Influence of fiber type and carbohydrase supplementation on nutrient digestibility, energy and nitrogen balance, and physiology of sows at mid and late gestation

Carbohydrase supplementation in grow-finish pig diets improves energy, nutrient digestibility, and gastrointestinal function, but their efficacy in gestation diets is understudied. The experimental objective was to evaluate the efficacy of a multicarbohydrase to improve digestion, energetics, and various physiological functions in gestating sows fed soluble and insoluble fiber diets. On day 28 of gestation, 36 sows (186 ± 4.6 kg body weight), blocked by parity, were randomly assigned to a 2 × 2 factorial arrangement of dietary treatments (n = 9). Factors included fiber type of insoluble (IF; 20% dried distiller grains with solubles) or soluble fiber (SF; 20% sugar beet pulp) and with (+) or without (-) enzyme (0.05%, Rovabio Advance P10; Adisseo, Antony, France). Diets were fed from days 28 to 109 of gestation at a feeding level of 2.1 kg (SID-Lys 11 g/d and 4.5 net energy-Mcal/d). Two separate 9-d metabolism periods were conducted on days 50 to 59 (mid) and 99 to 108 (late) of gestation. During each period, days 1 to 3 served as an adaptation period, days 4 to 7 total urine and feces were collected (96-h) and followed by a 48-h lactulose-mannitol study. Serum and plasma were collected on days 50 and 99. Data were analyzed as repeated records using a linear mixed model with block as a random effect and fiber type, enzyme, and period and their interactions as fixed effects. Sows fed SF+ had increased serum IL-1ra (Fiber × Enzyme P = 0.035), and IL-2 (Fiber × Enzyme P = 0.042). In the presence of IF, multicarbohydrases increased serum lipopolysaccharide-binding protein, but not when supplemented with SF (Fiber × Enzyme P = 0.028). Circulating IL-8 and TNF-α were decreased in sows fed multicarbohydrases (P < 0.05). Multicarbohydrase supplementation increased the apparent total tract digestibility (ATTD) of gross energy (GE), dry matter, and neutral detergent fiber by 2.8%, 3.4%, and 8.3%, respectively (P < 0.05). Compared to IF-, the ATTD of hemicellulose was 5.3% greater in sows fed IF+ but did not differ from SF- and SF+ (Fiber × Enzyme P = 0.037). Sows fed IF+ had the greatest ATTD of insoluble dietary fiber (Fiber × Enzyme P = 0.011). Sows fed multicarbohydrases excreted less energy in their urine (519 vs. 469 GE kcal/d; Enzyme P = 0.033) and in their feces (985 vs. 900 GE kcal/d; Enzyme P = 0.003). This resulted in an improvement in both digestible energy (Enzyme P < 0.01) and metabolizable energy (Enzyme P = 0.041), irrespective of fiber type. In conclusion, multicarbohydrase supplementation increased the digestibility and energetic contribution of fiber, irrespective of adaptation time or fiber type, but modulation of inflammatory responses was unique to dietary fiber type.

A proteomic approach to identify digestive enzymes, their exocytic and microapocrine secretory routes and their compartmentalization in the midgut of Spodoptera frugiperda

A proteomic approach was used to identify the digestive enzymes secreted by exocytosis and by microapocrine vesicles and enzyme midgut compartmentalization in Spodoptera frugiperda larvae. For this, proteomic analyses were performed in isolated midgut enterocyte microvillar membrane, in a fraction enriched in microapocrine vesicles (separated in soluble and membrane fractions), in the washings of the peritrophic membrane to isolate its loosely- and tightly-bound proteins, and in the peritrophic membrane contents. PM washings correspond to proteins extracted from the mucus layer surrounding PM. Serine endopeptidases (trypsins, chymotrypsins and serine endopeptidase homologs that have substitutions in the catalytic residues) and lipases are mainly secreted by exocytosis. Aminopeptidases are mainly microvillar enzymes and some are secreted membrane-bound to microapocrine vesicles, whereas carboxypeptidase isoforms follow different secretory routes. The results also showed that most polymer hydrolases (such as amylase and endopeptidases) are not retained in the ectoperitrophic fluid (found in PM washings but absent from PM contents). On the contrary, most enzymes involved in intermediate digestion (exemplified by carboxypeptidase and aminopeptidase) do not pass through the peritrophic membrane. Finally, the data revealed that the protein composition of PM includes peritrophins classified as peritrophic membrane proteins, PMP, and chitin deacetylase.

Cocktail of carbohydrases from Aspergillus niger: an economical and eco-friendly option for biofilm clearance from biopolymer surfaces

Biofilm formation on both biotic and abiotic surfaces accounts for a major factor in spread of antimicrobial resistance. Due to their ubiquitous nature, biofilms are of great concern for environment as well as human health. In the present study, an integrated process for the co-production of a cocktail of carbohydrases from a natural variant of Aspergillus niger was designed. The enzyme cocktail was found to have a noteworthy potential to eradicate/disperse the biofilms of selected pathogens. For application of enzymes as an antibiofilm agent, the enzyme productivities were enhanced by statistical modelling using response surface methodology (RSM). The antibiofilm potential of the enzyme cocktail was studied in terms of (i) in vitro cell dispersal assay (ii) release of reducing sugars from the biofilm polysaccharides (iii) the effect of enzyme treatment on biofilm cells and architecture by confocal laser scanning microscopy (CLSM). Potential of the enzyme cocktail to disrupt/disperse the biofilm of selected pathogens from biopolymer surfaces was also assessed by field emission scanning electron microscopy (FESEM) analysis. Further, their usage in conjunction with antibiotics was assessed and it was inferred from the results that the use of enzyme cocktail augmented the efficacy of the antibiotics. The study thus provides promising insights into the prospect of using multiple carbohydrases for management of heterogeneous biofilms formed in natural and clinical settings.

A novel multi-enzyme preparation produced from Aspergillus niger using biodegradable waste: a possible option to combat heterogeneous biofilms

Extracellular polymeric substance (EPS) produced by the microorganisms provides protection and stability to them when they are encased within biofilms. Heterogeneous polysaccharides form a major constituent of the EPS and are crucial for the formation and integrity of the biofilms/slime. Thus, breakdown of polysaccharides might help in dispersion of biofilms from abiotic surfaces. In the present study we isolated a fungus, Aspergillus niger APS, capable of concurrently producing a cocktail of carbohydrases and optimized the conditions for higher yields of all the enzymes by one variable at a time (OVAT) approach. The optimization studies resulted in 1.5 to 12 fold augmentation in the enzyme yields using biodegradable waste. Further, keeping in view the heterogeneous nature of polysaccharides in biofilm matrix, the in-house produced enzyme cocktail was used for the dispersal of biofilms formed by Salmonella enterica serovar Typhi, Escherichia coli and Staphylococcus aureus. Treatment with enzyme preparation caused 90.23 ± 4.0, 82.64 ± 5.0 and 76.32 ± 5.0% reduction of the biofilms formed by these organisms respectively which was also evidenced by Field emission scanning electron microscopy (FESEM) revealing the loss of biofilm architecture. Interestingly, the enzyme cocktail could also remove viscous slime formed under natural conditions in the kitchen drainage pipe (KDP). To the best of our knowledge, this is the first report on biotreatment of abiotic surfaces for removal of biofilms/slime formed under natural conditions. The study thus indicates the prospects of using multiple carbohydrases as an anti-biofouling agent on abiotic surfaces like equipments as well as implants/prostheses and pipelines.

Green processing: minimising harmful substances in leather making

Conventional leather processing poses serious threat to the environment due to its numerous chemical treatments which include hazardous chemicals such as sodium sulphide and lime. To minimise the pollutants and harmful substances during leather processing, an enzymatic rehydration-dehairing-fibre-opening process has been achieved in shortest possible time compared to conventional process. The physicochemical characteristics of experimental leathers were found to be comparable with those of conventionally processed leathers. The releases of sugar and proteoglycans were found to be in congruence with the scanning electron micrographs and histology. TGA and DSC results ascertained the stability of enzymatically processed leathers. Pollution load in terms of TOC, BOD, COD, and TDS was reduced up to 80% compared to that of the conventional process. The present work provides immense potential for a new approach in leather making with environmental safeguards. Graphical abstract.

Effect of different salinities on gene expression and activity of digestive enzymes in the thick-lipped grey mullet (Chelon labrosus)

The effects of different environmental salinities (0, 12, 40, and 55 ppt) on pepsinogen 2 (pga2), trypsinogen 2 (try2), chymotrypsinogen (ctr), and pancreatic alpha-amylase (amy2a) gene expression, and on the total activities of their corresponding enzymes, were assessed in Chelon labrosus juveniles, after their corresponding full-complementary DNA sequences were cloned. Furthermore, the quantitative effect of different salinities on the hydrolysis of feed protein by fish digestive enzymes was evaluated using an in vitro system. Relative pga2 expression levels were significantly higher in animals maintained at 12 ppt, while a significantly higher gene expression level for ctr and try2 was observed at 40 ppt. amy2a gene expression showed its maximum level at 40 ppt and the lowest at 55 ppt. A significant reduction in the activity of amylase with the increase in salinity was observed, whereas the maximum activity for alkaline proteases was observed in individuals maintained at 40 ppt. A negative effect of high salinity on the action of proteases was confirmed by the in vitro assay, indicating a decreased efficiency in the digestive function in C. labrosus when maintained at high environmental salinities. Nevertheless, individuals can live under different environmental salinities, even though gene expression is different and the enzymatic activities are not maintained at the highest studied salinity. Therefore, compensatory mechanisms should be in place. Results are discussed on the light of the importance as a new species for aquaculture.

Physiology of digestion and the molecular characterization of the major digestive enzymes from Periplaneta americana

Cockroaches are among the first insects to appear in the fossil record. This work is part of ongoing research on insects at critical points in the evolutionary tree to disclose evolutionary trends in the digestive characteristics of insects. A transcriptome (454 Roche platform) of the midgut of Periplanetaamericana was searched for sequences of digestive enzymes. The selected sequences were manually curated. The complete or nearly complete sequences showing all characteristic motifs and highly expressed (reads counting) had their predicted sequences checked by cloning and Sanger sequencing. There are two chitinases (lacking mucin and chitin-binding domains), one amylase, two α- and three β-glucosidases, one β-galactosidase, two aminopeptidases (none of the N-group), one chymotrypsin, 5 trypsins, and none β-glucanase. Electrophoretic and enzymological data agreed with transcriptome data in showing that there is a single β-galactosidase, two α-glucosidases, one preferring as substrate maltase and the other aryl α-glucoside, and two β-glucosidases. Chromatographic and enzymological data identified 4 trypsins, one chymotrypsin (also found in the transcriptome), and one non-identified proteinase. The major digestive trypsin is identifiable to a major P. americana allergen (Per a 10). The lack of β-glucanase expression in midguts was confirmed, thus lending support to claims that those enzymes are salivary. A salivary amylase was molecularly cloned and shown to be different from the one from the midgut. Enzyme distribution showed that most digestion occurs under the action of salivary and midgut enzymes in the foregut and anterior midgut, except the posterior terminal digestion of proteins. A counter-flux of fluid may be functional in the midgut of the cockroach to explain the low excretory rate of digestive enzymes. Ultrastructural and immunocytochemical localization data showed that amylase and trypsin are released by both merocrine and apocrine secretion mainly from gastric caeca. Finally, a discussion on Polyneoptera digestive physiology is provided.