Advancement of fermentable sugars from fresh elephant ear plant weed for efficient bioethanol production

Environ Dev Sustain. 2022;24(5):7377-7387. doi: 10.1007/s10668-021-01753-x. Epub 2021 Aug 17.

Abstract

Bioethanol is considered one of the most promising next-generation automotive fuels, as it is carbon neutral and can be produced from renewable resources, like lignocellulosic materials. The present research investigation aimed to utilize the elephant ear plant, a hazardous plant (weed) also considered an invasive species, as a font of non-edible lignocellulosic biomass for bioethanol production. The freshly collected elephant ear plant (leaves and stalk) was chopped into small pieces (1-2 cm) and then homogenized to a paste using a mechanical grinder. The sample pretreatment was done by flying ash for three different time durations (T1 = 0 min, T2 = 15 min, and T3 = 30 min) with 3 replications. All treatment samples were measured for total sugar and reducing sugar content. The concentration of reducing sugar archived was T1 = 0.771 ± 0.1 mg/mL, T2 = 0.907 ± 0.032 mg/mL, and T3 = 0.895 ± 0.039 mg/mL, respectively. The results revealed that the chemical composition was different among treatments. The hydrolysis was performed using cellulase enzymes at 35 °C for the hydrolysis process. The hydrolysate was inoculated with 1% of S. cerevisiae and maintained at room temperature without oxygen for 120 h. Bioethanol concentration was measured by using an ebulliometer. The efficient ethanol percentage was 1.052 ± 0.03 mg/mL achieved after the fermentation. Therefore, the elephant ear plant invasive weed could be an efficient feedstock plant for future bioethanol production.

Keywords: Elephant ear plant; Fermentation; Hydrolysis; Reducing sugar; Total sugar.