Exogenous Gene Integration for Microalgal Cell Transformation Using a Nanowire-Incorporated Microdevice

Area of Science:

• Biotechnology
• Renewable Energy
• Materials Science

Background:

• Microalgae are promising for green energy due to high lipid production and growth rates.
• Genetic engineering is key to enhancing microalgal properties for biomass energy.
• The rigid cell walls of microalgae pose challenges for effective gene delivery.

Purpose of the Study:

• To develop a high-throughput microdevice for efficient genetic transformation of microalgae.
• To overcome the challenge of gene delivery into microalgal cells with rigid cell walls.

Main Methods:

• A microdevice incorporating ZnO nanowires and a pneumatic polydimethylsiloxane (PDMS) microvalve was designed.
• A hygromycin B resistance gene (Hyg3) was functionalized on ZnO nanowires.
• Algal cells (Chlamydomonas reinhardtii) were brought into contact with nanowires using PDMS microvalve manipulation for gene transfer.
• Gene integration was confirmed using polymerase chain reaction (PCR) and DNA sequencing.

Main Results:

• The microdevice demonstrated significantly higher gene delivery efficiency.
• Efficiency was 6.52 × 10^4- to 9.66 × 10^4-fold greater than traditional glass bead beating and electroporation.
• Successful integration of the Hyg3 gene into Chlamydomonas reinhardtii was confirmed.

Conclusions:

• The ZnO nanowire-incorporated microdevice offers a highly efficient method for microalgal genetic transformation.
• This technology advances the development of engineered microalgae for sustainable energy applications.
• The microdevice design facilitates both gene delivery and recovery of transformed cells.