Structural Carbohydrate Content Research Articles

Structural carbohydrate and lignin content of perennial cereal forage grasses depending on the growth phase and digital innovations in forage composition analysis

The article is devoted to the study of the content of cell wall carbohydrates – neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL) – in cereal forage grasses depending on the growth phases. An increase in all cell wall fractions was revealed as the growth phases changed. The content of acid detergent fiber, neutral-detergent fiber and acid detergent lignin (% in dry matter) in cereal forage grasses (awnless brome, meadow fescue, meadow timothy) is 31‑32, 50‑55, 4‑6 before earing; in the earing phase – 32‑37, 55‑65, and 5‑6; in the flowering phase – 40‑45, 70‑72, 7‑9, respectively. As grasses grow, their composition changes with the accumulation of cell walls. The increase in the proportion of neutral detergent fiber occurs mainly due to an increase in the proportion of cellulose and a decrease in the proportion of hemicellulose, which is consistent with a higher digestibility of grasses in the early growth stages. According to the results of the study, the relationship between crude fiber and acid detergent fiber was closer (n = 64, s = 2.4%, r = 0.93) than between crude fiber and neutral detergent fiber (n = 64, s = 4.4%, r = 0.87). As the composition of grass changes daily during the growing season, it is advisable to determine its composition as soon as possible. As chemical methods are time-consuming, an express method based on an infrared analyzer can be used to solve this problem. The express method involves, after the grinding of the sample, sequential operations such as calibrating the analyzer, placing the sample in the analyzer and analyzing the samples with the analyzer. This means that this method is also quite time-consuming. To obtain information more quickly (two hours), digital technologies are now increasingly being used. The method based on digital technologies involves the sequential execution of the following operations: UAV launch, crop survey, transmission of multispectral data to the server, information processing and calculation of crude fiber content.

Effect of Biochar Application and Mineral Fertilization on Biomass Production and Structural Carbohydrate Content in Forage Plant Mixture

Biochar, a fine-grained porous material, exhibits properties that improve soil quality on agricultural land. Biochar, in combination with mineral fertilizers in perennial mixed crops, has so far not been studied for its effect on biomass production and feed value. The study, conducted in 2021 and 2022, aims to investigate the impact of different biochar application rates (alone and in combination with high and low NPK (nitrogen, phosphorus, potassium) fertilizer dosages) on the yield and structural carbohydrate content in grass–legume mixtures. Thus, a two-factorial pot study consisting of 36 pots was established in 2021. The study was set up in a randomized block design with nine fertilization treatments in four replicates. The factors studied were the rate of biochar (0, 5, and 10 Mg ha−1) and the rate of NPK mineral fertilizer application (0, 105, and 185 kg ha−1). First, biochar was applied and then the grass–legume mixture was sown, consisting of Lolium perenne L., Festuca arundinacea Schreb., Dectylis glomerata L., Lolium multiflorum Lam., Phleum pratense L., Festuca rubra L., Festuca ovina L., Poa pratensis L., Trifolium repens L., and Medicago sativa L. In both years of the study, during the growing season, plant biomass was harvested three times to assess biomass production and structural carbohydrate content. In the collected samples, neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) were examined, and, based on these, dry matter digestibility (DDM), dry matter intake (DMI), and relative feed value (RFV) were calculated. Compared to the control, the biochar addition increased the biomass production by 6.7–14.4% in the first year and by 49–59% in the second year after application. The addition of biochar in combination with NPK fertilization caused an increase in biomass production—22–45% in the first year and 71–136% in the second year after application. The structural carbohydrate content in the mixture depended neither on the biochar dose nor on fertilization. On the other hand, the most significant differences for the studied parameters were observed due to different harvest dates.

Evaluation of the Effectiveness of NBPT and NPPT Application as a Urease Carrier in Fertilization of Maize (Zea mays L.) for Ensiling

The study presents the results of a 3-year field trial aimed at assessing the yield and quality of raw material for ensiling in the cultivation of three maize varieties differing in their agronomic and genetic profile, conditioned by the selection of nitrogen fertilizer. Maize cultivar ES Metronom showed a significant advantage over other cultivars when fertilized with UltraGrain stabile, or alternatively Super N-46. The application of nitrogen-stabilized fertilizers or urea + N-Lock significantly increased the yield of maize green fodder for ensiling. The “stay-green” maize cultivars were characterized by a higher content of non-structural carbohydrates, including starch and water-soluble sugars, and a lower content of structural carbohydrates, compared to the conventional cultivar, which increased their suitability for ensiling. The negative effect of maize fertilization with ammonium nitrate and ammonium nitrate + N-Lock on the chemical composition of green fodder was demonstrated by a reduced starch content and increased structural carbohydrate contents, including crude fiber and NDF. In turn, the positive effect of maize fertilization with urea and urea + N-Lock on the chemical composition of maize fodder was shown by increased starch content and reduced structural carbohydrate contents, including crude fiber and its NDF and ADF fractions. The analysis of the number and weight of leaves may indicate a highly effective utilization of nitrogen (“stay-green” maize hybrids), leading to the faster formation of leaves with a larger assimilation surface, which is the basis for the efficient absorption of solar radiation. The results obtained clearly show that only the correct choice of maize variety for silage cultivation, combined with nitrogen fertilizer guaranteeing access to N during the growing season, can guarantee a high yield for ensiling.

EFFECT OF DIFFERENT CONTENTS OF NEUTRAL DETERGENT AND ACID DETERGENT FIBER IN THE DIET OF ANIMALS DURING THE FIRST PHASE OF LACTATION ON RUMINAL DIGESTION

The main limiting factor in the consumption by ruminants of large quantities of bulk feed is the presence of fiber in plants, an increase in which above the optimal level has a negative impact on digestion, leading to a decrease in the digestibility of nutrients in the diet. By changing the structure of the diet and the ratio of nutrients in the diet, it is possible to stimulate or inhibit both the general nature of rumen processes and the level of nutrient utilization. This article presents the materials of the work aimed at studying the effect of different content of neutral detergent and acid detergent fiber in the diet of animals during the first phase of lactation on ruminal digestion.
 Studies showed that feeding cows of control and experimental groups in the first 100 days of lactation with diets with different content of structural carbohydrates predetermined some changes in the microbiological and enzymatic activity of ruminal digestion.

Response of the common reed (Phragmites australis) to nutrient enrichment depends on the growth stage and degree of enrichment: A mesocosm experiment

Human-induced nutrient enrichment is a major stressor in aquatic ecosystems that has resulted in the alteration of ecosystem structures and functions. However, to date, relatively few studies have explored the temporal dynamics of reed biomass and morphological and biochemical traits under different nutrient levels, as well as the phenological pattern. Based on a mesocosm experiment, we monitored the aboveground and underground biomass of reed at the different plant growth stages, along with plant height, ramet and leaf number, leaf length and width, and carbohydrate and nutrient contents in different organs. We found that the significantly different ratio of aboveground to underground biomass was only observed at the late flowering stage between the slight enrichment (S-E) and heavy enrichment (H-E) groups. The start of the fast-growth phase of the aboveground part and underground part was delayed in the higher nutrient enrichment groups. The length of the fast-growth phase of the aboveground part was the same in the medium enrichment (M-E) and H-E groups and longer than that in the S-E group. For the underground part, the longest fast-growth phase was found in the S-E group (105 days), followed by the H-E and M-E groups (46 and 41 days, respectively). As the nutrient level increased, both increased and decreased values were observed for the 29 monitored morphological and biochemical traits, and the magnitude changed with the different growth stages. Moreover, different degrees of nutrient enrichment could differentially enhance or weaken the relationships among the groups between total biomass and the integrated morphological trait, between structural carbohydrate (SC) and total nitrogen (TN) contents, between total organic carbon (TOC) and TN, between total phosphorus (TP) contents, between TOC and SC contents. Our findings highlight a crucial contribution of ambient nutrient supply to temporal variation in plant biomass and phenological, morphological and biochemical traits.

ZMIANY WĘGLOWODANÓW W MIESZANKACH MOTYLKOWO-TRAWIASTYCH POD WPŁYWEM PODŁOŻA POPIECZARKOWEGO I GNOJOWICY BYDLĘCEJ

The aim of the research was to assess the effect of mushroom substrate and slurry on the content of structural and non-structural carbohydrates in hybrid alfalfa mixtures with grasses. The three-year research was conducted in an experimental field between 2013 and 2015, with the following variables: (1) spent mushroom substrate (SMS) and cow slurry (CS), applied in different combinations; (2) three legume grass mixtures: orchard grass, perennial ryegrass, hybrid alfalfa (M1); orchard grass, hybrid alfalfa (M2); perennial ryegrass, hybrid alfalfa (M3). In each growing season, the mixtures were harvested three times. Plant material was used to determine dry matter content and the content of neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), cellulose, hemicellulose, lignin, total protein, crude ash, and crude fat by near infrared spectroscopy (NIRS), using the NIRFlex N-500 spectrometer and ready-to-use INGOT® calibration applications. Generally, mushroom substrate applied on its own increased the amounts of cellulose and hemicellulose in legume grass mixtures more than slurry. The most cellulose, the least hemicelluloses, and the highest degree of lignification were recorded in the mixture of ryegrass with alfalfa, while the degree of lignification was the smallest in the forage of alfalfa and orchard grass, which also contained the least cellulose but the most hemicellulose. On average, the highest amount of cellulose was in the biomass of the first harvest and the least in the third.

Characterization and identification of a novel microbial consortium M2 and its effect on fermentation quality and enzymatic hydrolysis of sterile rice straw.

To isolate and enrich lignocellulolytic microbial consortia from yak (Bos grunniens) rumen and evaluate their effects on the fermentation characteristics and enzymatic hydrolysis in rice straw silage. A novel microbial consortium M2 with high CMCase and xylanase activities was enriched and observed to be prone to use natural carbon sources. Its predominant genus was Enterococcus, and most carbohydrate-active enzyme (CAZyme) genes belonged to the glycosyl hydrolases class. The consortium M2 was introduced with or without combined lactic acid bacteria (XA) to rice straw silage for 60days. Inoculating the consortium M2 notably decreased the structural carbohydrate contents and pH of rice straw silages. Treatment that combines consortium M2 and XA resulted in the highest levels of lactic acid and lignocellulose degradation. The consortium M2 alone or combined with XA significantly (p<0.01) increased water-soluble carbohydrates (WSCs), mono- and disaccharides contents compared with the XA silage. Combined addition obviously improved the enzymatic conversion efficiency of rice straw silage with higher glucose and xylose yields (23.39 and 12.91 w/w% DM, respectively). Ensiling pretreatment with the microbial consortium M2 in sterile rice straw improved fermentation characteristics. The combined application of consortium M2 with XA had synergistic effects on promoting the degradation of structural carbohydrates and enzymatic hydrolysis. Rice straw is difficult to ensile because of its low WSC and high structural carbohydrate contents. The microbial consortium M2 identified herein exhibits great potential for degrading fibrous substrates, and their combination with XA provides a faster and more effective synergistic strategy for biorefinery of lignocellulosic biomass.

Foliar application uniconazole enhanced lodging resistance of hybrid indica rice by altering basal stem quality under poor light stress

AbstractPoor light stress causes lodging risks in hybrid indica rice (Oryza sativa L.) in Sichuan Basin, China. However, the effective way of improving lodging resistance of hybrid indica rice by plant regulation strategy under poor light stress has not yet been investigated. A 2‐yr field study, comparing the three foliar application uniconazole rates under normal light and shading condition, was conducted to determine the lodging resistance and its physiological mechanism by using two hybrid rice varieties (Yuxiang203 [YX203] and Cliangyouhuazhan [CLYHZ]). The results showed that shading significantly decreased grain yield, but, increased lodging index (LI) due to poor stem breaking strength (M). Also, shading increased the non‐structural carbohydrates (NSC), but reduced structural carbohydrate (SC), especially for lignin in basal culm and thus, weakened the stem stiffness. Grain yield was first increased, and then declined with increasing foliar uniconazole rates. And, LI decreased sharply owing to improvement of M while reduction of bending moment by whole plant (WP). Larger section modulus (SM) of YX203 and higher bending stress (BS) of CLYHZ were contributed to higher M. Correlation analysis showed that M was significantly correlated with culm diameter, culm wall thickness and SC content for YX203, and that with SC content for CLYHZ, respectively. The results indicated that foliar application of uniconazole increased lodging resistance of hybrid indica rice for larger M and SC accumulation in basal stem. Uniconazole foliar application at 40 mg L–1 can increase lodging resistance while maintaining grain yield of hybrid indica rice in the Sichuan Basin, China.

Comparison and Characterization of Oxidation Resistance and Carbohydrate Content in Cd-Tolerant and -Sensitive Kentucky Bluegrass under Cd Stress

Kentucky bluegrass (Poa pratensis L.), a turf grass species that is hypertolerant of cadmium (Cd), is a potential phytoremediation material for soil polluted with Cd. However, the mechanism of Cd phytotoxicity in Kentucky bluegrass is unclear. Here, we compared the phenotype, induction of oxidative stress, and structural and non-structural carbohydrate contents between a Cd-tolerant genotype (‘Midnight’, M) and Cd-sensitive genotype (‘Rugby’, R). The results showed that both genotypes accumulated more Cd in the roots, whereas the R genotype distributed more Cd into the leaves compared with the M genotype. In both genotypes, Cd inhibited the length and fresh weight of the leaves and roots; increased the peroxidase (POD) activity but inhibited ascorbate peroxidase (APX) and catalase (CAT) activity; and increased the superoxide radical (O2−), hydrogen peroxide (H2O2), and malondialdehyde (MDA) contents. However, the M genotype exhibited lower root length inhibition, and the H2O2 and MDA contents confirmed that the M genotype had increased Cd accumulation and resistance, while the R genotype exhibited a better distribution of Cd. Moreover, Cd stress significantly increased the soluble sugar, trehalose, and sucrose contents of both genotypes. Pectin, lignin, and cellulose were significantly increased to prevent the entry of Cd into the roots. The Cd-induced growth inhibition and physiological responses in Kentucky bluegrass were preliminarily explored herein, with the chelation of pectin, lignification, and antioxidant response being possible contributors to Cd detoxification in Kentucky bluegrass. In addition, the Cd-induced increase in trehalose, sucrose, and soluble sugar contents might play a pivotal role in the defense against Cd stress in Kentucky bluegrass.

Classification of Megathyrsus Maximus Accessions Grown in the Colombian Dry Tropical Forest by Nutritional Assessment During Contrasting Seasons

The diversity and use of tropical forages for cattle feeding are the protagonists in livestock systems. The production and nutritional quality of forages represent a strategy of continuous research in animal feeding to help mitigate the environmental impact generated by tropical livestock. The objective of this study was to classify the nutritional behavior in contrasting seasons and the relationship with agronomic traits of a collection of 129 CIAT (Centro Internacional de Agricultura Tropical) accessions of Megathyrsus Maximus established in the Colombian dry tropics. By means of the near-infrared reflectance spectroscopy (NIRS) technique, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and in vitro dry matter digestibility (IVDMD) were determined under rainy and dry seasons as fixed effects. We measured plant height, dry matter biomass (DMB) and flowering in field. Aspects such as plant height and DMB did not show correlation with nutritional aspects, whereas flowering was correlated with the content of structural carbohydrates. Despite genotype and precipitation affecting nutritional value, there is relative nutritional steadiness in NDF, ADF, and IVDMD between seasons for some accessions. According to the cluster analysis carried out for each season, it was evidenced that from the total collection, 51.2% of the accessions during the dry season and 19.4% of the accessions during the rainy season were classified with a better nutritional profile, thus, showing a higher number of materials with better nutritional behavior in the dry season. Both the genotypic characteristics of M. maximus and environmental conditions during contrasting seasons are factors that might influence the variability of the nutritional content, productive parameters, and flowering. Additionally, fodder material classification under Hotelling's T-squared test and Nutritional Classification Index suggests accessions that might be promising for resilient nutritional quality and adequate DMB, which proves that M. maximus could become an alternative for animal feeding and sustainable livestock production during critical dry periods in tropical agroecosystems.

COMPOSICIÓN BOTÁNICA Y EVALUACIÓN NUTRICIONAL IN VITRO DE PASTO KIKUYO COMPARADO CON GRAMÍNEAS DE CLIMA TEMPL

&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Intensive continuous grazing of temperate grass and legume pastures has been a feeding strategy adopted in small-scale dairy systems (SSDS) in the highlands of central Mexico that reduces costs and increases profitability of farms. However, temperate grasses have low persistency due to agroclimatic and management conditions, so that pastures are invaded by kikuyu grass (&lt;em&gt;Cenchrus clandestinus&lt;/em&gt;), a sub-tropical grass that may be a valuable forage resource in these systems. There are not many studies in Mexico on kikuyu grass pastures and on the relationship between botanical composition, nutritional value and ruminal fermentation parameters, important aspects for their inclusion in feeding strategies for dairy cattle. &lt;strong&gt;Objective: &lt;/strong&gt; The objective was to determine the botanical composition and to assess the &lt;em&gt;in vitro &lt;/em&gt;digestibility of dry matter (DM), organic matter (OM), and neutral detergent fibre (NDF), and to characterize the kinetics of &lt;em&gt;in vitro &lt;/em&gt;ruminal fermentation of a pasture based on with kikuyu grass (KY) in comparison to pastures based on festulolium cv. Spring Green (FL), tall fescue cv. TF-33 (TF), and perennial ryegrass cv. Pay Day (RG), all associated with white clover. &lt;strong&gt;Methodology: &lt;/strong&gt; There were four sampling periods every 14 days. On the last day of each period, five random samples in each pasture were cut to ground level to determine botanical composition by manual separation, and 200g samples from each pasture taken by simulated grazing to determine digestibilities and the &lt;em&gt;in vitro &lt;/em&gt;fermentation dynamics. Statistical analyses were following a split-plot model. &lt;strong&gt;Results: &lt;/strong&gt;There was a higher proportion of grasses in KY and a better &lt;em&gt;in vitro &lt;/em&gt;nutritional value for RG, related to a higher content of structural carbohydrates in KY, being a subptropical grass compared to temperate pastures with lower content of cell walls. &lt;strong&gt;Results: &lt;/strong&gt;There was a higher proportion (P&amp;lt;0.05) of live grass in KY. There were no differences (P&amp;gt;0.05) among pastures for &lt;em&gt;in vitro &lt;/em&gt;nutritional value. There were differences (P&amp;lt;0.05) among pastures and periods for the insoluble fraction fermentation rate (C&lt;sub&gt;B&lt;/sub&gt;) and for the interaction between pastures and periods for gas production in 4.0 h of the soluble fraction (A) and the soluble carbohydrate fermentation rate (C&lt;sub&gt;A&lt;/sub&gt;), but no differences between pastures, periods or the interaction (P&amp;gt;0.05) for other parameters of ruminal fermentation (lag time and total gas production). &lt;strong&gt;Implications: &lt;/strong&gt; Pastures of kikuyu grass associated with white clover have a similar &lt;em&gt;in vitro &lt;/em&gt;nutritional value as pastures of temperate grasses representing a valuable forage resource for SSDS. &lt;strong&gt;Conclusion: &lt;/strong&gt;In spite of differences in some &lt;em&gt;in vitro &lt;/em&gt;ruminal fermentation parameters, the &lt;em&gt;in vitro &lt;/em&gt;nutritional value of kikuyu grass pastures associated with white clover is similar to pastures based on temperate grasses with white clover.&lt;/p&gt;

Brewers’ spent grain as carbon source for itaconate production with engineered Ustilago maydis

Brewers’ spent grain (BSG) is produced worldwide in millions of tons during the beer brewing process. Due to its high content of structural carbohydrates, BSG is a promising material for being valorised in biorefineries. In this study three process routes for producing itaconate from BSG hydrolysates are presented using the previously engineered smut fungi UstilagomaydisMB215Δcyp3ΔPria1::Petef as whole-cell biocatalyst. Using a fermentation medium based on BSG hydrolysate a yield of 0.38gIta/gSugar and a productivity of 0.11gIta/(L·h) were achieved. The addition of detoxified hydrothermal supernatant to the fermentation medium did not result in improved performance parameters but resulted in a decreased yield (0.29gIta/gSugar) and productivity (0.053 gIta/(L·h)). Simultaneous saccharification and fermentation with hydrothermal pretreated BSG is possible, although at lower rate. In summary, the valorisation of BSG in fungal fermentations might complement the end-of-life options of this industrial side product.

Decay resistance of thermally modified Eucalyptus grandis wood against wild strains of Trametes versicolor and Pycnoporus sanguineus

ABSTRACT Eucalyptus grandis presents low durability, and due to its anatomical characteristics, impregnation with chemicals is not an effective alternative to increase it. This work analyses the effect that thermal modification carried out in an oxygen depleted atmosphere has on mass, density, hygroscopicity, chemical composition of the cell wall and decay resistance against locally collected wild strains of wood destroying Basidiomycetes, Trametes versicolor and Pycnoporus sanguineus. E. grandis boards were modified in a vacuum environment (P = –100 kPa) at 160°C, 180°C and 200°C for 1, 2 and 3 h. Hygroscopicity was determined by a sorption isotherm over saturated saline solutions at 25°C. The cell wall composition was characterized by the content of structural carbohydrates, lignin and total extractives. A mini-block fungal test was performed by exposing treated wood samples to mycelia, using Populus sp. as reference. The results showed that the thermal treatment caused mass and density reduction. Modified samples showed a reduction in xylose content while lignin content increased, and cellulose content remained constant. Treated samples presented lower hygroscopicity, especially the ones modified at higher temperatures. The analysis by the Hailwood-Horrobin model showed that the main effect occurred at the monomolecular level, causing a reduction of the sorption capacity of the treated wood. The fungi test evidenced that the modification increased the decay resistance of E. grandis against T. versicolor and P. sanguineus. Both fungi were capable of degrading modified wood, but had limited activity, explained by a reduction of moisture content and a change in the chemical composition of the wood.

PSII-5 Chemical composition, in vitro dry matter digestibility, gas production and methane emission of maintenance, growth and production diets/rations of buffaloes

Abstract Ten types of diets were prepared to meet the nutrient requirements of buffaloes for maintenance (MD1 to MD10), growth (GD1 to GD10) and production/lactation (PD1 to PD10). A total of 30 diets were evaluated for chemical composition, in vitro gas and methane production, and dry matter (DM) disappearance using buffalo rumen liquor. The CNCPS was used to estimate the carbohydrate and protein fractions. Protein fractions PB1 and PB2 of maintenance diets were lower (P &amp;lt; 0.05) than growth and production diets, while protein fractions (PB3) and Pc were (P &amp;lt; 0.05) higher in maintenance than in growth and production diets. Mean values of PA was (P &amp;lt; 0.05) higher in growth diets (136.9) than production (114.8) and maintenance diets (105.6 g/kg DM). Maintenance diets had (P &amp;lt; 0.05) higher structural carbohydrate contents (586.2 g/kg DM) than production diets (513.0 g/kg DM). Carbohydrate fraction (CB1) was highest (P &amp;lt; 0.05) in production diets (187.2 g/kg DM) followed by growth (129.5 g/kg DM) and maintenance diets (96.1 g/kg DM). In vitro gas production at different time periods (12, 24 and 48 h) was similar for maintenance (63.04, 51.98 and 48.15 ml/g DM), growth (63.83, 52.73 and 48.250) and production diets (63.51, 52.54 and 47.21 ml/g DM). Cumulative methane production was numerically lower for maintenance (28.40 ml/g DM) than growth (29.58 ml/g DM) and production diets (33.13 ml/g DM). In vitro methane production as a proportion of degraded DM (ml/g DDM and g/kg DDM) was similar for maintenance (14.21 and 29.53), growth (42.19 and 30.25) and production diets (41.26 and 29.58). Dietary chemical constituents such as EE, lignin, NDIN, ADIN and PB3 and Cc were (P &amp;lt; 0.05) negatively associated with methane production, while OM, NPN, SP, PA and PB1, TCHO and CB2 were positively (P &amp;lt; 0.05) correlated with methane production.

Effect of Pasteurisation on Methane Yield from Food Waste and Other Substrates in Anaerobic Digestion

The effect of pasteurisation and co-pasteurisation on biochemical methane potential values in anaerobic digestion (AD) was studied. Pasteurisation prior to digestion in a biogas plant is a common hygienisation method for organic materials which contain or have been in contact with animal by-products. Tests were carried out on food waste, slaughterhouse waste, animal blood, cattle slurry, potato waste, card packaging and the organic fraction of municipal solid waste (OFMSW); pasteurisation at 70 °C for 1 h was applied. Pasteurisation had increased the methane yields of blood (+15%) and potato waste (+12%) only, which both had a low content of structural carbohydrates (hemi-cellulose and cellulose) but a particularly high content of either non-structural carbohydrates such as starch (potato waste) or proteins (blood). With food waste, card packaging and cattle slurry, pasteurisation had no observable impact on the methane yield. Slaughterhouse waste and OFMSW yielded less methane after pasteurisation in the experiments (but statistical significance of the difference between pasteurised and unpasteurised slaughterhouse waste or OFMSW was not confirmed in this work). It is concluded that pasteurisation can positively impact the methane yield of some specific substrates, such as potato waste, where heat-treatment may induce gelatinisation with release of the starch molecules. For most substrates, however, pasteurisation at 70 °C is unlikely to increase the methane yield. It is unlikely to improve biodegradability of lignified materials, and it may reduce the methane yield from substrates which contain high contents of volatile components. Furthermore, in this experimental study, the obtained methane yield was unaffected by whether the substrates were pasteurised individually and then co-digested or co-pasteurised as a mixture before batch digestion.

Chemical characterisation and technical assessment of agri-food residues, marine matrices, and wild grasses in the South Mediterranean area: A considerable inflow for biorefineries

The integration of easily available and under-exploited biomasses is considered a sustainable strategy in biorefining approaches. Mediterranean countries, especially Algeria, Morocco, and Tunisia, offer such under-exploited waste of different origins. This study revealed the chemical composition and phytochemical characteristics of various agri-food side-products, marine residues, and wild grasses collected in the Maghreb region. Results showed that these wastes contained variable proportions of polysaccharides, lignin, constitute molecules (proteins, lipids, and inorganic molecules) and, various secondary metabolites, mainly flavonoids and condensed tannins. Based on this, the Mediterranean waste was divided into three categories. The first category included waste with high lignin content (40 wt%). The second category contained waste with lignin content below 10 wt% and structural carbohydrate content below 50 wt%. Additionally, the waste in this category comprised noticeable amounts of flavonoids and condensed tannins, particularly from thistle, speedwell, and spurge. Finally, the third category included waste with lignin content above 15 wt% and carbohydrate content in the range of 45–55 wt%. The results also showed that the waste in the third category has a chemical composition similar to that of raw materials envisioned for use in European or North American commercial biorefineries. The findings of this study indicate that the biomass waste employed in this study can be used to develop marketable bioproducts and may be a potential raw material for a biorefinery facility.

Response of Fine Root Carbohydrate Content to Soil Nitrogen Addition and Its Relationship with Soil Factors in a Schrenk (Picea schrenkiana) Forest

Fine roots are vital for water and nutrient uptake in plants. Understanding the responses of metabolic traits to changing environmental conditions is critical, but little is known. In this study, the carbohydrate content of fine roots was characterized for six soil layers and three diameter classes in a Schrenk spruce (Picea schrenkiana) forest on the Tianshan Mountains of China. Soil nitrogen addition can influence carbohydrate content, but the degree is related to soil layer and fine root diameter. Specifically, as nitrogen (N) levels increased, the soluble sugar, cellulose, lignin and structural carbohydrate content (SC) all increased and then decreased; the starch and non-structural carbohydrate content (NSC) decreased gradually. In addition, N addition had significant effects on starch and cellulose content, as well as total carbohydrates. The interaction between root diameter and N addition also influenced soluble sugars, cellulose and NSC, while the three-way interaction among N addition, soil layer and diameter only affected cellulose content and NSC/SC. In the control treatment (no nitrogen addition), the following soil factors influenced fine root metabolism in order of decreasing importance: C:N, C:P, N:P, C, N, water content, bulk density, pH, conductivity, and P. In the N addition treatments, the soil conductivity, pH, and N content were strongly correlated with root metabolic characteristics.

Effects of Soil Fertilization on Terpenoids and Other Carbon-Based Secondary Metabolites in Rosmarinus officinalis Plants: A Comparative Study.

Rosmarinus officinalis is an evergreen aromatic plant with important commercial interest as it contains numerous essential oils (composed of terpenoid compounds) and phenolic constituents (natural antioxidant compounds). This work aims at evaluating the concomitant effects of different inorganic and organic fertilization treatments and the subsequent increases in soil nutrient availability on terpenoids and other carbon-based secondary metabolites, e.g., flavonoids and phenolic compounds, in Rosmarinus officinalis leaves. The results showed that, as expected, the structural carbohydrate content (lignocellulosic compounds) in stems was higher in fertilized plants than in controls. Additionally, positive correlations were observed of the absolute amounts of total terpenoids and some single terpenoid compounds with N or P contents in leaves. On the contrary, the phenolic and flavonoid concentrations in all the rosemary plant parts were lower with the fertilization treatments. Indeed, negative correlations between the phenolic compounds (and flavonoids) and N in rosemary leaves were also found. Overall, the results suggest that the terpenoid production’s response to fertilization was due to N, which is essential for protein synthesis and terpene synthase activity, and to P, which is necessary for the synthesis of both terpenoid precursors and ATP and NADPH, also needed for terpenoid synthesis. On the other hand, the basis for the fertilization’s effects on the production of phenolic compounds is the direct nitrogen trade-off between growth and the shikimic acid pathway by which phenolics compounds are synthesized.

A Decrease in Mesophyll Conductance by Cell-Wall Thickening Contributes to Photosynthetic Downregulation.

It has been argued that accumulation of nonstructural carbohydrates triggers a decrease in Rubisco content, which downregulates photosynthesis. However, a decrease in the sink-source ratio in several plant species leads to a decrease in photosynthesis and increases in both structural and nonstructural carbohydrate content. Here, we tested whether increases in cell-wall materials, rather than starch content, impact directly on photosynthesis by decreasing mesophyll conductance. We measured various morphological, anatomical, and physiological traits in primary leaves of soybean (Glycine max) and French bean (Phaseolus vulgaris) grown under high- or low-nitrogen conditions. We removed other leaves 2 weeks after sowing to decrease the sink-source ratio and conducted measurements 0, 1, and 2 weeks after defoliation.

Canopy and understory additions of nitrogen change the chemical composition, construction cost, and payback time of dominant woody species in an evergreen broadleaved forest

Simulated nitrogen deposition experiments in forests have mainly used understory nitrogen application, i.e., they failed to consider how canopy interception may alter the effects of nitrogen deposition on forest plants. This study used canopy addition of nitrogen, understory addition of nitrogen, and no-nitrogen addition control to study the effect of nitrogen deposition on the allocation of carbon assimilation products of representative woody species in an evergreen broad-leaved forest. Results showed that the maximum photosynthetic rate (Asat) of Blastus cochinchinensis (a shrub), Ardisia quinquegona (a small tree), and Schefflera octophylla (a small tree) were significantly higher, but Asat of Schima superba (a large tree) was significantly lower under canopy addition of nitrogen than under the control. Canopy and understory additions of nitrogen did not change Asat of Lasianthus chinensis (a shrub). Compared with the control, leaf chemical compositions of these plants were differentially changed by canopy and understory additions of nitrogen. These changes were accompanied by a significant increase in construction cost of A. quinquegona, S. octophylla, and S. superba under canopy addition of nitrogen and of L. chinensis, A. quinquegona, and S. superba under understory addition of nitrogen. The payback time was significantly shorter for B. cochinchinensis, A. quinquegona, and S. octophylla but was significantly longer for S. superba under canopy addition of nitrogen than under the control. In contrast, the payback time was significantly shorter for B. cochinchinensis and A. quinquegona under understory addition of nitrogen than under the control. Correlation analyses showed that the changes in protein and structural carbohydrate contents helped explain the changes in payback time. In summary, nitrogen deposition may increase carbon assimilation and allocation in shrubs and small trees, and large trees may require a longer period to increase carbohydrates, which may help explain the ongoing transformation of evergreen broad-leaved forests into shrublands.