Biomass Constituents Research Articles

Biomass-derived heteroatom-doped carbons: Unlocking the potential of cellulose, hemicellulose, and lignin co-pyrolysis with ammonium polyphosphate for high-performance supercapacitors

Carbon materials were prepared via cellulose, hemicellulose, and lignin co-pyrolysis with ammonium polyphosphate (APP) to scrutinize the influence of these biomass constituents on the materials’ electrochemical performance. During co-pyrolysis, the synergistic interaction between APP and the three components facilitated the doping of heteroatoms including nitrogen, oxygen, and phosphorus. APP with polymerization n > 1000 exhibited the best doping performance. The incorporation of KHCO3 effectively tailored the carbon materials into a hierarchically porous structure predominantly composed of micropores. The cellulose-derived carbon materials outperformed with a remarkable specific capacitance of 398 F/g at 0.5 A/g. Its exceptional electrochemical performance was credited to a notable N content of 3.73 % and a high specific surface area of 1851 m2/g. Our research underscored the potential of cellulose as a readily available and affordable feedstock for crafting carbon materials, suitable for the electrodes in high performance supercapacitors.

Efficient extraction of light-colored lignin from bamboo by p-toluenesulfonic acid assisted tetrahydrofurfuryl alcohol aqueous solution

Acidic hydrotropes exhibit effective performance in fractionating the constituents of lignocellulosic biomass owing to their amphiphilic characteristics. However, the requirement for excessively high concentrations may lead to the condensation and aggregation of lignin. In this case, bamboo was extracted with 70 % (w/v) tetrahydrofurfuryl alcohol (THFA) aqueous solution containing 5–20 % (w/v) p-toluenesulfonic acid (pTsOH) at 90–120 °C for 1–4 h. Results indicated that 91 % of lignin was efficiently removed from bamboo, with subsequent recovery of 73.5 % achieved through extraction with 10 % pTsOH at 110 °C for 4 h. Furthermore, the resulting lignin exhibited a relative content of β-O-4 bonds of 64.1 %, displayed a light color (L*: 70.48), boasted a purity of 99.64 %, and possessed a moderate molecular weight. These attributes position it as a valuable candidate in functional material production. The aqueous solution provides an ideal medium for efficient extraction of uncondensed, light-colored lignin, thereby furnishing insights for advancing the utilization.

Adaptive laboratory evolution of Lipomyces starkeyi for high production of lignin derivative alcohol and lipids with comparative untargeted metabolomics-based analysis.

Adaptive laboratory evolution (ALE) is an impactful technique for cultivating microorganisms to adapt to specific environmental circumstances or substrates through iterative growth and selection. This study utilized an adaptive laboratory evolution method on Lipomyces starkeyi for high tolerance in producing lignin derivative alcohols and lipids from syringaldehyde. Afterward, untargeted metabolomics analysis was employed to find the key metabolites that play important roles in the better performance of evolved strains compared to the wild type. Lignin, a prominent constituent of plant biomass, is a favorable source material for the manufacture of biofuel and lipids. Nevertheless, the effective transformation of chemicals produced from lignin into products with high economic worth continues to be a difficult task. In this study, we exposed L. starkeyi to a series of flask passaging experiments while applying selective pressure to facilitate its adaptation to syringaldehyde, a specific type of lignin monomeric aldehyde. Using ALE, we successfully developed a new strain, DALE-22, which can synthesize syringyl alcohol up to 18.74 mM from 22.28 mM syringaldehyde with 41.9% lipid accumulation. In addition, a comprehensive examination of untargeted metabolomics identified six specific crucial metabolites linked to the improved tolerance of the evolved strain in the utilization of syringaldehyde, including 2-aminobutyric acid, allantoin, 4-hydroxyphenethyl alcohol, 2-aminoethanol, tryptophan, and 5-aminovaleric acid. The results of our study reveal how L. starkeyi adapts to using substrates produced from lignin. These findings offer important information for developing strategies to improve the process of converting lignin into valuable products for sustainable biorefinery applications.

Reduction characteristics and mechanism of mechanically activated iron ore powder by lignin

As a primary constituent of renewable biomass fuel, lignin can be effectively utilized as a reducing agent in the ironmaking process, thereby significantly mitigating CO2 emissions throughout the procedure. This study meticulously evaluates the impact of lignin on the reduction of iron ore powder across diverse levels of mechanical activation through thermogravimetric analysis. It elucidates the intricate reduction mechanism at play. The reduction process is characterized by two pivotal stages: the initial reduction of pyrolysis gases followed by the reduction of fixed carbon, which predominantly drives the transformation of iron ore powder. While mechanical activation exhibits a negligible influence on the first stage, it exerts a pronounced effect on the second. An extended activation time elevates the depth of reduction in the latter stage. Furthermore, the heating rate plays a crucial role in the reduction process, with slower rates favoring the reduction of pyrolysis gases and faster rates boosting carbon fixation reduction. Enhanced activation durations lead to improve linear regression fits for the reduction reaction data. Utilizing the carbon gasification model for iron ore powder treated with 480 min of activation yields a calibration variance of 0.99, with the derived activation energy of 48.75 kJ/mol aligning closely with empirical values. This research provides a thorough analysis of the reduction kinetics and mechanism, underscoring the transformative potential of lignin as a reducer in ironmaking processes, thus contributing to the development of sustainable, low-carbon technologies.

Supercritical CO2 as effective wheat straw pretreatment for subsequent mild fractionation strategies

The efficient utilization of lignocellulosic biomass in biorefineries is pivotal for the transition to a carbon–neutral society, emphasizing the need for environmentally friendly fractionation techniques. While the extensive use of chemicals in biorefinery operations can yield favorable quantities of specific biomass components, adopting less chemically intense conditions is crucial for holistic methodologies that preserve the inherent potential of all biomass constituents. This study comprehensively investigates the use of supercritical carbon dioxide (sc-CO2) as a green pretreatment to improve subsequent mild fractionation on wheat straw. Sc-CO2 at 300 bars, 100 °C and 70% moisture was found to have minimal impact on the chemical composition and the lignin structure, while there were significant morphological changes as heightened surface area and reduced density. Apart from increasing enzymatic saccharification efficiency, the treatment notably enhanced subsequent mild delignification through alkaline and flow-through organosolv extractions. The combination of the pretreatments enhances the lignin solubilization yields from 49 to 79% for alkaline and 74 to 91% for organosolv extractions, while retaining a high β-O-4 conservation of 49 and 59 linkages per 100 aromatic units, respectively. Additionally, the combined use of sc-CO2 with mild dilute acid pretreatment improved xylose solubilization from 59 to 76 % and enzymatic saccharification from 53 to 90%, albeit with increased lignin condensation. In summary, this study demonstrates the potential of sc-CO2 pretreatment as a versatile tool for biomass valorization within the evolving bioeconomy, by combining enhanced extraction yields with minimal lignin structural impact. Our work thereby highlights the promise of the use of sc-CO2 to contribute to the overall economic potential of improved biorefinery processes.

Efficient Conversion of Glucose to Hydroxymethylfurfural: One-pot Brønsted Base and Acid Promoted Selective Isomerization and Dehydration.

Development of elegant, selective, and efficient strategies for the production of value-added platform chemicals from renewable feedstocks are in high demand to achieve the future needs and sustainable goals. In this context, an efficient acid-promoted synthesis of highly valuable hydroxymethylfurfural (HMF) has been demonstrated from glucose, a major constituent of lignocellulosic biomass. The major challenge in the conversion of glucose to HMF is the selective isomerization of glucose to ketose, which in the present work has been successfully addressed through the amine-mediated rearrangement of glucose to aminofructose under Amadori rearrangement. Importantly, subsequent dehydration step affords HMF and regenerates the amine employed in the first step, which could be readily recovered. In addition, scale-up and successful integration into one-pot synthesis of HMF proves the efficiency and applicability of the present transformation in large scale application. In addition, the method was also successfully extended to other monosaccharides and disaccharides to produce HMF.

Green pathways for biomass transformation: A holistic evaluation of deep eutectic solvents (DESs) through life cycle and techno-economic assessment

The utilization of renewable biomass resources to manufacture biofuels, chemicals, and materials has garnered considerable attention. Deep eutectic solvents (DESs) have surfaced as a promising instrument within the realm of biomass conversion, owing to their distinctive attributes such as biodegradability, negligible toxicity, easier fabrication, liquid-phase stability and renewability as opposed to ionic liquids (ILs). Research into DESs, particularly those derived from natural sources, is expanding to advance affordable and sustainable biomass conversion. However, the bottlenecks of DES are its limited solubility for certain biomass constituents, cost and availability. To overcome these hurdles, ongoing research and technological innovations strive to tap into the complete potential of DESs in biomass conversion. This review underscores the importance of evaluating DESs' eco-friendly potential comprehensively, encompassing ecological, financial, and technological standpoints which aims to illuminate how DESs can effectively contribute to sustainable biomass utilization, fostering an environmentally conscious circular bio-based economy.

Potassium silicate and vinasse enhance biometric characteristics of perennial sweet pepper (Capsicum annuum) under greenhouse conditions

An effective strategy for enhancing fruit production continuity during extended sweet pepper season involves adopting innovative biostimulants such as potassium silicate (PS) and vinasse. Adjusting PS and vinasse concentrations are crucial for maintaining the balance between vegetative and fruit growth, particularly in sweet pepper with a shallow root system, to sustain fruiting over prolonged season. However, the interaction between PS and vinasse and the underlying physiological mechanisms that extend the sweet pepper season under greenhouse conditions remain unclear. This study aimed to investigate the impact of PS and vinasse treatments on the yield and biochemical constituents of perennial pepper plants cultivated under greenhouse conditions. For two consecutive seasons [2018/2019 and 2019/2020], pepper plants were sprayed with PS (0, 0.5, and 1 g/l) and drenched with vinasse (0, 1, 2, and 3 l/m3). To estimate the impact of PS and vinasse on the growth, yield, and biochemical constituents of pepper plants, fresh and dry biomass, potential fruit yield, and some biochemical constituents were evaluated. Results revealed that PS (0.5 g/l) coupled with vinasse (3 l/m3) generated the most remarkable enhancement, in terms of plant biomass, total leaf area, total yield, and fruit weight during both growing seasons. The implementation of vinasse at 3 l/m3 with PS at 0.5 and 1 g/l demonstrated the most pronounced augmentation in leaf contents (chlorophyll index, nitrogen and potassium), alongside improved fruit quality, including total soluble solid and ascorbic acid contents, of extended sweet pepper season. By implementing the optimal combination of PS and vinasse, growers can significantly enhance the biomass production while maintaining a balance in fruiting, thereby maximizing the prolonged fruit production of superior sweet pepper under greenhouse conditions.

Biomass energy transformation: Harnessing the power of explainable ai to unlock the potential of ultimate analysis data

Biomass fuels are a promising renewable energy source for both heat and electricity generation. When weighing the economics of biomass energy, the higher heating value (HHV) is a significant factor to consider. To estimate HHVs, a full understanding of the chemical constituents of biomass is required, which can be costly and time-consuming to find experimentally. To solve this issue, this study applies three modern and robust machine learning algorithms XGBoost, Random Forest (RF), and Adaptive Boosting (AdaBoost), to predict HHVs reliably based on final analysis data, which includes carbon (C, %), hydrogen (H, %), nitrogen (N, %), and oxygen (O, %) content in biomass. The linear regression (LR) was used for measuring baseline performance. The XGBoost, AdaBoost, and RF models exhibit endurance in model prediction, however, the XGBoost model outperforms all other models. A Bayesian strategy for hyperparameter optimization was employed to optimize the prediction outcomes. The R2 values achieved during the model testing for LR, RF, XGBoost, and AdaBoost-based models were 0.8425, 0.9822, 0.9967, and 0.8367, respectively. Once the best-performing model (XGBoost) was determined, it was evaluated with Shapley additive explanations (SHAP) for feature analysis. This study report adds to informed decision-making and instills trust in biomass energy applications by putting light on the fundamental mechanisms driving HHVs.

Yield and Energy Modeling for Biochar and Bio-Oil Using Pyrolysis Temperature and Biomass Constituents.

Pyrolysis offers a sustainable and efficient approach to resource utilization and waste management, transforming organic materials into valuable products. The quality and distribution of the pyrolysis products highly depend on the constituents' properties and set process parameters. This research aims to investigate and model this dependency, offering decision-makers a tool to guide them when designing the process for a particular application. Experimental data on the pyrolysis of various types of feedstocks processed at a wide range of pyrolysis temperatures (350-650 °C) are utilized to develop the prediction models. Four variables are modeled: the yield and energy content for both the biochar and bio-oil as a function of the pyrolysis temperature and feedstock characteristics. The models developed had very good prediction power with the coefficient of determination above 90%. The results highlight the advantages of food waste (leftover) as a suitable feedstock to produce biochar at the pyrolysis temperature within the range of 450-550 °C. Furthermore, the biofuels produced from food waste are found to be of good quality, with the bio-oil exceptionally high in energy content (HHV = 34.6 MJ/kg), which is almost 80% of that of diesel. The developed models provide a tool for predicting the biofuel yield and quality based on the feedstock selection and process temperature.

Elucidating reaction mechanisms in the oxidative depolymerization of sodium lignosulfonate for enhancing vanillin production: A Density Functional Theory study

Lignin is a vital organic constituent of plant biomass and it can be transformed into value-added chemicals through chemical processes. This study employs the Density Functional Theory (DFT) to investigate the mechanistic effects of various oxidants on the depolymerization of sodium lignosulfonate model compounds into vanillin. Under alkaline conditions, OH- ions participation in the hydrolysis of β-O-4 bonds has been predicted. The dehydration of dihydroconiferyl alcohol to form eugenol, with an energy barrier of 69.0 kcal/mol was identified as the major rate-determining step in the oxidation reaction. In the absence of an oxidant, the energy barrier for the oxidation of eugenol to vanillin was 77.8 kcal/mol. However, when using nitrobenzene or H2O2 as oxidants, the energy barrier has significantly decreased to 12.6 kcal/mol and 21.4 kcal/mol, respectively. The effects of temperature and pressure on the rate-determining step of the reaction were analyzed using Statistical Product and Service Solutions (SPSS) software. These results have demonstrated that the energy barrier for the hydrolysis reaction's rate-determining step is positively correlated with temperature but negatively correlated with pressure. These theoretical findings would potentially help in designing the experiments and aid in enhancing the selectivity and yield of vanillin.

Assessment of anthropogenic and climate-driven water storage variations over water-stressed river basins of Ethiopia

Abstract Globally, surface water, groundwater, soil moisture, snow storage, canopy water, and wet biomass constituents make up water storage, which plays a significant role in the hydrological water balance. Evaluating the variations in water storage anomalies associated with climate forcing and human activities over river basins is crucial for assessing water scarcity and predicting potential pressures on water resources in the future. In this study, we assessed the impacts of climatic and anthropogenic drivers on the change in water storage in the river basins of Ethiopia by using the independent component analysis to examine Gravity Recovery and Climate Experiment with the Global Land Data Assimilate System-based water storage and comparing the independent component analysis with hydro-meteorological data and statistical data related to human activities. It is of great significance for helping people better understand the evaluation of terrestrial water storage anomalies under the combined influence of climatic change and anthropogenic activities and providing information for better protection and utilization of water resources at river basin level. It is crucial to take effective measures to protect these precious land and water resources and prevent their further deterioration. The estimated result will be essential for sustainable water management and protection.

Biomass higher heating value prediction machine learning insights into ultimate, proximate, and structural analysis datasets

ABSTRACT In this study machine learning (ML) models have been employed to predict the higher heating value (HHV) of biomass by utilizing input variables derived from ultimate, proximate, and structural analyses. In total, 180 models were developed, with 124 utilizing ultimate analysis data, 28 based on proximate analysis, and 28 relying on structural analysis. Various ML techniques, including polynomial models (SOP), support vector machines (SVM), random forest regression (RFR), and artificial neural networks (ANN), were employed for analysis. The study found that ANN models, when “fed” with FC and VM data, provided considerable accuracy in prediction results, with the best results obtained with 2-12-1 architecture (R2 = 0.96). In addition, a separate model configuration that processed inputs on biomass constituents such as cellulose, lignin, and hemicellulose showed remarkable agreement with empirical data. Additional findings revealed that the models created using SOP (R2 = 0.95), SVM (R2 = 0.95), and RFR (R2 = 0.90) demonstrated minimal discrepancies when predicting HHV. This study provides significant insights into the investigation of biomass analysis techniques employing ML tools, paving the way for future research aimed at constructing a robust tool for HHV prediction. Subsequent models may explore integrating inputs from diverse analysis methods and leveraging advanced machine learning techniques to enhance accuracy further.

The Potential of Commercial Biomass-Based Activated Carbon to Remove Heavy Metals in Wastewater – A Review

Commercial activated carbon is a type of adsorbent commonly used in adsorption processes. However, the use of commercial carbon in wastewater treatment is still limited, due to the scarce availability of precursors and their high cost. Biomass as an activated carbon precursor has been reported to have high efficiency in removing various heavy metals in wastewater. This study aims to review the potential of biomass-based activated carbon to adsorb heavy metals in terms of biomass constituent components, heavy metal removal, and future prospects. The method in this study is a systematic literature review, or SLR, to collect data from online databases such as Google Scholar, PubMed, and ScienceDirect. The results show that biomass-based activated carbon is effective in the removal of heavy metals in various types of wastewater. The removal effectiveness for different types of biomass ranged from 84–99% for Pb2+ ions, 55–92% for Cd2+ ions, 84–99% for Pb2+ ions, 96% for As2+ ions, 80–100% for Cr2+ ions, 25–97% for Fe2+ ions, 50–99% for Ni2+ ions, and 62–98% for Cu2+ ions, and 98% for Ti ions. These results show that heavy metals have different affinities to activated carbon from biomass, from all heavy metals, Fe2+ and Cd2+ ions have the lowest affinity, so the activated carbon used to remove Fe2+ and Cd2+ metals needs to be produced with higher porosity and surface area. The removal of heavy metals using activated carbon from biomass is limited by adsorbent dosage, contact time, solution pH, temperature, initial adsorbate concentration, particle size, and stirring speed. In future research, it is expected that activated carbon from biomass has a high adsorption capacity, is economical cost, is environmentally friendly and can be used on a larger scale.

Pairing combustion experiments and thermogravimetric analysis to uncover timescales controlling cellulose ignition and burnout in a Hencken burner

Solid biomass fuels are potential components of several industrial and power-generation decarbonization pathways. Despite considerable literature that documents the fuel properties of lignocellulosic biomass, the fundamental combustion characteristics of biomass constituents are not well understood. We tackle this knowledge gap by analyzing the combustion properties of cellulose (a key biomass component) in a Hencken burner across various temperature and oxygen mole fractions of the oxidizer gases. Combustion data are compared with results from thermogravimetric analysis (TGA) and scaling analyses to reveal two rate-controlling timescales in the ignition of cellulose: devolatilization time and volatile ignition delay time. TGA shows that the devolatilization time is only a function of temperature and occurs on a considerably shorter timescale than oxidation. Hencken burner experiments show that ignition delay time is highly sensitive to temperature; at very low levels of oxygen in the oxidizer gas (mole fractions of 0.01–0.04), the ignition delay time is sensitive to oxygen mole fraction, but this sensitivity disappears at higher oxygen levels. Burnout time is the least sensitive parameter investigated. The combination of experiments and chemical kinetic simulations begins to explain the ignition behavior of the volatiles from cellulose decomposition and lays groundwork for future research to address uncertainties in quantifying the kinetics of cellulose ignition. Finally, this combined combustion-fuel science study raises serious doubts about the use of combustion indices and TGA-calculated properties to predict the true combustion behavior of biomass.

Light-Driven Depolymerization of Cellulosic Biomass into Hydrocarbons.

Cellulose and hemicellulose are the main constituents of lignocellulosic biomass. Chemical derivatization of lignocellulosic biomass leads to a range of C5 and C6 organic compounds. These C5 and C6 compounds are valuable precursors (or fine chemicals) for developing sustainable chemical processes. Therefore, depolymerization of cellulose and hemicellulose is essential, leading to the development of various materials that have applications in biomaterial industries. However, most depolymerized processes for cellulose have limited success because of its structural quality: crystallinity, high hydrogen-bond networking, and mild solubility in organic and water. As a result, various chemical treatments, acidic (mineral or solid acids) and photocatalysis, have developed. One of the significant shortcomings of acidic treatment is that the requirement for high temperatures increases the commercial end cost (energy) and hampers product selectivity. For example, a catalyst with prolonged exposure to high temperatures damages the catalyst surface over time; therefore, it cannot be used for iterative cycles. Photocatalysts provide ample application to overcome such flaws as they do not require high temperatures to perform efficient catalysis. Various photocatalysts have shown efficient cellulosic biomass conversion into its C6 and C5 hydrocarbons and the production of hydrogen (as a green energy component). For example, TiO2-based photocatalysts are the most studied for biomass valorization. Herein, we discussed the feasibility of a photocatalyst with application to cellulosic biomass hydrolysis.

Ectopic callose deposition into woody biomass modulates the nano-architecture of macrofibrils

Plant biomass plays an increasingly important role in the circular bioeconomy, replacing non-renewable fossil resources. Genetic engineering of this lignocellulosic biomass could benefit biorefinery transformation chains by lowering economic and technological barriers to industrial processing. However, previous efforts have mostly targeted the major constituents of woody biomass: cellulose, hemicellulose and lignin. Here we report the engineering of wood structure through the introduction of callose, a polysaccharide novel to most secondary cell walls. Our multiscale analysis of genetically engineered poplar trees shows that callose deposition modulates cell wall porosity, water and lignin contents and increases the lignin–cellulose distance, ultimately resulting in substantially decreased biomass recalcitrance. We provide a model of the wood cell wall nano-architecture engineered to accommodate the hydrated callose inclusions. Ectopic polymer introduction into biomass manifests in new physico-chemical properties and offers new avenues when considering lignocellulose engineering.

Effect of torrefaction on yield, reactivity and physicochemical properties of pyrolyzed char from three major biomass constituents

Torrefaction is an efficient pretreatment technology for large-scale and high-value utilization of biomass fuel. To understand the effects of torrefaction pretreatment on the physicochemical characteristics of the pyrolyzed char from the three major constituents of lignocellulosic biomass (cellulose, xylan-representative of hemicelluloses, and lignin), torrefied samples were produced at 200, 260, 320, and 380 ℃, and then pyrolyzed at 1028 ℃ with a heating rate of 65 ℃/s and 0.25 ℃/s, respectively. The experimental results demonstrate that the torrefaction temperature strongly influences the pyrolyzed char’s yields, oxidative reactivities, and physicochemical structure. The sensitivity of the accumulated char yield and char reactivity to the torrefaction temperature differed with varied constituents. Accurate modeling of accumulated char yield is achieved through a weighted summative law, showing a decreasing deviation from 2.4 wt% to 0.6 wt% as torrefaction temperatures increase. Raman spectra indicate that there is a strong correlation between the relative amount of small and large aromatic rings and the accumulated char yield of torrefied samples, with the determination coefficient R2 of 0.98, 0.88, and 0.77 for cellulose, xylan, and lignin, respectively.

The pelagic ecosystem of the Black Sea goes gelatinous

ABSTRACT Following up on the issue of worldwide growing gelatinous plankton dominance, we analysed historical records on zooplankton biomass from the 1970s to the present, in order to assess the ratio of gelatinous- to-non-gelatinous zooplankton (GN). The latter is poorly analysed in current publications featuring the Black Sea pelagic ecosystem. The GN characterizes the quality of zooplankton as a food source for small pelagic fishes which dominate Black Sea fishery. The retrospective analysis of zooplankton biomass constituents in coastal and open sea waters retrieved from published papers was complemented by an 11-year sampling (up until 2021), across the Crimean shelf. The comparison over regions (represented by the north-eastern, the northern, the north-western, the southern and the open sea) showed that the jellyfish Aurelia aurita, the ctenophore Mnemiopsis leidyi, and the dinoflagellate Noctiluca scintillans act as major contributors to the total gelatinous biomass of the 2000s, on a basin scale. On average, the wet gelatinous biomass is about one hundred times that of the non-gelatinous one. High values of the GN ratio (in wet mass and in carbon units) in coastal waters indirectly imply a leading role of a detritus pathway of organic matter in a pelagic ecosystem.

Metagenomic insight into the biodegradation of biomass and alkaloids in the aging process of cigar

A significant distinction between cigar production and tobacco lies in the necessary aging process, where intricate microbial growth, metabolic activities, enzymatic catalysis, and chemical reactions interact. Despite its crucial role in determining the final quality of cigars, our comprehension of the underlying chemical and biological mechanisms within this process remains insufficient. Biomass and alkaloids are the primary constituents that influence the flavor of cigars. Consequently, investigating the entire aging process could begin by exploring the involvement of microbes and enzymes in their biodegradation. In this study, handmade cigars were aged under different conditions. Metagenomic sequencing was employed to identify the microbes and enzymes responsible for the degradation of biomass and alkaloids derived from tobacco leaves. The results revealed that various environmental factors, including temperature, humidity, duration time, and turning frequency, yielded varying contents of total sugar and alkaloids in the cigars. Significant correlations were observed between microbial communities and starch, reducing sugars, total sugars, and alkaloids. Key species involved in the breakdown of biomass constituents, such as starch (Bacillus pumilus, Pseudomonas sp. 286, and Aspergillus cristatus), reducing sugars and total sugars (Aspergillus cristatus and Nitrolancea hollandica), were identified. Furthermore, Corynespora cassiicola and Pseudomonas fulva were found to potentially contribute to the degradation of alkaloid compounds, specifically nornicotine and neonicotinoid. Our work contributes to a deeper understanding of the microbial roles in the aging of cigars. Moreover, the selection of specific microbial strains or starter cultures can be employed to control and manipulate the aging process, thereby further refining the flavor development in cigar products.Graphical