Synthetic Biology Chassis Cells: Creating Infinite Potential 'Cell Engines'!
Chassis cells are an important concept in synthetic biology, serving as the foundational platform for constructing biosynthetic pathways or biological systems. They carry inserted exogenous genes or synthetic circuits, enabling reprogramming and regulation of cellular functions to produce useful substances or perform specific tasks.
Definition and Concept: Chassis cells refer to host cells that have been modified or selected to have specific genetic backgrounds and physiological characteristics, and are able to accept and stably express exogenous genes or synthesize biological circuits.
It is like a 'blank canvas', providing a basic framework for synthetic biologists to add various functional modules to achieve expected biological functions or production goals.
Common types of chassis cells: 1. Escherichia coli.
Characteristics: It grows rapidly, and in suitable culture media, its doubling time is usually around 20-30 minutes. It can obtain a large amount of cell biomass in a short period of time, which is conducive to the rapid production of target products.
The genetic background is clear, and its genome sequence has been fully sequenced, with in-depth research on its gene regulatory mechanisms, metabolic pathways, and other aspects. This enables scientists to accurately perform genetic manipulation on it and predict the effects of genetic modification.
Easy to perform gene manipulation, there are multiple mature gene editing techniques and tools available, such as traditional plasmid transformation, gene knockout, gene insertion, etc., all of which can be efficiently implemented in E. coli.
Application areas: Widely used in the production of recombinant proteins, amino acids, organic acids and other biochemical products, as well as in the construction of synthetic biology applications such as biosensors.
For example, by introducing specific genes into Escherichia coli, medicinal proteins such as insulin and growth hormone can be produced; Using Escherichia coli fermentation to produce lactic acid for use in industries such as food and chemical.
2. Saccharomyces cerevisiae
Characteristics: It has the cell structure and protein processing modification system of eukaryotes, which can correctly fold and modify expressed eukaryotic proteins, making them have similar activity and function to natural proteins.
For example, for the production of some complex glycoproteins, brewing yeast can perform correct glycosylation modifications, which are difficult for prokaryotic chassis cells to achieve.
High safety, brewing yeast has a long history of use in the food industry and is recognized as a safe microorganism (GRAS), suitable for the production of food additives, biopharmaceuticals, and other products closely related to human health.
The fermentation process is mature and has accumulated rich fermentation experience and mature large-scale cultivation techniques in traditional fermentation industries such as brewing and bread making, making it easy to achieve industrial production.
Application areas: commonly used in the production of vaccines, biopharmaceuticals, industrial enzymes, biofuels (such as ethanol), etc.
For example, in the field of biofuels, brewing yeast can efficiently convert sugars into ethanol and is an important strain for bioethanol production.
3. Bacillus subtilis
Characteristics: Strong ability to secrete proteins, capable of efficiently secreting expressed proteins outside the cell, facilitating protein separation and purification. This has great advantages for the production of secreted protein products such as industrial enzymes, which can reduce downstream production costs.
Non pathogenic, relatively safe for human body and environment, and does not require special biosafety measures during production, suitable for large-scale industrial production.
The growth rate is fast, which can achieve high cell density in a short period of time and improve production efficiency.
Application areas: Mainly used for the production of industrial enzymes (such as amylase, protease, cellulase, etc.), antibiotics, biological surfactants, etc.
For example, in the agricultural field, some antibiotics and biosurfactants produced by Bacillus subtilis can be used for biological control of pests and diseases.
4. Filamentous fungi (such as Aspergillus niger, Aspergillus oryzae, etc.)
Characteristics: It has strong protein secretion ability and complex protein post-translational modification ability, and can produce structurally complex and functionally diverse proteins and secondary metabolites.
It can grow on simple and low-cost culture media with relatively low nutritional requirements, suitable for large-scale industrial production, and can reduce production costs.
The mycelial structure of filamentous fungi endows them with excellent performance in solid-state fermentation, enabling better utilization of nutrients in the solid matrix. Additionally, the heat generated during fermentation is easily dissipated, which is beneficial for maintaining the stability of the fermentation process.
Application areas: Used in the food industry for the production of fermented foods such as soy sauce, fermented black beans, citric acid, and food additives; Used in the industrial field to produce industrial enzyme preparations such as cellulase, amylase, protease, etc.
