甘氨酸甜菜碱对植物乳杆菌YSQ18的渗透压胁迫耐受性的影响

从传统泡菜中分离出一株耐盐的酸菌,对其进行形态学、生理生化特性及16S rRNA序列分析鉴定,确定其种属地位;并初步研究相容性溶质甘氨酸甜菜碱在高渗透压环境下对所筛菌株的生长曲线和发酵糖耗速率的影响。结果表明:筛选出的乳酸菌中有一株符合乳杆菌属植物乳杆菌的鉴别特征,与16S rRNA序列鉴定和发育树分析结果一致。在含有1.2mol/L NaCl和1.5mol/L NaCl的化学合成培养基中,该植物乳杆菌的生长受到完全的抑制。在培养基中添加0.80mmol/L的甘氨酸甜菜碱对植物乳杆菌有较明显的保护作用,能减弱高渗胁迫,有效缩短迟滞期,提高耐盐能力。发酵中糖耗速率测定结果表明添加0.80mmol/L的甘氨酸甜菜碱能有效保持细菌活性。因此,在高渗环境发酵过程添加甘氨酸甜菜碱也许能有效提高微生物的活性,如传统的酿制酱油以及腌制泡菜等。     

The effect of betaine on in vitro fermentation of carbohydrate and protein combinations under osmotic stress in pigs

BACKGROUND: There is evidence that dietary betaine might improve nutrient digestibilities in pigs due to its osmoprotective properties. This in vitro study was performed to assess the potential of supplemented betaine sources to affect fermentation characteristics of different carbohydrate and protein combinations, under conditions of osmotic stress. In vitro fermentation was performed by use of the modified Hohenheim gas test with pig faeces as microbial inoculum. RESULTS: At the end of in vitro fermentation under osmotic stress conditions, differences (P < 0.05) in gas production, ammonia concentration, and concentration of short‐chain fatty acids were observed for the different carbohydrates, while for the two proteins only differences (P < 0.05) in ammonia and short‐chain fatty acid concentration were obtained. Supplementation of a native betaine source rather than addition of pure betaine increased propionic acid (P < 0.05) and butyric acid (P < 0.05) production. CONCLUSION: These results suggest that only supplementation of a native betaine source but not of pure betaine products affects microbial fermentation under osmotic stress. Furthermore, both the carbohydrate and protein source play an important role in modifying microbial activity under osmotic stress conditions. It can also be concluded that the modified Hohenheim gas test is suitable to scrutinise fermentation activity of different assay substrates under osmotic stress. Copyright © 2012 Society of Chemical Industry     

一种压裂用黏弹性表面活性剂的合成及其应用性能研究

为降低压裂过程对地层的伤害,以芥酸为主要原料,合成了一种可生物降解的甜菜碱型黏弹性表面活性剂,并对其反应条件进行了优化。最佳合成工艺如下:酰胺化反应中芥酸与N,N-二甲基-1,3-丙二胺的摩尔比为1∶1.2,反应温度150℃,反应时间为12h;季铵化反应中环氧氯丙烷与Na2SO3以等摩尔量混合后与中间体反应,摩尔比为1.2∶1,反应温度80℃,反应时间为6h。最终产物为表面活性剂有效含量为65%的黏稠状物质。同时,利用红外光谱和1 H NMR对提纯后的表面活性剂结构进行表征。对黏弹性表面活性剂压裂液进行应用性能测试,结果表明,该体系在剪切速率170s1,温度高于80℃时,黏度仍大于25mPa.s,60℃剪切3600s后黏度仍大于85mPa.s,说明该体系具有良好的耐温抗剪切性和增稠性能。     

非抑制离子色谱法检测甜菜碱的含量

建立了甜菜碱含量的非抑制离子色谱分析方法,优化了色谱分离条件。采用5mmol/L甲磺酸水溶液作为淋洗液,Dionex Ionpac CS17(4×250mm)+CG17(4×50mm)阳离子交换柱等度分离,柱温30℃,电导检测器检测。在优化实验条件下,甜菜碱的线性范围为5～300mg/L,相关系数为0.999 98,回收率在95%～101%之间,相对标准偏差小于2%,检出限为0.13mg/L。该法操作方便,简单快速,精密度高,重复性好,适用于常见甜菜碱产品含量的检测。     

甜菜碱对人体健康作用的研究进展

甜菜碱对人类的营养和健康起到重要的作用,本文综述了甜菜碱对人体健康作用的研究进展,展望了甜菜碱应用前景。     

双-十二醇聚氧乙烯醚甲基羧基甜菜碱的合成及性能

双十二烷基甲基甜菜碱(diC₁₂B)是一种优良的无碱驱油用表面活性剂,但由于亲油性太强,在水中的溶解性较差,并且在油砂表面具有较大的吸附量。本文试图在diC₁₂B分子中引入EO基团,以改善其性能。为此以溴代十二烷和三缩四乙二醇为原料合成了单分布的十二醇聚氧乙烯(4)醚,再经氯代并与一甲胺和氯乙酸锂反应,最终合成了双十二醇聚氧乙烯(4)醚甲基羧基甜菜碱(diC₁₂EO₄B)。产物经核磁和质谱表征,证明与目标产物的分子结构相符。与diC₁₂B相比,diC₁₂EO₄B在水中的溶解度显著增加,25℃时达到1.5×10^-4mol/L,是diC₁₂B 的3倍左右,45℃下在石英砂/水界面的饱和吸附量是diC₁₂B的70%左右。diC₁₂EO₄B保留了diC₁₂B的高表面活性,如较低的临界胶束浓度,1.6×10^-5mol/L;较高的降低表面张力的效能,g_cmc=29.3mN/m;在空气/水界面具有较大的饱和吸附量,6.5×10^-10mol/cm²;和较小的分子截面积,0.26nm²。diC₁₂EO₄B具有优良的降低油/水界面张力的能力,45℃下单独能将大庆地层水/C₇~C₉正构烷烃界面张力降至10^-3mN/m数量级,将大庆原油/地层水的界面张力降至10^-2mN/m数量级。通过与亲油性表面活性剂diC₁₂B以及C₁₆B复配,能在0.0625~5mmol/L总浓度范围内将大庆原油/地层水的界面张力降至10^-3mN/m数量级,无需加入任何碱或电解质。     

益生菌乳酸发酵提高低聚果糖含量生产的新方法

研究报告了一种新的提高低聚果糖(FOS)含量的生产方法。以市售低聚果糖为原料,通过添加甜菜碱进行益生菌乳酸发酵,将原料中可发酵性糖葡萄糖、果糖转化为乳酸,蔗糖部分转化为乳酸,使原料中低聚果糖的含量由51%提高到84%,而发酵液无需进行菌体分离即可用于食品加工,为低聚果糖的生产提供了一种低成本、高效率的纯化方法。     

Supplementing limited methionine diets with rumen-protected methionine, betaine, and choline in early lactation Holstein cows

Eighty lactating Holstein cows from 21 to 91 d in milk were fed a corn silage-based total mixed ration (TMR) formulated with the Met content limited (42 g/ d) to investigate the impact of supplementing rumen-protected (RP) forms of Met, betaine, and choline on performance and metabolism. One of 4 supplements was blended into the TMR to produce 4 dietary treatments: 1) control, 2) 20 g/d of RP-Met, 3) 45 g/d of RP-betaine, and 4) 40 g/d of RP-choline. Calcium salts of fatty acids were used to protect both RP-betaine and RP-choline supplements. A similar amount of Ca salts of fatty acids was included in both control and RP-Met supplements to provide equal amounts of fat to all treatments. Overall, no differences in intake, milk yield, or milk composition were observed in primiparous cows. Average dry matter intake, body weight, and body condition score were not different among treatments in multiparous cows. Milk yield was higher in multiparous cows fed RP-choline compared with the other treatments. Multiparous cows fed RP-choline had higher milk protein yield than cows fed control or RP-betaine but was not different from cows fed RP-Met. Multiparous cows fed RP-choline had higher milk fat yield than cows fed RP-Met but was not different from cows fed control or RP-betaine. There were no beneficial effects of RP-betaine supplementation to a Met-limited TMR.     

Research on Oleic Acid Amide Betaine Used in Surfactant-Polymer Compound Flooding for Ordinary Heavy Oil

In view of the low recovery rate associated with water flooding, as well as the scaling problems caused by traditional alkali-surfactant-polymer flooding, the feasibility of using a betaine surfactant with high interfacial activity for chemical flooding of ordinary heavy oil was investigated. Aqueous solutions of oleic acid amide betaine (OAAB) with the mass concentration of 0.01% can reduce the oil–water interfacial tension to the ultralow level (10⁻³ mN m⁻¹), making it suitable for chemical flooding. To solve the problem of high adsorption onto sandstone, static adsorption tests and dynamic adsorption tests were carried out. The results show that the weakly alkaline lignin can significantly reduce the adsorption quantity of OAAB by more than 40%, based on which, a compound-flooding system of 0.1% partially hydrolyzed polyacrylamide (HPAM) + 0.1% OAAB +0.75% lignin was constructed. Compared with water flooding, the ultimate rate was enhanced by 20.4%, resulting in a final recovery rate of 53.9%. The study of oil displacement mechanism shows that the excellent ability to reduce the oil–water interfacial tension of OAAB can emulsify heavy oil to small droplets easily, exhibiting better capacity in oil displacement efficiency. The polymer can increase the viscosity of the aqueous phase, reduce the mobility ratio of water to oil, weaken the fingering effect, and improve the sweep efficiency. Lignin can not only reduce the adsorption quantity of betaine surfactant, but also promote the adsorption of OAAB onto the oil–water interface, leading to enhance the emulsification performance of OAAB and maintain the oil displacement efficiency effectively. Therefore, the surfactant-polymer flooding system based on the betaine surfactant can be developed into an economically and technically feasible flooding technology suitable for ordinary heavy oil reservoirs.     

基于高效液相色谱法测定水产品中甘氨酸甜菜碱

应用高效液相色谱技术,建立水产品中甘氨酸甜菜碱定量检测方法。针对甘氨酸甜菜碱极性特点,选用BEH HILIC色谱柱,以乙腈:水为80:20构成优化的流动相,等度洗脱,紫外法于195 nm波长处检测甘氨酸甜菜碱特征峰。结果表明在15~200 μg/mL浓度范围内,检测目标物浓度与特征峰面积呈良好线性关系(R2=0.9999),方法检出限为5.12 μg/mL,定量限为12.00 μg/mL,平均回收率在96.5%~97.7%,相对标准偏差(RSD)为1.0%~2.2%。三类水产品实样测定,梭子蟹、对虾、花蛤所含甘氨酸甜菜碱分别为0.435、1.685和4.384 mg/g,相对标准偏差分别为0.5%、0.5%及1.8%。本方法简单快速、灵敏度高、重复性好,适用于水产品中甘氨酸甜菜碱定量检测。