真养产碱杆菌WSH3的连续培养动力学研究

以葡萄糖为生长限制性基质,对真养产碱杆菌ＷＳＨ３的连续培养动力学进行了研究。研究结果表明：该菌在稀释率为０．２１ｈ＾－１时,残留菌体浓度达最大值为２６．２ｇ／Ｌ,在稀释率为０．２２５ｈｍ＾１－时,残留菌体的生产强度在到了最大值为５．６９ｇ（Ｌ．ｈ）;残留菌体对基质的产率系数在稀释率为０．２ｈ＾－１时达到最大值为０．５３;     

固定化细胞生产L－苹果酸新工艺及动力学研究

对产氨短杆菌ＭＡ－２固定化细胞在富马酸铵体系中转化生成Ｌ－苹果酸的优化工艺条件做了探讨，结果表明，富马酸铵浓度为１．８ｍｏｌ／Ｌ，ｐＨ７．０～８．０，反应温度为３７℃时，Ｌ－苹果酸得率达２００ｇ／Ｌ左右。同时，对固定化细胞的动力学进行了研究，结果为：ｒ（ｍａｘ）＝５８ｍｍｏｌ／（Ｌ·ｈ·ｇ固定化湿细胞）），Ｋｍ＝６．２５×１Ｏ￣（－２）ｍｏｌ／Ｌ，Ｐ＿ｍ＝１．５６ｍｏｌ／Ｌ     

鱼腥藻 Anabaena sp. PCC7120的混合营养生长

在高光强为１６０μＥ／（ｍ２·ｓ）、低光强为１６μＥ／（ｍ２·ｓ）、葡萄糖浓度０～３０ｇ／Ｌ范围内,、进行了鱼腥藻Ａｎａｂａｅｎａｓｐ．ＰＣＣ７１２０的摇瓶光自养和混合营养培养．在高光强下最大藻细胞密度（０．９２～３．１ｇ／Ｌ）明显高于低光强（０．１１～０．５８ｇ／Ｌ）,而且高光强使混合营养培养的对数期缩短．在不同光强下,葡萄糖浓度在０～１８ｇ／Ｌ范围内提高显著促进了细胞的生长,在１８～３０ｇ／Ｌ范围内变化对细胞生长不再有更大的影响．高光强促进了藻细胞对葡萄糖的利用．在高光强下随着葡萄糖浓度的提高,细胞得率逐渐变小．     

固定化黄色短杆菌生产L－苹果酸新工艺及动力学研究

研究了固定化黄色短杆菌ＭＡ－３在富马酸盐体系中转化生成Ｌ－苹果酸的新工艺，研究结果表明当富马酸铵盐浓度为１．８ｍｏｌ／Ｌ，体系ｐＨ为７．０～８．０，反应温度为３７℃时，Ｌ－苹果酸的得率达２１６ｇ／Ｌ。对固定化黄色短杆菌的动力学研究结果为Ｖｍａｘ＝７６ｍｍｏｌ／［Ｌ·ｈ·ｇ（固定化湿细胞）］，Ｋｍ＝４．７６×１０－２ｍｏｌ／Ｌ，Ｃｐｍ＝１．６９ｍｏｌ／Ｌ。     

PVC－U饮水管材和管件萃取液中铅、镉的电位溶出法测定

本文提出了用电位溶出法测定硬聚氯乙烯（ＰＶＣ－Ｕ）饮水管材和管件中铅、镉。在２．４×１０~（－３）ｍｏｌ／Ｌ　ＨＣｌ介质中，铅、镉浓度在２．０－１００μｇ／Ｌ范围内与峰高呈线性，检测限为１．０μｇ／Ｌ。用本法测定了５０批样品中铅、镉，结果满意。     

生物转化法生产果糖1,6-二磷酸反应条件优化

研究了利用游离酵母细胞转化葡萄糖为果糖１,６－二磷酸（ＦＤＰ）的反应条件。采用甲苯进行细胞透性化处理获得优化效果。合适的反应条件为：温度３５～４０℃、ｐＨ６．０、葡萄糖浓度大于０．１ｍｏｌ／Ｌ和无机磷浓度小于０．２ｍｏｌ／Ｌ。在该条件下,于补料分批式反应中,ＦＤＰ积累浓度达到０．３９９ｍｏｌ／Ｌ（１３５．６５ｇ／Ｌ）,对糖收率达到２８．２％。     

西洋参细胞液体培养人参皂甙的动力学研究

重点研究了西洋参细胞在改良 ＭＳ培养液中代谢生长状况（ＭＳ培养基加 ＫＴ０． ２ ｍｇ／Ｌ，ＩＢＡ５ｍｇ／Ｌ，ＭｇＳＯ４９２·５ｍｇ／Ｌ），对其发酵曲线及细胞生长作了检测，并对细胞 生长动力学作了研究，结果表明细胞生长动力学基本符合Ｍｏｎｏｄ比生长速度式，μｍａｘ＝ ０．１６１３ｄ－１，Ｋｓ＝４７．５９ｇ／Ｌ。     

Pd~(2+)-I~--TBAB三元缔合物萃取光度法测定钯含量

介绍了Ｐｄ２＋－Ｉ－－ＴＢＡＢ（四丁基溴化铵）三元缔合物萃取光度法测定钯的方法。该方法以Ｌ（＋）抗坏血酸作为掩蔽剂，干扰离子Ｃｕ２＋，Ｆｅ３＋的允许量均为２．５μｇ／ｍＬ，Ｐｄ２＋浓度为０～４μｇ／ｍＬ，完全符合比耳定律（萃取剂作参比），方法的相关摩尔吸光系数ε为２．０９×１０４Ｌ／（ｍｏｌ·ｃｍ），桑德尔灵敏度Ｓ为５．０７×１０－３μｇ／ｃｍ２。工作曲线的应用范围为１～４μｇ／ｍＬ。     

醋酸乙烯生产中触媒的配制

配制醋酸锌－活性炭触媒，醋酸锌溶液的浓度为，喷酒速度控制为２６０－３００Ｌ／ｈ，喷洒时间不低于４小时，醋酸锌在活性炭上的载量在０．３ｇ／ｇ，有效载量要求（３３±１）％，新制得的触媒收率〉１．１５，选择性较好，寿命延长。     

固定化米根霉在三相流化床中间歇发酵生产L－乳酸的研究

研究了海藻酸钙包埋法固定米根霉在三相流化床反应器中间歇发酵生产Ｌ－乳酸的工艺。实验结果表明，固定化颗粒具有较好的重复使用效果；并考察了颗粒装填密度、通气量、糖浓度及温度对产酸速率的影响，在通气量大于１．０ｖｖｍ、温度为３９℃、糖浓度为（１０～８０）ｇ／Ｌ的条件下，产酸速率达到２０．６ｇ／Ｌ·ｈ，糖对Ｌ－乳酸的转化率为（７０～８０）％；还建立了糖浓度和温度与产酸速率间的数学模型     

Effect of different fermentation parameters on bioethanol production from corn meal hydrolyzates by free and immobilized cells of Saccharomyces cerevisiae var. ellipsoideus

BACKGROUND: Bioethanol produced from renewable biomass, such as corn meal, is a biofuel that is both renewable and environmentally friendly. Significant scientific and technological investments will be needed to achieve substitution of conventional fossil fuels with alternative fuels. The ethanol fermentation of enzymatically obtained corn meal hydrolyzates by free and immobilized cells of Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system was studied. The initial glucose and inoculum concentration and the time required for the efficient ethanol production were optimized taking into account parameters such as ethanol concentration, ethanol yield, percentage of the theoretical yield of ethanol and volumetric productivity in both immobilized and free cell systems. RESULTS: The yeast cells were immobilized in Ca–alginate by an electrostatic droplet generation method. An optimal initial inoculum concentration of 2% (v/v) and optimal fermentation time of 38 h for both immobilized and free yeasts were determined. An optimal initial glucose concentration of 150 g L^?1 for free system was achieved. At the initial glucose concentration of 176 g L no substrate or product inhibition were achieved with immobilized yeast. CONCLUSION: By immobilization of the yeast into Ca–alginate using the method of electrostatic droplet generation a superior system was realized, which exhibited lower substrate inhibition and higher tolerance to ethanol. The cells of S. cerevisiae var. ellipsoideus yeast entrapped in Ca–alginate showed good physical and chemical stability, and no substrate and product diffusion restrictions were noticed. Copyright © 2008 Society of Chemical Industry     

豆粕水解液为氮源细菌厌氧流加发酵生产L-乳酸

采用细菌厌氧发酵法生产L-乳酸,由实验确定了最佳接种量、发酵温度和pH调节剂,考察了初始葡萄糖浓度对L-乳酸生产的影响,确定初始糖浓度为70~90 g/L时得率、产率、最终生物量分别达到92.68 g/g, 3.17 g/(L×h)和8.5′107 mL-1. 为进一步降低L-乳酸生产成本,以豆粕水解液为氮源代替酵母粉,同时应用流加发酵技术,L-乳酸产量、得率、产率及转化率分别达到155 g/L, 95.5 g/g, 1.64 g/(L×h)和96.9%. 在保证L-乳酸最终浓度的同时可降低生产成本,为进一步工业化奠定了基础.     

硅橡胶膜生物反应器中乙醇发酵与渗透汽化的耦合

用硅橡胶膜生物反应器(SMBR)实验研究连续发酵-渗透汽化的耦合性能。发酵微生物采用酿酒干酵母,所用碳源为工业级葡萄糖。发酵过程由于产物抑制作用,在乙醇质量浓度达到73 g/L时趋于停滞,而耦合渗透汽化膜后,发酵罐内的乙醇质量浓度降低并维持在40 g/L,使发酵可以连续稳定地进行。在SMBR运行达到稳态后,乙醇的体积产率为4.02 g/(L.h)。发酵液中乙醇质量浓度维持在20~63 g/L,聚二甲基硅氧烷(PDMS)膜的总渗透通量为1 220~800 g/(m2.h),分离因子为5~9.2。与传统发酵和分离相同进料质量分数的乙醇溶液相比,乙醇发酵和渗透汽化在硅橡胶膜生物反应器中能相互耦合并得到强化。与较小规模耦合系统(发酵体积1 L和2 L)比较,性能稳定良好。     

Bioethanol production from corn meal by simultaneous enzymatic saccharification and fermentation with immobilized cells of Saccharomyces cerevisiae var. ellipsoideus

The simultaneous enzymatic saccharification and fermentation (SSF) of corn meal using immobilized cells of Saccharomycescerevisiae var. ellipsoideus yeast in a batch system was studied. The yeast cells were immobilized in Ca-alginate by electrostatic droplet generation method. The process kinetics was assessed and determined and the effect of addition of various yeast activators (mineral salts: ZnSO₄ · 7H₂O and MgSO₄ · 7H₂O, and vitamins: Ca-pantothenate, biotin and myo-inositol) separately or mixed, was investigated. Taking into account high values of process parameters (such as ethanol concentration, ethanol yield, percentage of the theoretical ethanol yield, volumetric productivity and utilized glucose) and significant energy savings the SSF process was found to be superior compared to the SHF process. Further improvement in ethanol production was accomplished with the addition of mineral salts as yeast activators which contributed to the highest increase in ethanol production. In this case, the ethanol concentration of 10.23% (w/w), percentage of the theoretical ethanol yield of 98.08%, the ethanol yield of 0.55 g/g and the volumetric productivity of 2.13 g/l·h were obtained.     

拟薄水铝石-海藻酸铝固定化酵母生产乙醇

在原位合成拟薄水铝石中加入酵母和海藻酸钠,搅拌并冷冻后制备固定化酵母,以甘蔗废糖蜜生产乙醇。通过复合材料固定化酵母增殖机理发现,固定化酵母数达4.1×109个/mL,批式发酵中14h消耗了90.5%的总糖;40d连续流动中,稀释率为0.100h-1时,最大载体乙醇产率为52.0g/(L.h)。SEM表征表明,该固定化酵母细胞密度高,孔道结构丰富,利于细胞的繁殖生长和物质传送。乙醇发酵过程彻底,速率快,残糖水平低,原料利用率和发酵醪乙醇质量浓度均超过传统工艺。     

气提法弱化超高浓度乙醇发酵过程中自絮凝酵母振荡行为

超高浓度(very high gravity,VHG)连续乙醇发酵过程中的振荡行为会导致发酵终点的乙醇浓度振荡和降低,是VHG连续乙醇发酵面临的主要问题。研究表明,游离酵母Saccharomyces cerevisiae 4126和自絮凝酵母BHL01在VHG连续乙醇发酵过程中,生物量、残糖、乙醇、甘油等发酵参数都呈现130～145 h的周期性振荡,且絮凝酵母发酵体系的平均乙醇浓度和乙醇生产强度都明显高于游离酵母体系。在絮凝酵母VHG连续乙醇发酵过程中利用发酵尾气气提分离乙醇,酵母细胞振荡行为被明显弱化,达到拟稳态状态,并且使发酵液中的残糖浓度控制在0.1 g·L^-1以下,平均乙醇浓度为110.87 g·L^-1,乙醇产率达到2.99 g·L^-1·h^-1。因此,本研究为弱化VHG连续乙醇发酵中的参数振荡行为提供了新的技术手段。     

酿酒酵母在硅橡胶膜生物反应器中连续发酵的生长动力学

实验研究了酿酒酵母在硅橡胶膜生物反应器中的细胞生长速率与操作参数之间的关系。在三水平正交实验基础上,用Gauss Newton非线性最小二乘法拟合了细胞比生长率与葡萄糖浓度、乙醇浓度和细胞浓度3变量之间的关系式,得到硅橡胶膜生物反应器乙醇连续发酵的细胞最大比生长率、饱和常数、产物抑制常数和群聚抑制常数等基本动力学参数,表明当细胞浓度达到15g/L或乙醇浓度达到70g/L时细胞生长受到完全抑制。连续发酵实验验证了硅橡胶膜生物反应器中的细胞生长动力学满足拟合模型的规律。     

Continuous ethanol production from wood hydrolysate by chemostat and total cell retention culture

Chemostat and total cell retention cultures with internal filter system ofSaecharomyc.es cerevisiae H1-7 were carried out to produce ethanol from wood hydrolysate. Maximum ethanol productivity obtained in a chemostat with the aeration rate of 1 vvm was 3.79 g/(L·h). This was 20% higher than that in a chemostat without aeration. However, the substrate was not completely consumed at the dilution rate with the maximum productivity. The realistic productivity, which has higher than 99% conversion rate of substrate, was. 2.95 g/(L·h). The maximum productivity in the total cell retention culture was 6.65 g/(L·h) at the dilution rate of 0.19 h¹ and the residual glucose concentration was negligible.     

Detoxification and concentration of corn stover hydrolysate and its fermentation for ethanol production

Environmental and energy concerns have increased interest in renewable energy sources, particularly biofuels. Thus the fermentation of glucose from sulfuric acid-hydrolyzed corn stover for the production of bioethanol has been explored using a combined acid retardation and continuous-effect membrane distillation treatment process. This process resulted in the separation of the sugars and acids from the acid-catalyzed hydrolysate, the removal of most of the fermentation inhibitors from the hydrolysate and the concentration of the detoxified hydrolysate. The recovery rate of glucose from the sugar-acid mixture using acid retardation was greater than 99.12% and the sulfuric acid was completely recovered from the hydrolysate. When the treated com stover hydrolysate, containing 100 g/L glucose, was used as a carbon source, 43.06 g/L of ethanol was produced with a productivity of 1.79 g/(L· h) and a yield of 86.31 %, In the control experiment, where glucose was used as the carbon source these values were 1.97 g/(L·h) and 93.10% respectively. Thus the integration of acid retardation and a continuous-effect membrane distillation process are effective for the production of fuel ethanol from com stover.     

产朊假丝酵母流加发酵法生产谷胱甘肽

研究了产朊假丝酵母在不同葡萄糖浓度下的谷胱甘肽(GSH)分批发酵过程,在此基础上进一步考察了重复补料、恒速流加和指数流加等不同培养方式对GSH发酵生产的影响. 结果发现,这几种培养方式都可以实现酵母细胞和GSH的高产. 综合比较,无论是从细胞还是从GSH的产量、得率和生产强度的角度来看,指数流加都是较为理想的选择. 经过48 h的指数流加培养,细胞干重达到40.9 g/L, GSH产量和胞内GSH含量分别达到857.2 mg/L和2.25%.