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Background. Cellulolytic bacterial consortia (CBC) serve as additives to improve fiber degradation in ruminants, since they improve biogas production and in vitro fermentation characteristics. Objective. To evaluate the biogas production and fermentative characteristics in vitro of mulato grass inoculated with ruminal CBC obtained from ground sawdust, ground mulato grass or whole stem as substrates in the selective culture medium. Methodology. The CBC were obtained from ruminal fluid from a Suiz-Bu cow fitted with a ruminal cannula, which was transferred six times in a selective anaerobic medium. The test consisted of preparing sterile biodigesters with 0.5 g of mulatto grass with 63 d of regrowth, 45 mL of culture medium. The inoculation was with 5 mL of a type of CBC. The biodigesters were incubated 72 h at 39 °C. Biogas production was measured at 3, 6, 9, 12, 24, 48 and 72 h. In the culture media, ammonia nitrogen (N-NH3), total bacterial count, cellulase activity, pH, dry matter degradation (DMD) and neutral detergent fiber degradation (NDFD) were determined at 12, 24, 48 y 72 h. In the biogas production a completely random design was used; while in the rest of the variables a completely randomized design was carried out with a 3x4 factorial arrangement, with fiber source and incubation time as factors. Results. The biogas production of the CBC obtained from the ground grass showed higher (p |
