益生菌Lactobacillus casei Zhang固态发酵条件的优化

利用一株分离自传统发酵酸马奶中的益生干酪乳杆菌（Lactobacillus casei Zhang）进行固态发酵（Solid State Fermentation,SSF）。以发酵物中的活菌数为主要指标,采用九因素四水平（L32（4^9））的正交试验优化固态发酵培养基,并在优化的培养基基础上研究不同的初始含水量及培养时间对Lactobacillus casei Zhang活菌数的影响。实验结果表明,在固态发酵培养基组成为4g豆粕、5g麸皮、0．6g乳清粉、0．3g葡萄糖、0．3g碳酸钙、0．02g硫酸铵、0．01g硫酸镁,初始含水量为55％的优化条件下,37℃发酵60h,发酵物中Lactobacillus casei Zhang活菌数可达到4．08×10^10CFU／g。     

益生菌Lactobacillus casei Zhang增殖培养基的优化

Lactobacillus casei Zhang是一株分离自传统酸马奶中的益生菌。本文研究了不同碳源、氮源、碳氮比例、微量元素及缓冲盐对Lactobacillus casei Zhang增殖培养的效果, 并采用响应面法对优选的碳源、氮源和缓冲盐类的组成含量进行优化, 得到Lactobacillus casei Zhang的增殖培养基为：葡萄糖 20.9 g/L、大豆蛋白胨10.45 g/L、酵母粉10.45 g/L、K2HPO4 3.5 g/L、醋酸钠14.6 g/L、柠檬酸钠2.3 g/L、MgSO4?7H2O 1 g/L、MnSO4?5H2O 54 mg/L、CuSO4?5H2O 10 mg/L、吐温80为1 g/L。Lactobacillus casei Zhang在此增殖培养基中经37℃18 h培养活菌数可达到4.78×109 CFU/mL, 比在MRS中(4.8×108 CFU/mL)提高近10倍。     

补料分批法高密度培养凝结芽孢杆菌

研究在摇瓶条件下通过补加含有不同浓度的葡萄糖与酵母膏的料液及不同流加方式对凝结芽孢杆菌(Bacillus coagulans)TQ33菌体量和芽孢生成量的影响,确定了补料液中的葡萄糖与酵母膏比例为61(w/w),采用将葡萄糖浓度控制在3.0g/L～6.0g/L的流加方式进行高密度培养凝结芽孢杆菌.在5L自动发酵罐中进行补料分批培养,最终菌体浓度达到4.5×109cfu/mL,芽孢浓度为1.2×109cfu/mL,分别是分批培养的5.9倍和3.8倍.     

益生乳酸菌Lactobacillus casei Zhang和Lactobacillus plantarum P8对全价饲料pH及微生物类群变化的研究

研究了益生乳酸菌干酪乳杆菌Zhang(Lactobacillus casei Zhang)和植物乳杆菌P8(Lactobacillus planta-rum P8)对全价饲料pH及微生物类群变化的影响。分别将L.casei Zhang、L.plantarum P8单一菌种及复合菌种(11)以6.30 lg cfu/g的接种总量发酵全价饲料,测定25℃10 d发酵期间全价饲料pH和微生物类群的变化,应用选择培养基测定发酵饲料中的乳酸菌及杂菌(酵母菌、霉菌、大肠菌群、芽胞杆菌和梭状芽胞杆菌)的动态变化,应用RT-PCR技术测定试验组中的L.casei Zhang和L.plantarum P8的动态变化。结果显示,试验组pH下降显著,发酵10 d时,L.casei Zhang、L.plantarum P8单一菌种和复合菌种发酵饲料的pH分别为4.23、4.24和4.22,显著低于对照组(P0.05);L.casei Zhang、L.plantarum P8单一菌种和复合菌种发酵饲料中的L.casei Zhang、L.plantarum P8活菌数分别为8.91、8.89、6.58和8.69 lg cfu/g。发酵期间,试验组中酵母菌、霉菌、大肠菌群、芽胞杆菌及梭状芽胞杆菌活菌数显著低于对照组(P0.05),其中L.plantarum P8单一菌种发酵和复合菌种发酵对杂菌抑制效果显著优于L.casei Zhang单一菌种发酵(P0.05)。结果表明,全价饲料经L.casei Zhang、L.plantarum P8发酵可以显著降低其pH,抑制其中杂菌的生长,同时L.casei Zhang、L.plantarum P8在饲料中具有良好的稳定性。     

基因工程菌生产重组人组织因子的发酵研究

根据表达重组人组织因子基因工程菌的自身特点,在30L发酵罐上,通过控制发酵pH、葡萄糖浓度、诱导物磷酸浓度、搅拌速度及采用分批补料等方法,对重组人组织因子基因工程菌高密度发酵和高效表达的条件进行了研究。实验结果表明:诱导物终浓度低于0.1mmol/L,菌体密度OD60014,发酵周期10.5h,基因工程菌批发酵平均产量为37.41g/L,重组人组织因子表达量为6.56 mg/L。关键词:基因工程菌;高密度发酵;组织因子     

猪源屎肠球菌WEI-9的高密度培养

目的对分离自健康仔猪肠道的屎肠球菌(Enterococcus faecium)WEI-9的高密度发酵培养基进行响应面优化,为菌株WEI-9的工业化生产奠定基础。方法首先采用单因素试验确定最适高密度发酵培养基的碳源和氮源,随后采用Plackett-Burman设计筛选出影响菌株WEI-9发酵活菌数的显著因素,利用最陡爬坡试验得出显著因素逼近最大活菌数产量的响应区域,最后应用Box-Behnken设计和响应面分析法确定显著影响因子的最佳浓度。结果优化后的最适高密度发酵培养基成分和配比为:乳清粉21.34 g/L,蛋白胨21.94 g/L,Na AC·3H2O 5 g/L,柠檬酸铵2 g/L,K2HPO4·3H2O 2 g/L,Mg SO4·7H2O 0.2 g/L,Mn SO4·H2O 0.05 g/L,吐温-80 1 g/L,发酵液最高活菌数达到1.6×109CFU/m L,是相同条件下MRS培养基中活菌数的1.98倍。结论本研究实现了猪源屎肠球菌(Enterococcus faecium)WEI-9的高密度培养。     

一株维氏气单胞菌发酵培养基优化及其制备疫苗免疫效力比较

采用单因素试验、响应面试验法对维氏气单胞菌（Aeromonas veronii）发酵培养基的氮源、碳源、无机盐和磷酸盐成分及用量进行优化组合,确定优化培养基组成：胰蛋白胨10.8 g/L,葡萄糖5.0 g/L,牛肉膏3.0 g/L,磷酸二氢钾2.0 g/L,硫酸镁0.4 g/L,NaCl 5.0 g/L。并与基础培养基的发酵活菌数、制备的灭活疫苗免疫效力进行比较,经过验证试验绘制维氏气单胞菌在优化培养基条件下的7 L发酵罐生长曲线。在优化发酵培养基条件下,维氏气单胞菌活菌数为5.94×10⁹ cfu/mL,比基础培养基增幅43.13%;制备的灭活疫苗相对保护率为77.78%,比基础培养基提高了14.81%。7 L发酵罐发酵培养10 h,活菌数达到最大8.85×10⁹ cfu/mL。通过对发酵培养基的优化,可以获得低成本、优质高效的维氏气单胞菌发酵菌液,为今后维氏气单胞菌灭活疫苗规模化发酵培养提供参考。     

益生菌Lactobacillus casei Zhang增殖培养基的优化

Lactobacillus casei Zhang 是一株分离自传统酸马奶中的益生菌.本文研究了不同碳源、氮源、碳氮比例、微量元素及缓冲盐对 Lactobacillus casei Zhang 增殖培养的效果,并采用响应面法对优选的碳源、氮源和缓冲盐类的组成含量进行优化,得到 Lactobacillus casei Zhang 的增殖培养基为:葡萄糖20.9 g/L、大豆蛋白胨10.45 g/L、酵母粉10.45 g/L、K2HPO4 3.5 g/L、醋酸钠14.6 g/L、柠檬酸钠2.3 g/L、MgSO4·7H2O 1 g/L,MnSO4·5H2O 54 mg/L、CuSO4·5H2O 10 mg/L、吐温80为1 g/L.Lactobacillus casei Zhang 在此增殖培养基中经37℃ 18 h培养活茵数可达到4.78×109 CFU/mL,比在MRS中(4.8×108 CFU/mL)提高近10倍.     

基于BP神经网络和遗传算法的面包酵母高密度发酵培养基优化

为实现面包酵母的高密度发酵培养,构建一个BP神经网络模型,用于回归面包酵母高密度发酵培养基中显著影响因子与菌体密度之间的非线性关系,并在此基础上结合遗传算法进对此模型进行全局寻优,得到关键因子最佳浓度分别为:葡萄糖52.3 g/L,酵母浸出粉10.4 g/L,(NH4)2SO41.9 g/L.采用此优化配方进行摇瓶培养,所得菌体密度为3.95×108个/mL,比对照提高了61.2％.结果证实了人工神经网络的模拟和预测功能在微生物培养基优化方面有一定应用价值.     

赭曲霉的高密度培养对坎利酮转化的影响

目的:研究赭曲霉高密度培养的发酵培养基及条件,实现坎利酮的高转化.方法:选取廉价易得的培养基成分并进行优化,同时对发酵条件进行优化,得到了最优发酵培养基配方及培养条件.结果:发酵培养基最优配方为:葡萄糖20g/L,玉米浆20g/L,酵母膏20g/L,K2HPO4 2.5g/L.种子液最佳培养时间为24h,发酵培养基初始pH 5.8,接种量为8%,装液量200mL/1000mL,摇床转速为180 r/min,28℃,底物投料时间24h,发酵结束时间72 h.结论:将该工艺在7L发酵罐中放大,菌体密度达到25.36g/L,11α羟基坎利酮的转化率为86.1%.     

一株具有藻毒素清除功能的干酪乳杆菌细胞高密度发酵条件优化

为提高一株具有藻毒素清除能力的干酪乳杆菌Lactobacillus casei BBEi0—212单位体积的活菌数,针对其营养需求,研究了不同碳源、氮源、缓冲盐、微量元素及生长因子对该菌株生长情况及发酵特性的影响。通过响应面法对碳源、氮源、生长因子等进行优化,获得最佳培养基配方为：α-乳糖43．8g/L,酵母膏79．5g/L,无水乙酸钠13．12g／L,冰醋酸9．17mL／L,MnSO4·H20190mg／L,吐温-805．15mL/L。经37℃培养18h,菌体干重达到4．97g/L,比在普通MRS培养基中（1．32g／L）提高近4倍。基于乳酸菌发酵过程中的产酸特性,通过外源添加5g／L谷氨酸,促使菌体浓度进一步提高15％,并提前1．2h进入生长稳定期。上述研究结果为食品行业重要生产菌株干酪乳杆菌的高密度培养技术提供了可借鉴的研究思路。     

内生解淀粉芽孢杆菌CC09产Iturin A摇瓶发酵条件优化

【目的】提高内生解淀粉芽孢杆菌CC09发酵产抗菌脂肽Iturin A的产量。【方法】首先采用单因子实验研究了碳源、氮源、NaCl浓度、pH、温度、转速和装液量等因子对CC09产Iturin A能力的影响,然后对其中显著性因子:氮源浓度、pH、温度及装液量4个因素进行正交实验,进一步优化发酵条件。【结果】优化培养基组成及发酵条件可以提高CC09菌株的生长速度及产Iturin A的量,其中可溶性淀粉以及一定比例的蛋白胨和酵母粉是CC09菌株产Iturin A的良好碳源和氮源;培养温度、装液量、培养液pH等也对CC09菌株产Iturin A有显著影响。优化后的培养基成分:可溶性淀粉(碳源)5 g/L、比例为3:1的胰蛋白胨酵母粉混合氮源15 g/L、NaCl 1 g/L;最佳培养条件:pH 6.0、28°C、摇床转速120 r/min、培养瓶装液量20%。【结论】在此条件下,Iturin A的产量可达到690 mg/L,较优化前的138 mg/L提高了4倍。     

益生菌体外增殖因子的初步研究

目的研究单糖、pH、温度及时间对青春双歧杆菌、长双歧杆菌和类干酪乳杆菌体外增殖的影响。方法用甘露糖、半乳糖、山梨醇及果糖代替MRS中的葡萄糖,筛选出每种细菌的最适碳源。以此为基础,选择其最佳初始pH、培养温度、碳源添加量及培养时间。结果青春双歧杆菌、长双歧杆菌和类干酪乳杆菌的最适碳源分别为葡萄糖、甘露糖和半乳糖;最佳初始pH为6.0、7.0和6.0;培养温度为42、30和30℃;碳源添加量为20、15和25 g/L;培养时间都为28-48 h。结论益生菌具有不同的最适增殖条件,本文研究结果为优化益生菌的生长条件提供了基础数据。     

富铬蚁巢伞（鸡菌）液体培养(英文)

A species of mushroom, Termitomyces albuminosus, was cultured in liquid medium for production of chromium-enriched mycelium. The influence of chromium (Ⅲ ) on mycelial growth of T. albuminosus was investigated. An optimum medium composed of 5.6g/L yeast extract, 51.6g/L hydrolyzed rice, 2g/L KH2PO4, and 20mg/L chromium(Ⅲ ) with initial pH of 4.5 was obtained by using method of central composite design (CCD). After incubation of 84h, the maximal biomass of chromium-enriched mycelia reached 24.23g DMW(dried mycelial weight)/L with 272μg/g DMW chromium content in 500mL flasks containing 100mL medium with an inoculum of 8% on a shaker of 100r/min under an optimized cultivation condition at 28℃.     

Technical Factors of Artemisin Biosynthesis in Artemisia annua Hairy Root Culture

The optimum cultural conditions of growth and artemisinin accumulation of hairy roots in Artemisia annua L. were identified as follows: the initial pH 5.8 ~ 6.0; the rate of flask shaking, 130 ~ 150 r/min; the liquid medium volume per flask, 25%; light cycle, 16 h/d; temperature, 30 ℃. Under the above conditions, up to 233.3 mg/L of artemisinin could be obtained after 25 days of culture.     

Multistrain probiotic production by co‐culture fermentation in a lab‐scale bioreactor

Most commercial probiotic products intended for pharmaceutical applications consist of combinations of probiotic strains and are available in various forms. The development of co‐culture fermentation conditions to produce probiotics with the correct proportion of viable microorganisms would reduce multiple operations and the associated costs. The aim of this study was to develop a fermentation medium and process to achieve biomass comprising the desired proportion of two probiotic strains in co‐culture. Initially, a quantification medium was developed, and the method was optimized to allow the quantification of each strain's biomass in a mixture. The specific growth rates of Lactobacillus delbrueckii spp. bulgaricus and Lactobacillus plantarum were determined in media with different carbon sources. The inoculum volume was optimized to achieve equal proportion of biomass in co‐culture fermentation in test tubes. Next, fermentation was carried out in a 3‐L bioreactor. A biomass concentration of 2.06 g/L, with L. delbrueckii spp. bulgaricus and L. plantarum in the ratio of 47%:53% (by weight), was achieved with concomitant production of 12.69 g/L of lactic acid in 14 h. The results show that with careful manipulation of process conditions, it is possible to achieve the desired proportion of individual strains in the final biomass produced by co‐culture fermentation. This process may serve as a model to produce multistrain probiotic drugs at industrial scale.     

不同摇瓶条件对侧耳菌生长及漆酶分泌的影响

研究了小试液体摇瓶下不同pH培养条件、摇瓶转速、装液量对侧耳属白腐菌BP漆酶分泌及生长状况、形态变化的影响。结果表明：BP在中、酸性条件下生长较好且表现较高的分泌漆酶能力,用硫酸调pH为5．0时,漆酶活力和生物量分别在第10d和第6d达到最高,分别为742U／mL和8．4g(干重)/L,高于相应缓冲液调节pH体系的结果;天然(pH6．5)培养条件下,最佳转速与装液量分别是150r／min、200mL/500mL三角瓶,此时菌球较小,四周为毛刺状,漆酶酶活和生物量分别在第5d和第6d达到最高,分别为714．2U／ml和9．2gtL。同时,运用SPSS统计软件对各影响因素进行差异显著性检验,获得白腐菌生长及漆酶分泌特性的主要影响因子。     

Production of biomass and beta-D-galactosidase by Candida pseudotropicalis grown in continuous culture on whey

The production of biomass and beta-D-galactosidase by the lactose-utilizing yeast Candida pseudotropicalis NCYC 744 in whey medium was studied. Apparent optimization of growth conditions and medium was done in continuous culture. Optimaql pH and temperature were 2.6 and 36-38 degrees C, respectively, Limitations in Cu, Zn, and possbily Mn were detected in deproteinized whey medium. Additions of tryptophan estimulated growth of the yeast. Under optimal conditions in medium supplemented with excess tryptophan, Cu, Zn, and Mn the maximum values obtained: yeast concentration, 4.6 g/L; yeast productivity, 1.4 g/L h (at D = 0.35 h(-1)); enzyme volumetric productivity, 2100 U/L h (at D = 0.25 h(-1)); maintenance coefficient, 5-10 mg lactose/g cell h; saturation constant (K(s)) for lactose, 4.76mM; maximum specific growth rate, (mu(max)), 0.47 h(-1). No significant increase in specific enzyme activity (U/mg cell) was observed after medium optimiztion evidencing the importance of regulatory controls in enzyme synthesis.     

产生物表面活性剂芽孢杆菌培养条件的优化

为了提高生物表面活性剂的表面活性,通过单因素及正交试验对已筛选的产生物表面活性剂芽孢杆菌的培养基及培养条件进行了优化,优化后的培养基成分为可溶性淀粉20 g/L,氯化铵2 g/L,KH2PO46 g/L,K2HPO42 g/L,MgSO4.7H2O 0.3 g/L,NaCl 2 g/L,CaCl20.08 g/L,EDTA 0.4 g/L。培养条件为4%接种量,种龄16 h,初始pH7,培养温度37℃,摇床转速160 r/min,发酵48 h。优化发酵条件后,发酵液表面张力由初始67.5 mN/m降低至24.8 mN/m,生物表面活性剂产量达到1.08 g/L。