ANAEROBIC FERMENTATION OF THE EPIPHYTIC MICROBIOTA OF ELEPHANT GRASS FOR THE PRODUCTION OF FERMENTATION METABOLITES OF BIOENERGY INTEREST

• DOI: https://doi.org/10.22533/at.ed.13176226240213

• Palavras-chave: Bioenergy. Elephant grass. Anaerobic fermentation. Fermentative metabolites. Epiphytic microbiota.

• Keywords: Bioenergy. Elephant grass. Anaerobic fermentation. Fermentative metabolites. Epiphytic microbiota.

• Abstract:

  The epiphytic microbiota of elephant grass (Pennisetum purpureum) plays a crucial role in hydrolysis and anaerobic fermentation processes, promoting the release of sugars and their conversion into metabolites of energy interest, such as organic acids and ethanol. This study evaluated the fermentative potential of this microbiota under two experimental conditions: (i) solid-state fermentation with different levels of initial acidification (0–4%) and residence times of 10, 20, and 30 days (Rounds 1 and 2), and (ii) liquid-state fermentation supplemented with sucrose (50%) and acetic acid (4%), with and without agitation (Round 3). The results showed intense acidogenic and alcoholic activity, particularly in the production of lactic acid (up to 86.6 g/L) and ethanol (up to 41.9 g/L) in reactors with additives and agitation. Initial acidification significantly modulated the metabolic profile, favoring glucose release and increased levels of acetic and lactic acids. The data demonstrate that the epiphytic microbiota of elephant grass has high potential as a natural inoculant in anaerobic bioprocesses, making it relevant for bioenergy production through biofuels and biogas precursors.