PHA Production via Flagellar Gene Inactivation in Cupriavidus necator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing polyhydroxyalkanoic acid (PHA) by microbes face challenges such as low productivity and high production costs due to complex operations and low product concentration, necessitating an improvement in microbial culture efficiency.
Innovation Solution
A method involving the culture of microbes with an inactivated flagellar protein gene, specifically Cupriavidus necator, which enhances PHA productivity and reduces extracellular protein excretion, utilizing a PHA synthase gene and additional inactivated genes like lipase or dephosphorylating enzymes to achieve higher PHA accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional microbial culture methods are used for PHA production, then microbes can produce PHA as an energy storage material, but productivity is low and production cost increases due to complex operations and low product concentration
Solution Approach 1:
The invention changes the genetic parameters of the microorganism by inactivating the rpoN gene encoding the sigma-53 factor. This genetic modification alters the microbial physiology to reduce extracellular protein secretion while enhancing PHA accumulation, thereby improving productivity without increasing operational complexity
Solution Approach 2:
The invention extracts or removes the problematic rpoN gene from the microbial genome. By deleting this specific gene responsible for excessive protein secretion and low PHA productivity, the system eliminates the source of the problem while preserving normal microbial growth and PHA synthesis capabilities
2Quantity of substance
If microbes are cultured to produce PHA, then PHA can be accumulated in cells as an energy storage material, but product concentration remains low reducing production efficiency
Solution Approach 1:
The invention modifies the genetic parameters of the microorganism by inactivating the rpoN gene, which fundamentally changes the cellular resource allocation. This leads to increased PHA content in cells and improved production efficiency, as the modified microbes redirect metabolic resources away from excessive protein synthesis toward PHA accumulation
3Reliability
If microbes are used for PHA production, then biodegradable plastic can be produced with environmental benefits, but production cost increases due to low productivity and complex operations
Solution Approach 1:
The invention changes the productivity parameter through genetic modification, achieving high PHA productivity with simplified operations. This cost-effective approach maintains the environmental benefits of biodegradable plastic production while eliminating the economic disadvantages of low productivity and complex processing requirements
Solution Approach 2:
The modified microbes serve themselves by automatically directing metabolic flux toward PHA accumulation without requiring complex external control systems. The genetic modification enables the microbes to self-regulate their physiology for optimal PHA production, reducing the need for complex operational interventions and lowering production costs
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
This approach significantly improves PHA productivity, achieving production levels of 150 g/L or more with reduced protein concentration in the culture supernatant, thereby lowering production costs and increasing raw material yield.
Implementation Method 1
production of polyhydroxyalkanoic acid (hereinafter also referred to as PHA) by a microbe... sugar, vegetable oils and fatty acids as a carbon source are given to the bacterium Cupriavidus necator to accumulate PHA in cells
Data Source
AI summary
Provided is a method for producing PHA by a microbe with improved productivity of PHA, and a PHA-producing microbe used for the production method. A method for producing polyhydroxyalkanoic acid, the method including a step of culturing a microbe having a polyhydroxyalkanoic acid synthase gene and an inactivated gene encoding a flagellar protein to cause the microbe to produce polyhydroxyalkanoic acid. In the microbe, a lipase, a dephosphorylating enzyme, and a protein represented by the amino acid sequence of SEQ ID NO: 6 or 7 may be additionally inactivated. The microbe may be Cupriavidus necator.