Identification of Probiotic Bacteria Isolated from Domestic Chickens (Gallus domesticus) Using the 16S rRNA Gene Method

Abstract

The intestines of domestic poultry (Gallus domesticus) are one of the potential sources of probiotic bacteria that can produce antibacterial agents. The objective of this study was to identify the types of probiotic bacteria obtained from the digestion of domestic poultry using the molecular analysis method of 16S rRNA gene sequencing. Observations were conducted on colony morphology, gram staining, biochemical tests, and antibacterial activity using the diffusion agar method. Molecular analysis of DNA extraction was carried out, followed by the amplification of samples using a 16S rRNA universal primer. Dielectrophoresis and sequencing were performed on the 16S rRNA gene. The identification of morphological observations, gram staining, and biochemical tests showed that probiotic bacteria isolates, including Gram-positive, rod-shaped, rounded colony form, flat elevation, entire nonmotile edge, and catalase-negative, could ferment all carbohydrate content in the TSIA medium. The antibacterial potential was also found in probiotic bacteria, as evidenced by the inhibition zone formed in the test. The results of the bacterial gene sequences of PaTa5 probiotic bacterial isolates had a similarity of 98.37% with Lactobacillus plantarum. These findings indicated the presence of some bacteria species that have antibacterial activity in the intestines of domestic chickens (Gallus domesticus). Keywords: Lactobacillus plantarum, Native chicken, Probiotic, 16S rRNA