Production and characterization of holocellulolytic enzymes from Cladosporium sp and their valorisation in bioethanol production

Abstract

Bioethanol production is a hot-button subject in the development of sustainable green fuels for the future sustenance. In India, the current sources of ethanol are sugar mills (produce from molasses) and of the total available ethanol, the maximum of about 45% is used to produce potable liquor, about 40% is used in the chemical industry and the rest (15%) is used for fuel blending purposes. In 2003, the Planning Commission of India recommended a phase-wise bioethanol blending policy (EBP) and later it was mandated as the National Policy on Biofuels (NPB) of India (approved on Dec, 24th, 2009 and coordinated by MNRE), projected an indicative target of 20 % blending of bioethanol by 2017 (20% ethanol + 80% gasoline). Moreover, it was intended to produce the substantial portion of this ethanol from lignocellulosic biomass. Lignocellulose conversion to ethanol is being carried out by means of biochemical routes, which often rely on effective biocatalysts, such as enzymes and microorganisms, in addition to chemicals and heat (thermochemical pretreatment of biomass). But, commercialization of the present-day bioethanol production technology is hindered mainly by the prohibitive cost of the existing enzyme preparations as well as the pretreatment (conversion) technologies. Meeting the ambitious goals of the NBP of India (E20 fuel) will require ~4157 million liters of ethanol that needs to be made from biochemical processing of ~17106013 metric tonnes of the raw lignocellulosic biomass (contains ~5987104 metric tonnes of cellulose). The enzymes for existing Indian industrial cellulosic-ethanol RandDs (Praj Matrix, Qteros, BPCL, Adi Biotech Pvt ltd, Tata chemicals, etc.) are being supplied by several enzyme developers such as Rossari biotech, Novozymes, Advanced enzymes, etc. newline