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以从牛乳中筛选出的高产共轭亚油酸乳酸菌M9为研究对象,以亚油酸为发酵底物,探究培养条件对M9共轭油酸产量的影响。通过全波长扫描判定亚油酸和共轭亚油酸的最大吸收波长是否重合;使用紫外分光光度法测定发酵液中共轭亚油酸的含量;以共轭亚油酸含量为指标,通过单因素试验确定M9的最适培养温度、培养时间和发酵液初始pH值;在单因素试验的基础上通过响应面优化得到最佳培养条件。结果表明:亚油酸和共轭亚油酸两者的吸收波长互不干扰;共轭亚油酸标准曲线线性关系良好;响应面模型拟合程度高。经过优化,M9在培养温度为30℃,培养时间为28 h、发酵液初始pH值为6的条件下进行发酵,CLA含量为67.53μg/mL与预测值(70.27μg/mL)接近。 相似文献
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产共轭亚油酸乳酸菌的选育及培养基的确定 总被引:9,自引:0,他引:9
共轭亚油酸(conjugatedlinoleicacid简称CLA)是一种具有多种生理活性的天然脂肪酸。用气相色谱法对十八株乳酸菌产共轭亚油酸的能力进行比较,发现十四株乳酸菌具有明显的产共轭亚油酸的能力,其中德氏乳杆菌保加利亚亚种(L.delbrueckiisubsp.bulgaricus)a2的产量最高,为4.06μg/mL,并且在MRS培养基的基础上确定了乳酸菌产共轭亚油酸的最佳碳源为果糖,氮源为硫酸铵。 相似文献
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从传统泡菜中筛选得到1 株乳酸菌lp15 能够合成共轭亚油酸(CLA),经16S rRNA 全序列分析法和API 系统鉴定法鉴定为植物乳杆菌(Lactobacillus plantarum)。利用人工诱变方法,以lp15 为出发菌株,采用紫外线、硫酸二乙酯(DES)依次诱变处理,经进一步液体发酵复筛获得多株突变菌株,CLA合成能力较出发菌株提高了29.3%~52.2%。其中lp15-2-1 突变菌株为CLA 生成能力最高菌株,MRS 培养液中添加0.2mg/mL LA 培养48h,CLA 产量达30.13μg/mL。经气相色谱(GC)检测分析,产物中cis9, trans11- 共轭亚油酸(c9, t11-CLA)占76.5%,trans10, cis12-共轭亚油酸(t10,c12-CLA)占23.5%。 相似文献
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对植物乳杆菌(Lactobacillus plantarum)lp15-2-1 转化亚油酸生成共轭亚油酸(CLA)发酵工艺进行研究。通过单因素试验确定最佳接种量、培养温度、初始pH 值、培养时间、亚油酸添加时间、亚油酸质量浓度。采用响应面Box-Benhnken 试验设计,建立初始pH 值、培养温度和亚油酸质量浓度的二次多项式回归方程模型,所得植物乳杆菌发酵产共轭亚油酸的最佳参数为:温度30℃、亚油酸质量浓度0.21mg/mL、初始pH6.3,此条件下,CLA得率为44.77μg/mL,CLA 理论得率为45.326μg/mL,转化率为21.32%,与优化前转化率7.78% 相比,有了很大提高。 相似文献
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《中国食品学报》2017,(2)
共轭亚油酸(CLA)为天然脂肪酸亚油酸(LA)的立体和位置异构体混合物的总称,具有多种生理活性。为了开发优良的高产共轭亚油酸的菌株,本文研究7株乳酸菌在MRS培养基中经0.04%(体积分数)的亚油酸诱导培养后,采用紫外分光光度法测定其产共轭亚油酸的能力,结果表明,罗伊氏乳杆菌显示最高的共轭亚油酸生产能力,产量为5.34μg/m L。对筛选出的高产共轭亚油酸菌株——罗伊氏菌株的培养条件进行优化,通过单因素和正交试验确定产共轭亚油酸的最佳发酵条件是:LA的添加量为0.06%(体积分数),培养温度37℃,培养时间30 h,pH 7.0,共轭亚油酸含量达到6.59μg/m L,含量提高了23.4%。作为益生菌的罗伊氏乳杆菌可转化亚油酸为共轭亚油酸,可将其应用于生产富含共轭亚油酸的乳制品中。 相似文献
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共轭亚油酸高产菌株选育及其发酵条件的研究 总被引:8,自引:1,他引:8
以嗜酸乳酸杆菌PB1 (Lactobacillusacidophilus )为出发菌株 ,经紫外线、亚硝基胍单独处理和复合处理 ,获得一株CLA高产菌株U N f3 4,通过单因子和正交试验对该菌株生产共轭亚油酸的发酵条件进行了优化 ,优化的发酵条件是 :培养温度 43℃ ,pH值 7 5 ,培养时间 48h ,在优化条件下 ,U N f3 4可以生产共轭亚油酸达 42 0 5 μg/mL。 相似文献
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ABSTRACT: Natural sauerkraut fermentations contain a great number of lactic acid bacteria. The aim of this study was to identify lactic acid bacterial strains with high conjugated linoleic acid (CLA)-producing ability from natural sauerkraut fermentations. Fifteen CLA-producing lactic acid bacterial strains were isolated in the study. One of these strains, designated as NCUL005, showed the highest CLA-producing ability (0.623 mg/mL). The transformation efficiency of converting linoleic acid into CLA by NCUL005 was 26.67%. The CLA produced by NCUL005 comprised a mixture of 32.2% cis9, trans11-C18:2 isomer and 67.8% trans10, cis12-C18:2 isomer. NCUL005 was identified as Lactobacillus plantarum , based on its cell morphology, characteristics of lactic acid production, and analysis result from Biolog Microbial Identification System (BMIS). 相似文献
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Production of conjugated fatty acids by lactic acid bacteria 总被引:3,自引:0,他引:3
Ogawa J Kishino S Ando A Sugimoto S Mihara K Shimizu S 《Journal of Bioscience and Bioengineering》2005,100(4):355-364
Conjugated fatty acids have attracted much attention as a novel type of biologically beneficial functional lipid. Some isomers of conjugated linoleic acid (CLA) reduce carcinogenesis, atherosclerosis, and body fat. Considering the use of CLA for medicinal and nutraceutical purposes, a safe isomer-selective process is required. The introduction of biological reactions for CLA production could be an answer. We screened microbial reactions useful for CLA production, and found several unique reactions in lactic acid bacteria. Lactic acid bacteria produced CLA from linoleic acid. The produced CLA comprised a mixture of cis-9,trans-11-octadecadienoic acid (18:2) and trans-9,trans-11-18:2. Lactobacillus plantarum AKU 1009a was selected as a potential CLA producer. Using washed cells of L. plantarum AKU 1009a as a catalyst, CLA production from linoleic acid reached 40 mg/ml under the optimized conditions. The CLA-producing reaction was found to consist of two successive reactions, i.e., hydration of linoleic acid to 10-hydroxy-12-octadecenoic acid and dehydrating isomerization of the hydroxy fatty acid to CLA. On the basis of these results, the transformation of hydroxy fatty acids by lactic acid bacteria was investigated. Lactic acid bacteria transformed ricinoleic acid (12-hydroxy-cis-9-octadecenoic acid) to CLA (a mixture of cis-9,trans-11-18:2 and trans-9,trans-11-18:2). Castor oil, which is rich in the triacylglycerol form of ricinoleic acid, was also found to act as a substrate for CLA production by lactic acid bacteria with the aid of lipase-catalyzed triacylglycerol hydrolysis. L. plantarum AKU 1009a produced conjugated trienoic fatty acids from alpha- and gamma-linolenic acid. The trienoic fatty acids produced from alpha-linolenic acid were identified as cis-9,trans-11,cis-15-octadecatrienoic acid (18:3) and trans-9,trans-11,cis-15-18:3. Those produced from gamma-linolenic were cis-6,cis-9,trans-11-18:3 and cis-6,trans-9,trans-11-18:3. The conjugated trienoic fatty acids produced from alpha- and gamma-linolenic acid were further saturated by L. plantarum AKU 1009a to trans-10,cis-15-18:2 and cis-6,trans-10-18:2, respectively. 相似文献
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Increase of Conjugated Linoleic Acid Content in Milk by Fermentation with Lactic Acid Bacteria 总被引:19,自引:0,他引:19
ABSTRACT: The objectives of this study were to identify the factors and procedures responsible for increasing the conjugated linoleic acid (CLA) content in fermented milk. Fourteen lactic acid bacteria were screened for CLA-producing ability using sunflower oil (containing 70% linoleic acid) as a substrate. Among the screened strains, Lactococcus lactis I-01 showed the highest CLA-producing ability. The optimal concentration of sunflower oil for CLA production was 0.1 g/L in whole milk, which accounted for 0.25% of total milk fat. Our results demonstrated that CLA formation in fermented milk could be affected by numerous factors such as bacterial strain, cell number, optimal substrate concentration, and the period of incubation at neutral pH. 相似文献
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Ruminal conjugated linoleic acid (CLA) production from linoleic acid (LA) was characterized in vitro. Rumen bacteria from grain‐fed cows were more active in BH than those from hay‐fed cows. Particleassociated bacteria produced more hydrogenated products leaving less CLA than the planktonic bacteria (P < 0.05). CLA production by planktonic bacteria did not always correlate to LA given; longer incubations generally decreased CLA concentration and increased c9, t11/t10, c12 ratio, especially at higher LA concentrations. The preincubated cells to LA produced more CLA than the unexposed ones and the increase was more evident with c9, t11 CLA (P < 0.05). This study provides insight into how cattle diet and LA feedings affect ruminal CLA production. 相似文献
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ASHISH PANDIT SANJEEV ANAND KENNETH KALSCHEUR ASHRAF HASSAN 《International Journal of Dairy Technology》2012,65(4):603-608
This study was undertaken to evaluate the production and isomeric distribution of conjugated linoleic acid (CLA) in milk fermented with lactic acid bacteria (LAB. A total of 155 cultures of LAB were analysed. Control milk samples had an average CLA content of 0.41 g/100 g of fatty acids (FA), while the lactic cultures produced CLA in the range of 0.43–1.12 g. No major changes in free fatty acids profiles were observed in milk samples fermented with CLA‐producing LAB. The present study demonstrated that LAB can increase levels of CLA in nonsupplemented milk fermented for a short period of 4 h. 相似文献