The effects of <i>Carnobacterium divergens</i> AS7 bacteriocin on gastrointestinal microflora <i>in vitro</i> and on nutrient retention in broiler chickens

Abstract

The present study was undertaken to evaluate the effects of divercin, a bacteriocin produced by lactobacilli strain Carnobacterium divergens AS7, on the microflora status under in vitro conditions and on nutrient retention and nitrogen-corrected apparent metabolizable energy (AME N ) of divercin in an in vivo trial on broiler chickens. Low (DL) 200 AU•ml 1 (0.05% of the liquid divercin prepatation), and high (DH) 1600 AU•ml -1 (0.4% of the liquid divercin prepatation) doses of divercin were used in both trials. In the in vitro trial divercin at concentration, 1600AU ml -1 of divercin had stronger antibacterial effects as compared with 200 AU•ml -1 . In the crop and ileal digesta, the DH treatment was characterized by the lowest lactic acid bacteria (LAB) and coliform bacteria counts (0.4-0.8 log cycle reduction). There were no differences in nutrient retention between treatments. Salinomycin and divercin supplementation tended to increase fat digestibility and N retention, however. The highest AME N were obtained in the DL treatment. The results of both studies show positive effects of divercin in terms of reduction of microbial populations isolated from the gastrointestinal tract (GIT) of broiler chickens as well as improvement in AME N . The presented data may suggest that bacteriocin derived from Carnobacterium divergens AS7 could play a role in controlling the microbial ecosystem in the broiler chicken GIT.

LyophilizedCarnobacterium divergens AS7 bacteriocin preparation improves performance of broiler chickens challenged withClostridium perfringens

“…In the present study, divercin AS7 improved AME n of the diets, whereas the C. perfringens challenge had no effect, partially agreeing with earlier findings also indicating a positive effect of divercin AS7 on AME n values (Józefiak et al, 2010b;Józefiak et al, 2011). However, in the present study, C. perfringens-challenged birds had numerically the lowest AME n value accompanied with the lowest apparent digestibility of crude fat.…”

“…Use of the lyophilized divercin preparation was observed to improve performance of the challenged birds, however, not to the same degree as in our previous work (Józefiak et al, 2010b(Józefiak et al, , 2011, where we demonstrated dietary supplementation of divercin AS7 as a liquid preparation to improve broiler performance similar to the use of the ionophore coccidiostat salinomycin.…”

“…The apparent digestibility coefficients of fat were analyzed as described in detail by Józefiak et al (2010b). The AME n content of the experimental diets was calculated according to Hill and Anderson (1958) using titanium dioxide as an indigestible marker.…”

The dose response effects of liquid and lyophilized <i>Carnobacterium divergens</i> AS7 bacteriocin on the nutrient retention and performance of broiler chickens

“…at an activity of 800 AU/ml, this bacteriocin does not impair body weight gain or feed conversion and tends to potentially increase AME N contents (P=0.0672; Table 3); however, it also should be pointed out that increasing dietary divercin AS7 levels do not gradually improve the performance results. This observation agrees with our earlier studies which showed that high dosages had better in vitro bacteriostatic effects but did not improve nutrient digestibility in comparison with lower dosages (Józefiak et al, 2010). Moreover results of the present studies may suggest that in vivo divercin AS7 mode of action, is also correlated with GIT microflora composition and/or activity, giving beneficial effects for the host bird when the dietary factors disrupt GIT homeostasis.…”

“…Previous studies in our laboratories have shown that C. divergens AS7 bacteriocin (divercin AS7) may reduce bacterial colonization in vitro and in vivo, potentially improving broiler performance (Józefiak et al, 2010). In the experiments considering the influence of divercin on the broiler GIT microflora and nutrient retention, we used a constant liquid-form dosage of divercin AS7 that was estimated on the basis of in vitro experiments.…”