Enhanced production of biohydrogen from lignocellulosic feedstocks using microorganisms: A comprehensive review

Biohydrogen (BioH(2)) is a low-carbon fuel with high energy efficiency. Although it can be produced using various technologies, the biological method has been deemed more sustainable and economically feasible. Extensive research has also led to identifying of lignocellulosic feedstocks (LCFs) as the highly abundant and renewable raw material for BioH(2) production. Although there are many hurdles, the use of microbes-dependent processes for BioH(2) production could bring down the operational cost and waste produced, and is efficient enough to meet future energy demands. In this review, the latest developments made in recent years regarding the biological conversion of LCFs to BioH(2) are discussed. The microorganisms involved in the technologies of biological pretreatment, photo- and dark fermentation are presented. The recent developments made with genetic engineering and other factors (like pH, temperature, external additives, and nanomaterials) for enhancing the BioH(2) production from microorganisms using the LCFs are discussed in detail. Each parameter has been explored and analysed to highlight its effects on maximizing hydrogen yield and enhancing the production rate. This aims to contribute to the ongoing research about the potential of these individual parameters to improve BioH(2) production. Furthermore, future perspectives on integration and improvement required to enhance the lignocellulosic-biohydrogen production process are also reviewed.