Role of a family 11 carbohydrate-binding module in the function of a recombinant cellulase used to supplement a barley based diet for broiler chickens

Cellulases and xylanases display a modular architecture that comprises a catalytic module linked to one or more non-catalytic carbohydrate-binding modules (CBMs). CBMs have been classified into 52 different families, based on primary structure similarity. These non-catalytic modules mediate a prolonged and intimate contact of the enzyme with the target substrate eliciting efficient hydrolysis of the target polysaccharides. 2. A study was undertaken to investigate the importance of a family 11 CBM, displaying high affinities for barley -glucans, in the function of recombinant derivatives of cellulase CtLic26A-Cel5E of Clostridium thermocellum used to supplement a barley-based diet for broiler chicken. 3. The results showed that birds fed on diets containing the recombinant CtLic26A-Cel5E modular derivatives or the commercial enzyme mixture RovabioTM Excel AP displayed improved performance when compared with birds fed on diets not supplemented with exogenous enzymes. 4. It is suggested that the enzyme dosage used in this study (30 U/kg of basal diet), was probably too high for the efficacy of the family 11 CBM to be noticed. It remains to be established if the targeting effect resulting from the incorporation of CBMs in plant cell wall hydrolases may be effective at lower exogenous enzyme dosages

Influence of dietary Chlorella vulgaris and carbohydrate-active enzymes on growth performance, meat quality and lipid composition of broiler chickens

Article in pressHerein, we investigated the effect of Chlorella vulgaris as ingredient (10% of incorporation) in broiler diets, supplemented or not with 2 formulations of Carbohydrate-Active enZymes (CAZymes; Rovabio Excel AP and a mixture of recombinant CAZymes, composed by an exo-b-glucosaminidase, an alginate lyase, a peptidoglycan N-acetylmuramic acid deacetylase and a lysozyme), on growth performance, meat quality, fatty acid composition, oxidative stability, and sensory traits. One hundred twenty 1-day-old Ross 308 male birds were randomly assigned to one of the 4 experimental diets (n 5 30): corn-soybean meal–basal diet (control), basal diet with 10% C. vulgaris (CV), CV supplemented with 0.005% of a commercialCAZymecocktail (Rovabio Excel AP), (CV1R), and CV supplemented with 0.01% of a 4- CAZyme mixture previously selected (CV 1 M) during the experimental period lasted from day 21 to day 35. Body weight gain and feed conversion rate of broilers were not affected by C. vulgaris but digesta viscosity increased more than 2-fold (P , 0.001) relative to the control. In addition, neither cooking loss, shear force, juiciness, flavor nor off-flavor was impaired by dietary treatments (P.0.05). By contrast, the dietary C. vulgaris increased tenderness, yellowness (b*) and total carotenoids in breast and thigh meats. However, no additional protective effect against lipid oxidation was observed in meat with the inclusion of microalga. Chlorella vulgaris, independently of CAZymes, had a minor impact on meat fatty acid composition but improved the proportion of some beneficial fatty acids. In summary, our data indicate a slight improvement of broiler meat quality and lipid nutritional value, without impairment of broilers’ growth performance, thus supporting the usefulness of this microalga in poultry diets, up to this high level of incorporation. By contrast, the selected CAZyme mixtures used do not significantly improve the release of microalga nutrients in poultry diets, through the disruption of microalga cell wall, which warrants further researchinfo:eu-repo/semantics/acceptedVersio

Impact of dietary incorporation of Spirulina (Arthrospira platensis) and exogenous enzymes on broiler performance, carcass traits and meat quality

This study assessed the effect of Spirulina (Arthrospira platensis), individually and in combination with exogenous enzymes, on growth performance, carcass traits, and meat quality of broiler chickens. One hundred and twenty Ross 308 male chickens were allocated into 40 battery brooders, with 3 birds per cage, and fed ad libitum a corn-based diet during the first 21 D of the trial. The experimental period lasted from day 21 to 35, during which birds were fed 4 different diets: a corn-soybean basal diet, taken as the control group, a basal diet containing 15% Spirulina (MA), a basal diet containing 15% Spirulina plus 0.005% Rovabio Excel AP (MAR), and a basal diet containing 15% Spirulina plus 0.01% lysozyme (MAL). Body weight gain (P , 0.001) and feed conversion rate (P , 0.001) were improved in control chickens, when compared with those fed with Spirulina. In addition, Spirulina increased the length of duodenum plus jejunum in relation to the other treatment (P , 0.01). Chickens on the MAL diet showed a considerable increase in digesta viscosity (P , 0.05) compared with the control group. Breast and thigh meats from chickens fed with Spirulina, with or without the addition of exogenous enzymes, had higher values of yellowness (b*) (P , 0.001), total carotenoids (P , 0.001), and saturated fatty acids (P , 0.001), whereas n-3 polyunsaturated fatty acid (P , 0.01) and a-tocopherol (P , 0.001) decreased, when compared with the control. In conclusion, the incorporation of 15% Spirulina in broiler diets, individually or combined with exogenous enzymes, reduced birds’ performance through a higher digesta viscosity, which is likely associated with the gelation of microalga indigestible proteins. In addition, cell wall of Spirulina was successfully broken by the addition of lysozyme, but not by Rovabio Excel AP. Therefore, we anticipate that the combination of lysozyme with an exogenous specific peptidase could improve the digestibility of proteins from this microalga and avoid their detrimental gelationinfo:eu-repo/semantics/publishedVersio

A family 11 carbohydrate binding module (CBM) improves the efficacy of a recombinant cellulase used to supplement barley-based diets for broilers at lower dosage rates

1. Exogenous microbial -1,3-1,4-glucanases and hemicellulases contribute to improving the nutritive value of cereals rich in soluble non-starch polysaccharides for poultry. 2. In general, plant cell wall hydrolases display a modular structure comprising a catalytic module linked to one or more non-catalytic carbohydrate-binding modules (CBMs). Based on primary structure similarity, CBMs have been classified in 50 different families. CBMs anchor cellulases and hemicellulases into their target substrates, therefore eliciting efficient hydrolysis of recalcitrant polysaccharides. 3. A study was undertaken to investigate the effects of a family 11 -glucan-binding domain in the function of recombinant derivatives of cellulase CtLic26A-Cel5E of Clostridium thermocellum that were used to supplement a barley-based diet at lower dosage rates. 4. The results showed that birds fed on diets supplemented with the recombinant CtLic26A-Cel5E modular derivative containing the family 11 CBM or the commercial enzyme mixture RovabioTM Excel AP tended to display improved performance when compared to birds fed diets not supplemented with exogenous enzymes. 5. It is suggested that at lower than previously reported enzyme dosage (10 U/kg vs 30 U/kg of basal diet), the -glucan-binding domain also elicits the function of the recombinant CtLic26A-Cel5E derivatives. 6. Finally, the data suggest that exogenous enzymes added to barley-based diets act primarily in the proximal section of the gastrointestinal tract

The effects of restricting enzyme supplementation in wheat-based diets to broilers

The performance of broilers fed on xylanase supplemented diets for part or all of the production cycle was evaluated in two experiments. In a preliminary experiment, 1-day-old chicks were fed a wheat-based diet supplemented with a commercial xylanase for the entire duration of the experiment of 28 days, or during the last 21, 14, or 7 days of the trial. In experiment 2, the growth period was extended to 36 days, and birds were fed xylanase supplemented diets for the entire duration of the experiment, or during the last 27, 18, or 9 days of the trial. In both experiments, an additional group was fed a non-supplemented control diet. Xylanase-supplemented broilers outperformed non-supplemented birds. Significant differences in body weight emerged at 21–28 days of age, suggesting that the response to xylanase supplementation occurs primarily during the latter stages of broiler growth. Broilers fed xylanase-supplemented diets for the entire experiment presented similar growth performance, intestinal viscosity, gastrointestinal enzyme activity and organ sizes when compared with birds supplemented with the exogenous xylanase for the last 14 (experiment 1) or the last 18 days (experiment 2) of the trials. Birds exposed to exogenous xylanase for the entire duration of the experiment showed, however, a non-significant trend (P<0.1) towards an improved final body weight and feed conversion ratio. Nevertheless, it appears that an early exposure to the exogenous xylanase is of marginal importance in obtaining a significant response to xylanase supplementation by broilers fed wheat-based diet

The effects of restricting enzyme supplementation in rye-based diets for broilers

The purpose of the current study was to restrict enzyme addition in order to evaluate if supplementation throughout the broiler production cycle is required. Here we analyze the possibility of circumscribing xylanase supplementation in rye-based diets to the earliest periods of the life of the broiler. In the current experiment, 1-day-old chicks were divided into 5 treatments and fed a rye-based diet supplemented with a commercial enzyme mixture containing a microbial xylanase. The five treatments consisted of birds fed a nonsupplemented diet and birds fed diets supplemented with the exogenous enzyme for the entire period of the experiment (28 days), the first 21 days, the first 14 days or the first 7 days of the trial. The data revealed that broilers fed diets supplemented with enzymes during 28 days had similar (P>0.05) growth performance, gastrointestinal enzyme activity and relative organ sizes to broilers fed supplemented diets only in the first 21 days of the experimental period. These results suggest that the action of exogenous enzymes, when used to supplement rye-based diets for broilers, may be restricted to the first 21 days of the broiler’s production cycle without compromising animal performanc