<p>A comprehensive overview of fermentative biohydrogen production from wheat and rice straw hydrolysate and emphasize the role of these agricultural residues in sustainable circular bio-energy development. In contrast to previously published approaches, the article introduces a conditional-logic heat-map that classifies thirteen pretreatment alternatives into strategic tiers including “efficiency leaders” and “sustainable options”, resulting in an integrated, multi-dimensional decision support for technology selection. This manuscript details the lignin-carbohydrate architecture including bonds (e.g., benzyl esters, phenyl glycosidic linkages) that need to be targeted with dedicated disruption techniques. It explains the biochemistry of dark fermentation and describes acetate and butyrate pathways, as well as how mesophilic species co-metabolize glucose, xylose, and arabinose. One significant contribution is the mechanistic study of inhibitory compounds short-chain acids, furans, phenolics and the elaboration of mitigation strategies including activated-charcoal adsorption and in-situ biodetoxification. The work also combines metabolic-engineering strategies such as (<i>ldh</i>) deletions and (<i>hydA</i>) over-expression, in order to increase the theoretical maximum. Sophisticated AI/ML models (ANN-RSM, XGBoost) can be used for real-time process control and a full-scale LCA for AI-enabled biohydrogen systems is suggested. economic analysis of a reduction in the unit cost to $3.5&#xa0;kg^-1 by 2025 and identified competitive drivers which are global benchmarking and regional logistics as well as a key technology driver for increased salinity gradient energy resource harness. The review concludes with critical research gaps, including the requirement for long-duration stability data, real-time sensors for inhibitors and innovative reactor designs that to prevent foaming and fiber fouling.</p>