초록
<P><B>Abstract</B></P> <P>The main drivers to develop biorefineries are the energetic and environmental crisis. Consequently, bioenergies have become a scientific and industrial trend. In North Africa, especially in Tunisia, <I>Luffa cylindrica</I> (LC) is a promising energy crop providing lignocellulosic biomass for biofuels production. Three principal fractions compose LC biomass, viz.: α-cellulose (45.8 ± 1.3)%, hemicellulose (20.76 ± 0.3)% and lignins (13.15 ± 0.6)%. The hydrothermal pretreatment of LC fibers was carried out at 96 °C for 54 min. After pretreatment, the reducing sugars amount reached 33.55 g/kg. The subsequent enzymatic saccharification was performed during 1 h at a temperature of 60 °C, by means of two commercial enzymes AP2 and SPC. The enzyme AP2 seemed to be more suitable for the enzymatic hydrolysis of pretreated LC fibers by allowing the release of 59.4 g/kg of reducing sugars, which correspond to a reducing sugars recovery about 93.29%. After that, the liquid state fermentation (LSF) was achieved with <I>Saccharomyces cerevisiae</I> strain during 24 h, in sterile and non-sterile conditions at 30 °C, pH 4.8 ± 0.2 and stirring 250 rpm, in order to conclude about the influence of contamination microflora on fermentation efficiency. After the LSF step, 88.66% of reducing sugars were transformed into alcohol with a conversion rate of 1.58% and a volumetric yield about 70% in sterile conditions. Thus, this work confirms that the potential conversion yield of cellulosic bioethanol is 1 Ton (dry matter) of LC fibers to 13.8545 kg (= 3.6599 Gallon) of biofuel.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The maximum reducing sugars amount is 59.4 g/kg for the hydrolysis made with AP2. </LI> <LI> Ethanol conversion efficiency is 1.58% and its volumetric yield 70%. </LI> <LI> The potential conversion yield of 1 Ton of LC fibers is 3.6599 Gallon of biofuel. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>