12.4 Role of Biotechnology in Lignocellulosic Biorefineries
Biorefineries are facilities that providefiber products, biofuels, and other chemical
materials including plastics, sugar polymers, oils, and biomass derived proteins
(Cañas and Camarero 2010 ). Biorefineries combine and integrate various tech-
nologies, among which major are biotechnical methodologies which have the
potential to reduce carbon emissions through different ways; substituting petroleum
as a fuel and as a starting material, increasing process efficiency, closing loops, and
diminishing wastes (Erickson et al. 2012 ). In nature, lignin oxidation performed by
wood-rotting fungi is an important issue for carbon cycling, and its implementation
in the industry can improve the accessibility of chemicals or enzymes to cellulose.
Application of ligninolytic fungi and its enzymes has been extensively studied in
the pulp and paper industry and the production of biofuels (Camarero et al. 2014 ).
Cellulose and hemicelluloses can be hydrolyzed by acid treatments or enzymatic
hydrolysis after pre-treatment, conversion into bioethanol by a microbial fermen-
tation. In contrast, lignin is not constituted of fermentable sugars and due to their
structural properties has an unruly structure challenging to discompose. The
introduction of a pre-treatment step is indispensable to improve digestion ability of
lignocellulose and sugars production (Parawira and Tekere 2011 ; Salvachúa et al.
2011 ; Kataaria et al. 2013 ; Ofori-Boateng and Lee 2013 ). Several physico-chemical
and chemical pre-treatment processes exist for ammoniafiber explosion to improve
lignocellulose saccharification thereby (Kumar et al. 2009 ). However, these tech-
nologies include high high-capital investment with energy demand and also pro-
duce certain sugars that influence the subsequent fermentation (Moreno et al.
2015b). In order to overcome this disadvantages produced by the physico-chemical
pre-treatment, different eco-friendly approaches using biotechnology have been
studied to degrade lignocellulose (biodelignification) and to decrease the quantity of
inhibitors (biodetoxification) (Parawira and Tekere 2011 ; Moreno et al.2015b).
These biotreatments exhibit higher product yield and few side reactions (Moreno
et al.2015b). Moreover, biotechnology processes use mild reaction conditions that
reduced reactor requirements to resist pressure and corrosion and also energy costs
(Moreno et al.2015b). White-rot fungi and their oxidative enzymes avoid the
formation of inhibitors and are an alternative or an additional pre-treatment step to
physico-chemical methods for bioethanol production (Moreno et al.2015a; Castoldi
et al. 2014 ; Castoldi et al. 2014 ; Kudanga and Le Roes-Hill 2014 ; Singh et al. 2014 ;
Ghorbani et al. 2015 ; Moreno et al. 2013 ;Ruíz-Dueñas and Martínez 2009 ).
On the other hand, the pulping process consists of the separation of pulpfibers
from wood for papermaking. One of the less harmful and more promising alter-
natives to improve conventional pulping processes is the use of microorganisms
(such as white-rot fungi) and their enzymes for biotreatment wood chips to reduce
lignin content (Fonseca et al. 2014 ). This process was industrialized to reduce the
electrical energy required for pulping wood chips and to economize active alkali
charge or cooking time for chemical pulping (Mendonça et al. 2002 ; Villalba et al.
2006 ). As mentioned above endophytic fungi have been widely studied as
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