MLEs (Mannan:lignin etherase)
Tethys designed a bioprospecting strategy based on an indicating model substrate that would fluoresce when a model of the phenyl-mannan bond was broken and devised a proprietary synthesis of this substrate. The search strategy was designed to exclude enzymes that use a free radical mechanism to break down wood. With these tools, Tethys isolated a previously unknown microbe with a novel enzyme activity.
Tethys has cloned and sequenced the gene encoding the enzyme (patent pending) that cleaves the phenyl ether bond between 4-methylumbelliferone and mannan.
Unengineered HLE in a first-generation expression system extracts an orange color from pulp and decreases the kappa number of oxygen delignified pulp relative to controls. The enzyme has also been shown to increases sugar yield from biomass. A second generation expression system has been developed.