Microbial Thiamine Factories Using ThiO and ThiI Pathway Engineering
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Solution Overview
Problem
Current methods for thiamine production rely on chemical synthesis using non-renewable fossil fuels, and there is a need for sustainable, bio-based production processes from renewable sources like sugar, with E. coli being a potential microbial cell factory but facing challenges in efficiently producing large amounts of thiamine due to limitations in enzymes like ThiH and ThiI.
Innovation Solution
Replace the E. coli ThiH enzyme with ThiO enzymes from B. subtilis or P. putida and co-express ThiI at optimal levels to enhance the production of dehydroglycine and sulfur transfer, improving the thiamine biosynthesis pathway by incorporating heterologous ThiO and ThiI enzymes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If chemical synthesis process is used for thiamine production, then production efficiency is high, but sustainability is poor due to reliance on non-renewable fossil fuels
Solution Approach 1:
The patent replaces the chemical synthesis process (mechanical/chemical system) with a biological system using genetically modified E. coli cells that produce thiamine through metabolic engineering. This substitution enables sustainable production using renewable resources while maintaining high productivity through optimized microbial cell factories
2Adaptability or versatility
If E. coli is engineered to produce thiamine using native ThiH enzyme, then bio-based production is achieved, but production amount is limited due to low enzyme turnover
Solution Approach 1:
The patent changes the enzyme parameter by replacing the native ThiH enzyme with heterologous ThiO enzymes from B. subtilis or P. putida that have significantly higher turnover numbers. This parameter change increases the catalytic efficiency and enables large-scale thiamine production while maintaining the bio-based production pathway
Solution Approach 2:
The patent creates a composite enzymatic system by combining heterologous ThiO enzymes with optimized ThiI enzyme expression. This composite approach integrates multiple enzymatic functions to overcome the limitations of individual enzymes and achieve high-level thiamine production
3Reliability
If ThiH enzyme is used for dehydroglycine production, then thiamine pathway is complete, but turnover value is very low limiting production
Solution Approach 1:
The patent changes the kinetic parameter of the dehydroglycine production step by replacing ThiH with ThiO enzymes that have turnover values orders of magnitude higher. This maintains the completeness of the thiamine biosynthesis pathway while dramatically increasing the production rate of dehydroglycine and subsequently thiamine
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Significantly increases thiamine production by up to 300% through optimized expression of ThiO and ThiI enzymes, enhancing the thiamine biosynthesis pathway in genetically modified E. coli cells.
Implementation Method 1
ThiO enzymes from B. subtilis or P. putida...converting glycine into dehydroglycine (DHG)
Implementation Method 2
ThiI enzymes catalyzing the transfer of sulfur from IscS to the sulfur carrier protein ThiS
Data Source
AI summary
The present disclosure relates to a genetically modified host cell having improved production of thiamine, wherein the host cell expresses one or more heterologous ThiO enzymes converting glycine into dehydroglycine (DHG) in the host cell and/or one or more heterologous ThiI enzymes catalyzing the transfer of sulfur from IscS to the sulfur carrier protein ThiS in the host cell, whereby the production of the thiamine in the genetically modified host cell is improved compared to an unmodified parent host cell.