Design and manufacture of emulsion liquid membrane based on various amine extractants for separation and extraction of succinic acid from fermentation broth

The aim of this study was to design a new emulsion liquid membrane(ELM)system for the separation of succinic acid from aqueous solutions.The concentration of succinic acid varied from 20 to 60 mmol·L^(-1).The prepared ELM system includes tributylamine(TBA)as a carrier,commercial kerosene as a solvent,Span 80 as a surfactant,and Na2CO3as a stripping agent.In order to control the membrane swelling,different values of cyclohexanone were added to the membrane phase.The effect of various empirical variables on the extraction of the succinic acid such as acid concentration in the feed solution,initial feed concentration,carrier concentration,the stirring speed of the extraction,Na2CO3,surfactant,and cyclohexanone concentrations,and treat ratio in the ELM system.The best result was obtained when TBA was used as the carrier.The final acid extraction efficiency was independent of pH variations of the aqueous feed solution.The extraction of succinic acid solution with a concentration of 40 mmol·L^(-1)was improved by increasing the treat ratio 1:7-1:3,stripping phase concentration 0.5-1.5 mol·L^(-1),stirring speed 300-500 r·min^(-1)and cyclohexanone concentration in the membrane phase 1.2-1.6 mol·L^(-1).No considerable effect on the extraction rate was observed for the carrier concentration in the membrane phase.But,the surfactant concentration in the feed phase showed a dual effect on the extraction efficiency.

Determination of Candicidin/FR-008 and Related Components in Fermentation Broth by RP-HPLC

Aim A liquid chromatographic method for the determination ofcandicidin/FR-008 and related components in fermentation broth has been developed. Methods Therewere four major components in the candicidin/FR-008 complex, which were separated by HPLC under thefollowing conditions: SB-C8 column (4.6 mm x 250 mm, 5 μm) was used, the mobile phase consisted ofacetonitrileam-monium acteate (20 mmol·L^(-1) , pH 4.0) (40:60, V/V) , with a flow rate of 1 .0mL·min^(-1) , the UV detection wavelength was 380 nm, and the whole process was performed at 25℃ .Results The linearity was obtained in the range of 6.25 - 500 μg· mL^(-1) candicidin/FR-008 withthe regression equation of Y = 20 461 x + 30 748 and the correlation coefficient of 0.999 1. Theinstrument precision was 1.84% and the method precision was 3.8%. Conclusion This method isaccurate, rapid and simple; it can be used for determination of candicidin/FR-008 and relatedcomponents in fermentation broth.

The effects of fermentation and adsorption using lactic acid bacteria culture broth on the feed quality of rice straw

To improve the nutritional value and the palatability of air-dried rice straw, culture broth of the lactic acid bacteria community SFC-2 was used to examine the effects of two different treatments, fermentation and adsorption. Air-dried and chopped rice straw was treated with either fermentation for 30 d after adding 1.5 L nutrient solution（50 m L inocula L–1, 1.2×1012 CFU m L–1 inocula） kg–1 straw dry matter, or spraying a large amount of culture broth（1.5 L kg–1 straw dry matter, 1.5×1011 CFU m L–1 culture broth） on the straw and allowing it to adsorb for 30 min. The feed quality and aerobic stability of the resulting forage were examined. Both treatments improved the feed quality of rice straw, and adsorption was better than fermentation for preserving nutrients and improving digestibility, as evidenced by higher dry matter（DM） and crude protein（CP） concentrations, lower neutral detergent fiber（NDF）, acid detergent fiber（ADF） and NH3-N concentrations, as well as higher lactic acid production and in vitro digestibility of DM（IVDMD）. The aerobic stability of the adsorbed straw and the fermented straw was 392 and 480 h, respectively. After being exposed to air, chemical components and microbial community of the fermented straw were more stable than the adsorbed straw.

Antimicrobial Activity in Kombucha Fermentation Broth

[Objective] The aim was to study if the fermentation broth of Kombucha has protein with antimicrobial activity. [Method] The effects of different cultivation time on cell concentration, pH, total protein concentration and inhibition zone were studied. The fermentation broth of Kombucha on the sixth day was adjusted to different pH. Fermentation broth treated with protease was put into the plates of Escherichia co/i, Bacillus cereue and Staphylococcus aureus as control, as well as ampenicilin. The zone of broth inhibition was measured. [ Result] The concentration of general protein was of positive relevance to the antimicrobial activity of Kombucha fermentation broth. The zone of inhibition decreased with rising pH and was the lowest when pH was 7. Later, as pH increasing, it enlarged. The inhibition effect of processed protease reduced remarkably. [ Conclusion] The fermentation broth of Kombucha revealed antimicrobial proteins.

The Simulation Experiment of Ethanol Separation from Fermentation Broth by Gas Stripping

The feasibility of ethanol separation from ethanol-water solution saturated with glucose by gas strippingis showil theoretically and experimentally. The effects of glucose on the saturated vapor pressure of ethanol, and thatof operating temperature and gas stripping flow rates, K/G, on Stripping result are discussed.

EXTRACTION OF CITRIC ACID FROM FERMENTATION BROTH USING ION-EXCHANGEMETHOD

A number of ion-exchange resins were tested on their capacity to adeorb citric acid,among them resin 335, D315, Amberlite IRA-35 andIRA-68 exhibited higher adsorptioncapacity We Chose resin 335 and D315 to be used for extraction of citric acid fromfermentation broth, followed by elution with 10% ammonia liquor decoloration with K-15 carbon and removal of ammonia with resin 732, converting citrate to free citric acidwith a concentration of 10% and on amount of readily carbonizable substance meetingthe GB 8269-87 standard.

Process operation performance of PDMS membrane pervaporation coupled with fermentation for efficient bioethanol production

There would be strong product inhibition on ethanol fermentation process if ethanol is not removed in situ from broth. PDMS membrane pervaporation coupled with fermentation is a promising process for efficient bioethanol production since ethanol inhibition is relieved or eliminated. From the perspective of process operation, membrane separation performance, ethanol fermentation performance and the subsequent processing on membrane downstream are the three key issues. This review aims at contributing a comprehensive overview on the operation performance of the integrated process. The state-of-the-art of the three key issues related to the operation performance is focused. Finally, the tentative perspective on the possible future prospects of the integrated process is briefly presented.

蛹虫草菌株胞外发酵液抗氧化能力评价及优良菌株筛选

为建立高抗氧化能力的蛹虫草优良菌株评价筛选方法,以蛹虫草(Cordyceps militaris)胞外发酵液为研究对象,采用相关性分析对10株蛹虫草菌株进行抗氧化能力评价及优良菌株筛选。以菌株生长活性、胞外酶活力、抗氧化能力为指标,在相关性分析、隶属函数赋值计算的基础上建立线性回归方程,得到蛹虫草菌株抗氧化综合能力与发酵生物量、菌丝平均生长速度、β-葡萄糖苷酶活力、蛋白酶活力的蛹虫草菌株定向筛选模型,采用模型筛选得到优势菌株CH-1及CA-1。通过结实性实验进一步验证,蛹虫草菌株CH-1与CA-1生物学转化率可达90%以上,其虫草素含量较野生菌株高60%左右,菌株生长周期短10 d以上,试验结果说明此模型可用来快速筛选出具有高抗氧化能力的蛹虫草优良菌株。

己酸菌发酵液酯化合成己酸乙酯的研究

己酸乙酯是浓香白酒的特征香气成分,其含量的多少决定着浓香型白酒的品质。本研究对己酸菌发酵液酯化合成己酸乙酯的最佳条件进行探究,研究了不同条件下的酯化pH、不同酸调节pH以及乙醇、己酸浓度对己酸菌发酵液中己酸乙酯转化率的影响。结果表明,pH在3~4时己酸乙酯转化率较高,用乳酸调节p H效果最优,增加酯化体系中乙醇、己酸浓度均有利于提高己酸乙酯的转化率;使用己酸含量为18.86 g/L的浓缩己酸菌液,加入30%的无水乙醇,0.15%的酯化酶,用乳酸调节pH至4,34℃酯化24 h,己酸乙酯含量达到8962.99 mg/L,转化率为49.77%。

栝楼根腐病镰孢菌拮抗菌SJ1623发酵代谢物的抑制活性

检测了6株拮抗菌发酵上清液对栝楼根腐病菌的抑制活性,采用菌丝生长速率法测定优势拮抗菌不同接种量和发酵时间对发酵上清液抑菌活性的影响,测定了不同稀释倍数的发酵上清液和脂肽粗提物对栝楼根腐病菌的抑制活性。结果表明,对栝楼根腐病菌抑制活性最高的拮抗菌为SJ1623,种子液培养时间为10 h,0.75%(体积比)的接种量效果较好;发酵上清液稀释10倍对病菌的抑制率为87.6%,脂肽粗提物50倍稀释液对病菌的抑制率为83.1%。

一株云南木霉菌培养条件的优化及其对茶炭疽病的防控研究

为优化对茶炭疽病菌Colletotrichum camelliae有拮抗作用的云南木霉菌Trichodema yunnanense的发酵培养条件,并明确发酵液对茶炭疽病的防控效果,以对C.camelliae的抑菌率为评价指标,通过单因素和响应面试验,优化云南木霉菌的发酵条件并获得发酵液,比较其对茶炭疽病的抑菌活性、离体叶片和盆栽茶树叶片防效及茶树生长的影响。结果显示,T.yunnanense的最佳发酵条件为马铃薯200 g·L^(-1)、甘露醇18.85 g·L^(-1)、酵母浸膏4.73 g·L^(-1)、装液量372.60 mL·L^(-1)、培养温度25℃、pH 6.6、12L∶12D。10%的发酵液对C.camelliae的抑菌率达92.61%,对感染茶炭疽病的离体茶树叶片与盆栽茶树叶片的防效分别为63.71%与68.95%,均显著高于哈茨木霉菌(T.harzianum)可湿性粉剂与多菌灵的防效。同时,10%发酵液处理后的茶树幼苗根长提升69.16%,根鲜重提升215.70%,株高增加42.13%,地上部鲜重增加212.11%。表明T.yunnanense发酵液兼具抗菌和促生作用。研究结果为T.yunnanense在茶炭疽病生物防治中的应用奠定了一定的理论基础。

乳酸菌发酵液对面团发酵特性及面包品质的影响

选用从扬州富春茶社老酵面团和西藏奶酥中筛选的3株乳酸菌作为发酵菌,等质量比复配后分别制备乳酸菌发酵液和酸面团,并探讨这两种发酵基质对面团特性及面包品质的影响。结果表明:与对照组(CG)相比,添加乳酸菌发酵液(LF)和酸面团(SD)的面团发酵力和酸度均显著提高,pH值显著降低(P<0.05);其中LF组在发酵4 h后的pH值最低(4.48),酸度(TTA)最高(5.47 mL),体积变化率最大(3.28倍)。与CG组面包相比,LF和SD组面包的比容和感官评分均显著提高,硬度和咀嚼性显著降低(P<0.05),且都能改善面包的内部组织,其中LF组整体效果最好;相同的贮藏时间,SD组和LF组面包的老化焓值均显著低于CG组,其中LF组最低(2.017 J/g)。综上可知,添加乳酸菌发酵液能提高面团的发酵速度,改善面包的感官品质、质构和内部组织,延缓面包的老化速度,是可以替代酸面团的新型乳酸菌发酵基质。

4种功能性肥料对菜心生长和品质的影响

为筛选出适宜菜心栽培的功能性肥料,本研究探讨PSO_(4)菌株发酵液(PSO_(4))、玉米提取液(CE)、水解羽毛粉(HFP)、肌醇粉(IN)4种不同成分的功能性肥料对菜心生长及品质的影响。结果表明,适宜的4种功能性肥料对菜心均有显著增产作用,增产幅度为IN>HFP>PSO_(4)>CE。HFP和IN促进菜心根系横向生长,PSO_(4)促进菜心根系纵向生长,同时显著提升可溶性固溶物、可溶性糖及维生素C含量,从而提高菜心品质。在菜心栽培中,PSO_(4)和CE的最适宜浓度为300倍稀释浓度,HFP最适宜浓度为0.05%,IN最适宜浓度为0.1%。研究结果可为4种功能性肥料在菜心生产和品质栽培中的应用提供一定的理论依据。

暗褐脉柄牛肝菌发酵液多糖的分离纯化与结构表征

[目的]高效利用暗褐脉柄牛肝菌资源,开发其多糖功能性食品。[方法]取暗褐脉柄牛肝菌菌丝发酵培养,低温减压浓缩,乙醇沉淀,DEAE-52纤维素柱色谱分离纯化,透析袋透析除去小分子杂质制备多糖。总糖含量采用苯酚—硫酸显色法测定,液质联用法测定单糖组成,紫外分光光度法判断是否存在核酸和蛋白等杂质;通过红外光谱和核磁共振波谱,对多糖的结构进行分析。[结果]制备的多糖总糖含量为84%,主要单糖种类有:葡萄糖、甘露糖、半乳糖和阿拉伯糖,其物质的量比为2.07∶1.95∶1.00∶1.58。红外光谱和核磁共振波谱分析具有多糖吸收峰,含α型吡喃糖。[结论]从暗褐脉柄牛肝菌发酵液中制备的多糖主要由4种单糖组成,结构中含α型吡喃糖。

3种来源黑木耳黑色素的性质及其体外抗氧化活性比较

该研究以黑木耳“1703”的子实体、菌丝体和发酵液为试验材料,采用碱溶酸沉法提取黑色素,采用紫外可见光谱(ultraviolet–visible spectroscopy,UV-Vis)、傅里叶变换红外光谱(Fourier transform infrared spectrometer,FTIR)、扫描电子显微镜(scanning electron microscope,SEM)、高效液相色谱(high performance liquid chromatography,HPLC)法研究黑色素的结构表征,测定黑木耳黑色素的溶解性、稳定性和体外抗氧化活性。UV-Vis结果表明3种来源黑木耳黑色素最大吸收波长均为210 nm。FTIR结果表明3种来源黑木耳黑色素均具有天然黑色素的3个特征吸收区。HPLC结果表明3种来源黑木耳黑色素均只有一个吸收峰,且保留时间基本一致。溶解性结果表明3种来源黑木耳黑色素均易溶于碱性溶液,微溶于75%乙醇溶液,难溶于水和多数有机溶剂。稳定性结果表明3种来源黑木耳黑色素均具有良好的温度稳定性和光照稳定性,Fe^(3+)能够促进黑色素溶解,Fe^(2+)和Cu^(2+)导致黑色素不稳定。体外抗氧化试验结果表明3种来源黑木耳黑色素对DPPH自由基、ABTS^(+)自由基和羟基自由基均具有较强的清除能力,其中发酵液黑色素清除能力最强。

重组大肠杆菌全细胞催化法生产N-乙酰神经氨酸

N-乙酰神经氨酸具有多种生物学功能,在食品添加剂和药物合成等方面有着重要的应用。为了降低成本,作者利用重组大肠杆菌,并以含有N-乙酰葡萄糖胺的发酵液为底物进行全细胞催化生产N-乙酰神经氨酸。结果表明,在温度为30℃、转化液初始pH为6.5、底物丙酮酸浓度为1.38 mol/L、Triton X-100添加质量分数为0.4%、菌体OD_(600)为30的条件下在5 L发酵罐等条件下进行全细胞转化,可以得到N-乙酰神经氨酸180 mmol/L,摩尔转化率为65.45%。用阴离子树脂对产物进行初步分离纯化,经高效液相色谱分析证实纯化后产品为高纯度N-乙酰神经氨酸,其纯度为98.3%,结晶回收率为42.5%。作者建立并优化了一种以含有N-乙酰葡萄糖胺的发酵液为底物直接进行全细胞催化生产N-乙酰神经氨酸的工艺流程,既节约了成本,又具有可持续发展的优势。

棕色绿僵菌胞外酶的诱导及发酵液生化特性研究

为了研究不同液体培养基及诱导物对棕色绿僵菌作用过程中胞外酶的最佳诱导条件和发酵液的生化性质,从而在对家畜外寄生虫进行防治过程中更好地利用该菌,在前期研究基础上,试验使用培养效果较好的3种液体培养基加入不同诱导物对棕色绿僵菌进行液体发酵培养,检测发酵液的蛋白质含量、蛋白酶活性、磷酸酶活性以及杀蝇蛆效力等,确定该菌产生胞外酶和杀虫作用最适的培养基与诱导物。结果表明,蝇蛆三期幼虫诱导的枸橼酸培养基发酵液蛋白质浓度较高达404.45 mg/L、蛋白酶活性42.28 U/mL、酸性磷酸酶活性37.06 U/L、碱性磷酸酶11.04 U/L,同时杀蝇蛆效力也是最高的,达60%。因此,枸橼酸液体培养基是产生胞外蛋白质最佳培养基,较好的诱导物为蝇蛆三期幼虫。说明不同培养基及诱导物对棕色绿僵菌的代谢进程会产生显著影响,导致其代谢过程中分泌的蛋白质含量、蛋白酶和磷酸酶的活性产生明显差异,对杀蝇蛆效率产生影响。

响应面法优化枇杷发酵液发酵条件

该试验以枇杷汁为原料、短乳杆菌(Lactobacillus brevis)为发酵菌株,制作枇杷发酵液。在单因素试验基础上,以感官评分为响应值,利用响应面法优化枇杷发酵液的发酵条件。结果表明,枇杷发酵液最佳发酵条件为白砂糖添加量6%、发酵时间72 h、发酵温度37℃、接种量6%,以此优化条件得到的枇杷发酵液感官评分为91分,总黄酮含量为8.90 mg/100 mL,维生素C含量为1.05 mg/100 g,总酚含量为11.56 mg/100 mL,超氧化物歧化酶(SOD)活力为36.70 U/mL,制备的枇杷发酵液澄清透明,酸甜可口,具有较高的营养价值,为枇杷的深加工产业及其衍生产品的开发提供参考依据。

硫酸盐还原菌利用玉米发酵液为碳源还原地下水中的硫酸盐

将玉米发酵液作为微生物硫酸盐还原体系的碳源,可大幅降低还原成本,对实现硫酸盐废水经济、高效处理具有重要意义。探究了复合碳源比例、碳硫比(C S)和pH等对硫酸盐还原菌(SRB)还原硫酸盐的影响。结果表明:在初始SO_(4)^(2-)浓度为(1000±50)mg L时,5种复合碳源比例均能获得较好的硫酸盐还原效果,剩余SO_(4)^(2-)浓度均小于地下水质量标准Ⅳ类水质350 mg L要求;当初始C S=0~3.5时,随C S比升高,SRB的硫酸盐还原速率增加,但碳源的硫酸盐还原利用效率下降;在初始pH接近7.0时SRB硫酸盐还原活性最佳。反应体系pH和ORP值的变化可准确指示细菌活性变化。

发酵液中吡咯分离提纯研究

吡咯是现代化工制药工业中的重要原料,探索极具潜力的生物合成法中的吡咯提纯方法具有重要实践价值。采用萃取和蒸馏两种分离方法,主要围绕萃取剂的选择、萃取条件的优化、蒸馏条件的优化等内容开展提纯研究,辅以高效液相色谱法和质谱法两种分析方法。最终选择二氯甲烷为萃取剂,室温萃取3次,在25℃、真空度0.07MPa条件下进行减压蒸馏,得到高纯度吡咯样品,收率94.4%。