Effective microwell plate-based screening method for microbes producing cellulase and xylanase and its application

Area of Science:

• Biotechnology
• Enzymology
• Microbiology

Background:

• Cellulase and xylanase are key enzymes for breaking down cellulosic and hemicellulosic biomass.
• Efficient screening methods are crucial for identifying microbes with these enzymatic activities.

Purpose of the Study:

• To develop and validate a rapid, high-throughput method for screening cellulase- and xylanase-producing microorganisms.
• To optimize the 3,5-dinitrosalicylic acid (DNS) method for microwell plate-based screening.

Main Methods:

• Modified the 3,5-dinitrosalicylic acid (DNS) method for 96-microwell plate screening.
• Cultured microbial isolates on cellulose and xylan substrates, then tested culture supernatants.
• Assessed the stability of glucose and xylose standards at 100°C.

Main Results:

• Identified 21 cellulase-producing and 31 xylanase-producing microbial strains.
• Determined a minimum 20-minute incubation time for stable color development in standard solutions.
• Found 19 strains capable of hydrolyzing both cellulose and xylan.

Conclusions:

• The developed microwell plate method is effective for high-throughput screening of hydrolytic enzyme-producing microbes.
• The identified microbial strains hold potential for applications in bioethanol production.
• Optimized DNS method provides a reliable approach for enzyme screening.