed several times to high concentrations of glucose and ethanol in order to select ethanol- and glucose-tolerant yeast; 10 were obtained that adapted best to these conditions and that showed "Killer" activity. Of these strains, U3-11, M11, JC10 and U2-10 (obtained from grape juice, sugarcane molasses and cane juice) demonstrated the highest adaptation to both ethanol (5–7% w/v) and glucose (20% w/v). The maximum yield obtained was 0.46 g/g (90% theoretical yield) in a 20-L bioreactor with cane molasses under nonsterile conditions.

PRACTICAL APPLICATIONS

The selected yeasts could be introduced into industrial processes in Mexican distilleries using sugarcane molasses in order to improve productivity and diminish contamination problems.     

Optimization of bioprocess for production of copper-enriched biomass of industrially important microorganism Saccharomyces cerevisiae

The production of Saccharomyces cerevisiae cells enriched with copper and the effects of adding copper ions to different media on yeast cell growth and ethanol production were studied. In the media Cu(2+) concentrations of up to 0.094 mM had no effect on alcoholic fermentation, whereas higher Cu(2+) concentrations markedly decreased yeast cell growth rate and ethanol production. Under static conditions, the maximum amounts of copper uptake (i.e., 1.16 mg/g, 1.2 mg/g and 0.81 mg/g dry matter yeast biomass for glucose, sucrose and molasses media, respectively) were obtained after 8 h of fermentation, whereas under dynamic conditions smaller amounts of copper uptake (i.e., 0.98 mg/g, 1.02 mg/g and 0.7 mg/g dry matter yeast biomass for glucose, sucrose and molasses media, respectively) were obtained after 6 h of fermentation.     

酵母生产废水用于酒精发酵的研究

将酵母生产废水代替清水用于酒精发酵前的糖蜜稀释,根据出酒率、残糖率2个发酵指标,驯养适于其生长的酿酒酵母菌种甘化Ⅰ号A,其优化发酵条件为培养时间64h、培养基浓度29Brix、营养液0;pH值、温度等不变。此条件下的酵母废水用于正式的酒精工业大生产中被证实可行。     

Utilization of soybean vinasse for α-galactosidase production

The enzyme α-galactosidase was produced by submerged fermentation using as substrate the soybean vinasse, a residue of the alcoholic fermentation of soybean molasses. Soybean molasses is a by-product of the protein-concentrate soybean meal production. The strain Lactobacillus agilis LPB 56 was selected among nine for presenting the highest enzymatic activity. The C:N relation in the vinasse-based inoculum medium was optimized and adjusted in 6 with yeast extract. The effects of soluble solids concentration in the fermentation medium, C:N relation and size of inoculum were investigated. Results demonstrated that the medium concentration of 30% soluble solids, with a C:N relation of 9, and size of inoculum of 25% (v/v) were the best conditions for α-galactosidase production. The highest enzyme activity (11.07 U/mL) was achieved after 144 h of fermentation.     

Isolation and Characterisation of Sri Lankan Yeast Germplasm and Its Evaluation for Alcohol Production

Use of inferior yeast cultures represents one of the reasons for low fermentation efficiencies in Sri Lankan alcohol distilleries that use sugarcane molasses. The present study isolated and characterised yeast strains found in natural environments in Sri Lanka and evaluated their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Yeasts were characterised based on morphological and physiological features such as sugar fermentation and nitrate assimilation. Ethanol production, alcohol tolerance and growth rate of the most promising strains were monitored following laboratory fermentations of molasses. Over a thousand yeast cultures were collected and screened for fermentative activity and a total of 83 yeast isolates were characterised as higher ethanol producers. Most of these belonged to the genus Saccharomyces. Certain strains produced over 10% (v/v) alcohol in molasses media during 72 h laboratory fermentations. Only two strains, SL‐SRI‐C‐102 and 111, showed an appreciable fermentation efficiency of about 90%. The latter strain produced the highest level of ethanol, 11% (v/v) within a 48 h fermentation and exhibited improved alcohol tolerance when compared with the baker's yeast strains currently used in Sri Lankan alcohol distilleries. This study highlights the benefits of exploiting indigenous yeasts for industrial fermentation processes.