Journal of Technology Innovations in Renewable Energy, 2018, 7, 7-18 7
E-ISSN: 1929-6002/18 © 2018 Lifescience Global
Endophytic Fungi from Aegle marmelos Plant: A Potent and
Innovative Platform for Enhanced Cellulolytic Enzyme Production
Pradeep Kumar Badiya
a
, Sai Praneeth Thota
a
, Sandeep Yerram
a
, Praveen V. Vadlani
b,c
,
Pallavi Vedantam
d
, Sai Sathish Ramamurthy
a,*
, Nageswara Rao Golakoti
a
, Robin Sharma
e
and B.S. Vijaya Kumar
e
a
Molecular Bioprocessing Laboratory, Department of Chemistry, Sri Sathya Sai Institute of Higher Learning,
Prasanthi Nilayam, A.P-515134, India
b
Bioprocessing and Renewable Energy Laboratory, Department of Grain Science and Industry, India
c
Department of Chemical Engineering, Kansas State University, Manhattan, KS 66506, USA
d
Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, 10065, USA
e
Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam Campus,
Puttaparthi, Anantapur Dist., Andhra Pradesh, India
Abstract: Fungi have a prominent status in fermentation for the production of different bio-products. Endophytic fungi
isolated from medicinal plants are particularly formidable in their adaptability to solid state fermentation as an extension
of its natural habitat and are also a potent source of broad-spectrum cellulolytic enzymes. We report for the first time the
use of endophytic fungus isolated from Aegle marmelos for enhanced cellulolytic enzymes production from groundnut
shell (GNS) as substrate. ImageJ software identified Trichoderma harzianum as an endophytic fungus having maximum
radial growth rate. A systematic comparison of the endophytic fungus with Aspergillus oryzae, under solid state
fermentation (SSF) and submerged fermentation (SmF) conditions was performed and enhanced cellulase production
was observed by the endophytic fungus (4.27 FPU/ml) under SSF environment compared to SmF (2.35 FPU/ml). A
comprehensive understanding of the systemic breakdown in the structural integrity of the biomass has been achieved
using a synergy of enzyme assay protocols, spectral and thermal based techniques. The use of endophytic fungi in SSF
systems in our study lays the basis for the production of other industrially important enzymes. The present study opens
the door for the synergistic use of endophytic and epiphytic fungi for the production of cellulolytic enzyme.
Keywords: Fermentation, Biomass, Fungi, Extraction, Agricultural Wastes.
INTRODUCTION
Fossil fuels are a non-renewable energy source
used to make products such as chemicals, solvents,
lastics, synthetic fabrics, and lubricants; the major end
use being transportation fuels [1]. Natural gas and
battery operated vehicles are alternatives to liquid fuels
but not cost effective and the technology is at its early
stage [1]. However, biofuels produced from renewable
bio-sources such as lignocellulosic biomass (LCB) offer
a cleaner, sustainable and affordable alternative [2, 3].
A study reported that ethanol from cellulosic biomasses
reduces 85% of greenhouse gases emission over
gasoline [4].
An extension to cellulosic ethanol from biomass has
been the use of agricultural wastes for bioethanol
production [5, 6]. The agro crop residues being the
most abundant source of carbon in nature have
significantly helped to alleviate global warming and
balance the growing global energy demands [6].
*Address correspondence to this author at the Department of Chemistry, Sri
Sathya Sai Institute of Higher Learning, Prashanthi Nilayam, 515134, India;
Tel: +918790314405; Fax: 08555286919; E-mail: rsaisathish@sssihl.edu.in
However, the main limiting factor in bioprocessing is
the structural integrity of LCB which contributes to
soaring costs of ethanol production [7]. Bioprocessing
in this context plays a key role in lowering the cost of
ethanol production with the use of enzymatic and
fermentation methods [8]. Structural composition of
LCB in particular plays a vital role in the choice of
pretreatment of LCB [3, 9-11]. We have shown in an
earlier investigation that lignin content and its binding
pattern is a significant factor in cellulosic ethanol
production from mutant brown midrib sorghum [12].
In continuation to our effort on low-cost ethanol
production, we have explored in the current
investigation an under-researched and unique class of
fungal species for enhanced generation of cellulase
enzymes. Several studies have reported different
fungal species employed in the production of cellulase
enzymes from LCB using solid state (SSF) and
submerged (SmF) methods [3, 13-21]. However, a
comparative study on the cellulolytic enzymes
production from SSF and SmF by endophytic fungi with
epiphytic fungi has not been reported so far.