Pretreatment of agave bagasse with ruminal fluid to improve methane recovery.

[Display omitted] • The hydrolysis of agave bagasse by rumen microorganisms was studied. • Substrate concentration had an inhibitory effect on hydrolytic activity. • Low S 0 /X 0 ratios increased agave bagasse's efficiency and hydrolysis rate. • With an S 0 /X 0 ratio of 0.33 up to 6.1 kJ/g TS (155 mL CH 4 /g TS) was obtained. • The most abundant ruminal bacteria were Prevotella , Ruminococcus , and Fibrobacter. Agave bagasse, a lignocellulosic waste that results from the milling and juice extraction of Agave tequilana var azul pineapples, is a suitable substrate for the production of methane through anaerobic digestion. However, it is necessary to apply a pretreatment to convert the bagasse into energy. In this context, this paper proposes using ruminal microorganisms to hydrolyze agave bagasse. This study evaluated the effect of the initial agave bagasse to ruminal fluid (S 0 /X 0) ratio (0.33, 0.5, 1, and 2) on the hydrolysis efficiency. Subsequently, the supernatant was used for methane production. The hydrolysis efficiency increased as the S 0 /X 0 ratio decreased. A hydrolysis efficiency of 60 % was achieved using an S 0 /X 0 ratio of 0.33. The S 0 /X 0 ratio of 0.33 optimally improved the specific methane production and energy recovery (155 ± 2 mL CH 4 /g TS and 6.1 ± 0.1 kJ/g TS) compared to raw biomass. The most abundant hydrolytic bacteria were Prevotella , Ruminococcus and Fibrobacter , and Engyodontium was the most abundant proteolytic fungus. [ABSTRACT FROM AUTHOR]