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嗜酸乳杆菌转化菜籽油生成共轭亚油酸条件的优化 总被引:1,自引:0,他引:1
文中对嗜酸乳杆菌静息细胞转化菜籽油生成CLA工艺进行了优化研究,通过单因素试验,确定了最适转化液介质、介质浓度、pH、温度、转化时间和细胞浓度,同时,研究了不同金属离子对亚油酸异构酶活性的影响。在该基础上,利用Box-Benhnken中心组合设计和响应面法对转化时间、pH、温度、细胞浓度进行了工艺优化分析,确定了在菜籽油浓度为7.5 mg/mL、脂肪酶的加入量为2 mg/30 mL时,以0.1 mol/L柠檬酸-柠檬酸钠缓冲液为转化液介质条件下,最优转化工艺条件是时间25 h,pH6.5,温度36℃,细胞浓度40 mg/mL,经优化后CLA的生成量可以达到230.12±7.52μg/mL。 相似文献
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从传统泡菜中选育高产共轭亚油酸(Conjugated Linoleic Acid,CLA)的菌株L28,利用人工诱变方法,以L28为出发菌株,采用紫外线、亚硝基胍(NTG)依次诱变及紫外、亚硝基胍复合诱变处理,经进一步液体发酵复筛获得多株突变菌株,CLA的最优产量为95.1425μg/mL.其中L44突变菌株为CLA生成能力最高菌株.经16S rDNA全序列分析法和生理生化试验确定菌株的种属,然后经过Gene Bank基因比对确定同源基因,最后经鉴定为嗜酸乳杆菌(Lactobacillus acidophilus). 相似文献
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一株嗜酸乳杆菌突变株转化亚油酸为共轭亚油酸条件的研究 总被引:10,自引:0,他引:10
以嗜酸乳杆菌为出发菌株,用紫外诱变方法,得到一株共轭亚油酸转化量较高的突变株,其转化亚油酸为共轭亚油酸的最佳条件为:反应温度35℃,pH值4.0,保温时间48h,亚油酸与培养液的比例为1000mg:100ml,在此条件下共轭亚油酸的产率达38.1%。在1mmol/L浓度下,Na^ 、Fe^2 、Mg^2 有助于提高共轭亚油酸的产量,而Hg^2 、Co^2 、Cu^2 、Mn^2 、Fe^3 不利于共轭亚油酸的合成。用超声波处理细胞后,共轭亚油酸的产率显著提高。 相似文献
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以鲜羊奶为原料,保加利亚乳杆菌和嗜热乳链球菌为基础发酵剂,在此基础上分别添加嗜酸乳杆菌和干酪乳杆菌,研究温度对两菌株发酵羊奶过程中酸度、pH、活菌数及总活茵数的影响.结果表明:嗜酸乳杆菌酸羊奶的最佳发酵温度为37℃,此时凝乳时间为4h,酸度、pH、嗜酸乳杆菌数和总活菌数分别为97.8 0T、3.88、1.8×107 CFU/mL和1.38×109 CFU/mI,感官评价总分可达到8.35分;干酪乳杆菌羊奶的最佳发酵温度为39℃,此时酸羊奶凝固时间为4.5h,酸度、pH、干酪乳杆菌数和总茵数分别为79.2 °T、4.48、1.56×108 CFU/mL和1.81×109 CFU/mL,感官评价总分可达到7.00分. 相似文献
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针对益生菌嗜酸乳杆菌(Lactobacillus acidophilus)包被发酵的形成特性和营养需要,采用Plackett-Burman试验设计优化其增殖培养基,获得高密度培养条件和提高菌粉存活率方法。结果表明,嗜酸乳杆菌包被发酵的增菌最佳培养基组成为:葡萄糖7.77%、蛋白胨2%、牛肉膏2%、酵母粉3%、柠檬酸氢二铵0.3%、K2HPO4·7H2O 0.2%、MgSO4·7H2O 0.09%、MnSO4·4H2O 0.025%、NaAc·3H2O 0.3%、吐温-80 0.1%、海藻酸钠1.45%、纳米碳酸钙2.93%。在此优化条件下,嗜酸乳杆菌活菌数达4.32×1010 CFU/mL,制备成的冻干粉在37 ℃条件下贮藏100 d后仍保留75%以上的存活率。 相似文献
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Optimisation of fermentation conditions for probiotication of sorghum wort by Lactobacillus acidophilus LA5 下载免费PDF全文
Ahmed Hassani Martin Zarnkow Thomas Becker 《International Journal of Food Science & Technology》2015,50(10):2271-2279
Probiotics are considered as significant segments of functional foods. The response surface methodology was used to optimise the fermentation process conditions for the development of a probiotic sorghum wort beverage fermented with Lb. acidophilus LA5. The central composite design was applied with three fermentation parameters such as temperature, inoculation dosage and initial pH. Each parameter was varied at three levels. All parameters had single or interaction significant effects (P < 0.05) on the response variables. The models were highly significant with very low P ‐values. The optimum fermentation conditions were as follows: temperature 33 °C, inoculation dosage 0.8 OD600 and pH 5.3. Under these conditions, a probiotic beverage with viable bacterial cell concentration of 8.0 log10 cfu mL?1, final pH 3.7, lactic acid 3.2 g L?1 and total sugar 52.7 g L?1 can be produced. The validation experiments showed a good agreement between the experimental and predicted values. The results showed that sorghum wort is a suitable medium to produce probiotic beverages fermented with Lb. acidophilus LA5. 相似文献
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对嗜酸乳杆菌发酵复原乳酸奶(凝固型)的最适配方、生产条件及保藏性进行了研究。结果表明,以12%全脂无糖奶粉做的还原乳为原料,添加6%的蔗糖,接种量为5%,在37℃下发酵4h后,放在室温(25℃)下24h,可获得风味较好的酸奶,其酸度可达到72oT,粘度为500mPa·s,活菌数3.7×107cfu/mL。常温下(25℃)贮藏期为3d,冷藏(4℃)贮藏期为15d,冷藏后酸度和粘度都没有太大变化,活菌数可保留106cfu/mL以上,仍具有良好的感官品质和保健作用。 相似文献
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Optimisation of fermentation variables for conjugated linoleic acid bioconversion by Lactobacillus fermentum DDHI27 in modified skim milk 下载免费PDF全文
Effects of fermentation variables on conjugated linoleic acids (CLAs) biosynthesis of Lactobacillus fermentum DDHI27 in modified skim milk were evaluated. A total of 0.5 mg/mL was found to be the optimum linoleic acid concentration for maximum CLA production and this level was used in utilised for all successive experiments. The highest production of CLA isomers was detected at pH 6.0 when compared to other pH levels. Maximum biosynthesis of CLA isomers occurred during stationary growth (48 h) phase at all pH values tested. Validation of CLA isomers produced in selected samples was made by GC‐MS. These results indicate that these parameters strongly influence the CLA production capabilities of the strain. 相似文献
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