Xylanase and cellulase activities during anaerobic decomposition of three aquatic acrophytes

Abstract

Enzymatic activity during decomposition is extremely important to hydrolyze molecules that are assimilated by microorganisms. During aquatic macrophytes decomposition, enzymes act mainly in the breakdown of lignocellulolytic matrix fibers (i.e. cellulose, hemicellulose and lignin) that encompass the refractory fraction from organic matter. Considering the importance of enzymatic activities role in decomposition processes, this study aimed to describe the temporal changes of xylanase and cellulose activities during anaerobic decomposition of Ricciocarpus natans (freely-floating), Oxycaryum cubense (emergent) and Cabomba furcata (submersed). The aquatic macrophytes were collected in Óleo Lagoon, Luiz Antonio, São Paulo, Brazil and bioassays were accomplished. Decomposition chambers from each species (n = 10) were set up with dried macrophyte fragments and filtered Óleo Lagoon water. The chambers were incubated at 22.5°C, in the dark and under anaerobic conditions. Enzymatic activities and remaining organic matter were measured periodically during 90 days. The temporal variation of enzymes showed that C. furcata presented the highest decay and the highest maximum enzyme production. Xylanase production was higher than cellulase production for the decomposition of the three aquatic macrophytes species.

Biosynthesis, purification and characterization of endoglucanase from a xylanase producing strain Aspergillus niger B03

“…These results may be explained by the degradation of xylan networks between cellulose microfibrils, which allows endoglucanase to degrade cellulose microfibrils in the deeper structure (14). Similar synergistic effect was reported for other xylan and cellulose degrading enzymes (14, 15). …”

Anaerobic decomposition of a native and an exotic submersed macrophyte in two tropical reservoirs

“…The values of POC LS for the two species are close to values found for the submerged species (34.1%) (Nunes et al, 2011). The coefficients of mass loss for both species were higher during the first stage of decomposition (first week).…”

“…This pattern was due to a more rapid mass loss because of the leaching processes of protoplasmic fractions and subsequent dominance of the decomposition processes of the most recalcitrant fraction (Godshalk and Wetzel, 1978;Danell and Sjoberg, 1979;Ayyappan et al, 1986;Asaeda et al, 2000;Chimney and Pietro, 2006). The t ½ for the decay of organic matter from both species (88 days for E. densa and 94 days for H. verticillata) were low when compared with the values obtained for submerged species in various studies (Cunha and Bianchini Junior, 1998;Bianchini Junior, 1999, 2003Asaeda et al, 2000;Nunes et al, 2011): an average of 156 days. However, these periods of half-life can not be accepted as the patterns of the two species because temperature acts as a fundamental role in determining the decay rate of organic matter (Barillier and Garnier, 1993).…”

Cellulase and xylanase activity during the decomposition of three aquatic macrophytes in a tropical oxbow lagoon

“…These released nutrients can increase the bacterial production (33), causing the enzymatic production peak. Nunes et al (25) also observed an initial peak in cellulase and xylanase production in an in vitro anaerobic experiment with 3 other macrophytes of Óleo lagoon ( Ricciocarpus natans (L.) Corda, Oxycaryum cubense (Poepp. & Kunth) and Cabomba furcata Schult.…”