Search Results (33)

The critical nitrogen (N) dilution curve is widely used to diagnose crop N status, but no such model has been developed for sugar beet. This study evaluated the effects of irrigation amount and N rate on sugar yield, N use efficiency, and soil nitrate-N (NO₃-N) residue of drip-fertigated sugar beet in the arid southern Xinjiang of China. A reliable N nutrition index (NNI) for sugar yield was also established based on a critical N dilution curve derived from the dry matter of sugar beet. A three-year field experiment was established with six N rates (25–480 kg N ha⁻¹) and three irrigation levels based on crop evapotranspiration (ET_c) (0.6, 0.8, and 1.0 ET_c in 2019 and 2020, and 0.4, 0.6, and 0.8 ET_c in 2021). Results showed that sugar yield and N uptake increased and then generally stabilized with increasing N rate, while N use efficiency decreased. Most soil NO₃-N was mainly distributed in the 0–60 cm soil layer, but increasing irrigation amount reduced residual NO₃-N in the 0–80 cm soil layer. Additionally, the established critical N dilution curve of sugar beet was considered stable (Normalized RMSE = 16.6%), and can be used to calculate plant N requirements and further N rates during sugar beet growth. The results indicated that the optimal NNI was 0.97 under 0.6 ET_c for sugar yield production of sugar beet in this study. This study provides a basis for efficient water and N management in sugar beet production in arid and semi-arid regions globally. Full article

A bioassay study was conducted to determine the differences in the sensitivity of selected crops to simulated clomazone residues (nine concentrations were used ranging from 5.625 to 1440 μg a.i./kg soil). White mustard was the most susceptible as measured by shoot fresh weight (SFW) and shoot dry weight (SDW) inhibition, with EC₅₀ values of 94.6 and 128.2 μg a.i./kg soil, respectively. Regarding the EC₅₀ values for the inhibition of pigment content (carotenoids, chlorophyll a and chlorophyll b), sugar beet and white mustard showed a high sensitivity, as the EC₅₀ values for all three pigments were in the range of 45.8–47.4 and 57.5–63.3 μg a.i./kg soil, respectively. However, as the SFW and SDW of sugar beet were only reduced at the three highest clomazone concentrations applied, white mustard proved to be the most sensitive crop. Wheat was less sensitive (EC₅₀ = 214.4–243.8 μg a.i./kg soil, for all three pigments), while sunflower and maize were the least sensitive (EC₅₀ = 359.7–417.5 and 456.1–535.8 μg a.i./kg soil, respectively). Field trials were conducted for two years in the Srem region to study the dynamics of clomazone degradation in sandy loam soil. Clomazone was applied pre-plant incorporated (PPI) and post-emergence (POST-EM) in three doses: 480, 720 and 960 g a.i./ha. Soil samples were taken at regular intervals from the day of herbicide application until one year after application and residue concentrations were determined using the white mustard bioassay (based on the measurement of carotenoid content inhibition). The application rate had no consistent effect on the persistence of clomazone. Slower degradation was observed in the PPI treatment than in the POST-EM treatment (8.5 and 15 days longer average half-lives in the first and second year, respectively). Persistence was affected by lower rainfall, resulting in a longer half-life in the second year (12 days on average). Herbicide residues caused no visible injury to white mustard one year after application, while the reduction in carotenoid content ranged from 0.37 to 22.89%, indicating that no injury can occur to any of the tested crops one year after application of clomazone in sandy loam soil. Full article

d-Xylitol is a low-calorie and anti-cariogenic sweetener suitable for diabetic patients, making it a valuable ingredient in various health-related applications. In this study, we investigated the production of d-xylitol from l-arabinose derived from sugar beet press pulp (SBPP) hydrolysate using an engineered Aspergillus niger strain. Initial batch studies applying stirred tank bioreactors demonstrated d-xylitol production of 4.6 g L⁻¹ with a yield of 0.37 g d-xylitol g⁻¹ l-arabinose with a synthetic medium. Subsequently, the conversion of enzymatically produced and clarified SBPP hydrolysate was studied. We found that pre-treatment of the enzymatic hydrolysate with activated carbon was essential to remove inhibitory components. Moreover, an automated aeration switch-off was implemented based on the CO₂ signal of the off-gas analyzer of the stirred tank bioreactor to prevent d-xylitol degradation after l-arabinose depletion. This resulted in a final d-xylitol concentration of 4.3 g L⁻¹ with an improved yield of 0.43 g d-xylitol g⁻¹ l-arabinose. The feasibility of utilizing the agricultural residue SBPP for d-xylitol production was successfully demonstrated with engineered A. niger. Full article

Bioenergy with carbon capture and storage (BECCS) or utilization (BECCU) allows net zero or negative carbon emissions and can be a breakthrough technology for climate change mitigation. This work consists of an energetic, exergetic, and economic analysis of an integrated process based on chemical looping combustion of solar-torrefied agro-industrial residues, followed by methanation of the concentrated CO₂ stream with green H₂. Four agro-industrial residues and four Italian site locations are considered. Depending on the considered biomass, the integrated plant processes about 18–93 kg h⁻¹ of raw biomass and produces 55–70 t y⁻¹ of synthetic methane. Global exergetic efficiencies ranged within 45–60% and 67–77% when neglecting and considering, respectively, the valorization of torgas. Sugar beet pulp and grape marc required a non-negligible input exergy flow for the torrefaction, due to the high moisture content of the raw biomasses. However, for these biomasses, the water released during drying/torrefaction and CO₂ methanation could be recycled to the electrolyzer to eliminate external water consumption, thus allowing for a more sustainable use of water resources. For olive stones and hemp hurd, this water recycling brings, instead, a reduction of approximately 65% in water needs. A round-trip electric efficiency of 28% was estimated assuming an electric conversion efficiency of 40%. According to the economic analysis, the total plant costs ranged within 3–5 M€ depending on the biomass and site location considered. The levelized cost of methane (LCOM) ranged within 4.3–8.9 € kg_CH4⁻¹ but, if implementing strategies to avoid the use of a large temporary H₂ storage vessel, can be decreased to 2.6–5.3 € kg_CH4⁻¹. Lower values are obtained when considering hemp hurd and grape marc as raw biomasses, and when locating the PV field in the south of Italy. Even in the best scenario, values of LCOM are out of the market if compared to current natural gas prices, but they might become competitive with the introduction of a carbon tax or through government incentives for the purchase of the PV field and/or electrolyzer. Full article

The long-term performance of perennial energy crops and their elimination is important for long-term planning and use of agricultural land. In this study, the elimination of a six-year-old Sida hermaphrodita (hereafter referred to as Sida) stock for agricultural reclamation was investigated over three years. Crop rotation using maize, winter wheat, and sugar beet, a catch crop, as well as mechanical–chemical treatments were employed according to agricultural practices. After soil grubbing at the beginning of the experiment and prior to further treatments, on half of the former Sida planting area, visible Sida roots were manually removed in addition to determining their potential effect on total resprouting. Prior to each crop harvest, resprouted Sida plants were counted. At harvest, by the end of the first year, 476 versus 390 resprouted Sida plants were found in the investigated areas of 315 m² each, where preceding manual root removal either took place or not, respectively. This accounted for 76% and 62% of the initial Sida planted. In the second year, the overall number of resprouted Sida declined significantly, accounting for 15 and 11 plants (i.e., 2.4% and 1.8% of initially planted), and in the third year, only two and four residual plants (i.e., 0.3% and 0.6%) were found, representing an almost 100% Sida elimination rate. We conclude that additional root removal did not result in a significant difference in Sida regrowth compared to the mechanical–chemical treatments only. No impediments to harvesting and no loss of yield in any crops were observed due to resprouted Sida in the existing field crops. No Sida plants were found outside the initial field, indicating a low dispersion potential and invasiveness. The results show that successful recultivation of an established Sida stock is possible through common agricultural practices and that resprouting Sida plants did not negatively affect the subsequent crops. Full article

A bioassay study was conducted to determine the differences in the susceptibility of selected crops to simulated imazethapyr residues based on morphological and anatomical parameters. Sugar beet, white mustard, and rapeseed oil were found to be the most sensitive based on ED₅₀ values for the root length and the root fresh weight. Corn and sunflower were less sensitive, and wheat was the least sensitive. The measured anatomical parameters confirmed the different sensitivities of the tested plants, as evidenced by a shortening of the meristem and elongation zones, a reduction in the distance between the root tip and the absorption zone, and the distance between the root tip and the point where the primordium of the lateral root appears. An imazethapyr residue level equivalent to ED₂₀ (for root length) did not cause serious morphological changes in the less sensitive plants, nor did it cause significant changes in the length of the root cap, the beginning of the root absorption zone (root hair region), the beginning of lateral root formation (i.e., the permanent region), and the number of root primordia per root length. Therefore, ED₂₀ could be proposed as an acceptable residue level (ARL) or herbicide residue level at which these plants can be safely sown. Full article

Extracted sugar beet press pulp (SBPP) is a promising agricultural residue for saccharification and further bioconversion. Combining solid-state fermentation of SBPP with engineered Aspergillus niger for enzyme production followed by hydrolysis of additionally added SBPP in the same bioreactor was studied to produce a sugar solution (hydrolysate) in a one-pot process. The initial aerobic solid-state fermentations were carried out in duplicate on non-milled, wet SBPP (moisture content of 72% (w/v)) with an A. niger strain engineered for constitutive pectinase production for 96 h, and this resulted in polygalacturonase activities of up to 256 U mL⁻¹ in the wet media. Afterwards, water was added to the bioreactor, and the remaining solids were suspended by stirring to dissolve the hydrolytic enzymes. Metabolic activities of A. niger were inactivated by a N₂-atmosphere and by increasing the temperature to 50 °C. High solid loads of milled SBPP were added to the stirred-tank reactor with a delay of 24 h to enable sugar yield calculations based on the compositional analysis of the SBPP used. The resulting final sugar concentrations of the hydrolysate after 166 h were 17 g L⁻¹ d-glucose, 18.8 g L⁻¹ l-arabinose, and 12.5 g L⁻¹ d-galacturonic acid, corresponding to sugar yields of 98% d-glucose, 86% l-arabinose, and 50% d-galacturonic acid, respectively. Including the other sugars released during enzymatic hydrolysis in the one-pot process (d-xylose, d-mannose, d-galactose), a total sugar concentration of 54.8 g L⁻¹ was achieved in the hydrolysate. The one-pot process combining hydrolytic enzyme production in solid-state fermentation with high solid loads during enzymatic hydrolysis of the milled SBPP reduces hydrolytic process costs by replacing chemical pre-treatments, enabling the in situ production of SBPP-adapted hydrolytic enzymes, as well as avoiding intermediate enzyme extraction and preparation steps. Full article

High content of pro-health constituents in fruit and vegetable pomaces has led to their utilization as raw materials in food production. They are used mostly in dried form, which is microbiologically stable and allows their storage throughout a longer period. Nevertheless, some materials of these kind are still undervalued, among them sugar beet pulp, which is produced during sugar production in large quantities, often posing an environmental threat, and has been traditionally used for feeding animals. Earlier studies on chemical composition suggested that sugar beet pulp could be highly valuable in terms of health-promoting aspects. Therefore, in this work, research was directed to prove the nutritional potential of this raw material. Thus, an attempt was made to characterize sugar beet pulp in terms of its nutritional and carbohydrate profile, as well as its health-promoting qualities, with particular emphasis on the effect of the extraction on the content of polyphenols and phenolic acids, flavonoids, flavonols, and also their antioxidant activity, measured by ABTS and FRAP methods. The soluble and insoluble fraction of dietary fiber and total dietary fiber were also determined in the pulp. It was found that sugar beet pulp is a valuable source of nutrients (around 10% protein, 7% fat, 8% sugar, 4% ash), dietary fiber (nearly 70%), and has significant amounts of sugars present as free saccharides (fructose and glucose) and polysaccharide residues (arabinose, galacturonic acid, rhamnose, and glucose). In addition, it is a source of polyphenols, flavonoids, and phenolic acids and has a high health-promoting potential regardless of the applied extraction method. Therefore, we may suggest that sugar beet pulp could become an ingredient for pro-health functional food. Full article

Plant hemoglobins, often referred to as phytoglobins, play important roles in abiotic stress tolerance. Several essential small physiological metabolites can be bound to these heme proteins. In addition, phytoglobins can catalyze a range of different oxidative reactions in vivo. These proteins are often oligomeric, but the degree and relevance of subunit interactions are largely unknown. In this study, we delineate which residues are involved in dimer formation of a sugar beet phytoglobin type 1.2 (BvPgb1.2) using NMR relaxation experiments. E. coli cells harboring a phytoglobin expression vector were cultivated in isotope-labeled (²H, ¹³C and ¹⁵N) M9 medium. The triple-labeled protein was purified to homogeneity using two chromatographic steps. Two forms of BvPgb1.2 were examined, the oxy-form and the more stable cyanide-form. Using three-dimensional triple-resonance NMR experiments, sequence-specific assignments for CN-bound BvPgb1.2 were achieved for 137 backbone amide cross-peaks in the ¹H-¹⁵N TROSY spectrum, which amounts to 83% of the total number of 165 expected cross-peaks. A large proportion of the non-assigned residues are located in α-helixes G and H, which are proposed to be involved in protein dimerization. Such knowledge around dimer formation will be instrumental for developing a better understanding of phytoglobins’ roles in planta. Full article

The dissemination of soil tares in the potato and sugar beet processing industry is one of the main paths for the spread of potato cyst nematodes (PCN), a severe quarantine pest. Efficient measures for the disinfestation of tare soil from PCN, but also from beet cyst nematodes (BCN), are needed. In our study, Globodera pallida (a PCN) and Heterodera schachtii (a BCN) cysts were sealed in gauze bags and imbedded in sedimentation basins. The cysts were either placed (a) in a presedimentation basin (Brukner basin) for three days, (b) in the presedimentation basin for three days and subsequently in sedimentation basins for nine weeks or (c) in sedimentation basins for nine weeks (without presedimentation). We tested the viability of the eggs and juveniles by hatching assays and using the reproduction rates in bioassays. We demonstrated that PCN and BCN imbedded in a sedimentation basin were only still showing some hatching activity after 2.5 weeks, while no hatching was observed when an additional Brukner basin treatment was conducted before sedimentation. Full article

Neonicotinoids are pesticides widely used for pest control in agriculture with undesirable effects on pollinators. However, other beneficial insects are exposed to insecticides that are not lethal to them but may accumulate and affect their vital characteristics. The objective of this study was to determine neonicotinoid residues in two types of beneficial soil organisms. The first group includes ground beetles (family: Carabidae, order: Coleoptera). They are important in the food web within existing ecosystems, especially in agricultural areas. The second group includes earthworms (family: Lumbricidae, order: Opisthopora) as humifiers, important members of the soil fauna. Fauna was collected at two sugar beet growing areas in Croatia under intensive sugar beet management. Ground beetles were collected from six plots of sugar beet fields treated with imidacloprid and thiamethoxam or left untreated with neonicotinoids. Earthworms were collected from the eight fields involved in four-year sugar beet crop rotation (sugar beet, maize, soybean, oilseed rape). Detection of neonicotinoid residues was performed by LC-MS/MS, SPE-QuEChERS method. The limit of quantification (LOQ) was 0.001 mg/kg. In ground beetles, the highest concentration of imidacloprid was detected at 0.027 mg/kg, while the residues of thiamethoxam and clothianidin were below LOQ. The highest concentration of imidacloprid in earthworms was 0.2141 mg/kg, while residues of thiamethoxam did not exceed 0.0008 mg/kg. This is the first study of this kind on Croatian territory and provides a valuable first insight into the ecotoxicological status of beneficial soil fauna. More comprehensive studies are needed to assess the extent of accumulation in and to take further steps regarding conservation programs for beneficial soil organisms. Full article

Phytoglobins (Pgbs) are plant-originating heme proteins of the globin superfamily with varying degrees of hexacoordination. Pgbs have a conserved cysteine residue, the role of which is poorly understood. In this paper, we investigated the functional and structural role of cysteine in BvPgb1.2, a Class 1 Pgb from sugar beet (Beta vulgaris), by constructing an alanine-substituted mutant (Cys86Ala). The substitution had little impact on structure, dimerization, and heme loss as determined by X-ray crystallography, size-exclusion chromatography, and an apomyoglobin-based heme-loss assay, respectively. The substitution significantly affected other important biochemical properties. The autoxidation rate increased 16.7- and 14.4-fold for the mutant versus the native protein at 25 °C and 37 °C, respectively. Thermal stability similarly increased for the mutant by ~2.5 °C as measured by nano-differential scanning fluorimetry. Monitoring peroxidase activity over 7 days showed a 60% activity decrease in the native protein, from 33.7 to 20.2 U/mg protein. When comparing the two proteins, the mutant displayed a remarkable enzymatic stability as activity remained relatively constant throughout, albeit at a lower level, ~12 U/mg protein. This suggests that cysteine plays an important role in BvPgb1.2 function and stability, despite having seemingly little effect on its tertiary and quaternary structure. Full article

Rapid urbanization and industrialization around the world have created massive amounts of organic residues, which have been prioritized for conversion into valuable resources through the composting process to keep their harmful effect at a minimum. This research aimed to assess the influence of active and passive aeration on composting mass of sugar beet residues in the case of using additives (e.g., charcoal only or manure only or combination). Some physicochemical properties of composting mass were analyzed on certain days of composting. Some parameters including temperature–time profile, carbon to nitrogen ratio (C/N ratio), moisture content, electrical conductivity, pH, germination and microbial population enumeration of compost were measured. Cress germination test was conducted for each medium of germination which contains a mixture of soil and compost (at a ratio of 3:1) taken from each treatment. The results showed that temperature–time profile data of composting mass showed an irregularity. Forcedly aerated composting mass did not demonstrate a thermophilic phase while passively aerated ones did not show a mesophilic phase. Carbon to nitrogen (C/N) ratio reduction was greater in most forcedly aerated composting mass than passively aerated on days from 1 to 33 of composting period. The results further showed that electrical conductivity decreased at the end of the composting period where it ranged from 2.55 to 3.1 dS/m. Germination medium containing forcedly aerated compost treated with a combination of charcoal and manure achieved the highest germination index which was higher than the control sample by 58.63% followed by forcedly aerated composting mass treated by charcoal only which exceeded the control sample by 5.35%. Strong correlation coefficient (r > 0.80) for the relationship between germination index and number of bacteria was obtained on day 17th of composting period. Full article

Global economic development has led to the widespread use of fossil fuels, and their extensive use has resulted in increased environmental pollution. As a result, significantly more attention is being paid to environmental issues and alternative renewable energy sources. Bioethanol production from agro-industrial byproducts, residues, and wastes is one example of sustainable energy production. This research aims to develop a process and cost model of bioethanol production from spent sugar beet pulp. The model was developed using SuperPro Designer^® v.11 (Intelligen Inc., Scotch Plains, NJ, USA) software, and determines the capital and production costs for a bioethanol-producing plant processing about 17,000 tons of spent sugar beet pulp per year. In addition, the developed model predicts the process and economic indicators of the analyzed biotechnological process, determines the share of major components in bioethanol production costs, and compares different model scenarios for process co-products. Based on the obtained results, the proposed model is viable and represents a base case for further bioprocess development. Full article

Cultivated beets (sugar beets, fodder beets, leaf beets, and garden beets) belonging to the species Beta vulgaris L. are important sources for many products such as sugar, bioethanol, animal feed, human nutrition, pulp residue, pectin extract, and molasses. Beta maritima L. (sea beet or wild beet) is a halophytic wild ancestor of all cultivated beets. With a requirement of less water and having shorter growth period than sugarcane, cultivated beets are preferentially spreading from temperate regions to subtropical countries. The beet cultivars display tolerance to several abiotic stresses such as salt, drought, cold, heat, and heavy metals. However, many environmental factors adversely influence growth, yield, and quality of beets. Hence, selection of stress-tolerant beet varieties and knowledge on the response mechanisms of beet cultivars to different abiotic stress factors are most required. The present review discusses morpho-physiological, biochemical, and molecular responses of cultivated beets (B. vulgaris L.) to different abiotic stresses including alkaline, cold, heat, heavy metals, and UV radiation. Additionally, we describe the beet genes reported for their involvement in response to these stress conditions. Full article