文档介绍：生物工程专业毕业论文
从自然界筛选产乳酸微生物及菌种初步鉴定
生物工程专业毕业论文
摘要
酸菜是东北地区的一种传统发酵食品BCP选择培养基的分离方法对菌种进行筛选分离通过测定OD值和PH 值来绘制生长曲线
实验总结乳酸菌的最佳pH值和最适盐浓度以及温度H2O2酶试验硫化氢产生柠檬酸盐
关键词酸菜
Abstract
Pickle is a traditional fermented foods in the Northeast of China This experiment used self-brewed Pickle juice as the sources of collecting and breeding bacteria The unknown strains of lactic acid bacteria were isolated and screened from the Pickle juice This experiment used BCP method to select medium for isolating and screening bacteria The drawing of growth curves based on the OD values and the PH values
The results showed that the the optimum conditions for lactic acid bacteria were pH70 0-2 of salt concentration and 37℃ And the physiological and biochemical characteristics of the unknown bacteria were identificated The results showed that H2O2 enzyme test was negative hydrogen sulfide was positive citrate was positive there was acid production but no gas production gelatin liquefaction was negative litmus milk was positive glycogen tests of glucose sucrose fructose lactose were positive
Key words sauerkraut lactic acid bacteria identification
目录
摘要 I
Abstract II
1 绪论 1
1
12 乳酸菌的基本属性 1
13 乳酸菌的发展时期及分类 2
com 乳酸菌的发展时期 2
com 乳酸菌的分类 2
14 乳酸菌的发酵特性 2
15 乳酸菌的应用 3
com 乳酸菌在食品领域的应用 3
com 乳酸菌制剂 4
16 乳酸菌的生理作用和作用机理 4
com 乳酸菌的生理作用 4
com 乳酸菌的作用机理 5
17 6
com 乳酸菌的发展历史 6
com 乳酸菌的发展现状 7
18 7
com 乳酸的概述 7
com L乳酸的生产 8
com 乳酸提取工艺 10
1 本课题的目的及研究的意义 12
2 实验部分 13
21 实验材料与仪器 13
com 实验材料 13
com 13
com 实验试剂 14
com 实验培养基 14
22 实验方法 15
com 从自制酸菜汁中分离提纯乳酸菌的思路和原理 15
15
com 菌种储藏 15
com 样品采集 15
com 乳酸菌的分离和筛选 16
16
com 乳酸菌的生理生化鉴定 17
18
31 乳酸菌的形态学鉴定 18
18
com 乳酸菌的复筛 18
com 菌株形态 19
32 乳酸菌的产酸定性定量试验 20
com 菌株产乳酸试验 20
2 乳酸定量试验 20
3 乳酸菌的生长过程鉴定 21
21
com 菌株最适生长起始pH值的确定 21
com 乳酸菌株耐盐性的确定 22
com 乳酸菌的不同温度生长鉴定 23
33 乳酸菌的生理生化鉴定 25
结论 28
参考文献 29
致谢 31
绪论
乳酸菌是对能利用可发酵碳水化合物产生出大量乳酸的革兰氏阳性细菌的通称自然界中乳酸菌分布十分广泛可以存活在各种动物的消化道及其其他器官里在乳制品发酵植物食品自然界的湖泊和泥土都有所发现人们常常利用乳酸菌产酸等特性来处理和加工食品延长食物的储存时间和提高