Digestibility Of Cell Wall Components Research Articles

Transcriptomic and Expression Analysis of the Salivary Glands in Brown Planthoppers, Nilaparvata lugens (Hemiptera: Delphacidae).

The brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae), is a serious rice pest because of its destructive feeding. The salivary glands of the BPH play a key role in successful feeding. In this study, we explored the salivary gland transcriptome (sialotranscriptome) of adult BPHs using Illumina sequencing and a total of 55,913 transcripts and 45,421 unigenes were obtained. We identified one reference gene RPL9 (Ribosomal protein L9) and 19 salivary protein genes from the BPH sialotranscripome, which were categorized as those involved in sugar metabolism, extra-oral digestion of cell wall components, detoxification, and suppression of plant defenses. Tissue expression profiles of 19 salivary protein genes analysis revealed that the expression level of alpha-glucosidase family 31 had no difference in five tissues, suggesting that it may have functions in the whole-body parts. Glucose dehydrogenase (flavine adenine dinucleotide, quinone)-like was expressed highly in the salivary gland, which might play putative role in insect feeding. Glucose dehydrogenase (acceptor) was expressed the highest level in head without salivary gland. Other salivary protein genes were highly expressed in gut or malpighian tubule, suggesting that they may play roles in digestive and detoxification mechanism. Moreover, we detected RPL9 is one of the genes that is most consistently present for acquisition of gene expression in different tissues. Thus, RPL9 can be a new reference for expression studies of BPH. The obtained BPH sialotranscripome provides a list of genes that have potential roles in feeding and interaction between BPHs and rice plants.

Seed-coating fenugreek with Burkholderia rhizobacteria enhances yield in field trials and can combat Fusarium wilt

Two efficient bacterial strains (RHT8 and RHT12) were isolated from root nodules of fenugreek (Trigonella foenum-graecum L.) and identified as Burkholderia sp. on the basis of morphological, physiological, biochemical and molecular character. Both strains produced IAA, Siderophore, solubilized insoluble phosphate, but none of them showed volatile cyanogens production. The isolates exhibited chitinase, β-1,3-glucanase and ACC deaminase activity along with the growth inhibition of Fusarium oxysporum. It also caused degradation and digestion of cell wall components, resulting in hyphal perforation, loss of structural integrity of the mycelium, along with degradation of conidia. Both isolates Burkholderia sp. RHT8 and Burkholderia sp. RHT12 led to synergism and aggressive root coloniztion of the roots and enhanced growth. Bacterial consortia (RHT8 and RHT12) effectively resulted in increased grain yield by 40% of fenugreek as compared to control in field trial. Maximum vigour index, nodule number, root and shoot biomass were recorded with RHT8+RHT12 consortia in comparison to single inoculation as well as control. This study reveals the potential of Burkholderia sp. RHT8 and Burkholderia sp. RHT12 to be used as a bioinoculant for growth promotion of fenugreek along with the protection from Fusarium wilt.

Integrated approach for disease management and growth enhancement of Sesamum indicum L. utilizing Azotobacter chroococcum TRA2 and chemical fertilizer

Azotobacter chroococcum TRA2, an isolate of wheat rhizosphere displayed plant growth promoting attributes including indole acetic acid, HCN, siderophore production, solubilization of inorganic phosphate and fixation of atmospheric nitrogen. In addition, it showed strong antagonistic effect against Macrophomina phaseolina and Fusarium oxysporum. It also caused degradation and digestion of cell wall components, resulting in hyphal perforations, empty cell (halo) formation, shrinking and lysis of fungal mycelia along with significant degeneration of conidia. Fertilizer adaptive variant strain of A. chroococcum TRA2 was studied with Tn5 induced streptomycin resistant transconjugants of wild type tetracycline-resistant TRA2 (designated TRA2(tetra+strep+)) after different durations. The strain was significantly competent in rhizosphere, as its population increased by 15.29% in rhizosphere of Sesamum indicum. Seed bacterization with the strain TRA2 resulted in significant increase in vegetative growth parameters and yield of sesame over the non-bacterized seeds. However, application of TRA2 with half dose of fertilizers showed sesame yield almost similar to that obtained by full dose treatment. Moreover, the oil yield increased by 24.20%, while protein yield increased by 35.92% in treatment receiving half dose of fertilizer along with TRA2 bacterized seeds, as compared to untreated control.

Rumen digestion of rice straw structural polysaccharides: effect of ammonia treatment and lucerne extract supplementation in vitro

The combined effects of lucerne (Medicago sativa L.) extract supplementation and ammonia treatment of rice straw (Oryza sativa, variety Thaibonnet) on the ruminal digestion of cell wall components were investigated in six continuous culture systems using a randomised complete block design. Data were fitted to second-order polynomial models. Untreated rice straw had higher contents of ash-free cell wall residues (CWR; 763 v. 687 g/kg dry matter (DM)) and non-cellulosic sugars (191 v. 166 g/kg DM) than treated rice straw. Ammoniation preferentially removed xylose, which resulted in a lower xylose-to-arabinose ratio (5.1 v. 5.8). In absence of lucerne supplementation and ammoniation, degradability coefficients were 0.54, 0.46, 0.58, 0.54, 0.42 and 0.60 for cellulose–glucose, xylose, arabinose, galactose, mannose and uronic acids, respectively. Both factors had significant effects on the microbial degradation of structural polysaccharides. With lucerne extract at an optimal level, ammonia treatment increased ash-free cell wall degradation by more than 10%. The degradability coefficients were increased by ammoniation without any significant interaction with lucerne extract, except for glucose, whose degradability was mostly influenced by lucerne extract in a curvilinear way. The comparison of regression coefficients in cell wall and CWR models suggested that ammoniation improved the degradabilities of xylose, galactose and mannose by partly solubilising the corresponding hemicelluloses and by improving the susceptibility of the remaining fraction to microbial attack, whereas it increased the degradability of arabinose only by favouring microbial attack.

Wilt disease management and enhancement of growth and yield of Cajanus cajan (L) var. Manak by bacterial combinations amended with chemical fertilizer

Root nodulating Sinorhizobium fredii KCC5 and Pseudomonas fluorescens LPK2 were isolated from nodules of Cajanus cajan and disease suppressive soil of tomato rhizosphere, respectively. Both strains produced IAA, siderophore, solubilized insoluble phosphate, showed chitinase and β-1,3-glucanase activities, and strongly inhibited the growth of Fusarium udum. It also caused degradation and digestion of cell wall components, resulting in hyphal perforations, empty cell (halo) formation, shrinking and lysis of fungal mycelia along with significant degeneration of conidia. LPK2 produced volatile cyanogen (HCN). Combinations of S. fredii KCC5 and P. fluorescens LPK2 with half dose of chemical fertilizers showed a significant increase in seed germination (94%) while seed germination with co-inoculated strains (KCC5 + LPK2), KCC5 and LPK2 alone was 90, 84 and 82% respectively as compared to control 77%. After 120 days of sowing, per plant number of pods, nodules, shoot length, root length, shoot weight and root weight were greater for the combination with half dose of chemical fertilizers compared to the control. Combinations of S. fredii KCC5 and P. fluorescens LPK2 with half dose of chemical fertilizers resulted in an 82% increase in grain yield per hectare compared to the control. Both strains KCC5 and LPK2 led to proto-cooperation as evidenced by synergism, aggressive colonization of the roots, and enhanced growth, suggesting potential biocontrol efficacy against Fusarium wilt in C. cajan.

Comparative digestion of cell wall components of alfalfa hay cubes between Sika deer (Cervus nippon) and cattle

ABSTRACTFour female Sika deer (mean bodyweight, 48 kg) and three male Holstein cattle (mean bodyweight, 209 kg) were offered alfalfa hay cubes at 2% (deer) and 2.5% (cattle) of bodyweight, respectively. The digestibility of the cell walls and cell wall components (rhamnose, arabinose, xylose, mannose, galactose and glucose) in alfalfa and its retention time of the alfalfa in the digestive tract and rumen parameters were determined. Cell walls and xylose were less digestible in the deer than in the cattle (P < 0.01 and P < 0.05, respectively). The digestibility of galactose in the deer was as high as that in the cattle. The digestibility of the other sugars and total neutral sugars was numerically lower in the deer, but the differences were not significant. In the deer, mannose was most digestible, followed in order by galactose, arabinose, glucose, rhamnose and xylose; whereas, in the cattle, mannose was most digestible, followed in order by arabinose, glucose, galactose, rhamnose and xylose. The retention time in the digestive tract was shorter in the deer than in the cattle. In the deer, the number of ruminal protozoa was somewhat higher, and the concentrations of propionic acid and butyric acid were higher (P < 0.05) than in the cattle. These results indicate that Sika deer might utilize pectic polysaccharides as a carbon source in preference to glucose containing polysaccharides such as cellulose. The lower digestibility of all cell wall components except galactose in the Sika deer might be mainly due to its shorter retention time.

Ruminal digestion and glycosyl linkage patterns of cell wall components from leaf and stem fractions of alfalfa, orchardgrass, and wheat straw

Samples of alfalfa, orchardgrass, and wheat straw were hand-separated into leaf and stem fractions that were subjected to in situ ruminal fermentation for various lengths of time to assess the rate and extent of degradation of cell wall neutral monosaccharides, uronic acids, acetyl groups, and hydroxycinnamic acids. A second objective was to measure the glycosyl linkage patterns of leaf and stem fractions of substrates before and after ruminal fermentation. Samples were fermented for 0, 6, 12, 24, 48, 96, and 192 h in each of two ruminally cannulated steers. In situ disappearance data were fitted to a first-order exponential equation to estimate the following substrate parameters: insoluble, potentially digestible fraction (fd), indigestible fraction (fi), and fractional rate constant of degradation of the potentially digestible fraction (k). Leaves contained larger concentrations of crude protein and smaller concentrations of cell wall components than did stem fractions. Estimates of fi were 7.3, 39.2, 22.1, 49.3, 27.7, and 36.3 for dry matter disappearances for alfalfa leaf, alfalfa stem, orchardgrass leaf, orchardgrass stem, wheat straw leaf, and wheat straw stem, respectively. Averaged across substrates, estimates of fi for arabinose, galactose, glucose, xylose, uronic acids, acetyl groups, and p-coumaric acid were 16.5, 11.4, 14.8, 31.2, 12.8, 25.3, and 22.6% in leaf fractions and 29.5, 19.9, 37.5, 56.2, 35.0, 52.4, and 44.6% in stem fractions. Rates of digestion of all monomeric components except galactose and xylose were greater (P < .05) for alfalfa than for orchardgrass or wheat straw. Differences in digestibility of cell wall components from leaf and stem fractions were greater in alfalfa and orchardgrass than in wheat straw. Glycosyl linkage analysis indicated that xylans in leaf and stem fractions of alfalfa, orchardgrass leaf, and wheat straw stem that resisted degradation had a lower degree of substitution with acid-labile constituents (i.e., other monosaccharides) than was found in original substrates. Different rates and extents of digestion of leaf and stem fractions of forages explain part, but not all, of the observed differences in digestibilities of cell wall monomers by ruminants.

Metabolic and endocrine responses of lambs fed Acremonium coenophialum-infected or noninfected tall fescue hay at equivalent nutrient intake

Ten Hampshire x Western wether lambs (means weight = 30.1 kg) equipped with ruminal and abomasal cannulas were fed either low-Acremonium coenophialum (AC) Kentucky-31 (less than 1% infected) or high-AC G1-307 (greater than 95% infected) varieties of tall-fescue (TF) hay of similar nutrient composition in a completely randomized design. Lambs were housed in metabolism crates at 21 +/- 1 degrees C and fed 552 g DM/d of ground hay at 0800 and 2000. A 10-d adaptation preceded 7 d of sample collection. Levels of water and DM voluntarily consumed by the low-AC group during the adjustment period were held constant for both treatment groups throughout the collection period by intraruminal insertion of unconsumed DM and water. Fixed water intake markedly reduced voluntary water intake but it alleviated previous depressions in voluntary DM intake in lambs fed high-AC. Mean daily respiration and heart rates, rectal temperature and hematocrit were not affected (P greater than .10) by treatment. Compared with high-AC, lambs fed low-AC retained a greater (P less than .10) amount of N (1.8 vs 1.1 g/d) and a greater (P less than .10) percentage of their N intake (16.4 vs 9.9%). Abomasal total and bacterial N flow and ruminal digestion of cell wall components were not affected (P greater than .10) by treatment. Total tract digestion of DM, NDF and ADF was lower (P less than .01) for high- than for low-AC. Serum prolactin concentration was higher (P less than .10) for lambs fed low- than for those fed high-AC TF, but serum cortisol and thyroxine concentrations were not affected (P greater than .10) by treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Digestion of Cell Wall Components by Dairy Heifers Fed Diets Based on Alfalfa and Chemically Treated Oat Hulls

Four Holstein heifers were used in a 4 × 4 Latin square design to measure total tract digestion of cell wall components from diets based on alfalfa haylage and alkaline hydrogen peroxide-treated oat hulls. Diets contained 90% forage and 10% concentrate. Treatments were diets containing 90, 70, 50, or 30% alfalfa haylage with treated oat hulls supplying the remainder of the forage portion. Total tract digestion of cell wall-associated uronic acids, arabinose, galactose, mannose, rhamnose, and lignin were not affected by forage source. Digestibilities of cell wall glucose and xylose increased with increasing level of dietary treated oat hulls, reflecting the positive effect of alkaline hydrogen peroxide treatment on cell wall digestion. Cellulose (ADF minus acid detergent lignin) digestibilities were similar to those for cell wall glucose, whereas hemicellulose (NDF minus ADF) digestibilities were similar to those for cell wall arabinose plus xylose. Low digestibilities of alfalfa cell wall xylose indicate that some cell wall structure inhibits the degradation of alfalfa xylans. Low degradabilities of core lignin, esterified p-coumaric acid, and esterified acetyl groups suggest that these components may be involved primarily in depressing fermentation of cell wall polysaccharides.

The effect of composition on diet digestibility by pigs and on the biodegradability of the resulting pig faeces

The digestibility of the major dietary components, and the biodegradability of faeces from pigs fed each of three practical diets, were examined using diets formulated from different, commonly available, ingredients and containing different amounts of fibre. The digestibility by pigs of most dietary components depended on the amount of fibre in the diet, while digestibility of cell wall components depended more on the source of the fibre. The chemical composition of the faeces largely reflected the composition and the digestibility of the diets, particularly with respect to fibre content. Biodegradibility of the faeces, as measured by in vitro digestibility and anaerobic digestion in laboratory-scale digesters, depended on the origin, rather than the amount, of fibre in the faeces. Lignin appeared to be the cell wall constituent most affecting faeces biodegradability. It is concluded that, with appropriate ingredient selection, pig diets could be obtained that would result in satisfactory liveweight gain by the pigs, as well as in highly biodegradable faeces.

Digestion Kinetics of Sequentially Extracted Cell Wall Components of Forages1

Rate and extent of cell wall digestion are important factors limiting utilization of forages in ruminant diets. The objectives of this experiment were to compare two methods of calculating these parameters and to compare the in vitro digestion kinetics of cell wall, cellulose and hemicellulose sequentially extracted from alfalfa (Medicago sativa L.), tall fescue (Festuca arundinacea Schreb.), sorghum ✕ sudangrass [Sorghum bicolor (L.) Moench], and wheat (Triticum aestivum L.) straw. Plant tissue was incubated in a rumen fluid‐buffer medium for 3,6, 9,12, 24, 36, 48, 72, or 96 h. Cell wall components were extracted sequentially using glass microfiber filters with sintered glass crucibles. The kinetic model used was: C = CDe −k(t‐L) + C1; where C = concentration remaining at time t, CD — digestible concentration, k = rate constant, L = discrete lag time, and C1 = indigestible concentration. Parameter estimates were obtained using a In‐linear least squares procedure and the multivariate secant nonlinear least squares procedure to determine if one method was more appropriate than the other. Both methods resulted in equations that described the data very well. Predicted and observed values were highly correlated (r &gt; 0.99, P ≤ 0.01), and residual errors were similar for both procedures. There was, however, a bias associated with the nonlinear procedure, which tended to result in lower estimates of k and L when long lag times occurred. Within the grass species, there was no difference (P ≤ 0.05) among rate constants for digestion of cell wall components. Average rate constants for digestion of tall fescue, sorghum ✕ sudangrass, and wheat straw cell wall components were 0.046,0.059, and 0.045 h−1. Rate of digestion of alfalfa hemicellulose was 1.6 times faster than that of cellulose. Rate constants were 0.200 h−1 for alfalfa hemicellulose and 0.125 h−1 for cellulose. The results of this experiment indicate that use of the In‐linear calculation procedure is preferable when the digestion kinetics of species with a wide range of lag times are compared. Application of both calculation methods allowed for a comparison of cell wall digestion kinetics in vitro.

Rate and Extent of Digestion of Cell Wall Components of Brown‐Midrib Sorghum Species1

Cell wall composition and structure are important factors influencing utilization of forages in diets of ruminant animals. Our objective was to compare the cell wall composition and rate and extent of digestion of cell walls of normal and brown‐midrib (bmr) genotypes of sorghum [Sorghum bicolor (L.) Moench.) species. Brown‐midrib ‘Greenleaf’ sudangrass [Sorghum bicolor (L.) Moench.], and ‘Redlan’ ✕ ‘Greenleaf’ and Redlan ✕ ‘Piper’ sorghum ✕ sudangrass hybrids were planted in the field in a Zanesville silt loam soil (finesilty, mixed, mesic Typic Fragiudalf) along with corresponding normal genotypes. Stover was harvested and analyzed sequentially for fiber components, total nonstructural carbohydrates, and neutral sugar and phenolic acid composition of cell walls. Samples were incubated in buffered rumen fluid for 0, 6, 9, 14, 21, 48, and 72 h and rate constants were determined for neutral detergent fiber (NDF), cellulose, and hemicellulose digestion. The NDF, cellulose, and lignin concentrations of bmr genotypes were lower than the corresponding normal genotypes. This resulted in 7% higher in vitro dry matter digestibility of bmr tissues over the normal genotype. Rate constants for digestion of NDF, cellulose, and hemicellulose differed, averaging −0.083, −0.088, and −0.079 h−1 for the bmr genotypes, compared to −0.064, −0.068, and −0.066 h−1 for the normal genotypes, respectively. The bmr genotypes had a higher extent of NDF, cellulose, and hemicellulose digestion when compared to the normal genotypes. The lignin concentration in the cell wall of bmr genotypes was initially lower than normal genotypes, but as digestion progressed the lignin concentrations of both genotypes merged at 138 g kg−1 NDF. This indicates that the proportion of lignin in the cell wall may be a limiting factor for extent of cell wall digestion. A portion of the lignin initially present was apparently digested, with extent of lignin digestion at 111 g kg−1 for the bmr genotypes compared to 186 g kg−1 for its normal counterpart. Ferulic acid (FA) concentration on a NDF basis was higher and p‐coumaric acid (PCA) concentration lower in the bmr genotype, indicating considerable differences in linkages may exist between core lignin and structural carbohydrates. The FA/PCA ratio was 0.75 and 0.34 for the bmr and normal genotypes, respectively. This agrees with the suggested positive relationship between cell wall digestion and the FA/PCA ratio.

Effects of Cellulase from Trichoderma viride on Nutrient Utilization by Broilers

Studies were conducted to evaluate the effects of cellulase from Trichoderma viride in a diet for broilers containing high levels of wheat bran. Broiler-type, mixed-sex chicks were fed from 3 to 8 weeks of age. Wheat bran was added at 0, 10, and 20% levels. A fourth group received the 20% wheat bran plus the cellulase enzyme added at the level of .008%. A portion of the chicks was used in a digestibility study with chromic oxide as an indicator. The summarized data showed that cellulose treatment had a significant effect on reducing feed consumption (P<.01) and an apparent effect in improving feed-to-gain ratio. Cellulase supplementation significantly improved the digestibility of cell wall components (P<.01). Calcium, phosphorus, iron, zinc, and copper associated with cell walls were solubilized by cellulase. Iron balance was negative in the groups without cellulase; however, iron, which is bound by the bran, apparently was made available for absorption by cellulase.

Nutritive value for ruminants of sugar cane bagasse ensiled after spray treatment with different levels of NaOH

Sugar cane bagasse previously dried to a water content below 25% was sprayed with equal quantities of sodium hydroxide solutions to supply 0, 20, 40 or 60 g alkali/kg of dried product and ensiled for 90 days. The cell wall content (NDF) decreased with increasing NaOH ( P < 0.001), whereas the lignocellulose fraction (ADF) remained unaffected. The effect on lignin (ADL) was small. All this suggests a solubilization of the hemicellulose fraction with alkali application. Ensiling reduced the pH in the bagasse owing to partial neutralization of residual NaOH. From a microbiological point of view, the stability of the NaOH-treated product, whether during the period of silage or when exposed to air, was good. The presence of NaOH in the silo inhibited the development of bacteria and fungi, an effect which was probably enhanced by the reduced soluble carbohydrate content of the substrate. Sixteen digestibility experiments following a 4 × 2 × 2 factorial design were carried out on whethers of 55.0 kg given, ad libitum, isocaloric diets containing the NaOH-sprayed bagasse supplemented with molasses, a mineral—vitamin mixture and urea—biuret or soya bean meal, to provide a total N content of 1.65 and 2.10%, irrespective of the N source. Average daily intakes were 29.8, 35.7, 44.7 and 40.6 g/kg W 0.75 for diets containing bagasse sprayed with 0, 20, 40 and 60 g alkali/kg of dried product, respectively. The effects of NaOH level, N source and N level were highly significant ( P < 0.001). The apparent digestibility of dry matter (DM), organic matter (OM) and cell wall components, and the N retention increased linearly ( P < 0.001) as the level of chemical treatment increased. Except for hemicellulose, the digestibility of the cell wall components was improved when soya bean meal was included in the experimental diets. The effect of N content was not significant. The calculated average organic matter digestibility (OMD) for the sugar cane bagasse ranged from 32.6 for the water-treated product to 56.8% with the highest level of alkali, the effect of the chemical treatment being significant ( P < 0.001).

THE EFFECT OF CONCENTRATE ON THE DIGESTION OF BROMEGRASS CONSTITUENTS

A nylon bag technique was used to study the effect of concentrate feeding on the rate and extent of digestion of bromegrass constituents in eight fistulated sheep fed rations at or slightly above maintenance, at concentrate to bromegrass ratios of 3:97, 22:78, 44:56 and 66:34. The eight sheep were arranged in a double 4 × 4 latin square design with nylon bag incubation times of 3, 6, 12, 24 and 48 h. Rations containing 44 and 66% concentrate depressed rumen digestion of bromegrass dry matter at both 24- and 48-h incubation times. The extent of digestion depression varied among sheep and was related to the animal's ability to buffer increases in rumen acidity. Digestibilities of neutral detergent fiber, acid detergent fiber, cellulose and hemicellulose followed trends similar to that of dry matter. Rumen osmolality, total volatile fatty acids and ammonia levels appeared to have little relationship to bromegrass dry matter digestion. The apparent or total gut digestibility of cell wall components was not depressed. This suggested that additional digestion took place in the ileum, cecum and colon and that the proportion of concentrate supplementation may affect ruminal but not the total gut utilization of roughage at maintenance levels of intake.