Lactococcus lactis Protoplast Fusion for 2,3-BDO Production
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Solution Overview
Problem
Current industrial production of 2,3-butanediol is costly and environmentally unfriendly due to reliance on petrochemicals, and pathogenic bacteria used for fermentation pose safety and cost concerns, limiting the development of efficient and sustainable biotechnological production methods.
Innovation Solution
A genetically modified Lactococcus lactis strain with enhanced capacity for 2,3-butanediol production is developed through protoplast fusion of mutagenized parental strains, allowing high yields without the need for antibiotics or expensive supplements, and adaptable to produce acetoin and lactic acid based on culture conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pathogenic bacteria (Klebsiella pneumoniae, Klebsiella oxytoca) are used for 2,3-BDO production, then high production capacity is achieved, but biosafety risks and containment costs increase
Solution Approach 1:
The patent replaces expensive and risky pathogenic bacteria with a safe, non-pathogenic Lactococcus lactis strain that can be used without complex biosafety containment. The strain is designed to be disposable for industrial fermentation without requiring BSL-2 facilities, thereby eliminating containment costs while maintaining production capability
Solution Approach 2:
The patent modifies the metabolic parameters of Lactococcus lactis through genetic engineering to enhance 2,3-BDO production capacity. By altering gene expression levels and metabolic flux distribution, the strain achieves high productivity comparable to pathogenic bacteria but without the associated biosafety risks
2Productivity
If petrochemical feedstocks are used for 2,3-BDO production, then current industrial production is maintained, but environmental impact and cost increase
Solution Approach 1:
The patent replaces the chemical synthesis mechanism (petrochemical feedstocks undergoing chlorohydrination, cyclization, and hydrolysis) with a biological fermentation system using Lactococcus lactis. This substitution eliminates the harmful chemical reagents and processes while achieving the same production goal through metabolic pathways
Solution Approach 2:
The patent changes the fundamental production parameter from petrochemical-based chemical synthesis to biomass-based biological fermentation. This parameter change enables the use of renewable resources and eliminates the environmental pollution associated with traditional chemical processes
3Productivity
If complex chemical synthesis processes are used for 2,3-BDO production, then current production methods are maintained, but process complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the complex intermediate steps (chlorohydrination, cyclization, hydrolysis, vacuum fractionation) from the production process, replacing them with a single fermentation step followed by simple product recovery. This extraction of unnecessary complexity maintains productivity while simplifying the overall process
4Reliability
If wild-type Lactococcus lactis strains are used for fermentation, then safety is maintained, but 2,3-BDO production capacity is insufficient
Solution Approach 1:
The patent applies genetic engineering to change the metabolic parameters of Lactococcus lactis, specifically enhancing the expression of genes involved in the 2,3-BDO biosynthetic pathway. This parameter change increases production capacity while preserving the inherent safety of the non-pathogenic strain
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
The modified strain achieves significantly higher 2,3-butanediol production (up to 20 times that of wild-type strains) with reduced lactic acid production, enabling cost-effective and sustainable industrial-scale fermentation without the need for costly supplements or biosafety measures.
Implementation Method 1
A genetically modified Lactococcus lactis strain with enhanced capacity for 2,3-butanediol production is developed through protoplast fusion of mutagenized parental strains
Implementation Method 2
The modified strain achieves significantly higher 2,3-butanediol production (up to 20 times that of wild-type strains) with reduced lactic acid production, enabling cost-effective and sustainable industrial-scale fermentation
Data Source
AI summary
The present invention provides a modified strain of the bacterium Lactococcus lactis obtainable by a method that comprises a step of fusion of two protoplasts from two Lactococcus lactis parental strains which, compared to the wild type strain of Lactococcus lactis from which they derive, show: (a) an increased ability to produce acetoin and/or 2,3-butanediol (2,3-BDO), and (b) a decreased ability to produce lactic acid, when cultured under aerobic conditions, and wherein the modified strain of Lactococcus lactis has an increased ability to produce 2,3-BDO of at least 20 times the amount produced by the wild type strain, an increased ability to produce acetoin of at least 20 times the amount produced by the wild type strain and a decreased ability to produce lactic acid of at least 10 times the amount produced by the wild type strain, when cultured under aerobic conditions. Also provided are methods to produce acetoin and 2,3-BDO.