Enrichment and Characterization of Sheep Caecum Mixed Lactic Acid Bacteria as Potential Direct-fed Microbials (DFMs) in Livestock

Abstract

Abstract Lactic Acid Bacteria (LAB) have been widely used as feed supplements in the form of live bacteria or Direct-fed microbials (DFMs) which are expected to have a positive impact on livestock productivity. However, each LAB strain has different characteristics so its ability to influence its host livestock will also be different. This research aims to characterize the LAB enrichment process obtained from the caecum of sheep. The sheep caecum LAB underwent re-inoculated while being enriched in MRS broth medium. After obtaining the LAB isolates, characterization was carried out in the form of pH measurements, total plate count, bacteriocin production, and bacterial kinetic growth. The results showed that LAB could be grown from the digesta of sheep caecum as seen from the decrease in the average pH of the growth medium reaching pH 4.14 with a bacterial colony count of 6,01 log CFU/ml. The grown LAB had a Ks value of 0.24 μM glucose and a μmax value of 2.69 OD. Apart from that, the clear zone test showed a positive result. In conclusion, Enrichment of mixed LAB cultures from sheep caecum has decreased environmental pH by 33%. Sheep caecum mixed LAB culture has easy growth characteristics and antimicrobial activity so it can be a suitable alternative DMF candidate. Further research focusing on the application of this LAB strain is needed to be able to determine the effect of bacteria on livestock.