Background and Aim: Supplementation of AKBISprob (developed in a previous study) in feed can improve production efficiency and poultry health, especially laying hens. In addition, it can also increase cellulolytic lactic acid bacteria (LAB) in chicken intestines, but these bacteria are still unknown; thus, they need to be identified. This study aimed to identify cellulolytic LAB in the intestines of laying hens administered AKBISprob based on 16S ribosomal ribonucleic acid (16S rRNA) gene analysis.

Materials and Methods: The samples used in this study were 13 LAB isolates from the intestines of laying hens that were given AKBISprob 4%. Cellulolytic LAB DNA was isolated and 16S rRNA gene was amplified by polymerase chain reaction, followed by sequencing, bioinformatics analysis, and phylogenetic tree construction.

Results: From 10 cellulolytic LAB isolates with a clear zone of >6 mm, four were selected and their DNA was amplified with BaCF and UniB primers ∼1500 bp DNA fragments. Of these, the P31H62 isolate was genetically close to Enterococcus hirae strain 1-1X-16 with 92.90% maximum identity, the P33S52 isolate had homology with Enterococcus mundtii strain ZU 26 with 96.76% maximum identity, and the P33S62 isolate was closely related to E. hirae strain SJ3 with 72.96% maximum identity. The phylogenetic tree revealed that the cellulolytic LAB isolates P31H62 and P33S52 were in one cluster closely related to the genus Enterococcus.

Conclusion: This study suggests that the isolates P31H62, P33S62, and P33S52 from the intestines of laying hens administered 4% AKBISprob are cellulolytic LAB belonging to the genus Enterococcus.

Keywords: 16S ribosomal ribonucleic acid, AKBISprob, Enterococcus, phylogenetic tree, polymerase chain reaction.