Effect of replacing antibiotics using multi-enzyme preparations on production performance and antioxidant activity in piglets

The study was conducted to investigate the effects of replacing antibiotics using multi-enzyme preparations on growth performance,coefficient of total tract apparent digestibility,digestive enzyme activity,and antioxidant property in piglets.A total of 160 piglets（（21.35±0.22）kg）were randomly assigned to five dietary treatments：1）basal diet supplemented with antibiotics（AC）,2）antibiotic diet supplemented with 0.5 g kg^-1 multi-enzyme preparations（AC＋0.5EP）,3）antibiotic diet supplemented with 1.5 g kg^-1 multi-enzyme preparations（AC＋1.5EP）,4）basal diet supplemented with a half dosage of antibiotics and 1.5 g kg^-1 multi-enzyme preparations（AH＋1.5EP）,and 5）basal diet supplemented with 1.5 g kg^-1 multienzyme preparations（BC＋1.5EP）.The results showed that AC＋1.5EP significantly improved the feed efficiency,apparent digestibility of ether extract（EE）and crude ash（CA）,lipase activity in pancreas and duodenum content,maltase and lactase activity in jejunum and ileum mucosa,glutathione peroxidase（GSH-Px）concentration in serum and liver,and decreased malondialdehyde（MDA）concentration in serum and liver compared with piglets receiving AC（P〈0.05）.Piglets receiving BC＋1.5EP showed no significant difference in growth performance（P〉0.05）but had lower MDA concentration than piglets receiving AC（P〈0.05）.The apparent digestibility of EE and crude fiber（CF）,duodenal lipase activity,jejunum mucosa maltase,and ileum mucosa lactase activity of piglets receiving AH＋1.5EP or BC＋1.5EP were significantly improved compared with piglets receiving AC（P〈0.05）.These results indicated an additive growth promotion effect between antibiotics and multi-enzyme preparations on piglets,and the multi-enzyme preparations may be used as substitutes for antibiotics for improving piglet production performance and health status.

Effects of A Multi-Enzyme Complex or Probiotic Supplementation on Performance and Nutrient Digestibility of Broiler Chicks

This experiment was conducted to determine whether the performance of broilers fed diets based on corn and soybean meal could be enhanced with enzymes or probiotics. A total of 120 male broilers, three days of age, were assigned to one of four treatments in a completely randomized design, and housed in groups of five with six cages per treatment. The control diet was based on corn and soybean meal while the three experimental diets consisted of the basal diet supplemented with 0.1% of enzyme I, enzyme II, or probiotic. Enzyme I provided α-galactosidase and fl-mannanase, while enzyme II provided protease, amylase, α-galactosidase, xylanase, and cellulase. The probiotic was composed of Bacillus coagulance, Bacillus lichenformis , Bacillus subtilis , and Clostridium butyricum. Over the 28 day experiment, the weight gain of birds fed the probiotic treatment was superior （P = 0.03 ） to the control, while gains for the enzyme treatments were intermediate to those of the control and probiotic. Feed intake and feed conversion did not differ among treatments （P 〉 0.05 ）. Ammonia production was significantly （ P 〈 0.01 ） higher in the control compared with either of the enzyme or probiotic treatments. Compared with the control, supplementation with enzyme H significantly reduced the digestibility of arginine, isoleucine, and lysine （P 〈 0.05 ）. In contrast, the digestibility of energy was higher （P 〈 0.01 ） for birds supplemented with enzyme II than the control. Digestibility coeffi- cients did not differ for any other parameter with the exception of energy which was significantly higher for birds fed the probiotic treatment than the control （P 〈 0.01 ）. In summary, the performance of broilers was significantly enhanced by the addition of a probiotic to the diet. However, under the conditions of this experi- ment, supplementation with a multi-enzyme complex containing either α-galactosidase and fl-mannanase or the combination of protease, amylase, galactosidase, xylanase, and cellulase failed to improve broiler performance.

Growth performance,gastrointestinal weight,microbial metabolites and apparent retention of components in broiler chickens fed up to 11%rice bran in a corn-soybean meal diet without or with a multi-enzyme supplement

We investigated the effects of adding up to 11% rice bran(RB) in corn-soybean meal diets fed to broiler chickens without or with a multi-enzyme supplement(MES). The MES supplied xylanase, b-glucanase invertase, protease, cellulase, a-amylase and mannanase with targeted activity of 2,500, 300, 700, 10,0001,200, 24,000, and 20 U/kg of feed, respectively. The study used a two-phase feeding program(starter d 0 to 24; finisher, d 25 to 35) with RB added at 5% and 11%, respectively creating 4 diets in each phase Diets were iso-caloric and iso-nitrogenous and contained phytase(500 FTU/kg) and TiO_2 as a digestibility marker. Three hundred and sixty d-old male Ross 708 broiler chicks were placed in cages based on BW(15 birds/cage) and allocated to 4 diets(n = 6). Birds had free access to feed and water. Body weight and feed intake were recorded. Excreta samples were collected 3 d prior to the end of each phase for apparent retention(AR) of components. Samples of birds were sacrificed on d 24 and 35 for gut weight and ceca digesta for organic acid content. There was no interaction(P > 0.10) between RB and MES on BWG and FCR in starter or finisher phase. In finisher phase, birds fed MES had better BWG(961 versus 858 g) and FCR(1.69 versus 1.86) than birds fed non-MES diets(P < 0.01). Feeding RB reduced(P = 0.02) BWG in finisher phase resulting in lower d 35 BW. Birds fed RB had higher(P 0.01) gizzard weight on d 24 and 35 than non-RB birds. An interaction(P 0.01) between RB and MES on concentrations of propionic and iso-butyric acids in ceca digesta showed that MES reduced these acids in non-RB diet. The AR of gross energy was higher(P < 0.02) for MES versus non-MES birds in starter and finisher phases. In conclusion independently, RB increased gizzard weight and reduced final BW whereas MES improved growth and energy utilization.

Positional assembly of multi-enzyme cascade reaction in polyelectrolyte doped microcapsule through electrospray and layer-by-layer assembly

Polyelectrolyte-doped microcapsules(PDM)was fabricated by coaxial electrospray of a mixture of glycerol and water containing 10 mg/mL cationic polyelectrolyte poly(allylamine hydrochloride)(PAH)fed as the core phase solution,and a N,N-dimethylacetylamide solution of 10 wt%polyurethane fed as the shell phase solution.Multienzyme system involving Candida Antarctica lipase B(CALB),glucose oxidase(GOD),and horseradish peroxidase(HRP)for cascade reaction was assembled in the PDM at three different places,namely,surface,shell,and lumen.Placing of enzyme inside aqueous lumen of the PDM was realized by in situ encapsulation through adding the enzyme in the core-phase solution for coaxial electrospray.By ion-pairing of enzyme with cationic surfactant CTAB,an organic soluble enzyme-CTAB complex was prepared,so that in situ embedding of enzyme in the shell of the PDM was realized by adding it into the shell phase solution.Surface attachment of enzymes was achieved by layer-by-layer(LbL)technology,which is based on the ion-exchange interactions between oppositely charged enzymes and PAH that was doped in PDM.The enzyme-decorated microcapsule was then studied as a microbioreactor,in which 1-Oxododecyla-α-glucopyranoside was converted by CALB to glucose,which was oxidised by GOD to gluconolactone in a second step.The hydrogen peroxide produced was then used by HRP to oxidize ABTS to form coloured radical cation ABTS•+for activity analysis.The successful fabrication of the PDM and precise localization of enzymes in the PDM by different strategies were fully characterized.By varying the immobilization strategy,totally six PDM bioreactors with three enzymes precisely positional assembled in different strategies were constructed and their activities for the cascade reaction were investigated and compared.The PDM micro-bioreactor prepared by novel electrospray technologies provide a smart platform for positional assembly of multi-enzyme cascade reaction in a precise and well-controlled manner.

Conversion of acetate and glyoxylate to fumarate by a cell-free synthetic enzymatic biosystem

Fumarate is a value-added chemical that is widely used in food,medicine,material,and agriculture industries.With the rising attention to the demand for fumarate and sustainable development,many novel alternative ways that can replace the traditional petrochemical routes emerged.The in vitro cell-free multi-enzyme catalysis is an effective method to produce high value chemicals.In this study,a multi-enzyme catalytic pathway comprising three enzymes for fumarate production from low-cost substrates acetate and glyoxylate was designed.The acetyl-CoA synthase,malate synthase,and fumarase from Escherichia coli were selected and the coenzyme A achieved recyclable.The enzymatic properties and optimization of reaction system were investigated,reaching a fumarate yield of 0.34 mM with a conversion rate of 34%after 20 h of reaction.We proposed and realized the conversion of acetate and glyoxylate to fumarate in vitro using a cell-free multi-enzyme catalytic system,thus providing an alternative approach for the production of fumarate.

Enzymatic cascade systems for D-amino acid synthesis:progress and perspectives

D-amino acids,different from the ubiquitous L-amino acids,are recognized as the“unnatural”amino acids.The applications of D-amino acids have drawn increasing interest from researchers in recent years,and D-amino acids are widely used in various industries,including for food products,pharmaceuticals,and agricultural chemicals.Inspired by the prevalent appli-cations,many synthetic methods for D-amino acids have been developed,which are mainly divided into chemical synthetic methods and biosynthetic methods.Chemical synthesis of D-amino acids has a variety of disadvantages such as multiple reaction steps,low yields,low reaction rates,and difficulties in product extraction.Thus,biosynthetic methods utilizing enzymes are attracting increasing attention because they are more energy-saving and environmentally friendly compared to traditional chemical synthesis.Among all enzymatic methods,multi-enzymatic cascade catalytic methods have significant advantages,such as lower costs,no need for intermediate separation,and higher catalytic efficiency,which is ascribed to the spatial proximity of biocatalysts.In this review,advances in multi-enzyme cascade catalytic systems as well as chemo-enzymatic approaches to synthesize D-amino acids are discussed.

Cover Story

Construction of multi-enzyme systems not only can help expand the understanding of physiological and pathological mechanisms,but also holds great promise in biosynthesis,biosensing and biomedicine.Recently,lots of strategies have been exploited to arrange multiple enzymes into a confined space for the construction of artificial multi-enzyme complexes,including liposomes encapsulating,polymersomes entrapping,chemical crosslinking and covalent conjugation.Although these strategies are promising,there are still several obstacles remaining which may impede the practical applications.For example,synthesis of these multi-enzyme complexes involves tedious preparations and multiple steps,leading to the loss of enzyme activity and further decreasing the catalytic efficiency.Therefore,a simple and efficient strategy to develop multi-enzyme complexes remains a great challenge.