Screening of Lactobacillus isolates from gastrointestinal tract of guinea fowl for probiotic qualities using in vitro tests to select species-specific probiotic candidates.

A total of 32 Lactobacillus isolates, 8 each from the crop (LGFCP1-LGFCP8), proventriculus (LGFP9-LGFP16), ileum (LGFI17-LGFI24) and caeca (LGFCM25-LGFCM32) were isolated from 25 adult guinea fowl (Pearl variety), 22-28 weeks of age, and characterised morphologically, physiologically, biochemically and by molecular methods. Isolates were screened for their probiotic quality using range of in vitro tests: aggregation test, cell surface hydrophobicity, resistance to bile salts and acidic conditions, enzymatic tests and coaggregation and antagonistic test. Based on in vitro test results and a novel scoring method, the two best isolates were selected and partial 16S rRNA sequencing was done. BLAST (Basic Local Alignment Search Tool) analysis of sequence of isolate LGFCP4 showed 99% genetic identity with Lactobacillus plantarum and LGFP16 with Lactobacillus reuteri. The study shows that these two microbial agents may be suitable as potential probiotic candidates in guinea fowl, as well as in a feed supplement for other poultry species.