Mutants of Bacillus subtilis overproducing valine (B. subtilis VAL) could be an approach to supply pigs dietary valine (Val). In the study, 18 gilts were fed: (i) negative diet with a standardized ileal digestible (SID) Val:Lys of 0.63:1 (Neg); (ii) Neg added B. subtilis VAL (1.28 × 1011 cfu/kg as-fed) or; (iii) Neg added L-Val to a Val:Lys of 0.69:1. Using the Ussing chamber method, the study aimed to investigate whether (i) the diets affect intestinal transport of additions of 0, 5, 10 or 20 mmol Val/L from the mucosal to the serosal side and (ii) the B. subtilis VAL contributes to a net transport of Val produced in situ. The results showed that the Isc (ΔIscVal ) and release of Val to the serosal side solution (Srel ; μmol cm-2 min-1 ) increased with Val addition (linear and quadratic, p < .0001) but was similar for 5, 10 or 20 mmol Val/L and not affected by diet. No net transport of in situ produced Val by B. subtilis VAL was detected. In conclusion, feeding a Val-deficient diet with or without B. subtilis VAL or a Val sufficient diet did not affect the Val transport across intestinal epithelia. No in situ Val production by B. subtilis VAL was observed in the Ussing chambers.
Keywords: Bacillus subtilis; Ussing chamber; absorption; amino acids; pigs; valine transport.
© 2017 Blackwell Verlag GmbH.