Characterization of an extremely thermo-active archaeal β-glucosidase and its activity towards glucan and mannan in concert with an endoglucanase

Biomass-degrading glycoside hydrolases of archaeal origin

“…Studies focusing on transcriptomics of cultured archaea or reassembling of uncultured archaeal genomes will provide highly useful insights into new archaeal metabolisms, and novel catabolism reactions could be investigated for degradation of complex substrates [105]. [46,47], Pyrococcus horikoshii [52], Saccharolobus shibatae [65], Saccharolobus solfataricus [41], and three unknown archaea [42,81,83]; amylases of Pyrococcus furiosus [43,44,48,49], Sulfolobus acidocaldarius [67], Pyrococcus woesei [54], and Staphylothermus marinus [59]; sylanase of Saccharolobus solfataricus [69]; glucosidases of Pyrococcus furiosus [50,51], Pyrobaculum aerophilum [78] and two unknown archaea [22,40]; galactosidases of Saccharolobus solfataricus [70,71] and Caldivirga maquilingensis [76]; xylosidase of Saccharolobus solfataricus [73]; mannosidase of Saccharolobus solfataricus [74]…”

“…A third example for a combinatorial and multidisciplinary approach in regard to cultivation and omics technologies for archaeal enzyme discovery was performed using samples of the extremely shallow marine vents of Vulcano Island, which were taken at a temperature of 100 °C [22,42,82]. Enrichment cultures of samples were performed under anoxic conditions at a temperature of 90 °C, using carboxymethyl cellulose as carbon source, and the diversity of the enrichment culture was analyzed using a metagenomic approach.…”

“…Further genes encoding putative biomass-degrading enzymes were identified in the partially reassembled genome in which Vul_Cel5A was located. Cloning of the genes and production of the respective enzymes resulted in the identification and characterization of the archaeal β-glucosidase Vul_Bgl1A, which exhibited highest activity at 105 °C towards 4-nitrophenyl β-d-glucopyranoside and cellobiose [22]. Interestingly, by simultaneously applying Vul_Cel5A and Vul_Bgl1A, a significant increase of glucose formation was monitored indicating synergistic effects of the two enzymes.…”

“…[ 40 ] 90 > 67% activity after incubation at 90 °C for 1.5 h HG326254 Combinatorial approach of enrichment culture and screening Enrichment culture* Archaeon Characterized GH derived from enrichment culture T opt [°C] T stab Genbank accession no. *** Shallow marine vent sample from Vulcano Island, incubation 90 °C, cellulosic substrate, anoxic [ 82 ] Unknown, not cultivated in pure culture, probably related to Thermococcus Endoglucanase Vul_Cel5A (GH 5) extracellular enzyme [ 42 ] 115 T 1/2 43 min at 100 °C MH910342 Glucosidase (GH 1) intracellular enzyme [ 22 ] 105 T 1/2 99 min at 75 °C MN329095 Sample from 94 °C geothermal pool of northern Nevada, incubated at 90 °C, cellulosic substrates, anoxic [ 83 ] Unknown, not cultivated in pure culture, probably related to Ignisphaera Endoglucanase EBI-244 (multidomain) extracellular enzyme [ 83 ] 109 T 1/2 4.5 h at 100 °C JF509452 In situ enrichment culture in hot vent (76–99 °C, Kuril archipelago) using xylan as carbon source [ 84 ] Thermococcus sp. Strain 2319X1 Multidomain glycosidase MDG (Multidomain) extracellular enzyme Full-length protein Truncated GH5 version [ 84 ] 60 90 n.l.…”

“…As a consequence, enzymes derived from hyperthermophilic microorganisms have become highly popular for such high-temperature industrial processes since hyperthermozymes exhibit maximum activity at temperatures around 100 °C and are extremely thermostable [21]. Furthermore, when simultaneously applying hyperthermozymes with different substrate specificities, but similar temperature and pH preferences, synergistic effects can be especially beneficial for the efficient utilization of plant biomass [22] ( Fig. 1).…”