A research team from University of São Paulo (USP) and São Paulo State University (UNESP) has introduced a new enzymatic approach to pulp bleaching—one that could significantly reduce the industry’s reliance on chlorine-based chemicals.

The study, supported by São Paulo Research Foundation (FAPESP) and published in BioResources, demonstrates how a fungus-derived enzyme can improve bleaching efficiency while lowering environmental impact.

Rethinking a High-Impact Stage in Paper Production

Bleaching remains one of the most chemically intensive steps in pulp manufacturing.

Traditionally, mills rely on oxidizing agents such as:

• Chlorine dioxide
• Other chlorine-based compounds

While effective, these chemicals:

• Generate toxic byproducts
• Contaminate wastewater streams
• Release harmful gases into the atmosphere

👉 This has long been a critical environmental pressure point in the pulp and paper industry.

The Breakthrough: Xylanase from Agricultural Waste

The Brazilian team focused on producing xylanase, an enzyme that breaks down xylan—a hemicellulose component in plant cell walls.

This enzyme was extracted from the fungus:

👉 Aspergillus caespitosus

What makes this approach different is not just the enzyme—but how it is produced.

Low-Cost, Circular Production Model:

• Cultivated on sugarcane bagasse
• Also grown on wheat bran
• Produced via solid-state fermentation

👉 Both materials are abundant agricultural residues, turning waste into a functional industrial input.

Why Xylanase Matters in Bleaching

After pulping, residual lignin remains bound with xylan fractions.

This creates challenges:

• Reduced brightness
• Higher chemical demand in bleaching

Xylanase helps by:

• Breaking down xylan structures
• Releasing trapped lignin residues
• Improving pulp brightness

👉 Result:

Lower chemical consumption in subsequent bleaching stages

A Key Advantage: Thermal Stability

One of the biggest limitations of enzyme-based bleaching has always been temperature.

Most fungal enzymes:

• Degrade above ~40°C

But this enzyme performs differently.

👉 It remains active at around 60°C

This is significant because:

• Industrial bleaching temperatures decrease in later stages
• The enzyme can be integrated into final bleaching steps

👉 Not as a replacement—but as a complementary optimization layer

What This Means for Industrial Application

This technology does not eliminate chemicals entirely.

But it changes the equation:

Before:

Full reliance on chemical bleaching

Now:

Hybrid process:

• Chemical bleaching (primary)
• Enzymatic treatment (optimization stage)

👉 Outcome:

• Reduced chlorine dioxide usage
• Lower environmental load
• Improved process efficiency

Regional Advantage: Why Brazil Is Leading This Development

Brazil’s position as a global leader in eucalyptus pulp production makes this innovation strategically important.

Key factors:

• Abundant biomass resources
• Strong agro-industrial integration
• Established pulp export industry

👉 The ability to convert agricultural waste into industrial enzymes aligns directly with:

Circular bioeconomy principles

Substrate Selection: A Practical Industrial Consideration

The study also highlights a key operational detail:

👉 Feedstock choice depends on regional availability

Sugarcane Bagasse:

• Requires alkaline pretreatment
• High efficiency after processing
• Ideal in sugar/ethanol regions

Wheat Bran:

• No pretreatment required
• Easier fungal growth
• Suitable in grain-producing regions

👉 This flexibility supports localized industrial adoption.

What Comes Next: Enzyme Reusability and Scale-Up

The research team is now working on improving industrial viability through:

Enzyme Immobilization

• Fixing enzymes onto solid supports
• Allowing repeated reuse
• Improving process economics

Emerging Approach:

• Magnetic nanoparticles
• Combined with nanocellulose

👉 Potential benefits:

• Higher temperature resistance
• Easier recovery and reuse
• Cross-industry applications (e.g., bioethanol production)

Industry Insight: A Gradual but Strategic Transition

This development reflects a broader trend in pulp and paper:

Moving from fully chemical processes
To bio-assisted industrial systems

The shift is not immediate—but it is directional.

What This Means for Mills and Technology Providers

For Pulp Producers:

• Opportunity to reduce chemical costs
• Improved environmental compliance
• Enhanced sustainability positioning

For Equipment & Process Suppliers:

• New integration points for enzyme treatment stages
• Demand for temperature-controlled process optimization
• Increased focus on hybrid bleaching systems

Final Thought

This is not a disruptive replacement technology.

It is something more practical—and more likely to scale:

👉 A process enhancement that reduces chemical dependency without compromising performance

Last Updated on 09/04/2026 by Jota Machinery