具有抑制麦芽糖酶活性的乳酸菌筛选及其特性研究

发布时间：2018-05-19 20:40

本文选题：糖尿病 + 抑制　；参考：《江南大学》2009年硕士论文

【摘要】： 麦芽糖酶是一种α-葡萄糖苷酶(EC 3.2.1.20),本文以抑制麦芽糖酶为目的,采用α-葡萄糖苷酶抑制剂的体外筛选模型,筛选出具有较好麦芽糖酶抑制效果的乳酸菌菌株JH28。菌株JH28在MRS肉汤中生长后,其发酵上清及菌体破碎后的细胞裂解物均对麦芽糖酶有抑制作用。将从MRS肉汤培养的菌体细胞经过高压破碎、高速离心后,获得的细胞裂解物经截留分子量为1000 Da的膜透析后,取透析液冻干,获得透析细胞裂解物(DCL)。测定不同浓度DCL对麦芽糖酶的抑制活性,最高抑制率可达67.19%,经计算其IC50为4.12 mg/mL。此外,该菌株的脱脂乳发酵上清对麦芽糖酶也有一定的抑制作用。菌株JH28经过细胞形态观察、培养特征、生理生化特性鉴定以及16s rDNA全序列测定,鉴定为Lactobacillus casei,其16s rDNA全序列与Lactobacillus casei ATCC 343具有100 %的同源性。 Lactobacillus casei JH28的最适生长温度为37℃,最适生长pH为6.5。鉴于JH28具有较强的麦芽糖酶抑制活性,进一步考察了其作为益生菌应用的可能性,对其药敏性、酸耐受性、胆盐耐受性、消化酶耐受性及NaCl耐受性进行了研究。L.casei JH28药敏性试验结果表明,该菌株对试验的24种常见抗生素大多数呈现过敏性;L.casei JH28在pH3.0环境下生长1h后存活率可达128%;L.casei JH28的胆盐最高耐受浓度为0.3%;NaCl最高耐受浓度为8%。 Lactobacillus casei JH28发酵菌体的丙酮提取物经证实具有麦芽糖酶抑制效果,进行薄层色谱分析(TLC)后在254 nm紫外灯下可显示出五个不同组分,其中组分4对麦芽糖酶具有抑制作用,当其浓度为160μg/mL时对麦芽糖酶抑制率为21.74%。
[Abstract]:Maltase is an alpha glucosidase (EC 3.2.1.20). In order to inhibit maltase, this paper uses an in vitro screening model of alpha glucosidase inhibitor to screen out lactobacillus strain JH28. with better maltase inhibition effect.
After the strain JH28 was grown in the MRS broth, the fermentation supernatant and the broken cell lysate of the strain all inhibited the maltase. The cell lysates obtained from the bacterial cells cultured in the MRS broth were broken through high pressure, and after high speed centrifugation, the dialysate was frozen dry to obtain the dialysis cell fissure after the membrane dialysis with the molecular weight of 1000 Da. Hydrolysate (DCL). The inhibitory activity of different concentrations of DCL on maltase was determined. The maximum inhibitory rate was 67.19%, and the IC50 was 4.12 mg/mL.. The supernatant of the defatted milk fermentation of the strain also had a certain inhibitory effect on maltase.
The strain JH28 was observed by cell morphology, culture characteristics, identification of physiological and biochemical characteristics and full sequence determination of 16S rDNA, identified as Lactobacillus casei, and the whole sequence of 16S rDNA has 100% homology with Lactobacillus casei ATCC 343.
The optimum growth temperature of Lactobacillus casei JH28 was 37, and the optimum growth pH was 6.5. in view of the strong maltase inhibitory activity of JH28. The possibility of its application as probiotic was further investigated. The drug sensitivity, acid tolerance, bile salt tolerance, digestive enzyme tolerance and NaCl tolerance of.L.casei JH28 susceptibility test were studied. The results showed that the strain was allergic to most of the 24 common antibiotics in the test; the survival rate of L.casei JH28 after 1h growth in pH3.0 environment was up to 128%, the maximum tolerance of L.casei JH28 was 0.3%, and the highest NaCl tolerance was 8%..
The acetone extract of the Lactobacillus casei JH28 fermented strain proved to have a maltase inhibition effect. After the TLC analysis (TLC), five different components could be displayed under the 254 nm UV lamp, of which 4 of the components had inhibitory effect on maltase, and the inhibition rate of maltase was 21.74%. when its concentration was 160 u g/mL.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R371

【引证文献】