Ahmed M. Eldin( 2017). Synergistic saccharification by mixture of several fungal semi purified cellulose degrading enzymesMiddle East Journal of Applied Sciences (2017) volume 7(1): 110 - 125
Abstract: Candidates of 28 fungal pre-identified isolates and strains were tested qualitatively for their cellulolytic activities, among which 12 fungi were superior producers and consequently tested quantitatively. Three Aspergillus spp. namely A5, A6 and A7 were found to be best cellulolytic fungi, while both Aspergillus terreus NRRL260 and Phanerochaete chrysosporium NRRL6361 were found to be best xylanase producers. On solid state fermentation (SSF) using pretreated rice straw (RS), the Aspergillus spp. A5, A6 and A7 gave total cellulases (as FPase), exo-cellulases (as CMCase) and cellobiase (as β-glucosidase) activities of ≥ 16, 130 and 21U.g-1ds, respectively. On the other hand, Aspergillus terreus NRRL260 gave best xylanases activity of 804 U.g-1ds. The recovered crude enzymes forming the crude enzyme mixture (CEM) was concentrated (LCEM), ammonium sulfate fractionated (PPE1), semi-purified by gel permeation on Sephadex G100 and finally lyophilized to powder form (PPE2). The resulting cellulases specific activities were 0.50, 0.68, 1.01 and 1.47 U.mg-1, respectively. Those purification and concentration steps resulted in purification fold increase by 1.28, 2.08 and 2.78 for LCEM, PPE1 and PPE2, respectively. PPE2 achieved best degree of saccharification (DoS) at enzyme load ≥ 10 FPU, substrate concentration ≥ 5% and incubation period after 48 hr to be 85%, 87% and 88%, respectively.
Keywords: (Synergistic saccharification fungal purified cellulose degrading enzymes)
