Work

Experimentation of various co-culture fermentation strategies for better efficiency bioethanol production using wild cassava flour (Manihot glaziovii Muell. Arg) as substrate

Year: 2025

Type: article

Abstract: • Wild cassava presents a promising raw material option for bioethanol production. • Co-culture fermentation is able to increase the efficiency of bioethanol production. • Local isolates were simultaneously proven to be able to convert cassava flour into bioethanol. • Bioethanol production from wild cassava flour is a viable alternative energy source. The continuous increase in global demand for fossil-based fuels has driven the need for sustainable and renewable energy alternatives such as bioethanol. Wild cassava ( Manihot glaziovii Muell. Arg), a non-edible starch-rich crop with high cyanogenic content, represents a promising feedstock for bioethanol production without competing with food resources. This study aimed to enhance bioethanol production efficiency from wild cassava flour (WCF) through various co-culture fermentation strategies combining Aspergillus niger FNCC 6018, isolate R5I4, and isolate R5I3 under Simultaneous Saccharification and Fermentation (SSF) and Simultaneous Saccharification and Co-Fermentation (SSCF) conditions. The fermentation was conducted at 35°C and pH 5 for 7–8 days in a 250 mL bioreactor containing 33.33 g of WCF and 166.67 mL of distilled water, with agitation at 100 rpm. Among 17 treatment combinations, the co-culture of R5I4, A. niger FNCC 6018, and R5I3, added at the 96th hour, yielded the highest ethanol concentration (28.277 ± 0.228 g/L), efficiency (46.20 ± 0.37%), productivity (0.168 g/L/h), and yield coefficient (0.028 g/g). SEM and HPLC analyses confirmed efficient starch hydrolysis and glucose-to-ethanol conversion. Phylogenetic analysis identified R5I3 as closely related to Candida orthopsilosis (91 %) and R5I4 to Klebsiella variicola (83 %). These findings demonstrate that wild cassava flour is a viable substrate for efficient bioethanol production using co-culture SSF/SSCF systems. Future work should focus on scaling up fermentation, optimizing environmental parameters, and exploring the metabolic engineering of the microbial consortium to improve ethanol yield and process economics further.

Source: South African Journal of Chemical Engineering

DOI: 10.1016/j.sajce.2025.11.013

Authors: Ida Bagus Wayan Gunam, I Gede Arya Sujana, I M. Mahaputra Wijaya, I Wayan Arnata, Yohanes Setiyo, I Wayan Wisma Pradnyana Putra

Institution: Udayana University

Language: English

Topic: Biofuel production and bioconversion

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Responsible consumption and production, Zero hunger

Open Access status: gold

Estimated APC paid: $950