Abstract

Three fibrolytic bacteria were isolated from sheep’s colon using cellulose (b), xylan(c) and lignin (d) as selective substrates. The potency of fibrolytic was identified by Subbarao methods. These isolates were then used both in pure and mixed culture with cattle cellulolytic bacteria (a) from the previous research. The isolates were subsequently selected based on their ability to produce gas through biogas and methan measurement using in vitro gas test technique of Tilley and Terry methods. Based on the parameter, the potential isolates then were applied as inoculum for dairy cattle feces fermentation. The application research was based on Randomized Completely Design with inoculum concentration (0, 3, 6 and 9%) as the treatment with three replications. The result showed that the highest in vitrobiogas and methane production was obtained from a-c-d co-culture addition. The a-c-d co-culture as inoculum for in vitro feces fermentation could increase gas production 56.36% and methane 18.09% compared to natural fermentation by feces microbes. Application of 3 to 9% of a-c-d inoculum at the fermentation scale washighly significant (P < 0.01) in increasing biogas production, however, addition of more than 3% of a-c-d inoculum decrease methane concentration. The fibrolytic bacteria from sheep’s colon were potential to increase the efficiency of biogas and methane production; thus, it should be considered as an inoculum for anaerobic fiber waste fermentation.

Keywords: Fibrolytic bacteria, sheep’s colon, inoculum, biogas, methane.