Batch culture分批培养

• cells grow from seed to a final density over 4-7 days and then harvested.
• usually when the cell density reaches the summit or begin to die because of the deficiency of nutrition .

Fed-batch culture补料分批培养

• Cells are fed either continuously or intermittently and parts of the cell suspension are withdraw periodically.
• Primary inoculation normally is ½ ~1/3 of the final volume.
• Feeding time: interphase of the logarithmic phase and decay phase（对数期和衰退期之间）.
• It can be fed by one time or times.
• Variable substrate or product concentration.

Nutritional components for feeding

1. Glucose providing energy and carbon, be care of the production of lactate
2. Glutamine: providing energy and nitrogen source. Shortage may induce apoptosis凋亡
3. Amino acids, vitamine and other: maybe include choline胆碱, growth factors etc.

Continuous perfusion灌注 culture

• differs from chemostat恒化培养 in that all nutrients are kept in excess and cells are retained within the bioreactor. The cells are continuously separated by filtration or sedimentation沉淀、沉降 and recycled into the bioreactor.
• Wide-spread withdraw of the product (eg. antibody) are rotating filter cages, and tangential flow filtration units. 产品的广度提取（如抗体）是旋转滤网箱和切线流过滤装置。
• High cell density (>107),Product concentration up to 1000mg/ml. Sophisticated instrumentation is necessary to control the process

Semi-continuous batch culture半连续分批培养

• partially harvest (e.g. 70%), topped up with fresh medium, allowed to grow up and then harvested again.
• Typically, three or four harvests can be made, although usually with diminishing returns at each harvest.

Bioreactors for culture mode（培养模式的生物反应器）

1. Stirring type bioreactor with the withhold equipment of cell hollow fiber
2. Fixed bed固定床 Medium pass through the surface grown with cells
3. Fluidized bed流化床 The carrier beads with cells boiled by the current of medium or air

Continuous –flow (chemostat) culture 连续流动(恒化器)培养

• the culture is completely homogeneous for long periods of time whilst cells are in a steady state.
• An extremely useful tool for physiological studies but not very economical for production (by definition, cells are never at maximum density).
• Cell keeping growth exponentially. Cells grow evenly due to the constant environment.【透析dialysis对细胞有害的物质】
• High risk for contamination, and change for product for this long time culture.