chapter4细胞破碎1

Examples Animal tissue and cells Yeast enzymes Cell suspensions at least on a small scale
Large scale treatment of cell suspensions,
Moderate
Cheap
ultrasonication
Organic solvent dissolves in cell wall Moderate, cheap Toluene disruption of yeast
TABLE 4.0-1. Mechanical Cell Disintegration Techniques
Method
M或有机溶剂溶解法。
These chemical cases are often gentle so that the products are not irreversibly不可逆denatured even
while the cells are ruptured. Scale-up is easy: If we want
Harsh
Moderate
Cells crushed between glass or steel balls
Harsh
Cheap
Large scale treatment of cell suspensions and plant cells
Cells chopped in Waring blender Moderate(effect), Moderate Animal tissue and cells
“mechanical.”
In the chemical methods detailed in Section 4.2, the cell membrane is ruptured by osmotic pressure, dissolved by detergents, or enfeebled 使衰弱 by organic solvents.
In some cases, the products of interest are not in the broth but are in the biomass.
In particular, most proteins produced in quantity by genetically manipulated bacteria are not excreted into the broth, but are precipitated within the cell. Lipids and some antibiotics are also trapped in the biomass. In a few cases, like baker’s yeast, the desired product is the cell mass itself. In a few others, desired products like steroids can be extracted without rupturing the cells. In many cases,
Moderat Cheap e Harsh Cheap
[ 'ælkəlai ]
Osmotic rupture of membrane [ɔz'mɔtik] Gentle, cheap Rupture of red blood cells
cell wall digested providing disruption Gentle, expensive Egg lysozyme[ 'laisəzaim] Detergents solubilize cell membrane Gentle Moderateexpensive Bile salts acting on E.coli
Mechanical
methods
Homogenization (orifice type)
ultrasonication
Cells broken with ultrasonic cavitation Harsh expensive Cell suspensions at least on a small scale
Technique Homogenizati on (blade type) Grinding
Principle
Cells chopped in Waring blender Cells ruptured by grinding with abrasives
effect
Moderate
Cost
Moderate
to treat 10 times the biomass, we need to use 10 times as
much chemical.
TABLE 4.0-1. Chemical Cell Disintegration瓦解 Techniques整合,集成
Method Technique Principle Osmotic rupture of membrane cell wall digested providing disruption effect Gentle Cost Cheap Examples Rupture of red blood cells Egg lysozyme[ 'l
Chapter 4
Cell Disruption
第四章 细胞破碎
一、通过本章学习应掌握的内容 1、细胞破碎的意义
2、常用的细胞破碎方法
3、渗透压计算方法 4、了解机械破碎法所用设备
主 要 内 容 ※ 4.0 Summary
※ 4.1 Cell Membranes
※ 4.2 Chemical Methods ※ 4.3 mechanical disruption
We then consider the methods for cell rupture most
likely to be useful at larger scales.
These methods, listed in Table 4-1, are conveniently
split into two groups, described as “chemical” and
Organic solvent dissolves in cell wall Saponification of lipids solubilizes membrane
Gentle
Moderateexpensive
Bile salts acting on E.coli
Toluene disruption of yeast [ 'tɔljui:n ]
Osmotic Shock Alkali treatment
Enzyme digestion
Chemical methods
Lipid dissolution
solubilization
Saponification of lipids solubilizes membrane Harsh, cheap
from the paint industry, where it is used for the size
reduction of pigment.
In this chapter, we begin in Section 4.1 by reviewing
the structure of the cell wall.
Cells ruptured by grinding with abrasives Moderate, cheap(cost) Yeast enzymes
Homogenization (blade type) Crushing in ball mill
Grinding [ 'graindiŋ ]
The equipment which is used is not designed for
biotechnology. Some equipment is borrowed from the
dairy industry, where it was developed for the homogenization of milk; other equipment is taken
Cells broken with ultrasonic cavitation
Cells forced through small hole are broken by shear
Harsh
Expensive
Homogenizati on (orifice type) Crushing in ball mill
Cells crushed between glass or steel balls Harsh, cheap Large scale treatment of cell suspensions and plant cells
[ pɔli'sækəraid ] [ 'stiərɔid ]
Some
Antibiotics polysaccharides Extracellular products
most amino acids
Steroids
[ 'stiərɔid ]
extracellular enzymes
In all these cases, the separated broth can be treated to isolate and purify the product, as described in the chapters which follow. The biomass is discarded or sold as a byproduct.