Isolation and Molecular Identification of Potential Myo-Inositol-Utilizing Bacteria from the Gastrointestinal Tract of Laying Hens

Myo-inositol (MI) is an essential dietary polyol involved in host metabolism. However, the identity and diversity of MI-utilizing gut bacteria in poultry remain largely unknown. This study aimed to isolate anaerobically growing bacteria enriched under MI-based cultivation conditions from two commercial laying hen breeds. Digesta samples were cultured on minimal growth media containing MI as the sole (Trial 1) or principal (Trial 2) carbon source. Isolates were purified, screened by amplified ribosomal DNA restriction analysis (ARDRA), and identified using 16S rRNA gene sequencing. Among 42 sequenced isolates, ten representative strains were classified within the phyla Pseudomonadota (n = 5), Bacillota (n = 4), and Bacteroidota (n = 1). Members of the Escherichia-Shigella clade were most frequently recovered, followed by Clostridium, Enterococcus, Pediococcus, and Bacteroides. Selected Escherichia-Shigella isolates were screened negative for ipah and ial virulence genes, except for three isolates that tested positive only for the ipah gene. These findings provide the first culture-based framework for investigating MI-responsive bacteria in the chicken gut.