Enzymes built to last
Enzymes from microbes that thrive in hot springs, acid, radiation and other extremes are intrinsically stable. That extreme stability makes them easier to study and ready for real-world applications.
Microbes thrive in the most extreme conditions, including high temperature, acidity, high pressure, radiation, desiccation and poisonous environments. To survive there, their enzymes have evolved to withstand what would destroy most proteins.
Extreme stability is the key advantage of enzymes from extremophiles. They tolerate heat, extremes of pH and long storage, so they are easier to produce, purify and crystallize, and they can absorb the mutations introduced when engineering them. SsoPox, a lactonase from a hyperthermophilic archaeon, is a model case in our lab.
These intrinsic properties matter for applications: a stable enzyme survives formulation, coating, spraying and months of storage, where a fragile one would not. We study the structural determinants of this stability and use hyperstable lactonases as starting points for quorum quenching and for insecticide decontamination.
Potential applications
- Industrial use
- Decontamination
Try it. Drag the slider across the hot spring. One side tells what the water is like, the other what its microbes give us. Click the glass to send a ripple.
Inside a hot spring
- Grand Prismatic Spring, in Yellowstone, is 200-330 ft (about 60-100 m) across and more than 121 ft (37 m) deep.
- Colorless and yellow microbes live in the hottest water, and orange, brown and green ones in the cooler water.
- Yellowstone's springs range from acidic (pH 0-5) to alkaline (pH 7-11). In the alkaline geyser basins, bacteria and archaea dominate above 75 °C (167 °F).
- The record for life is 122 °C, for the archaeon Methanopyrus kandleri strain 116, from a deep-sea vent and grown under high pressure.
Thermostable enzymes at work
- Taq DNA polymerase comes from Thermus aquaticus, first isolated from Yellowstone hot springs. Its activity half-life is 9 min at 97.5 °C, so PCR can heat DNA in every cycle without fresh enzyme.
- Industrial starch processing runs in jet cookers at 100 °C or more, with thermostable α-amylases.
- Our lactonase SsoPox, from the archaeon Saccharolobus solfataricus, resists heat, solvents, sterilization and storage, and stays active at subzero temperatures.
Sources: US National Park Service, Grand Prismatic Spring; US National Park Service, thermophilic communities; Takai et al., PNAS 2008; Brock and Freeze, J Bacteriol 1969; Lawyer et al., PCR Methods Appl 1993; J Sci Food Agric 2014, thermostable α-amylase and jet cooking; Rémy et al., Sci Rep 2016.
Potential use of enzymes
