When biology entered the paper mill

With biosolutions taking the center stage, it’s the story of how an industry once defined by heavy machinery and chemical use began learning from the lightest touch in nature.

From its first known sheets in China, paper has played an indispensable role in human life, and for almost 1,800 years, the possible environmental and health impacts of its production went largely unnoticed.

By the 1980s, however, the pulp and paper industry faced growing scrutiny, as researchers began uncovering a concerning outcome of wood-based, large-scale paper production: 

Highly toxic chemicals, known as dioxins, were appearing in rivers, fish, and even everyday products like diapers ^1,3,5 — posing serious health risks, including cancer, reproductive disorders, and immune system damage. In 1987², the U.S. Environmental Protection Agency confirmed elevated dioxin levels downstream from pulp and paper mills, while in Sweden, fish in the Gulf of Bothnia showed skeletal deformities⁴.

One major source of concern was the use of elemental chlorine in bleaching. While cheap and effective, it reacted with wood’s natural compounds, producing toxic byproducts such as dioxins and furans, another harmful class of chemicals. Governments imposed stricter environmental standards, but global paper demand — already 61 million tonnes annually⁶ — did not pause. The industry turned to alternative chemical bleaching methods, including elemental chlorine free (ECF) with chlorine dioxide, and total chlorine free (TCF) using hydrogen peroxide or ozone, though these often affected paper quality.

Cellulase for refining efficiency and fiber strength

After bleaching, the pulp is a mass of long fibers — stiff, smooth, and stubborn. Left alone, they barely stick together. To make strong paper, these fibers need to fray into tiny, hair-like strands called fibrils. The more fibrils, the more contact points, and the stronger the sheet.

Traditionally, mills relied on massive machines to do the job — pounding fibers into shape with brute force. It worked, but at a cost: huge energy use and frequent fiber damage. Then came cellulase, a quiet biological hero. This enzyme gently softens the fiber’s surface, making fibril formation easier and the refining process far gentler. The result: smoother control, less energy use, and stronger paper. One European mill using cellulase cut refining energy by half while boosting paper strength by 16%¹².

Cellulase also enables more efficient use of fillers like calcium carbonate, which improve smoothness and brightness. By enhancing fiber bonding, mills can add up to 20% filler without weakening the paper¹³, stretching each tree’s potential.

While some enzymes strengthen fibers, others keep machines clean and running smoothly — quietly solving some of papermaking’s toughest operational headaches.
 

Lipase and esterase for tackling pitch and stickies

If you’ve ever scrubbed a greasy pan, you have a sense of what papermakers face — only their “pan” is a massive paper machine, often over 100 meters (300 feet) long, churning out hundreds of tonnes of paper every day.

A constant challenge inside these machines is sticky deposits. There are two main types: pitch and stickies. Pitch comes from the wood itself — natural resins and fats released during pulping that coat metal surfaces and build up over time¹². Stickies, on the other hand, come from recycled paper — labels, tape, and adhesives that melt during processing and create stubborn, sticky contaminants¹².

For decades, mills relied on harsh chemicals, acids, and dispersants to control these deposits, at the cost of energy, frequent shutdowns, and polluted wastewater¹². Enzymes have changed that:

Lipase breaks down the fatty components of pitch into smaller, harmless compounds that either wash away with the pulp or lose their stickiness, while esterase targets synthetic stickies, neutralizing their tackiness¹². Together, they allow paper machines to run longer between cleanings, improve paper quality, and reduce reliance on harsh chemical treatments¹².

Alongside xylanase and cellulase, these enzymes enable mills to work smarter, cleaner, and more sustainably than ever^{12, 13}. Other enzymes, such as alpha-amylase and laccase, have quietly joined the process, addressing starch and lignin residues. These newcomers illustrate how the enzyme palette is broadening, offering more precise, sustainable ways to tackle a wider range of challenges.

Enzymes turn a page in the pulp and paper industry

From a modest beginning in the 1980s, when the first xylanases offered a cleaner way to bleach pulp, enzymes have quietly reshaped the world of papermaking. What began as a response to an environmental challenge has evolved into a powerful industrial advantage.

Today, enzymes reduce chemical use, save energy, strengthen fibers, and improve recycling efficiency — all while maintaining quality. Originally a small experiment, each enzyme brings a touch of precision to a process once ruled by heat and force. These biosolutions are now essential to modern papermaking, pointing to a future where biology continues to inspire innovation.