International Journal of Scientific & Engineering Research, Volume 4, Issue 6, June-2013 1965
ISSN 2229-5518
IJSER © 2013
http://www.ijser.org
CELLULASE PRODUCTION BY ASPERGILLUS FLAVUS AND
SACCHARIFICATION OF WHEAT STRAW
Swati Pandit 1, Kapil Lawrence 1, Anupama Singh1 , Sangya Singh1 and Reena Lawrence2
[1] Department of Biochemistry and Biochemical Engineering, Sam Higginbottom Institute of Sciences and
Technology, Allahabad.
[2] Department of Chemistry, Sam Higginbottom Institute of Sciences and Technology, Allahabad.
FPase:Filter paper assay, CMCase : Carboxymethyl cellulase assay , DNS : Dinitrosalicylic acid, PDA : Potato dextrose agar ,
h: hour/s
Abstract:
Cellulase production from fungal sources is utilized in the processing of lignocellulosic biomass for production of alternative fuels.
Biomass selection is an important consideration in commercial production of cellulase. Wheat straw is a cheap and readily available
substrate with potential for bioconversion. The production of cellulase using wheat straw as substrate and subsequently
saccharification was investigated in this study. Rapid production of cellulase viz. FPase & CMCase derived from Aspergillus flavus
was observed. Maximum activity of FPase 167 IU/g and CMCase 415IU/g was obtained after 96h of incubation with cellulose as co-
substrate and pH 4.5. Highest saccharification yield was with 25gL
-1
(72%) substrate though higher concentration of wheat straw
inhibited enzyme activity. The study suggests that production of cellulase from Aspergillus flavus using low cost wheat straw as
substrate can be an alternative for large scale low cost enzyme production.
Key words: Cellulases, Lignocellulosic biomass, bioconversion, saccharification
Introduction:
Waste lignocellulosic biomass is considered as one of
the most promising alternatives to fossil fuels for the
production of biofuels and other useful chemicals. In
bio-conversion of cellulosic material into biofuels
cellulases are a perquisite.Agro-industrial wastes
being rich in carbohydrates and other vital
nutrients are considered promising substrates for
culturing fungi used in production of cellulases.
Cellulases are glycosyl hydrolases (GH) and play an
important role however; the major obstacle for the
conversion of lignocellulosic biomass into ethanol is
their production cost [1]. A great deal of effort has been
made to screen and develop cellulases with high
enzymatic activity, stability and low production costs.
Efficient cellulose hydrolysis requires the cooperative
action of endoglucanases (EC.3.2.1.4) which hydrolyze
the cellulose polymer internally, exposing reducing and
non- reducing ends and exoglucanases or
cellobiohydrolase (EC. 3.2.1.91) which act on the
reducing and non-reducing ends, releasing cellobiose
and cellooligosaccharides. The cellulose hydrolysis
process culminates through the action of β-glucosidase
(EC. 3.2.1.21) which cleaves cellobiose, liberating two
molecules of glucose. [2]
Solid-state fermentation resembles the natural
environment of the fungi and has tremendous
potential for the production of hydrolytic enzymes.
The use of low cost wastes as substrates helps to
reduce the cost of the enzymes for which raw
material translates into 40–60% of the production
cost [3]. Various agro-industrial wastes have been
Corresponding Author:
Swati Pandit, Research Scholar Deptt., Biochemistry &
Biochemical Engineering, SHIATS (Formally k/a Allahabad
Agriculture Institute- Deemed University)
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