耐消化道逆环境短双歧杆菌A04菌株的德育及其抗氧化活性的研究

发布时间：2018-10-09 12:36

【摘要】：双歧杆菌(Bifidobacterium)是人和动物肠道内重要的生理性细菌,它的存在直接影响消化道的健康状况。目前,在我国乃至世界范围内,优良双歧杆菌资源的开发和利用已成为热点。本课题通过体外及体内实验方法,共计五个实验,包括耐消化道逆环境双歧杆菌的筛选、生长特性和生长因子以及抗氧化活性的研究。 (1)以来源于母乳婴儿粪便、未断奶仔猪粪便、市售双歧杆菌制剂和本实验室保存的双歧杆菌为出发菌株,采用改良MRS培养基,模拟人体胃肠道逆环境,对其耐消化道特性进行了研究。研究结果表明,A03、A04和L-1菌株耐受消化道逆环境的能力最好,可用作微生态制剂菌株。同时,A04菌株的生长速度较快,因此最终选定A04菌株,经初步鉴定双歧杆菌A04为短双歧杆菌,定名为Bifidobacterium breve A04。 (2)应用改良MRS培养基,研究了B.breve A04的生长特性,结果表明,它的适宜生长条件为:35℃-37℃、起始pH 7.0、接种量3%,最高活菌数的Ig值达到9.26,生长速度快,产酸能力强,最终pH值为3.78,耐酸能力强,延滞期相对较短,2 h后就进入对数生长期,10 h就达到稳定期。 (3)研究了各种因素对B.breve A04的增殖作用。结果表明,大豆低聚糖的增殖效果最明显(P0.01),其次是低聚异麦芽糖和低聚果糖,水苏糖则几乎没有增殖效果,而且当MRS中低聚糖的浓度达到10%时,对其反而具有一定的抑制作用;8种中药在浓度为2%的时均有增殖效果,以Z_3、Z_1和Z_2效果最显著(P0.01),但其浓度不同对B.breve A04的增殖影响截然不同;4种食品原料对B.breve A04均有促生长作用,较好的增殖作用的组合分别为:M-5%,CJ-2%,TE-2%和LE-5%。 (4)体外清除自由基的初探实验,结果发现,活菌体、培养上清及菌体破碎物均具有明显的抗脂质过氧化能力,能有效地清除DPPH和活性氧自由基,同时还能很好地保护DNA免受自由基损伤。 (5)利用D-半乳糖诱导法建立的小鼠亚急性衰老动物模型,研究B.breve A04活菌体、培养上清及菌体破碎物的延缓衰老的作用。结果发现,活菌体、培养上清及菌体破碎物均能降低血清和肝脏中的MDA的含量;能提高血清中的SOD、CAT活力及总的抗氧化能力;能明显减少脑组织中的脂褐质和MAO的含量,同时能增强肝脏和脑组织的蛋白质的合成能力。结果显示,B.breve A04活菌体、培养上清及菌体破碎物均具有延缓衰老的作用,其机理可能是通过多种途径而实现的。
[Abstract]:Bifidobacterium (Bifidobacterium) is an important physiological bacterium in human and animal intestines. Its existence directly affects the health of digestive tract. At present, the development and utilization of excellent Bifidobacterium resources has become a hot spot in China and even the world. Five experiments were conducted in vitro and in vivo, including screening of bifidobacterium, growth characteristics, growth factors and antioxidant activity of bifidobacterium resistant to adverse environment of digestive tract. The main results are as follows: (1) the bifidobacterium from breast milk, unweaned piglets, market bifidobacterium and Bifidobacterium preserved in our laboratory were used as the starting strains. The modified MRS medium was used to simulate the adverse environment of human gastrointestinal tract. The resistance to digestive tract was studied. The results showed that strain A03 A04 and strain L-1 had the best ability to tolerate the adverse environment of digestive tract and could be used as microecological agents. At the same time, the growth rate of A04 strain was fast, so the strain A04 was selected, and the bifidobacterium A04 was identified as Bifidobacterium brevis, named Bifidobacterium breve A04. (2) the growth characteristics of B.breve A04 were studied by using the modified MRS medium. The results showed that the suitable growth conditions were: 1: 35 鈩，

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