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目的探究伯顿毕赤酵母菌在酸性及胆盐环境下的益生特性,为研制益生菌制剂提供理论依据。方法采用稀释平板计数法,在pH 1.0、1.5、2.0、2.5、3.0和胆盐浓度0.1%、0.2%、0.3%、0.4%的PDA液体培养基以及人工胃液作用0、2、4h,人工肠液作用0、2、4、6、8、10h环境下,分别测定伯顿毕赤酵母菌的活菌数。结果耐酸实验中,各酸性实验组活菌数与对照组比较均下降明显(P<0.01),酸度越高,活菌数越少;耐胆盐实验中,胆盐浓度越高,活菌含量越少,其中0.2%、0.3%和0.4%的胆盐浓度与对照组比较活菌数下降明显(P<0.01);人工胃液实验中,经过pH 1.5人工胃液处理4h,菌株存活率达42.78%,而经过pH 2.5和3.5的人工胃液处理4h,存活率分别为138.17%和182.90%;人工肠液实验中,随着处理时间的延长,活菌数也增加,且不同时间段的活菌数差异有统计学意义(P<0.05)。结论伯顿毕赤酵母菌能够在极高的酸性和较高的胆盐环境以及人工胃肠液环境中存活和定植,符合制备益生菌制剂的条件。
Objective To investigate the probiotic characteristics of Pichia pastoris in acidic and bile salt environments and provide a theoretical basis for the development of probiotic preparations. Methods Diluted plate counting method was used to observe the effect of artificial intestinal juice on PDA liquid medium at pH 1.0,1.5,2.0,2.5,3.0 and bile salts concentration 0.1%, 0.2%, 0.3% and 0.4% The role of 0,2,4,6,8,10 h environment, respectively, determination of viable count of Pichia pastoris. Results In acid-resistant experiment, the number of viable cells in each acidic experimental group decreased significantly compared with the control group (P <0.01), the higher the acidity was, the less the viable cell number was. In the bile salt tolerant experiment, the higher the bile salt concentration, (P <0.01). In the experiment of artificial gastric juice, the survival rate of the strain reached 42.78% after treated with artificial gastric juice at pH 1.5 for 4 hours, , While the survival rate after treated with artificial gastric juice at pH 2.5 and 3.5 for 4 h was 138.17% and 182.90% respectively. In artificial intestinal juice experiment, the number of viable cells increased with the prolongation of treatment time, and the number of viable cells in different periods There was statistical significance (P <0.05). Conclusions Pichia.Berton can survive and colonize in extremely acidic and high bile salt environment as well as artificial gastrointestinal fluid, which is in line with the conditions of preparation of probiotics.