Construction method of methanol bioconversion strain, and constructed strain and application thereof

Abstract

The invention discloses a method for constructing a methanol quick utilization strain. The method comprises the steps of firstly, constructing a methanol and xylose mandatory co-utilization basic strain, then performing adaptability evolution on the basic strain by using methanol and xylose as carbon sources to obtain a strain of which the growth rate is significantly accelerated, and finally strengthening the activity of downstream metabolic pathway relevant enzymes of ribulose 5 phosphate in the strain. The invention further discloses the constructed methanol bioconversion strain and a method for performing methanol bioconversion through the strain. Through the strain disclosed by the invention, the methanol and the xylose can be used as the carbon sources, even the methanol is used as the only carbon source, methanol bioconversion is performed, and the conversion efficiency of the methanol is significantly improved. The invention further discloses mutants of some enzymes in the strain, and a method for performing methanol bioconversion through the mutants.

Description

technical field [0001] The present invention relates to the field of biotechnology. Specifically, the present invention relates to a method for improving the methanol bioconversion efficiency of bacterial strains, the bacterial strain obtained by the method, and the application of the method and the obtained bacterial strain in the bioconversion of methanol. Background technique [0002] Methanol is a liquid one-carbon resource, a primary platform product for coal chemical industry, shale gas chemical industry, and gasification of industrial and agricultural waste, as well as an important chemical raw material. Methanol can be synthesized in various ways and from a wide range of sources. It can not only use petrochemical resources such as coal and natural gas as raw materials, but also use biomass resources such as agricultural waste straw, urban organic waste, industrial organic waste such as organic waste slag and steel factory exhaust, or carbon dioxide as a raw material...

AI Technical Summary

Problems solved by technology

[0006] In 2016, researchers such as Price in the United States used Mdh, Hps and Phi multi-enzyme complexes to improve methanol utilization efficiency. However, even with the application of this multi-enzyme complex, it is still impossible to use methanol as the sole carbon source for growth, and can only be catalyzed by resting cells. Methanol method to realize methanol biotransformation (Price, J.V., Chen, L., Whitaker, W.B., Papoutsakis, E., Chen, W., 2016. Scaffoldless engineered enzyme assembly for enhanced methanolutilization.Proc.Natl.Acad.Sci. U.S.A.113, 12691-12696)

In the same year, researchers such as Rohlhill in the United States used formaldehyde-inducible promoters to control the expression of methanol utilization-related genes. Although the efficiency of methanol utilization can be improved, the growth of genetically engineered strains still requires yeast powder and methanol as carbon sources (Rohlhill, J. ,Sandoval,N.R.,Papoutsakis,E.T.,2017.Sort-seq approach to engineering a formaldehyde-inducible promoter for dynamically regulated Escherichia coli growth onmethanol.ACS Synth.Biol.6,1584-1595)

In 2017, Chinese researchers used the linear methanol biotransformation pathway instead of the commonly used RuMP pathway to construct E.coli that biotransforms methanol, although 13 C labeling experiments confirmed that methanol was used by genetically engineered strains to synthesize some metabolites, but the strains still could not use methanol as the sole carbon source for growth (Wang, X., Wang, Y., Liu, J., Li, Q., Zhang, Z .,Zheng,P.,Lu,F.,Sun,J.,2017.Biological conversion of methanol by evolved Escherichia coli carrying a linear methanolassimilation pathway.Bioresour Bioprocess 4,41)

The research team replaced sarcosine oxidase Sox with Mdh, and tried to use methanol instead of sarcosine, but the obtained genetically engineered strains were still unable to utilize methanol in the presence of xylose as an additional carbon source

[0010] Due to the difficulty and complexity of methanol biotransformation research work, no research institutions or companies at home and abroad have constructed platform strains that can use methanol as the only carbon source for growth, which greatly limits the development and application of methanol biotransformation

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