Artículo
Characterization of the cellulase-secretome produced by the Antarctic bacterium Flavobacterium sp. AUG42
Fecha
2019Registro en:
Herrera, L, Braña, V, Franco-Fraguas, L. y otros. "Characterization of the cellulase-secretome produced by the Antarctic bacterium Flavobacterium sp. AUG42". Microbiological Research. [en línea] 2019, 223-225:13-23. 9 h. DOI: 10.1016/j.micres.2019.03.009
0944-5013
10.1016/j.micres.2019.03.009
Autor
Herrera, Lorena
Braña, Victoria
Franco-Fraguas, Laura
Castro-Sowinski, Susana
Institución
Resumen
Flavobacterium sp. AUG42 is a cellulase-producing bacterium isolated from the Antarctic oligochaete Grania sp.
(Annelida). In this work, we report that AUG42 produces a glycoside hydrolase cocktail with CMCase, PASCase
and cellobiase activities (optimum pHs and temperatures ranging from 5.5 to 6.5 and 40 to 50 °C, respectively).
The time-course analyses of the bacterial growth and cellulase production showed that the cocktail has maximal
activity at the stationary phase when growing at 16 °C with filter paper as a cellulosic carbon source, among the
tested substrates. The analyses of the CAZome and the identification of secreted proteins by shotgun Mass
Spectrometry analysis showed that five glycoside hydrolyses are present in the bacterial secretome, which
probably cooperate in the degradation of the cellulosic substrates. Two of these glycoside hydrolyses may harbor
putative carbohydrate binding modules, both with a cleft-like active site. The cellulolytic cocktail was assayed in
saccharification experiments using carboxymethylcellulose as a substrate and results showed the release of
glucose (a fermentable sugar) and other reducing-sugars, after 24 h incubation. The ecological relevance of
producing cellulases in the Antarctic environment, as well as their potential use in the bio-refinery industry, are
discussed.