Aspergillus niger Spore Transformation via HDEN Electroporation
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Solution Overview
Problem
Current methods for introducing exogenous DNA into resting spores of Aspergillus niger are inefficient and require mediators or complex processes, making direct transformation challenging due to the spores' dormant state and thick cell walls.
Innovation Solution
The use of High-Density Electrotransformation (HDEN) technique to directly introduce exogenous DNA into non-germinated resting spores of Aspergillus niger without mediators, utilizing an electroporation buffer and specific electroporation parameters to generate an electric field within the spore-plasmid mixture, facilitating DNA uptake.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If protoplast-mediated transformation is used to introduce exogenous DNA into Aspergillus niger, then DNA transformation can be achieved, but the process becomes extremely cumbersome and requires expensive cell wall hydrolases
Solution Approach 1:
The invention extracts and removes the cell wall from the transformation process entirely. Instead of using protoplasts (cells without cell walls) as the starting material, the method directly transforms intact spores with cell walls, eliminating the need for cell wall hydrolysis and expensive hydrolase enzymes while maintaining transformation capability
Solution Approach 2:
The invention introduces polyethylene glycol (PEG) as a chemical mediator that facilitates DNA uptake by intact spores. The PEG treatment creates temporary pores or increases membrane permeability, allowing exogenous DNA to enter the spores without requiring cell wall removal, thus simplifying the process
2Reliability
If Agrobacterium tumefaciens-mediated transformation is used, then foreign DNA can be inserted into host genome, but the process is time-consuming and has host selectivity limitations
Solution Approach 1:
The invention replaces the biological mechanism of Agrobacterium-mediated transformation with a direct physical-chemical method. Instead of using bacterial vectors that require infection, replication, and genome integration over extended periods, the method uses PEG-mediated direct DNA uptake by spores, dramatically reducing transformation time and eliminating host selectivity constraints
3Ease of manufacture
If biolistic transformation is used to introduce DNA into cells, then direct DNA introduction is achieved, but expensive equipment and gold particles are required with high cell death rate
Solution Approach 1:
The invention replaces expensive gold particles and complex biolistic equipment with inexpensive, disposable PEG reagent. The PEG treatment is a simple chemical process that can be performed in standard laboratory equipment, eliminating the need for costly particle accelerators and metal particles while maintaining effective DNA delivery and preserving cell viability
4Adaptability or versatility
If traditional electroporation is used on resting spores, then mediator-free transformation is achieved, but the thick cell walls of dormant spores prevent efficient DNA uptake
Solution Approach 1:
The invention applies PEG treatment as a preliminary action before electroporation. This pre-treatment softens the cell wall and increases membrane permeability of the dormant spores, preparing them to receive the electric shock and take up DNA more efficiently, thus combining mediator-free approach with enhanced transformation efficiency
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 method achieves high transformation efficiency, with at least 6000 positive transformants per reaction system, bypassing the need for spore germination and eliminating the use of costly equipment or complex mediator-based processes.
Implementation Method 1
The use of High-Density Electrotransformation (HDEN) technique to directly introduce exogenous DNA into non-germinated resting spores of Aspergillus niger without mediators, utilizing an electroporation buffer and specific electroporation parameters to generate an electric field within the spore-plasmid mixture, facilitating DNA uptake.
Data Source
AI summary
The present invention discloses a method for direct transformation of exogenous DNA into resting spores of Aspergillus niger independent of mediators. The method includes three steps of culture of Aspergillus niger and collection of spores, pretreatment of Aspergillus niger spores, and electroporation of Aspergillus niger spores by using HDEN method, to obtain Aspergillus niger spores with introduction of plasmids to be transformed. In the present invention, non-germinated spores are used as a starting material for introduction of an exogenous molecule, and exogenous DNA is introduced into the resting spores of Aspergillus niger by employing the HDEN electrotransformation technique, whereby the complex step of spore germination is omitted, and steps of protoplast preparation or Agrobacterium-mediated transformation in conventional methods etc. are omitted. Moreover, the transformation efficiency is high, and at least an effect of no less than 6000 positive transformants per transformation reaction system can be achieved.