TY - JOUR
T1 - High Activity CAZyme Cassette for Improving Biomass Degradation in Thermophiles
AU - Bomble, Yannick
AU - Brunecky, Roman
AU - Chung, Daehwan
AU - Hengge, Neal
AU - Mittal, Ashutosh
AU - VanderWall, Todd
AU - Michener, William
AU - Himmel, Michael
AU - Russell, Jordan
AU - Young, Jenna
AU - Pason, Patthra
AU - Westpheling, Janet
AU - Sarai, Nicholas
AU - Shollenberger, Todd
N1 - Publisher Copyright:
© 2018 The Author(s).
PY - 2018
Y1 - 2018
N2 - Background: Thermophilic microorganisms and their enzymes offer several advantages for industrial application over their mesophilic counterparts. For example, a hyperthermophilic anaerobe, Caldicellulosiruptor bescii, was recently isolated from hot springs in Kamchatka, Siberia, and shown to have very high cellulolytic activity. Additionally, it is one of a few microorganisms being considered as viable candidates for consolidated bioprocessing applications. Moreover, C. bescii is capable of deconstructing plant biomass without enzymatic or chemical pretreatment. This ability is accomplished by the production and secretion of free, multi-modular and multi-functional enzymes, one of which, CbCel9A/Cel48A also known as CelA, is able to outperform enzymes found in commercial enzyme preparations. Furthermore, the complete C. bescii exoproteome is extremely thermostable and highly active at elevated temperatures, unlike commercial fungal cellulases. Therefore, understanding the functional diversity of enzymes in the C. bescii exoproteome and how inter-molecular synergy between them confers C. bescii with its high cellulolytic activity is an important endeavor to enable the production of more efficient biomass degrading enzyme formulations and in turn, better cellulolytic industrial microorganisms. Results: To advance the understanding of the C. bescii exoproteome we have expressed, purified, and tested four of the primary enzymes found in the exoproteome and we have found that the combination of three or four of the most highly expressed enzymes exhibit synergistic activity. We also demonstrated that discrete combinations of these enzymes mimic and even improve upon the activity of the whole C. bescii exoproteome, even though some of the enzymes lack significant activity on their own. Conclusions: We have demonstrated that it is possible to replicate the cellulolytic activity of the native C. bescii exoproteome utilizing a minimal gene set, and that these minimal gene sets are more active than the whole exoproteome. In the future, this may lead to more simplified and efficient cellulolytic enzyme preparations or yield improvements when these enzymes are expressed in microorganisms engineered for consolidated bioprocessing.
AB - Background: Thermophilic microorganisms and their enzymes offer several advantages for industrial application over their mesophilic counterparts. For example, a hyperthermophilic anaerobe, Caldicellulosiruptor bescii, was recently isolated from hot springs in Kamchatka, Siberia, and shown to have very high cellulolytic activity. Additionally, it is one of a few microorganisms being considered as viable candidates for consolidated bioprocessing applications. Moreover, C. bescii is capable of deconstructing plant biomass without enzymatic or chemical pretreatment. This ability is accomplished by the production and secretion of free, multi-modular and multi-functional enzymes, one of which, CbCel9A/Cel48A also known as CelA, is able to outperform enzymes found in commercial enzyme preparations. Furthermore, the complete C. bescii exoproteome is extremely thermostable and highly active at elevated temperatures, unlike commercial fungal cellulases. Therefore, understanding the functional diversity of enzymes in the C. bescii exoproteome and how inter-molecular synergy between them confers C. bescii with its high cellulolytic activity is an important endeavor to enable the production of more efficient biomass degrading enzyme formulations and in turn, better cellulolytic industrial microorganisms. Results: To advance the understanding of the C. bescii exoproteome we have expressed, purified, and tested four of the primary enzymes found in the exoproteome and we have found that the combination of three or four of the most highly expressed enzymes exhibit synergistic activity. We also demonstrated that discrete combinations of these enzymes mimic and even improve upon the activity of the whole C. bescii exoproteome, even though some of the enzymes lack significant activity on their own. Conclusions: We have demonstrated that it is possible to replicate the cellulolytic activity of the native C. bescii exoproteome utilizing a minimal gene set, and that these minimal gene sets are more active than the whole exoproteome. In the future, this may lead to more simplified and efficient cellulolytic enzyme preparations or yield improvements when these enzymes are expressed in microorganisms engineered for consolidated bioprocessing.
KW - Anaerobe
KW - Biofuels
KW - Biomass
KW - Biomass degrading enzymes
KW - Caldicellulosiruptor bescii
KW - Cellulose
KW - Thermophile
UR - http://www.scopus.com/inward/record.url?scp=85041448368&partnerID=8YFLogxK
U2 - 10.1186/s13068-018-1014-2
DO - 10.1186/s13068-018-1014-2
M3 - Article
AN - SCOPUS:85041448368
SN - 1754-6834
VL - 11
JO - Biotechnology for Biofuels
JF - Biotechnology for Biofuels
IS - 1
M1 - 22
ER -