Unravelling the capability of Pyrenophora phaeocomes S-1 for the production of ligno-hemicellulolytic enzyme cocktail and simultaneous bio-delignification of rice straw for enhanced enzymatic saccharification

•Isolation of a natural fungal variant producing ligno-hemicellulolytic enzymes.•High co-productivities of laccase, xylanase and mannanase on rice straw under SSF.•Maximum yield of cocktail after 8 days by Pyrenophoraphaeocomes on rice straw.•Appreciable biodegradation of lignin and hemicellulose of rice straw in 40 days.•4.90 fold increase in released sugars upon enzymatic hydrolysis of treated biomass.

A natural variant of Pyrenophora phaeocomes isolated from natural biodiversity was able to grow on various agricultural residues by co-producing laccase, xylanase and mannanase. Solid state fermentation of rice straw induced the highest productivities corresponding to 10,859.51 ± 46.74, 22.01 ± 1.00 and 10.45 ± 0.128 IU gds−1 for laccase, xylanase and mannanase respectively after 4 days. Besides producing the ligno-hemicellulolytic enzyme cocktail, 40 days cultivation of P. phaeocomes S-1 on rice straw brought about the 63 and 51% degradation of lignin and hemicellulose. These components were further removed with mild alkali extraction revealing the overall losses amounting to 78 and 60% respectively for lignin, and hemicellulose. The biologically pretreated straw upon enzymatic hydrolysis revealed 50% saccharification efficiency releasing 470 mg g−1 sugars. Application of this knowledge will lead to efficient management of waste rice straw with low cost production of industrially important enzymes cocktail and its biological delignification for effective enzymatic hydrolysis to free sugars.

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