The objective of this experiment was to test the effects of a microbial inoculant with or without glucose addition on corn silage fermentation parameters. The microbial inoculant was isolated from ruminal contents after animal donors were induced to ruminal acidosis, then the inoculant was grown in vitro. Treatments evaluated were (1) CONT, corn silage mixed with deionized water with no inoculant, (2) BC, corn silage mixed with 1,600 × 10⁵ cfu of Bacillus coagulans; (3) BC+GLU; corn silage mixed with 1,600 × 10⁵ cfu of Bacillus coagulans, and with 0.25% glucose. The microbial inoculant was diluted in deionized water before combination with the corn silage samples. Air was removed from bags by automatic suction; ensiling was conducted during 60 d in plastic bags and using 400 g of forage for each silo (as-is basis). Data were analyzed with the MIXED procedure of SAS as a completely random design considering treatment as a fixed effect and replication load as a random effect. Statistical replications were achieved by replicating the procedures independently 2 times using corn silage samples from different plots, with 3 experimental silos per treatment within each run. Silage pH (P < 0.05) was affected by treatment with means of 3.90, 3.86, and 3.84 ± 0.009 for CONT, BC, and BC+GLU, respectively. Ammonia concentration (P = 0.43) was not affected by treatment and averaged 2.96 ± 0.338 mg/dL. Total volatile fatty acid concentration was not affected (P = 0.42) and averaged 11.5 ± 1.00 mM. Averages for acetate (P = 0.18) and butyrate (P = 0.22) concentrations were 96.2 ± 3.27% and 0.7 ± 0.97%, respectively. There was a tendency for a treatment effect on propionate concentration (P = 0.09) with means of 0.5, 8.9, and 1.2 ± 2.75% for CONT, BC and BC+GLU, respectively. Overall, although total volatile fatty acid concentration was not affected, inoculation of corn silage with Bacillus coagulans with or without glucose decreased substrate pH, indicating its potential as a microbial inoculant of corn silage.