植物乳杆菌烈性噬菌体P2生物学特性的研究

发布时间：2018-05-15 23:00

  本文选题：植物乳杆菌 + 噬菌体　； 参考：《内蒙古农业大学》2017年硕士论文

【摘要】：乳酸菌是一类广泛应用于发酵食品行业的有益菌种,可以生产乳制品、肉制品以及青贮饲料等产品。而发酵过程中常常会有噬菌体侵染到乳酸菌内,从而导致发酵过程缓慢甚至发酵失败,对发酵工厂造成巨大的经济损失。因此,噬菌体的污染被认为是食品发酵行业存在的巨大威胁之一。本实验从异常发酵液中分离并纯化了植物乳杆菌烈性噬菌体P2,并以之作为研究对象,分析了其形态特征、耐受能力、吸附特性,以及不同植物乳杆菌菌株对该噬菌体的敏感性。数据结果显示,噬菌体P2的头部是二十面体对称结构,直径大小约为66.67±3.00 nm,有一条长216.67±3.00 rnn且宽12.25±3.00nm非收缩性尾,属长尾噬菌体科B1型。该噬菌体的潜伏期为30min,裂解期为135 min,裂解量平均为214.49±3.98PFU。不同的pH值(2～11)对噬菌体P2的存活率有明显影响,在pH 2、3时其存活率为0,存活率在pH 6～9可达80%以上,且在pH 8时存活率最大;在50℃时下降到 12.89%。对于噬菌体P2,pH 5～9对该菌体的吸附率没有明显影响,均可达到90%以上。在pH为4、10、11时,噬菌体吸附率虽有所下降,但仍在50%以上。温度对噬菌体P2的吸附率影响较小,除50℃以外,其他温度下的吸附率均可达到88.29%以上。Ca2+对噬菌体P2的吸附能力起到了一定的促进作用,而Mg2;则会在一定程度上抑制噬菌体P2的吸附能力,其提高效果为Ca2+未添加Mg2+。氯霉素对噬菌体P2的吸附能力没有明显影响。经吸附30min后,吸附率仍可达到90.19%以上。实验选用的38株植物乳杆菌菌株中,仅有3株菌对噬菌体P2表现出敏感性,分别是NM20-4、WH6-1-1和NM24-2,说明P2具有较高的侵染特异性。本实验研究了植物乳杆菌烈性噬菌体P2的生物学特性,可在丰富乳杆菌噬菌体数据库的同时,为生产过程中对控制该噬菌体提供一定的理论依据和数据支持。
[Abstract]:Lactic acid bacteria (lactic acid bacteria) are a kind of beneficial bacteria widely used in fermented food industry, which can produce dairy products, meat products and silage products. During fermentation, bacteriophage often infects lactic acid bacteria, which leads to slow fermentation and even failure of fermentation, resulting in huge economic loss to the fermentation plant. Therefore, bacteriophage contamination is considered to be one of the great threats in food fermentation industry. The bacteriophage P2of Lactobacillus plantarum was isolated and purified from the abnormal fermentation broth, and its morphology, tolerance, adsorption and sensitivity to the bacteriophage were analyzed. The results showed that the head of the phage P2 was icosahedral symmetrical, with a diameter of about 66.67 卤3.00 nm, and a non-contractile tail with a length of 216.67 卤3.00 rnn and a width of 12.25 卤3.00nm, belonging to the B1 type of the long-tailed phage family. The latent period of the phage was 30 min, the lytic period was 135 min, and the average amount of cleavage was 214.49 卤3.98 PFU. The survival rate of phage P2 was 0 at pH 2,3, over 80% at pH 6 ~ 9, and the highest at pH 8, and decreased to 12.89 at 50 鈩，

本文编号：1894311