EVOL cell promotes adaptive evolution of Escherichia coli resistant to high osmotic pressure
Introduction
Salinization of soil has become a global problem related to human production activities. Under high-salt conditions, plants metabolic activities such as photosynthesis, respiration, and ion transport are greatly affected, leading to growth retardation, yield reduction, and even death. In industrial fermentation processes, it is usually necessary to add high concentrations of sugar or minerals to the reactor, during which microorganisms are prone to hyperosmotic stress, resulting in reduced growth and productivity. Therefore, how to improve the tolerance of organisms to harsh environments has become a key issue in industrial production activities. The traditional adaptive evolution usually places the microorganisms in a culture environment with special conditions (such as special substrates, hyperosmosis, pH value, etc.), and relys on researchers to repeatedly select microorganisms that grow faster, which has problems such as poor timeliness and heavy workload, and the domestication effect is often unsatisfactory.
Automatic Microbial Adaptive Laboratory Evolution Instrument (EVOL cell) is a microbial domestication instrument developed based on the high permeability pipeline and single-phase microfluidic technology, with functions such as microbial cultivation, subculture, gradient addition of chemical factors, real-time detection, oxygen partial pressure control, etc., and can be applied to the cultivation and adaptive evolution of various microorganisms.
Experimental process
Using 1% NaCl as the initial concentration of NaCl-resistant domestication of the strain, the total domestication time was 280 h, and 27 subcultures were completed automatically. Take out the strain when the NaCl concentration reached 2.4%, and compare the tolerance of the strain to NaCl before and after domestication in the shake flask culture system. The original strain and the tolerant strain were cultured in shake flasks in media containing 2% and 2.4% NaCl respectively, and the results were shown in Figure 2B. The growth of the strain domesticated in EVOL cell is better than that of the original strain in a medium with high NaCl concentration. After 10 h of culture in 2% shake flask, the OD values of the original strain and the tolerant strain reached 1.74 and 2.21 respectively, and the growth performance increased by 27.01%. After 10 h of culture in a 2.4% shake flask, the OD values of the original strain and the tolerant strain reached 1.43 and 2.09 respectively, and the growth performance increased by 46.15%.
Figure 2 Adaptive evolution results of E. coli resistant to high NaCl concentration with EVOL cell
Conclusion
In this case, Escherichia coli was used as the research object, and EVOL cell was used to conduct adaptive evolution of its NaCl tolerance to improve the strain's growth ability under high NaCl concentration environment. After 280 hours and 27 rounds of continuous automatic subculture evolution, E.coli had stable growth performance in a medium with high NaCl concentration, and its tolerance to NaCl has increased by 27.01~46.15%, which illustrated the important role of EVOL cell in strain improvement work. Automatic microbial adaptive laboratory evolution instrument greatly improves the automation of domestication work and reduces errors caused by man-made operation in experiments. Real-time detection also helps researchers grasp the growth of strains and adjust adaptive evolution strategies in a timely manner, which has become the future trend of adaptive evolution and cultivation of microorganisms in laboratories and industrial production.
EVOL cell promotes adaptive evolution of Escherichia coli resistant to high osmotic pressure
Introduction
Salinization of soil has become a global problem related to human production activities. Under high-salt conditions, plants metabolic activities such as photosynthesis, respiration, and ion transport are greatly affected, leading to growth retardation, yield reduction, and even death. In industrial fermentation processes, it is usually necessary to add high concentrations of sugar or minerals to the reactor, during which microorganisms are prone to hyperosmotic stress, resulting in reduced growth and productivity. Therefore, how to improve the tolerance of organisms to harsh environments has become a key issue in industrial production activities. The traditional adaptive evolution usually places the microorganisms in a culture environment with special conditions (such as special substrates, hyperosmosis, pH value, etc.), and relys on researchers to repeatedly select microorganisms that grow faster, which has problems such as poor timeliness and heavy workload, and the domestication effect is often unsatisfactory.
Automatic Microbial Adaptive Laboratory Evolution Instrument (EVOL cell) is a microbial domestication instrument developed based on the high permeability pipeline and single-phase microfluidic technology, with functions such as microbial cultivation, subculture, gradient addition of chemical factors, real-time detection, oxygen partial pressure control, etc., and can be applied to the cultivation and adaptive evolution of various microorganisms.
Experimental process
Using 1% NaCl as the initial concentration of NaCl-resistant domestication of the strain, the total domestication time was 280 h, and 27 subcultures were completed automatically. Take out the strain when the NaCl concentration reached 2.4%, and compare the tolerance of the strain to NaCl before and after domestication in the shake flask culture system. The original strain and the tolerant strain were cultured in shake flasks in media containing 2% and 2.4% NaCl respectively, and the results were shown in Figure 2B. The growth of the strain domesticated in EVOL cell is better than that of the original strain in a medium with high NaCl concentration. After 10 h of culture in 2% shake flask, the OD values of the original strain and the tolerant strain reached 1.74 and 2.21 respectively, and the growth performance increased by 27.01%. After 10 h of culture in a 2.4% shake flask, the OD values of the original strain and the tolerant strain reached 1.43 and 2.09 respectively, and the growth performance increased by 46.15%.
Figure 2 Adaptive evolution results of E. coli resistant to high NaCl concentration with EVOL cell
Conclusion
In this case, Escherichia coli was used as the research object, and EVOL cell was used to conduct adaptive evolution of its NaCl tolerance to improve the strain's growth ability under high NaCl concentration environment. After 280 hours and 27 rounds of continuous automatic subculture evolution, E.coli had stable growth performance in a medium with high NaCl concentration, and its tolerance to NaCl has increased by 27.01~46.15%, which illustrated the important role of EVOL cell in strain improvement work. Automatic microbial adaptive laboratory evolution instrument greatly improves the automation of domestication work and reduces errors caused by man-made operation in experiments. Real-time detection also helps researchers grasp the growth of strains and adjust adaptive evolution strategies in a timely manner, which has become the future trend of adaptive evolution and cultivation of microorganisms in laboratories and industrial production.
