Sweet Sorghum Research Articles

The effect of the moisture availability rate on the productivity and nutritional value of sorghum crops

Productivity reduced by drought is quite common. There can be up to 60.0% of the harvest losses. This is especially true for forage crops. The purpose of the current work was to identify the dependence of productivity and quality of green mass of sorghum crops on moisture availability during a vegetation period of plants. Sudan grass variety Alice, sugar sorghum variety Yuzhnoye, and sorghum-sudangrass hybrid variety Gustolistny were used as research objects. The study was carried out in the Rostov region. The soil of the experimental plot was ordinary carbonate black earth (chernozem). In order to study the variability of productivity and nutritional qualities, the years with the HTC level from 0.34 to 0.88 with an interval of 0.8–1.2 (2018–2022) were taken into account. The trials were conducted according to the methodology of the State Variety Testing. When the HTC increased from 0.34 to 0.88, there was a tendency to improve green mass productivity by 23.3–35.0% and decrease the protein percentage by 41.80–55.54%. A negative relationship between the amount of crude protein and the HTC value was revealed (r = –0.78... –0.92). The digestible protein yield decreased by 22.22–31.03% with increasing moisture content. The largest mean value was identified for the sorghum-sudangrass hybrid with 0.70 t/ha and the sweet sorghum variety with 0.71 t/ha. The variation coefficient of fiber content was 2.16–5.42%, which indicated weak variability of the trait over the years, and, consequently, a weak dependence on the moisture availability rate, which was confirmed by the correlation analysis (r = –0.03...0.32). The largest value of the metabolic energy was found in the sorghum-sudangrass hybrid (10.42–10.80 mJ/kg). At the same time, there was no dependence of this indicator, as well as the amount of feed units, on the moisture availability rate. The highest amount of digestible protein per feed unit was identified in sweet sorghum (83.4 g). A tendency to decrease this indicator by 22.6–42.5% was found as the HTC level increased (r = –0.69...–0.90).

Enhancing biomass conservation and enzymatic hydrolysis of sweet sorghum bagasse by combining pretreatment with ensiling and NaOH.

Lignocellulosic pretreatment is an important stage in biomass utilization, which usually requires high input. In this study, a low-cost method using combined ensiling and NaOH was developed for lignocellulosic pretreatment. Sweet sorghum bagasse (SSB) was ensiled for 21 days and then treated with diluted NaOH (0%, 1%, and 2%) for fermentation. The results showed that the application of Lactobacillus plantarum (L) reduced fermentation losses of the silages, mainly low water-soluble carbohydrate (WSC) and ammonia nitrogen loss. Meanwhile, the application of Lactobacillus plantarum and ensiling enzyme (LE) promoted lignocellulosic degradation, as evidenced by low neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin (ADL), and hemicellulosic (HC) contents. The dominant bacterial genera were Lactobacillus, uncultured_bacterium_f_Enterobacteriaceae, and Pantoea after silage, which corresponded to the higher lactic acid and acetic contents and lower pH. The reducing sugar yields of SSB increased after combined pretreatment of silage and NaOH and were further enhanced by the 2% NaOH application, as evidenced by the high reducing sugar yield and microstructure damage, especially in the L-2% NaOH group and the LE-2% NaOH group, in which the reducing sugar yields were 87.99 and 94.45%, respectively, compared with those of the no additive control (CK)-0 NaOH group. Therefore, this study provides an effective method for SSB pretreatment to enhance biomass conservation.

Advancing safe bioenergy production from cadmium-contaminated sweet sorghum through mild synergistic pretreatment

Phytoremediation is an eco-friendly and cost-effective method for treating cadmium (Cd)-contaminated soil. However, safe disposal of harvested hyperaccumulators remains scarce. Herein, a mild synergistic pretreatment combining dilute acid and alkali pretreatment was developed for safe biorefining of the Cd-containing sweet sorghum, and Cd was centrally extracted into the acid pretreatment liquid in the first step. The results showed that the synergistic pretreatment was more effective in removing Cd from the biomass and overcoming biomass recalcitrance. During the synergistic pretreatment, the Cd concentration in biomass dramatically decreased from 4.03 to 0.00626 mg/kg, and a considerable amount of lignin and hemicelluloses in biomass was removed, facilitating enzymatic saccharification and safe bioenergy production. The optimal conditions of the synergistic pretreatment resulted in a total sugar yield of 81.6 wt %, which was 4.7-fold higher than that of the original biomass. This strategy holds promise for reducing the cost of industrial saccharification and is a valuable inspiration for the safe handling and resource utilization of Cd-containing biomass.

Use of hybridization to develop new sorghum varieties and hybrids

Hybridization is the main method for developing new breeding material, obtaining genetic variability, and combining desired traits. The purpose of the current work is to characterize new promising varieties and hybrids of sweet and grass sorghum developed by the “ARC “Donskoy” because of hybridization on a sterile and fertile basis. The study was conducted on the breeding field of the FSBSI “ARC “Donskoy”, Zernograd, Rostov region in 2021–2023. The zone is characterized by ordinary carbonate chernozem (3.2 % of humus, 10–40 mg/kg of phosphorus, 70–110 mg/kg of nitrogen, 300–500 mg per kg of soil of potassium). Meteorological conditions during the years of study (2021–2023) were contrasting: in 2022, HTC = 0.52 indicated average aridity and insufficient moisture with 0.81–0.82 in 2021 and 2023. The objects of the study were the varieties and hybrids of Sudan grass and sugar sorghum developed by the FSBSI “ARC “Donskoy”. As a result of hybridization on a sterile basis, there was developed a number of sorghumSudan hybrids (‘Jetta x Kudesnitsa’, ‘APV-1115 x Topolina’, ‘APV-1115 x FP’, ‘Dobrynya’, ‘Gordey’) and sweet sorghum hybrids (‘APV-115 x Yuzhnoye’, ‘Jetta x Severanay Vishnya’, ‘Duet’), allowing to obtain green mass yields of 51–63 and 47–49 t/ha, which was higher than the standard by 5–17 t/ha (10.8–37.0 %) and 5–7 t/ha (11.9–16.7 %) respectively. Using intervarietal hybridization, almost all varieties developed by the FSBSI “ARC “Donskoy” have been created. Among them there are the Sudan grass varieties ‘Alisa’, ‘Gratsiya’, ‘Anastasiya’, ‘Kudesnitsa’, ‘FP’ and the sweet sorghum varieties ‘Yuzhnoe’, ‘Feniks’, ‘Orfey’, ‘SK-20/334’, ‘Severanay Vishnya’ with a green mass yield of 40–48 and 34–38 t/ha, which is higher than that of standard varieties by 3–11 t/ha (8.1–29.7 %) and 7–11 t/ha (25.9–40.7 %), respectively. Thus, hybridization is the main method for developing new breeding material and combining the desired traits in new samples.

Carbon footprint of four bioethanol cropping systems in a temperate region

Under the EU Renewable Energy Directive (2009/28/EC), estimating biofuel GHG emissions is essential to gauge emissions reductions compared to fossil fuels. Within this framework, the carbon footprint (CF) was calculated for four bioethanol cropping systems: a maize-wheat-sorghum rotation without the harvest of crop residues (MWS), a maize-wheat-sorghum rotation with harvested crop residues (MWS-R), switchgrass (Sw), and continuous sweet sorghum (Ss). The estimation followed a life-cycle analysis strategy. The CF varied between 0.04 and 3.68 kg CO2-eq l − 1 ethanol. Switchgrass had the smallest CF and the highest ethanol yield per hectare (4,263 L [ha yr] − 1). However, for annual systems, Ss had the highest CF (3.68 kg CO2-eq l − 1 ethanol), 2 and 4 times larger than MWS-R and MWS systems. The soil preparation, planting, and post-planting emissions were 80% of the mean emissions in the annual cropping systems. By comparison, 60% of Sw’s CF came from post-planting, and 46% from fertilizers. In Sw, soil erosion accounted for 11% of the soil organic carbon lost in the MWS-R and Ss systems. In addition, Sw was the system with the most significant carbon sequestration (−1,957 kg CO2-eq [ha yr − 1]), a value corresponding to 94% of the CF of this bioethanol cropping system.

PRODUÇÃO DE BIOGÁS A PARTIR DE SILAGEM DE SORGO DOCE E RESÍDUOS ANIMAIS

The objective of this work is to quantify the biogas produced in batch-type benchtop biodigesters, from the anaerobic fermentation of sweet sorghum, stored in silos for 12 months, associated with goat and cattle waste, respectively. The input and output waste (biofertilizer) from the biodigesters was analyzed for physical (solid) and physical-chemical parameters (pH and electrical conductivity). The yield (Lbiogas.kg-1SVad), biogas productivity (Lbiogas.L-1reator.d-1) and the added volumetric organic load - VOLad (kgSV.L-1reator.d-1) were calculated. The work was conducted at the Rural Construction Laboratory of the Federal University of Vale do São Francisco located on the Agricultural Sciences Campus. The hydraulic retention time was 30 days in the randomized block experimental design. The constructed biodigesters performed well in quantifying the production of biogas from organic substrate, promoting ideal conditions for the anaerobic digestion process to occur without oxygen contamination. However, there was no significant difference in biogas production between treatments. Treatment T2 (cattle manure) showed the highest yield (240 Lbiogas.kg-1SVad) with an average added volumetric organic load of 8 kgSV.L-1reactor.d-1. Treatment T5 (sorghum 50% + beef 50%) presented a higher numerical value of biogas productivity (0.0703 Lbiogas.L-1reator.d-1) in relation to the other treatments, however this difference was not significant at 5% probability using the Tukey test.

Effect of Tillage and Nitrogen Rates on Fodder Productivity and Juice Quality of Sweet Sorghum (Sorghum bicolar L.) in Himalayan Foothills of India

Effect of Tillage and Nitrogen Rates on Fodder Productivity and Juice Quality of Sweet Sorghum (Sorghum bicolar L.) in Himalayan Foothills of India

Cell-type-specific transcriptomics uncovers spatial regulatory networks in bioenergy sorghum stems.

Bioenergy sorghum is a low-input, drought-resilient, deep-rooting annual crop that has high biomass yield potential enabling the sustainable production of biofuels, biopower, and bioproducts. Bioenergy sorghum's 4-5 m stems account for ~80% of the harvested biomass. Stems accumulate high levels of sucrose that could be used to synthesize bioethanol and useful biopolymers if information about cell-type gene expression and regulation in stems was available to enable engineering. To obtain this information, laser capture microdissection was used to isolate and collect transcriptome profiles from five major cell types that are present in stems of the sweet sorghum Wray. Transcriptome analysis identified genes with cell-type-specific and cell-preferred expression patterns that reflect the distinct metabolic, transport, and regulatory functions of each cell type. Analysis of cell-type-specific gene regulatory networks (GRNs) revealed that unique transcription factor families contribute to distinct regulatory landscapes, where regulation is organized through various modes and identifiable network motifs. Cell-specific transcriptome data was combined with known secondary cell wall (SCW) networks to identify the GRNs that differentially activate SCW formation in vascular sclerenchyma and epidermal cells. The spatial transcriptomic dataset provides a valuable source of information about the function of different sorghum cell types and GRNs that will enable the engineering of bioenergy sorghum stems, and an interactive web application developed during this project will allow easy access and exploration of the data (https://mc-lab.shinyapps.io/lcm-dataset/).

Sweet Sorghum for Biofuel Production in Sub-Tropical India

Sweet sorghum (Sorghum bicolor L. Moench), a sugar crop with wider adaptation and high potential for bioenergy and ethanol production is expected to meet food, feed, fodder, fuel and fibre demands. It produces high biomass (50-80 t/ha) and alcohol (1500-2800 l/ha) and multiple income opportunities exist with this crop. Some sweet sorghum lines attain juice yields of about 78% of total plant biomass, containing from 15 to 23% soluble fermentable sugars which are composed mainly of sucrose (70–80%), fructose and glucose. Due to its short growing period (3-4 months), it could be cultivated and supplied during the lean period of sugarcane crushing thus extending the crushing period before and after sugarcane crushing and stretch the sugar mill operation. The major advantage with this crop is that no CAPEX is required when used in a sugar mill system as same machinery can be used for crushing and fermentation. It will help farmers to fetch additional income and provide an opportunity for better utilization of industrial facilities during sugarcane off-season. Promising sweet sorghum genotypes developed by ICAR-IIMR, Hyderabad are being tested for their suitability to sub-tropical conditions in February and June-July plantings at the NSI, Kanpur to establish a sustainable cropping system. Five sweet sorghum genotypes were tested during kharif 2021 for sweet sorghum productivity traits. The fresh stalk yield ranged from 45-60 t/ha and based on TRS, maximum alcohol percentage in wash was observed in three varieties, i.e., Phule Vasundhara, CSH 22SS and SSV 74 which was 8.4%, 8.38% and 7.8% respectively. Maximum ethanol yield of 53.05 L/T was recorded in CSH 22 SS followed by SSV 74 (50.93 L/T). Phule Vasundhara, with a highest stalk yield of 60 t/ha recorded highest ethanol content of 2837 L/ha followed by CSH 22SS (2780 L/ha) and SSV 74 (2411 L/ha).

Novel Batch and Repeated-Batch Butanol Fermentation from Sweet Sorghum Stem Juice by Co-Culture of Arthrobacter and Immobilized Clostridium in Scaled-Up Bioreactors

This research aims to study butanol fermentation from sweet sorghum stem juice (SSJ) by immobilized Clostridium beijerinckii TISTR 1461 cells on bamboo chopsticks using Arthrobacter sp. as an efficient bacterium for creating anaerobic conditions in scaled-up bioreactors. For batch culture in a 1-L screw-capped bottle, a butanol concentration (PB), butanol productivity (QB), and butanol yield (YB/S) were 12.09 g/L, 0.26 g/L·h and 0.28 g/g, respectively. These values were ~8 to 14% higher than those of a single culture using oxygen-free nitrogen (OFN) gas to generate anaerobic conditions. When butanol fermentation by the co-culture was scaled-up to 5-L and 30-L stirred-tank fermenters, the butanol production efficiency was not different from that using the 1-L bottles. Additionally, repeated-batch butanol fermentation in the 1-L bottles by the co-culture was successfully operated for four successive cycles with high butanol production. All results clearly indicate that Arthrobacter sp. is promising for creation of anaerobic conditions for butanol production by immobilized Clostridium in large scale bioreactors.

Effects of saline and water stress on sweet sorghum

Sweet sorghum (Sorghum bicolor [L.] Moench) is a plant that can be an alternative for the production of bioethanol in semi-arid regions. The objective of this work was to evaluate sweet sorghum 'BRS 506' under salt and water stress. The experimental design was in randomized blocks, in a factorial scheme (4x4), with the first factor referring to the electrical conductivities of the irrigation water (1.5; 3.0; 4.5; and 6.0 dS m-1) and the second refers to irrigation depths (53, 67, 85 and 95% of crop evapotranspiration). Gas exchange, leaf water status, leaf sugars and plant growth were evaluated. Salt and water stress cause negative effects on the growth of sweet sorghum 'BRS 506'. Salt stress causes disturbances in gas exchange and sugar levels. Sweet sorghum 'BRS 506' is tolerant to combined salt and water stress.

Analysis of seed dormancy breakage and seedling growth in sweet sorghum (Sorghum bicolor L.) through the electrical stimulation method: a scientific perspective aimed at promoting bioethanol production

This pioneering study meticulously focused on the underexplored realm of sweet sorghum (Sorghum bicolor L.), utilizing commercial seeds to mitigate potential biases. The research intricately interwove the intricate facets of electrical stimulation, delineating its profound implications on the estimative bioethanol production of sweet sorghum, with potential extrapolation to future investigations involving sugarcane. Executed within the controlled confines of a greenhouse, after seed treatment procured from a local market, the commercial seeds underwent an electrifying metamorphosis. In the pursuit of enhancing the fresh biomass output of sweet sorghum, a nuanced interplay with electrical currents transpired. Noteworthy findings surfaced, elucidating that the attainment of optimal outcomes necessitated meticulous control over the applied electrical current. The identified optimal parameter advocated maintaining a conservative threshold of 50 mA during a seed treatment duration spanning approximately 15 min. However, as the experimental cadence intensified, the narrative evolved with a bold revelation, indicating that exploration of higher electrical currents, peaking at 150 mA, could yield favorable results under the condition of a truncated seed treatment time, notably as brief as 5 min. The delicate equilibrium achieved in this electrical choreography presented a compelling prospect for redefining the production paradigm of sweet sorghum. After analyzing the germination results, the estimative production projections derived from treatment #3 paint a vivid picture of the sorghum biomass production potential. A visionary forecast materialized, envisioning an impressive 25 t/ha of sweet sorghum, coupled with a remarkable total conversion rate into bioethanol reaching 1.5 million cubic meters. This transcendence transcends the boundaries of a conventional study; it signifies a leap into the future, pushing the envelope of conventional wisdom in the relentless pursuit of innovation in sustainable energy.

Effects of cutting height and storage length on fermentation characteristics, microbial community, co-occurrence networks, potential functionality and pathogenic risk of fermented sweet sorghum stem

Postharvest management strategies like cutting height and anaerobic fermentation may affect the microbial risk of vegetables. This study evaluated the effects of cutting height and storage length on the fermentation characteristics, microbial diversity, co-occurrence networks, potential functionality and pathogenic risk of sweet sorghum stem (SSS). Fresh SSS harvested at two cutting heights (15 cm, F15; 45 cm, F45) was spontaneously fermented (S15 and S45) for 2, 4, 8, 16, 32 and 64 days. Decreasing the cutting height of SSS increased the dry matter, water-soluble carbohydrate content as well as Acinetobacter (23.0% vs. 44.9%) and Klebsiella (1.84% vs. 6.58%) proportion but decreased the crude protein content (P < 0.05). After fermentation, both cutting heights presented desirable fermentation. Anaerobic fermentation promoted the Glycolysis pathway (0.009 vs. 0.018) and related enzymes (l-lactate dehydrogenase, etc.) associated with lactate synthesis, but suppressed the degradation pathways of valine, leucine, isoleucine (0.011 vs. 0.003) and lysine (0.008 vs. 0.002). In microbial phenotype analysis, although F15 had higher proportions of ‘Potentially Pathogenic’ than F45, this undesirable phenotype declined to negligible levels via fermentation. These results concluded that, for SSS, concerns about the risk of microbial contamination and pathogens from low cutting height can be dispelled by well fermentation.

Hydrogen and Fatty Acid Production by Dark Fermentation of Sweet Sorghum Stalks as an Efficient Pre-treatment for Energy Recovery Before Their Bioconversion into Methane

Hydrogen and Fatty Acid Production by Dark Fermentation of Sweet Sorghum Stalks as an Efficient Pre-treatment for Energy Recovery Before Their Bioconversion into Methane

Major impacts of widespread structural variation on sorghum.

Genetic diversity is critical to crop breeding and improvement, and dissection of the genomic variation underlying agronomic traits can both assist breeding and give insight into basic biological mechanisms. Although recent genome analyses in plants reveal many structural variants (SVs), most current studies of crop genetic variation are dominated by single-nucleotide polymorphisms (SNPs). The extent of the impact of SVs on global trait variation, as well as their utility in genome-wide selection, is not yet understood. In this study, we built an SV data set based on whole-genome resequencing of diverse sorghum lines (n = 363), validated the correlation of photoperiod sensitivity and variety type, and identified SV hotspots underlying the divergent evolution of cellulosic and sweet sorghum. In addition, we showed the complementary contribution of SVs for heritability of traits related to sorghum adaptation. Importantly, inclusion of SV polymorphisms in association studies revealed genotype-phenotype associations not observed with SNPs alone. Three-way genome-wide association studies (GWAS) based on whole-genome SNP, SV, and integrated SNP + SV data sets showed substantial associations between SVs and sorghum traits. The addition of SVs to GWAS substantially increased heritability estimates for some traits, indicating their important contribution to functional allelic variation at the genome level. Our discovery of the widespread impacts of SVs on heritable gene expression variation could render a plausible mechanism for their disproportionate impact on phenotypic variation. This study expands our knowledge of SVs and emphasizes the extensive impacts of SVs on sorghum.

Assessing Fermentation Quality, Aerobic Stability, In Vitro Digestibility, and Rumen Degradation Characteristics of Silages Mixed with Sweet Sorghum and Aerial Parts of Licorice

Assessing Fermentation Quality, Aerobic Stability, In Vitro Digestibility, and Rumen Degradation Characteristics of Silages Mixed with Sweet Sorghum and Aerial Parts of Licorice

Lodging Variability in Sorghum Stalks Is Dependent on the Biomechanical and Chemical Composition of the Stalk Rinds

Stalk lodging contributes to significant crop yield losses. Therefore, understanding the biomechanical strength and structural rigidity of grain stalks can contribute to improving stalk lodging resistance in crops. From the structural constituents of the stalk, the rind provides the principal structure, supporting cells against tension and bending loads. In this work, the biomechanical and viscoelastic behavior of the rind from the internodes of two sweet sorghum varieties (Della and REDforGREEN (RG)), grown in two different growing seasons, were evaluated by three-point micro-bending tests using a dynamic mechanical analyzer (DMA). In addition, the chemical composition of rinds and the microfibril angle (MFA) of the cell wall were determined using XRD. The results revealed that the biomechanical behavior of Della varieties was stiffer and more resistant to loads than that of RG varieties. Two features of the rind biomechanical properties, flexural modulus (FM) and flexural strength (FS), showed a significant reduction for RG. Particularly, a reduction in FS of 16–37% and in FM of 22–41% were detected for RG1. Changes in the stalks’ rind biomechanical properties were attributed to cell wall components. Total lignin and glucan/cellulose contents were positively correlated with the FM and FS of the rind. Subsequently, an increase in the two cell wall components drove an increase in stiffness. Furthermore, the MFA of the rind was also found to influence the rind strength.

Optimization of alkali pre-treatment of sweet sorghum [Sorghum bicolor (L.) Moench] residue to improve enzymatic hydrolysis for fermentable sugars

Sweet sorghum was used as a bioenergy crop to improve the enzymatic hydrolysis for releasing fermentable sugars as compared to other crops. Effective pre-treatment with NaOH at 121 °C for up to 50 min was reported in this study before enzymatic hydrolysis. The response surface methodology approach was used to optimize the parameters for alkali pre-treatment. The optimized parameters of pre-treated sweet sorghum residue were 1–3 % NaOH concentration, 0.5–1.5 mm particle size, 10–50 min time studied using box-behnken design. The findings suggest that 2 % NaOH with a 1 mm reduction in particle size in 50 min leads to enzymatic saccharification for fermentable sugars with a maximum loading of 62.7 % of cellulose. Enzymatic hydrolysis was performed with the aid of enzymes cellulase and xylanase. The optimum conditions obtained for fermentable sugars were 50 °C, 72 h of hydrolysis duration with 20 FPU/g substrate of enzyme loading for 20 g/L sorghum residue from one factor at a time approach. Maximum concentration of 78.3 ± 0.23 g/L of glucose, 5.4 ± 0.47 g/L of xylose with 1.53 ± 0.11 g/L of cellobiose was obtained from hydrolysate after 72 h enzymatic treatment. The characterization, before and after pre-treatment were done by FTIR and FESEM shows effective pre-treatment is important for delignification and increase in cellulose digestibility for improving the enzymatic hydrolysis.

Optimization and benefit analysis of the supply chain for sweet sorghum bioenergy production in China

&lt;p&gt;Bio-liquid fuel is one of the effective ways to alleviate energy shortages and reduce greenhouse gas emissions. Sweet sorghum, as an energy crop used in fuel ethanol production, has enormous potential for development. However, due to seasonality, vulnerability, and logistical scheduling costs during transportation, the sweet sorghum ethanol supply chain faces significant difficulties and challenges in its development. To address the research gap, this paper proposes a multi-objective sustainable supply chain optimization model for Chinese sweet sorghum bioenergy based on mixed-integer linear programming. In this framework, the crop growth process model is first spatially extended to obtain the feedstock sources of the sweet sorghum ethanol supply chain. Then a site selection model for the feedstock collection stations and ethanol processing plants is constructed based on the geographic information system (GIS) to determine the candidate locations of the basic units of the sweet sorghum ethanol supply chain. Finally, a multi-objective supply chain optimization model based on the mixed-integer linear programming methodology is created to achieve the sweet sorghum ethanol supply chain layout and optimization at the national level. This framework takes into account the fuel ethanol market demand in China and the current state of the sweet sorghum ethanol supply chain industry, achieving national-level layout and optimization of the sweet sorghum ethanol supply chain. The total aboveground biomass (dry weight) of sweet sorghum on marginal land in China can be converted into approximately 37.212 million tons of fuel ethanol production, meeting the requirement to promote a nationwide 10% substitution rate for automotive ethanol gasoline. The lowest-cost supply chain layout scheme suggests establishing large ethanol processing plants near the Hu Huanyong Line, as this area benefits from abundant sweet sorghum yield on marginal lands and lower east-west direction transportation costs. However, the lowest carbon emission supply chain layout scheme recommends reducing the raw material supply area and increasing the ethanol transportation route to lower carbon emissions. The results of the sensitivity analyses indicate that lowering feedstock production and increasing ethanol demand increases the overall cost and carbon emissions of the sweet sorghum ethanol supply chain, while using rail transportation methods, increasing feedstock production, and decreasing ethanol demand reduces costs and carbon emissions.&lt;/p&gt;

Dynamic changes in carbohydrate components and the bacterial community during the ensiling of wilted and unwilted sweet sorghum.

Sweet sorghum can be used to produce a substantial quantity of biofuel due to its high biological yield and high carbohydrate content. In this study, we investigated the dynamic changes in fermentation characteristics, carbohydrate components, and the bacterial community during the ensiling of wilted and unwilted sweet sorghum. The results revealed a rapid fermentation pattern and high-quality fermentation quality in wilted and unwilted sweet sorghum, wherein lactic acid, and acetic acid accumulated and stabilized during the initial 9 days of ensiling, with the pH values less than 4.2, until 60 days of ensiling. We found that the ensiling of sweet sorghum involved the degradation (5% ~ 10%) of neutral detergent fiber (NDF) and hemicellulose and that the degradation of NDF fit a first-order exponential decay model. A shift in dominance from Lactococcus to Lactobacillus occurred before the first 9 days of ensiling, and the abundance of Lactobacillus (r = -0.68, p < 0.001) was negatively correlated with the NDF content. The relative abundances of Lactobacillus in wilted and unwilted sweet sorghum after ensiling for 60 days were 76.30 and 93.49%, respectively, and relatively high fermentation quality was obtained. In summary, ensiling is proposed as a biological pretreatment for sweet sorghum for subsequent biofuel production, and unlike other materials, sweet sorghum quickly achieves good fermentation quality and has great potential for bioresource production.