论文总字数：12519字

摘 要

脂肪酶又称甘油酯水解酶，是分解脂肪的酶，脂肪酶在各个应用领域都有很大的潜力价值。本文对脂肪酶生理生化性质作进一步的探索，为以后的研究提供技术资料。本实验首先从采集的富含油脂的土壤样品中培养筛选得到产脂肪酶菌株，对其生理生化性质鉴定和产酶条件的优化，实验结果表明，该菌株在以体积分数为1% 的橄榄油为诱导物，5g/L蔗糖为碳源，40g/L蛋白胨为有机氮源，1g/L (NH₄)₂SO₄ 为无机氮源，pH为6.5的培养基中，于28℃，180r/min摇床培养48h，可达最大酶产量（37.6±0.8）mmol/min/L。

关键词: 脂肪酶，筛选，理化性质，产酶条件

Abstract: Lipase is also known as triglyceride hydrolases. It is an enzyme to break down fat, and has great potential value in various application areas. Physiological and biochemical properties of lipase was further explored to provide technical information for future research in this paper. Lipase producing strain was screened from soil rich in fats at the first time and the nature of the strain producing lipase was identified, at the same time, its fermentation conditions was optimized. According to the experiment, the maximum lipase production of (37.6±0.8) mmol/min/L was obtained at 28℃, 180 r/min and pH 6.5 after 48h incubation using olive oil (1%) and sucrose (5g/L) as combination of peptone and carbon sources, yeast extract (40g/L) and ammonium sulfate (1g/L) as nitrogen sources．

Key words: lipase，screened，physical and chemical properties，fermentation condition

目录

1 前言...........................................................3

1.1脂肪酶的简介................................................3

1.2微生物脂肪酶的研究历程......................................3

1.3微生物脂肪酶的用途............................................4

1.4微生物脂肪酶的前景与展望.....................................4

2 材料和方法......................................................4

2.1 实验材料与仪器..............................................4

2.1.1菌种来源............................................4

2.1.2实验器材............................................4

2.2 实验方法.................................................5

2.2.1培养基与储存液....................................5

2.2.2实验步骤..........................................6

2.2.3筛选和酶活测定结果...............................8

3 菌种的生理生化性质鉴定........................................8

3.1鉴定方法.......................................8

3.2鉴定步骤.......................................8

3.2.1菌种形态的显微观察.................................8

3.2.2菌种的生理生化性质鉴定结果........................9

4 菌种产脂肪酶条件的优化和酶学性质的探索.....................10

4.1培养温度对产酶的影响.............................10

4.2初始pH值对产酶的影响............................10

4.3不同碳源对产酶的影响.............................11

4.4不同氮源对产酶的影响.............................12

4.5不同金属离子对产酶的影响.........................12

4.6培养时间对产酶的影响..............................13

结论..................................................15

参考文献..............................................16

致谢..................................................18

1 前言

1.1 脂肪酶的简介

脂肪酶（Lipase，EC3．1．1．3，甘油酯水解酶）是分解脂肪的酶。它在动植物体和微生物中广泛存在^{[1, 2]}，它能催化天然底物油脂（甘油三酯）的水解，在轻工、化工、医药、食品等行业有广泛的应用。脂肪酶还具有另一重要特征是对于异相的系统具有作用，即在油（或脂）一水界面上的作用，其对均匀分散的或者是水溶性底物无作用，即使有作用也是极其缓慢的，因而脂肪酶也可说是专门在异相系统或水不溶性系统的油（脂）一水界面上水解酯的酶。在脂肪酶的各种来源中，细菌脂肪酶在有机相中催化的反应类型多、反应活性及稳定性最高^[3]。

1.2 微生物脂肪酶的研究历程

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