Metabolic flux network and analysis of fermentative hydrogen production

Batch Fermentative Biohydrogen Production Process Using Immobilized Anaerobic Sludge from Organic Solid Waste

“…Based on these equations, 4 mols of biohydrogen are produced from the acetate-fermentation pathway and 2 mols of biohydrogen are produced from the butyrate-fermentation pathway. Earlier studies on biohydrogen production have also shown that biohydrogen-producing bacteria such as Clostridium species form these metabolites during their exponential growth phase [34]. The production of the aforementioned VFA components suggested that both fermentation pathways occurred simultaneously during the biohydrogen fermentation process, as reported in the literature [18].…”

“…A 10-fold and 20-fold biohydrogen increased was achieved using granular and biofilm sludge. A plausible reason for these findings may be due to the fact that these biocatalysts are entrapped within a matrix and therefore can withstand inhibitory fermentative end-products (e.g., alcohols) and extremely low pH during biohydrogen production, unlike suspended cultures which are in direct contact with the fermentation medium [34].…”

“…It has also been shown that incorporating the alginate matrix with supplemental materials such as cellulose, metals, and carbon-source nutrients improves the porosity and mechanical stability of alginate beads [28][29][30][31][32][33][34][35][36][37][38]. Wu et al [1] obtained a three-fold increase in biohydrogen production when alginate beads were supplemented with aluminum oxide and titanium oxide, giving a biohydrogen production rate of 20.3 and 21.3 mmol/L/h, respectively.…”

Biofuels from food processing wastes

“…Figure 1 outlines possible metabolic pathways in fermentative H 2 production using Clostridium sp. [14]. Anaerobic bacteria break down organic substrates via enzymatic oxidation to generate building blocks and produce metabolic energy for growth.…”

“…For example, Fats and lipids in dairy waste and wastewater are not bio-accessible carbon and nutrient sources for H 2 producing microorganisms [14,15]. Hydrolysis of dairy waste materials is able to convert lactose to galactose and glucose from fats and lipids, improving substrate availability and suppression of methanogenic activity [15,16].…”