Enzymes are emerging as a transformative force in shaping a sustainable chemical industry through industrial biocatalysis. This approach utilizes enzymes to craft intricate molecules, including pharmaceuticals, with minimal environmental impact.
A breakthrough has been achieved by researchers at the Karlsruhe Institute of Technology (KIT). Their innovation involves crafting remarkably robust and active enzyme foams, a novel class of materials. These scientists have already taken steps to protect their invention by filing a patent application for the enzyme foam production process.
Industrial biocatalysis predominantly serves the pharmaceutical and specialty chemicals sectors. Efforts to enhance this process focus on novel techniques. Unlike traditional chemical catalysts, enzymes propel reactions, conserving resources and energy.
Present endeavors center on consistently supplying ample enzyme biocatalysts under gentle conditions. To optimize molecule transformations, enzymes are immobilized within microstructured flow reactors. This immobilization concentrates enzymes, boosting productivity by limiting their mobility and enabling higher enzyme concentrations.
Foamed microdroplets from self-assembling enzymes
Ordinarily, foaming tends to alter enzyme structures, causing a decline in their biocatalytic prowess. Remarkably, the novel protein foams exhibit exceptional stability and activity. Activity gauges an enzyme’s efficacy in ensuring swift interaction between initial substances.
Creating these protein foams involves blending two dehydrogenase enzymes with complementary sites. This mixture spontaneously gives rise to a robust protein network. “Subsequently, a controlled gas flow is introduced to this blend within a microfluidic chip, generating uniformly sized microscopic bubbles,” elucidates Professor Christof Niemeyer of the Institute for Biological Interfaces 1. The resulting foam, with its consistent bubble size, is directly applied to plastic chips and subjected to drying. This process leads to protein polymerization, forming a resilient hexagonal lattice.
Prof. Niemeyer adds, “These uniform all-enzyme foams adopt a three-dimensional porous architecture composed solely of biocatalytically active proteins.” The stable hexagonal honeycomb pattern of the foams boasts an average pore diameter of 160 µm and 8 µm lamellae thickness. This distinctive structure materializes within minutes through the uniform spherical bubbles’ orchestrated interplay.
Efficient use of the active and stable full-enzyme foams
Efficient utilization of enzymes in conversion reactions necessitates their large-scale immobilization under gentle conditions to preserve activity. Previously, enzymes were immobilized on polymers or carrier particles, consuming reactor space and potentially diminishing activity. In contrast, the newly developed foam-based materials offer a significantly expanded surface area for the desired reactions, as highlighted by Niemeyer.
Counter to expectations, these foams display exceptional endurance, mechanical strength, and enzyme catalysis – an unprecedented feat in protein foaming. Researchers attribute this stability to enzyme matching junctions, enabling self-assembly and the formation of an immensely stable material network during drying.
Remarkably, these enzyme foams outperform enzymes lacking foaming, maintaining remarkable stability even after four weeks of drying. Niemeyer notes, “This enhances commercial viability, streamlining production and delivery.”
These pioneering biomaterials unlock avenues for innovation in industrial bioengineering, materials science, and food technology. Protein foams offer potential for biotechnological processes, enhancing efficient and sustainable production of valuable compounds. Notably, the researchers harnessed foams to create tagatose, a promising refined sugar substitute, underscoring their transformative potential.