Molecular tracking of cultivable lactic acid bacteria from digestive tract of Japanese quail ( Coturnix coturnix japonica ) fed with various grain sources

摘要

Lactic Acid Bacteria (LAB) possess many beneficial functions in the digestive tract of animals. The aim of the present study was to determine total LAB and Enterobacteriaceae counts and to track cultivable LAB isolates from proventriculus and small intestines of Japanese quails (Coturnix coturnix japonica) fed with various grain sources. Three treatment groups were fed with diets, designated as BAD, WAD or CAD, depending on replacement of 50% (w/w) of basal or control diet (CD) with barley, wheat and corn, respectively. The tracking of cultivable LAB isolates (n=66) was performed based on Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR) and Amplified Ribosomal DNA Restriction Analysis (ARDRA) with combination of 16S rRNA gene sequencing. The average LAB counts within proventriculus samples were the highest for quails fed with WAD (5.47 cfu/g) and control diet (5.43 cfu/g). The highest LAB counts were detected in small intestine samples for quails fed with CAD (6.28 cfu/g). Although proventriculus and intestinal samples of BAD fed animals had the lowest LAB count, they had the most diverse LAB community in terms of number of species detected with molecular tracking. Moreover, ERIC-PCR analysis and sequencing revealed that Lactobacillus salivarius was the most commonly detected species in both parts of digestive tract of quails. Overall, feeding quails with different grain containing diets affected both total number and diversity of LAB species within proventriculus and small intestine samples. In addition, ERIC-PCR was more powerful method than ARDRA to monitor diet dependent changes in cultivable LAB composition within proventriculus and small intestine.