Cellulase in Degradation of Lignocellulosic Wastes

Gunjal, Aparna; Patil, Neha N.; Shinde, Sonali

doi:10.1007/978-3-030-44671-0_2

Cited by 1 publication

(1 citation statement)

References 103 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For Tr Cel7A and Tr Cel7B at least nine glucosyl binding subsites have been identified (− 7 to + 2) [ 26 , 27 ]. GH3 BGs have pocket or crater topology [ 28 ] with only two glucosyl binding subsites (− 1 and + 1) generally described [ 29 ]. Thus, it is interesting to consider how some BGs can accommodate a cellulose chain in their active sites.…”

Section: Introductionmentioning

confidence: 99%

Activity of fungal β-glucosidases on cellulose

Keller

Sørensen

Krogh

et al. 2020

Biotechnol Biofuels

View full text Add to dashboard Cite

Background: Fungal beta-glucosidases (BGs) from glucoside hydrolase family 3 (GH3) are industrially important enzymes, which convert cellooligosaccharides into glucose; the end product of the cellulolytic process. They are highly active against the β-1,4 glycosidic bond in soluble substrates but typically reported to be inactive against insoluble cellulose. Results: We studied the activity of four fungal GH3 BGs on cellulose and found significant activity. At low temperatures (10 ℃), we derived the approximate kinetic parameters k cat = 0.3 ± 0.1 s −1 and K M = 80 ± 30 g/l for a BG from Aspergillus fumigatus (AfBG) acting on Avicel. Interestingly, this maximal turnover is higher than reported values for typical cellobiohydrolases (CBH) at this temperature and comparable to those of endoglucanases (EG). The specificity constant of AfGB on Avicel was only moderately lowered compared to values for EGs and CBHs. Conclusions: Overall these observations suggest a significant promiscuous side activity of the investigated GH3 BGs on insoluble cellulose. This challenges the traditional definition of a BG and supports suggestions that functional classes of cellulolytic enzymes may represent a continuum of overlapping modes of action.

show abstract