Saccharification and fermentation of pretreated banana leaf waste for ethanol production

Abstract

The present work reveals the potential applicability of banana leaf waste as feedstock for bioethanol production as very less work has been reported on this feedstock. For achieving the same, the performance of crude cellulases of Aspergillus niger JD-11 is explored for saccharification of untreated and pretreated (alkaline, dilute acid and steam) banana leaf waste. Therefore, to determine the best saccharifying conditions, the effects of various parameters such as enzyme loading (5-15 FPU/g), temperature (40-50 °C), surfactant addition (0.05-0.15% Tween 80 and PEG 6000) and substrate concentrations (2-6%) were studied at 150 rpm and pH 5.0. The crude cellulases yielded maximum reducing sugars (524.83 mg/g) from the dilute acid pretreated banana leaf waste at 45 °C, 15 FPU/g enzyme loading and 2% substrate loading in the presence of 0.15% PEG 6000 (w/v) as surfactant. The fermentation of enzymatic hydrolysate was carried out using initial reducing sugars concentration of 40 g/L in the medium at pH 5.5, 150 rpm and 30 °C for 30 h with the help of Saccharomyces cerevisiae. Ethanol production was estimated at every 6 h and maximum ethanol yield of 0.38 g/g sugar and productivity of 1.28 g/L/h was obtained after 12 h of fermentation of banana leaf waste hydrolysate. Thus, the easily obtained banana leaf waste could be a promising feedstock for bioethanol production.

Banana stem and leaf biochar as an effective adsorbent for cadmium and lead in aqueous solution

“…In 2017, the global banana production reached a record of 114 million tons, among which China accounted for ~ 10% (~ 11 million tons per year) and ranked the second largest banana producer 13 . However, banana fruit only weights ~ 12% of the whole plant, generating huge amounts (~ 220 t/hectare) of waste residues (i.e., stems, leaves, and rachis) during production 14 . Ortiz-Ulloa et al 15 reported that the average ratio of waste residue (i.e., above-ground biomass) to product (i.e., fruit) was 3.79, and that the biomass of stems and leaves contributed 78% and 17% to the above ground biomass, respectively.…”

Bacterial Nanocellulose Derived from Banana Leaf Extract: Yield and Variation Factors

“…In contrast, biological pretreatment is based on fungi [21] and enzymes [22][23][24][25]. The pretreatment step usually consists of solubilizing the hemicellulose structure and reducing the lignin composition of the biomass [23,26], which facilitates enzyme access to the polymers in the enzymatic hydrolysis stage of cellulose [27,28]. Enzymes are used to reduce the complex sugars present in the biomass, thereby increasing the concentration of simple sugars, such as glucose, galactose, arabinose, and xylose.…”

“…Tarrés et al [6], obtained lignocellulosic micro/nanofibers (LCMNF) where the results determined that this biomass has the potential to be used in paper manufacturing with lower production costs and higher yields than the cellulose nanofiber (CNF) production method. Regarding bioenergy production, Suhag et al [27] reported a maximum bioethanol yield of 0.38 g/g sugar, using dried banana leaf as a carbon source. The use of banana leaf extract has also been investigated.…”

Perspective Chapter: Bioconversion of Agricultural and Food Wastes to Vinegar

“…Microwave-assisted 1% NaOH pretreatment of mango peels for 2 min resulted in 0.704 g/g of reducing sugar yield where cellulose and hemicellulose were 44.2% and 26.2%, respectively [38]. Pretreatment of banana leaf in 0.1 N H 2 SO 4 at 45°C resulted in 524.483 mg/g of reduced sugar yield [39], while microwaveassisted acid pretreatment in 5% H 2 SO 4 at 180°C for 30 min resulted in the cellulose of $37% and hemicellulose of $48% from banana leaf and pith [37]. Nguyen et al did subsequent hydrothermal pretreatment at 95°C for 30 min and enzymatic hydrolysis with 2% cellulase and 0.125% Tween-20 on low-grade longan fruits wastes which yielded 240.396 g/L of reducing sugar [40].…”