16S rRNA sequencing of untreated sludge samples and filter cake for methane and hydrogen production

Sugarcane industry byproducts hold significant potential as feedstocks for biogas and biohydrogen production through dark fermentation. The utilization of vinasse and filter cake (FC) for hydrogen (H2) production has gained traction due to the FC's richness in micronutrients and microorganisms that expedite and facilitate the process. Silage, an anaerobic storage technique involving natural fermentation, in which microorganisms carry out the breakdown of macromolecules (primarily carbohydrates) into smaller molecules that are easier to consume, such as xylose, fructose, and glucose. Considering the inherent challenge of lignocellulosic material degradation in FC and the time required for dark fermentation processes, this study aimed to assess the impact of different ensiling durations on FC and its co-fermentation with sugarcane vinasse for H2 production and use the digestate to produce methane (CH4). FC was ensiled for 0, 20, 40, 80, and 100 days, employing an inoculum subjected to acid pretreatment to select for hydrogen-producing bacteria