【正文】 characteristics of different strains are screened out after a second screening. There are two kinds of lactic acid bacteria, 11 kind of yeast and five types of mold in total. （ 2） 42 strains of bacteria got in the early screening are put in the protease activity test of lactic acid bacteria. The highest enzyme activity of lactic acid bacteria, yeast and the mold of strains respectively are L4, Y14 and M14. And protease activity respectively are U/mL and U/mL and U/ mL. And L4 is identified as Streptococcus thermophilus according to the molecular biological and physiological and biochemical identification. （ 3） With the reference to Xu Zuyan’s patent, L4 and Y14 are made into enzyme. After 20 days, the protease activity of the experimental group are measured to be U/mL and protease activity to be U/mL in the control group. Preliminary it shows that L4 and L14 can improve the index of protease activity of enzyme, promote the enzyme fermentation as well as improve the functionality of the enzyme. Key words: Probiotics, Screening, Lactic acid bacteria, Yeast, Mold, Appraisal, Enzyme III 目 錄 第 1 章 緒論 ................................................................................................................................... 1 益生菌概述 ....................................................................................................................... 1 益生菌理論的產(chǎn)生 ................................................................................................. 1 益生菌的定義 ......................................................................................................... 1 益生菌作用基本機(jī)理概述 ..................................................................................... 1 益生菌的來(lái)源 ......................................................................................................... 2 益生菌的特征 ......................................................................................................... 2 益生菌的種類 ......................................................................................................... 2 益生菌的作用 ......................................................................................................... 3 益生菌的應(yīng)用 ................................................................................................................... 4 益生菌食品 ............................................................................................................. 4 益生菌保健品 ......................................................................................................... 5 益生菌存在的問(wèn)題 ........................................................................................................... 5 酵素 ................................................................................................................................... 6 酵素的定義、作用及應(yīng)用 ..................................................................................... 6 評(píng)價(jià)微生物酵素的指標(biāo) ......................................................................................... 6 本課題主要研究的內(nèi)容和意義 ....................................................................................... 6 研究?jī)?nèi)容 .................................................................................................................. 6 本課題研究的意義 ................................................................................................. 7 第 2 章 實(shí)驗(yàn)材 料與方法 ............................................................................................................... 8 材料與主要設(shè)備 ............................................................................................................... 8 實(shí)驗(yàn)材料 ................................................................................................................. 8 培養(yǎng)基 ..................................................................................................................... 8 主要試劑 ................................................................................................................. 8 主要儀器設(shè)備 ......................................................................................................... 9 實(shí)驗(yàn)方法 ......................................................................................................................... 10 菌株篩選 ............................................................................................................... 10 菌株蛋白酶活力的測(cè)定 ........................................................................................ 11 菌株鑒定 ............................................................................................................... 11 菌株作用于酵素中的初探 ............................................................................................. 14 第 3 章 實(shí)驗(yàn)結(jié)果與討論 ............................................................................................................. 15 益生菌菌株的篩選 ......................................................................................................... 15 IV 初篩 ....................................................................................................................... 15 復(fù)篩 ....................................................................................................................... 15 菌株蛋白酶活力的測(cè)定 ................................................................................................. 16 賴氨酸標(biāo)準(zhǔn)曲線的制作 ........................................................................................ 16 菌株蛋白酶活力的測(cè)定 ....................................................................................... 16 菌株鑒定 ......................................................................................................................... 17 菌落形態(tài)及菌體形態(tài)觀察 ................................................................................... 17 L4 菌株分子生物學(xué)鑒定 ....................................................................................... 25 L4 系