Review of bioethanol production using diverse substrates and fungal strains: from optimization to production

Abstract

The scarcity and unsustainable supply of fossil fuels in reservoirs instigate researchers to explored several alternate and sustainable energy sources from renewable feedstocks. Given the significance of bioethanol being produced in other to meet the energy demand but the available data is scattered with insignificant effort to condense the findings which will be imperative to comprehend. Therefore, this review highlights and summarizes various findings from previous work on bioethanol production in order to identify knowledge gaps and provide future direction. Published studies (found in the Google Scholar, Scopus and PubMed search engines) that reported bioethanol production from 2000 to 2024 were reviewed using the following search terms/phrases: "bioethanol production", "Renewable feedstocks", "substrates biomass", "Fungal strains", "biomass pretreatment", "reducing sugar" and "fermentation; agent, nutrient, condition and yield.". A total of 3,650 records were collected from various databases and sorted based on the title. Subsequently, titles and abstracts were reviewed to exclude records with incorrect subjects or results. The articles were further screened to remove irrelevant data, resulting in the inclusion of 55 full-text records in this review. The world is experiencing a severe global warming due to widespread usage of fossil fuels. Bioethanol has recently seen growing commercialization due to its market stability, low cost, sustainability alternative fuel energy composition, greener output and massive fossil fuel depletion but the major challenges that hindered bioethanol production are due to a lack of optimization which results in a lower yield of bioethanol produced and as a result, it cannot be applied for large-scale production. In fact, most of the studies that produced bioethanol they only tested the potential of the organism to produce the bioethanol without further optimizing the conditions that will increase the bioethanol yield. Hence, research is needed to address this gap through optimization using the successful candidates to optimize their conditions for large scale bioethanol production using the most successfully utilize substrates to produced bioethanol.