论文总字数：15764字

摘 要

嗜酸乳杆菌是能利用可发酵性碳水化合物，产生大量乳酸的一种革兰氏阳性菌，具有调节肠道菌群、抑制病原菌、降低血脂、增强免疫力等多种益生功效,其在食品、医药等领域中的使用日益增多。

高密度培养是指应用一定的培养技术和装置提高菌体的发酵密度，使菌体密度较普通培养有显著的提高，最终达到提高特定产物的比生产率的目的。

为了筛选出适合嗜酸乳杆菌增殖的培养基，得到其高密度培养的条件，本课题以嗜酸乳杆菌的高密度培养为中心开展研究。根据嗜酸乳杆菌对营养物质的要求，通过正交实验，单因素实验对嗜酸乳杆菌的培养条件及培养基进行优化。通过对碳源，初始pH，氮源，生长因子的优化，得到嗜酸乳杆菌增殖培养基最佳配比为：蔗糖2%、酵母蛋白胨1.5%、半胱氨酸盐酸盐0.1%、硫酸锰0.019%、牛肉浸粉0.5%、乙酸钠0.5%、0.1%吐温80、磷酸氢二钾0.2%、柠檬酸氢二铵0.2%、硫酸镁0.058%、番茄粉0.3%，初始pH5.5,37 ℃厌氧培养，到培养终点时，单位体积活菌数达2.8×10¹⁰ CFU/ml,活菌数较基础培养基提高了15倍，为其高密度培养提供了可供参考的理论基础。

关键词：嗜酸乳杆菌 培养基优化 高密度培养

Optimization of medium and high-density culture of Lactobacillus acidophilus

Abstract

Lactobacillus acidophilus is a Gram-positive bacterium that can produce fermentable carbohydrates and produce a large amount of lactic acid. It has various probiotic effects such as regulating intestinal flora, inhibiting pathogenic bacteria, lowering blood lipids, and enhancing immunity. The use in the fields of medicine and medicine is increasing.

High-density culture refers to the application of certain culture techniques and devices to increase the fermentation density of the cells, so that the cell density is significantly improved compared with the ordinary culture, and finally the purpose of improving the specific productivity of the specific product is achieved.

In order to screen a medium suitable for the proliferation of Lactobacillus acidophilus and obtain high-density culture conditions, the subject has been researched on high-density culture of Lactobacillus acidophilus. In order to meet the nutritional needs of Lactobacillus acidophilus, single factor experiments were carried out, and the culture medium and culture conditions of Lactobacillus acidophilus were optimized by orthogonal experiment. By optimizing the carbon source, nitrogen source, growth factor and initial pH, the optimal ratio of Lactobacillus acidophilus proliferation medium was: white sugar 2%, yeast protein 1.5%, cysteine ​​hydrochloride 0.1%, Beef dip powder 0.5%, diammonium hydrogen dichloride 0.2%, sodium acetate 0.5%, 0.1% Tween 80, magnesium sulfate 0.058%, dipotassium hydrogen phosphate 0.2%, manganese sulfate 0.019%, tomato powder 0.3%, initial PH 5. At 5,37 ℃ anaerobic culture, the number of live bacteria per unit volume reached 2.8×1010 CFU/ml, and the number of viable cells was 15 times higher than that of the basic medium, which provided a theoretical basis for high-density culture. .

Key Words: Lactobacillus acidophilus; medium optimization; high density culture

目录

摘 要 I

Abstract II

第一章 文献综述 1

1. 1乳酸菌概述 1

1.1.1乳酸菌简介 1

1.1.2乳酸菌分类 1

1.1.3乳酸菌的一般特性 1

1.1.4乳酸菌与益生菌的关系 2

1.1.5乳酸菌的作用 2

1.2嗜酸乳杆菌概述 3

1.2.1简介 3

1.2.2嗜酸乳杆菌的作用 3

1.2.3嗜酸乳杆菌在各行业的应用 4

1.3高密度培养概述 5

1.3.1定义 5

1.3.2影响因素 5

1.3.3高密度培养方法 6

第二章 培养基优化及高密度培养 8

2.1材料及设备仪器 8

2.1.1菌种 8

2.1.2材料试剂 8

2.1.3设备仪器 8

2.1.4培养基 8

2.2实验方法 9

2.2.1一级二级种子接种培养 9

2.2.2最佳碳源的筛选 9

2.2.3最佳氮源的筛选 9

2.2.4最佳初始pH的筛选 9

2.2.5最佳生长因子及其用量筛选 9

2.2.6正交实验优化 10

2.2.7验证实验 10

2.2.8测量方法及实验准备 10

2.3结果与分析 11

2.3.1最佳碳源筛选 11

2.3.2最佳氮源筛选 12

2.3.3最佳初始PH的筛选 13

2.3.4最佳生长因子及其用量筛选 14

2.3.5正交实验优化 15

2.3.6对照实验 16

2.4结论 16

参考文献 17

致 谢 19

第一章 文献综述

1. 1乳酸菌概述

1.1.1乳酸菌简介

乳酸菌，是指能应用简单的可发酵碳水化合物如葡萄糖、乳糖等糖类，产生大量乳酸、不产孢子、厌氧或兼性厌氧的革兰氏阳性球菌或杆菌的统称^[1]。其代谢产物里都含有乳酸，同时发酵可以产生大量有机酸、醇和各类氨基酸等。乳酸菌在自然界中分布广泛，如动物胃肠道中，土壤，植物根际，水体中等，且其在人胃肠道中能通过自身及代谢产物起促进宿主健康的作用，属于益生菌。而随着科技的发展，乳酸菌与人类生活也越加密切相关，被广泛用于乳制品加工业，食品业，医药行业及畜用饲料及疾病防治等方面，如从乳制品行业的起始培养物到膳食补充剂和生物转化剂等，其中都有乳酸菌的参与，其具有很高的应用价值。

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