Ng the presence of V. midae SY9::Tn10.52 along the inner surface of the crop/stomach of H. midae fed supplemented ABFEEDH. Similarly, Rengpipat et al. detected GFP-tagged Bacillus S11 cells attached to the intestinal mucous lining of the black tiger shrimp P. monodon. Additionally, strong hybridization signals were observed in association with feed or other particulate matter within the crop/stomach and intestine of H. midae fed the V. midae SY9::Tn10.52 supplemented diet. The extracellular ZK-36374 protease MedChemExpress 58-49-1 VmproA produced by V. midae SY9 was detected immunologically within the crop/stomach and intestinal regions of H. midae fed ABFEEDH S34 supplemented with V. midae SY9::Tn10.52. There was no immunohistochemical evidence of VmproA within the H. midae digestive tract of abalone fed the basal diet over the course of the 14 day experimental period. VmproA appeared to be less abundant in the crop/ stomach than the intestine 22948146 of abalone fed V. midae SY9::Tn10.52 supplemented feed. Similarly, elevated levels of in situ alkaline protease activity detected in the crop/stomach of abalone fed ABFEEDH supplemented with V. midae SY9 were not as pronounced as the protease activity observed in the intestinal regions of these animals. Since V. midae SY9::Tn10.52 cells detected in the intestine by in situ hybridization with the gfp-specific probes was more abundant in comparison to the crop/stomach, it is likely that the relative abundance of detectable VmproA 25837696 in the intestine is a function of the elevated V. midae SY9 cell number in this portion of the H. midae digestive tract. Indeed, a significant positive correlation was found between intestinal protease activity and the number of V. midae SY9.8 cells present, supporting an association between V. midae SY9 and protease activity in the intestine of H. midae. Probiotic and Protease Localisation in Abalone Gut VmproA appeared to be generally associated with the feed and/ or particulate matter within the intestine of H. midae fed the V. midae SY9::Tn10.52 -supplemented ABFEEDH diet. Immunohistochemical localisation of VmproA within the H. midae digestive tract appears to be similar to the in situ localisation of V. midae SY9::Tn10.52 detected by the in situ hybridization analysis of whole-animal tissue sections. Thus, it could be hypothesised that viable V. midae SY9 cells, ingested with the supplemented ABFEEDH pellets, may attach to the surface of the digestive tract but are mostly associated with food particles and/or other particulate matter in the abalone digestive tract. Presumably, proximity to protein-rich ABFEEDH induces V. midae SY9 to secrete proteases such as VmproA within the digestive tract of H. midae. H. midae fed a V. midae SY9-supplemented diet. The data suggests that V. midae SY9 may colonise and/or adhere to the mucous lining of the abalone gut, as well as associate with the surfaces of ingested food particles passing through the digestive tract. In so doing, V. midae SY9 may elevate in situ enzyme levels and thus enhance feed digestion. To the best of our knowledge this is the first study to localize an extracellular protease produced by a probiotic bacterium in the abalone digestive tract. Acknowledgments The authors wish to thank Dr Anna Mouton, Amanzi Biosecurity, Hermanus, South Africa, for kindly preparing the histological sections used in the study. Conclusion This study demonstrated that V. midae SY9 and its extracellular protease, VmproA, could be localised within the digestive tra.Ng the presence of V. midae SY9::Tn10.52 along the inner surface of the crop/stomach of H. midae fed supplemented ABFEEDH. Similarly, Rengpipat et al. detected GFP-tagged Bacillus S11 cells attached to the intestinal mucous lining of the black tiger shrimp P. monodon. Additionally, strong hybridization signals were observed in association with feed or other particulate matter within the crop/stomach and intestine of H. midae fed the V. midae SY9::Tn10.52 supplemented diet. The extracellular protease VmproA produced by V. midae SY9 was detected immunologically within the crop/stomach and intestinal regions of H. midae fed ABFEEDH S34 supplemented with V. midae SY9::Tn10.52. There was no immunohistochemical evidence of VmproA within the H. midae digestive tract of abalone fed the basal diet over the course of the 14 day experimental period. VmproA appeared to be less abundant in the crop/ stomach than the intestine 22948146 of abalone fed V. midae SY9::Tn10.52 supplemented feed. Similarly, elevated levels of in situ alkaline protease activity detected in the crop/stomach of abalone fed ABFEEDH supplemented with V. midae SY9 were not as pronounced as the protease activity observed in the intestinal regions of these animals. Since V. midae SY9::Tn10.52 cells detected in the intestine by in situ hybridization with the gfp-specific probes was more abundant in comparison to the crop/stomach, it is likely that the relative abundance of detectable VmproA 25837696 in the intestine is a function of the elevated V. midae SY9 cell number in this portion of the H. midae digestive tract. Indeed, a significant positive correlation was found between intestinal protease activity and the number of V. midae SY9.8 cells present, supporting an association between V. midae SY9 and protease activity in the intestine of H. midae. Probiotic and Protease Localisation in Abalone Gut VmproA appeared to be generally associated with the feed and/ or particulate matter within the intestine of H. midae fed the V. midae SY9::Tn10.52 -supplemented ABFEEDH diet. Immunohistochemical localisation of VmproA within the H. midae digestive tract appears to be similar to the in situ localisation of V. midae SY9::Tn10.52 detected by the in situ hybridization analysis of whole-animal tissue sections. Thus, it could be hypothesised that viable V. midae SY9 cells, ingested with the supplemented ABFEEDH pellets, may attach to the surface of the digestive tract but are mostly associated with food particles and/or other particulate matter in the abalone digestive tract. Presumably, proximity to protein-rich ABFEEDH induces V. midae SY9 to secrete proteases such as VmproA within the digestive tract of H. midae. H. midae fed a V. midae SY9-supplemented diet. The data suggests that V. midae SY9 may colonise and/or adhere to the mucous lining of the abalone gut, as well as associate with the surfaces of ingested food particles passing through the digestive tract. In so doing, V. midae SY9 may elevate in situ enzyme levels and thus enhance feed digestion. To the best of our knowledge this is the first study to localize an extracellular protease produced by a probiotic bacterium in the abalone digestive tract. Acknowledgments The authors wish to thank Dr Anna Mouton, Amanzi Biosecurity, Hermanus, South Africa, for kindly preparing the histological sections used in the study. Conclusion This study demonstrated that V. midae SY9 and its extracellular protease, VmproA, could be localised within the digestive tra.