Biomass Concentration Research Articles

Substrate-dependent lipid and β-carotene production in engineered Yarrowia lipolytica: a comparative study

This study evaluates the influence of various substrates (glucose, glycerol, and acetic acid) on the growth and metabolite production of Yarrowia lipolytica in fed-batch bioreactors. The primary aim is to understand how substrate choice impacts lipid and β-carotene production, critical for bioenergy and bioproducts. The study demonstrates that the choice of substrate significantly influences biomass yield, lipid content, and β-carotene levels. Among the substrates tested, glycerol yielded the highest biomass concentration of 5.31 g/L. Glucose led to the highest lipid content, with a yield of 35.8% (g lipids/g biomass), while acetic acid resulted in the highest lipid concentration, reaching 1.42 g/L. In terms of β-carotene production, glucose showed the highest content per cell at 63.3 mg/g, whereas glycerol led to the highest overall concentration of 202 mg/L. These findings highlight Y. lipolytica’s versatility and potential as a flexible platform to produce lipids and β-carotene, which are essential for developing sustainable biofuels and bioproducts. The study underscores the significant variations in metabolite production based on substrate choice, emphasizing on the importance of tailored strategies to optimize industrial applications. Further research may explore optimizing fermentation conditions to enhance production yields, making this yeast a viable option for various biotechnological applications.

Phytotoxic effects of stem aqueous extract of Lepidium didymum L. against Lens culinaris and Melilotus albus

Allelopathy involves plants releasing allelochemicals, inhibiting the growth of nearby plants, and influencing their physiological and morphological characteristics. Donor plants with allelopathic capabilities dominate, which affects the survival of other plant species. The effect of Lepidium didymum stem aqueous extract (SAE) on Lens culinaris and Melilotus albus was investigated in this study. The experiment involved extracting compounds from the stems of L. didymum and applying varying concentrations (0.5, 1, 2, and 4%) of these stem extracts to test plant seeds and seedlings. Multiple parameters, including germination percentage, growth parameters, and biochemical activities, were measured and compared to those of the control group. Germination percentage, seedling growth, seedling length, fresh and dry biomass, chlorophyll, and carotenoid content decreased notably, especially at higher concentrations (4%), whereas proline content increased in a concentration-dependent manner. Scanning electron microscopy revealed ultrastructural abnormalities in the roots of treated plants compared to those in the control. GC–MS analysis revealed the presence of 31 volatile chemicals in the methanolic stem extract. The compounds found in the major amounts are benzyl nitrile (29.19%), lauric acid (7.86%), benzene acetic acid (6.44%), 11-bromoundecanoic acid (7.36%), palmitic acid (4.85%), dodecanoic acid (4.80%), menthol, trans-1,3, cis-1,4 (3.28%), 11-bromoundecanoic acid (7.36%), and linolenic acid (8.64%). These compounds may be responsible for imparting allelopathic effects on the test species L. culinaris and M. albus. Our study revealed that the stem of L. didymum possesses a high concentration of water-soluble allelochemicals, which are thought to reduce test plant growth and can be used as potential weedicides.

Genotyping-by-sequencing derived SNP markers reveal genetic diversity and population structure of Dactylis glomerata germplasm

Orchardgrass (Dactylis glomerata L.), a widely cultivated cool-season perennial, is an important forage crop due to its adaptability, high nutritional value, and substantial biomass. Understanding its genetic diversity and population structure is crucial for developing resilient cultivars that can withstand climate change, diseases, and resource limitations. Despite its global significance in fodder production, the genetic potential of many regional accessions remains unexplored, limiting breeding efforts. This study investigates the genetic diversity (GD) and population structure of 91 accessions of D. glomerata from Turkey and Iran using genotyping-by-sequencing based single nucleotide polymorphism (SNP) markers. A total of 2913 high-quality SNP markers revealed substantial genetic variability across provinces. Notably, accessions from Erzurum exhibited the highest GD (mean GD: 0.26; He: 0.5328), while provinces such as Bursa and Muğla demonstrated lower GD (mean GD: 0.15; He < 0.22), suggesting potential genetic bottlenecks. Population structure analysis using Bayesian clustering, PCoA and UPGMA dendrograms divided the accessions into three distinct clusters, with cluster membership largely reflecting geographical origins, and dry biomass content. Cluster II revealed higher GD, associated with enhanced biomass production (128 g/plant), the most important agronomic trait in forage species, supporting the notion of heterosis in breeding programs. The majority of the genetic variation (85.8%) was observed within clusters, with minimal differentiation among clusters (FST = 0.007). Genome-wide association studies (GWAS) identified significant marker-trait associations for dry biomass weight, a critical agronomic trait, with markers DArT-100715788, DArT-101043591, and DArT-101171265 and DArT-101090822 located on Chromosomes 1, 6, and 7 respectively. These findings highlight the importance of regional diversity for maintaining adaptive potential in future breeding programs.

Exploring the Fermentation Potential of Kluyveromyces marxianus NS127 for Single-Cell Protein Production

Kluyveromyces marxianus is a food-grade yeast known for its diverse beneficial traits, making it an attractive candidate for both food and biotechnology applications. This study explores the potential of Kluyveromyces marxianus as a promising alternative protein source for single-cell protein (SCP) production. Various Kluyveromyces strains were isolated and screened from traditional fermented dairy products, with Kluyveromyces marxianus NS127 identified as the most promising strain due to its superior growth characteristics, high SCP yield, and environmental tolerance. Notably, Kluyveromyces marxianus NS127 demonstrated significant substrate conversion capacity with a biomass yield of 0.63 g biomass/g molasses, achieving a dry biomass concentration of 66.64 g/L and a protein yield of 28.37 g/L. The protein extracted from the dry biomass exhibited excellent solubility (62.55%) and emulsification properties (13.15 m2/g) under neutral conditions, alongside high foaming stability (93.70–99.20%) across a broad pH range (3–11). These results underscore the potential of Kluyveromyces marxianus NS127 as a viable alternative protein source and provide a solid theoretical foundation for its industrial application.

Determination of alkali metal elements in solid biomass fuel by laser-induced breakdown spectroscopy: Analysis and reduction of chemical matrix effects.

Rapid and accurate detection of the biomass potassium (K) content in biomass is crucial for mitigating ash deposition and fouling issues in biomass fuel combustion processes. Laser-induced breakdown spectroscopy (LIBS) offers a promising approach for rapid analysis of biomass elemental. However, the accuracy of LIBS detection is susceptible to chemical matrix effects. Particularly in the case of biomass, characterized by its complex composition, the absence of pertinent studies on effect mechanisms impedes the enhancement of analytical accuracy. In this study, we investigated and compared two types of matrix effects related to chemical properties in biomass samples (analyte forms and matrix composition). Firstly, the inconsistency of K spectral response among different chemical properties samples and the performance of univariate models were analyzed. The results indicate that, compared to the chemical forms, differences in composition are the dominant factor of chemical matrix effects. Moreover, the compositional content of biomass samples is analyzed to correlate the matrix effect in LIBS measurements to a chemical property of the specimen. It is indicated that differences in volatile and ash content may lead to variations in the plasma excitation process, resulting in distinct spectra. Finally, a knowledge-based regression approach was employed to attenuate chemical matrix effects, the main influencing factors identified were analyzed as a priori knowledge for variable selection and inputting them into a partial least squares model. And 13 real solid biomass fuels were measured, resulting in root mean square error of prediction (RMSEP), R2, and average standard deviation (ASD) of 0.99, 0.050%, and 0.001%, respectively. This study investigated the influence of matrix effects related to biomass chemical properties on LIBS measurements, achieving rapid measurement of K. It promotes the application of LIBS in solid fuels and provides a methodological reference for LIBS analysis of complex matrix materials.

Improving photosynthetic biogas purification via process aeration and nanoparticle supplementation.

This study evaluated the influence of nanoparticles in both suspension and solid format on the performance of a microalgal process devoted to photosynthetic biogas purification. The experimental system consisted of an enclosed tubular photobioreactor coupled to a biogas absorption column through a mixing chamber. The high NH4+ concentration in the inlet mineral medium (530mg N-NH4+ L-1) and the punctual addition of 115mL of nanoparticle suspension to the system caused inhibition of the microalgal-bacterial cultivation. Conversely, cultivation broth aeration (0.5 L min-1 air flowrate) allowed the biomethane production fulfilling the EN 16723 (CH4>90%, CO2<2%). The nanoparticle suspension performance was superior to that of their solid counterparts in terms of CO2 removal efficiency at equivalent nanoparticle dose (77% vs. 49%). However, parameters such as the nanoparticle suspension dosage and biomass concentration in the photobioreactor should be optimized to further improve biomethane quality before its industrial application.

Using a Soil Surfactant to Improve Kenaf Establishment under Deficit Irrigation

Kenaf (Hibiscus cannabinus) is a fiber crop that grows well in tropical climates and has numerous potential industrial and environmental benefits. However, like many crops, it may be limited by sensitivity to water stress, particularly at the seedling stage. Soil surfactants are frequently used as soil amendments to increase the volumetric water content (VWC), particularly under deficit irrigation. Two greenhouse experiments were conducted to determine the emergence and growth response of kenaf to three irrigation regimes and a one-time soil surfactant application. Kenaf seeds were planted in native Margate fine sand soil (siliceous, hyperthermic Mollic Psamnaquent) and sprayed with a nonionic surfactant at 3 quarts/acre (7.5 L/ha) (1×) and subjected to three irrigation regimes of 3.5 ounces (100 mL) of water applied every day (ED), every other day (EOD), or every 4 days (E4D). In Expt. 2, an additional surfactant treatment applied at 6 quarts/acre (15 L/ha) (2×) was included. The percent emergence, plant height, postexperiment biomass, and volumetric water content data were collected. During Expt. 1, kenaf emergence was significantly inhibited by ED irrigation with 1× when compared with E4D with 1×. In Expt. 2, seed treated with the 2× rate emerged faster and had better overall emergence under all irrigation regimes when compared with no soil surfactant. There was a trend for better kenaf emergence when less water was applied. The ED irrigation increased biomass in both experiments; however, in Expt. 2, the 2× rate doubled the biomass in the ED irrigation regime, and both 1× and 2× rates increased biomass in the EOD and E4D irrigation regimes. Soil surfactant treatment significantly increased the VWC in ED in Expt. 1 on four dates; however, in Expt. 2, both surfactant treatments increased the VWC in E4D irrigation until 35 days after planting. The results of this experiment suggest that a one-time soil surfactant treatment did not inhibit kenaf emergence under any irrigation regime. Kenaf emergence and biomass was greater and VWC was lower when a 2× rate of soil surfactant was applied to soil. In hydrophilic disturbed native sand soils, a one-time soil surfactant application increased kenaf emergence under deficit irrigation and the 2× rate of soil surfactant increased biomass under every irrigation regime. To maximize water savings, this study indicated that kenaf seed could withstand four-times less water to improve emergence. To maximize biomass, ED irrigation with a 2× soil surfactant treatment was significantly better.

Suppression of MdPRP6 enhances adaptation of apple plants to long-term drought.

Apples are one of the world's four most economically significant fruits, and drought stress is an important factor limiting the development of the global apple industry. Here, we demonstrate that a proline-rich protein (PRP), MdPRP6, is an important factor regulating the long-term drought adaptation of apple plants. Suppression of MdPRP6 in apple plants (MdPRP6-Ri) enhances their adaptation to long-term moderate drought conditions, as indicated by their significantly higher biomass and relative water content (RWC) compared with wild-type (WT) plants. Under drought stress, the net photosynthetic rate (Pn), intercellular CO2 concentration (Ci), stomatal conductance (Gs), and transpiration rate (Tr) were higher, and photosystem II (PSII) damage was lower in MdPRP6-Ri plants than in WT plants. Suppression of MdPRP6 increased the activity of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), which reduced oxidative damage to apple leaves under drought stress. The stomatal openings of MdPRP6-Ri plants were larger than those of WT plants; the WUEI and WUEL were thus higher in MdPRP6-Ri plants than in WT plants under long-term moderate drought stress. We also found that suppression of MdPRP6 increased the wax content of the leaf epidermis, which limits water evaporation caused by non-stomatal factors under drought stress. In sum, our findings suggest that MdPRP6 negatively affects the long-term drought adaptation of apple plants, possibly by modulating both stomatal and non-stomatal water loss.

The Hormesis effect of cadmium on Panax notoginseng and corresponding impact on the rhizosphere microorganism.

Panax notoginseng is a famous Chinese traditional medicinal. However, soil cadmium pollution seriously affected the yield and quality of notoginseng. This study systematically investigated the effects of soil Cd stress at different concentrations on the growth of one-year-old notoginseng. The results indicate that Cd exhibits a typical low-dose stimulation and high-dose inhibition effect on the development of notoginseng. At low concentrations (1 mg/kg), Cd promotes the growth of plants, including increased biomass (∼40 % of root dry weight) and higher saponin contents (∼30 % of total saponins). At high concentrations, Cd inhibits the overall growth and metabolism of notoginseng. Meanwhile, the impact of Cd on the rhizospheric micro-environment shows dose dependency. In a low Cd stress environment, the total and unique microbial populations increase, including Rhizobiaceae, Streptomycetaceae, and Mesorhizobium. Conversely, under strong Cd stress, the richness and diversity of the rhizospheric microbial community decrease, while the abundance of cadmium-tolerant species increases, such as Deinococcus and Rhodanobacter.

Biomass concentration enhances the stability of the biological desulfurization process through biochemical transformation of (poly)sulfides

Biomass concentration enhances the stability of the biological desulfurization process through biochemical transformation of (poly)sulfides

Development and application of a comprehensive numerical simulation model for microalgal pneumatic photobioreactors.

A novel and comprehensive multiphysics numerical simulation model for microalgal pneumatic photobioreactors was developed using the open-source Computational Fluid Dynamics (CFD) software OpenFOAM. This model integrates three distinct submodels: multiphase fluid dynamics, light transport, and microalgae growth. In particular, the light transport submodel accounts for light scattering caused by air bubbles. The model effectively addressed the challenges associated with the disparate time scales of the submodels, and its accuracy was validated by comparing with several experiments in different configurations. This study focuses on how an outdoor flat plate photobioreactor can maximize solar energy utilization. The results indicate that the daily productivity of the light-intensity adaptive reactor increased by 12.31% to 26.31% compared to those at constant biomass concentrations, demonstrating significant potential for employing this model in conjunction with automated systems to enhance productivity.

Essential fatty acids as major lipid fraction in Nostoc muscorum by optimization of mixotrophic culture

Linoleic and α-linolenic acids are essential fatty acids for animals and humans that must be provided in their diet. Several sources have been studied, however production by cyanobacterium Nostoc muscorum has not been thoroughly studied. We aim to evaluate the effect of mixotrophic culture on biomass and lipid content, and subsequently to characterize and quantify the fatty acids present in N. muscorum. The individual and interactive effects of three culture conditions (glycerol concentration, acetate concentration and culture time) on biomass and lipid production by N. muscorum were investigated through a three factor, three-level Box-Behnken experimental design of response surface methodology for process optimization. Glycerol and acetate addition proved to have a synergetic effect on growth of N. muscorum which caused an increased in biomass and lipid production at tenth day of culture compared to the control culture. Moreover, the fatty acid profile showed a high percentage of polyunsaturated fatty acids, especially linoleic (52.64%) and α-linolenic (33.34%), suggesting possible applications for nutraceutical and feed industries.

Statistical optimisation and analysis of biomass and exopolysaccharide production by Lacticaseibacillus rhamnosus LRH30

Exopolysaccharides (EPS) produced by lactic acid bacteria with immunomodulatory potential are promising natural food additives. This study employs small-scale, 250 mL bioreactors combined with a central composite design to optimise two important bioprocess parameters, namely temperature and airflow, to achieve high yields of biomass and EPS from Lacticaseibacillus rhamnosus LRH30 (L. rhamnosus LRH30). A quadratic model was determined to be the best fit for the production of both products. The optimum critical process parameters for maximised biomass were identified to be 37.01 °C with an airflow of 0.12 vvm, while optimum criteria was 20.1 °C with an airflow of 0.18 vvm for maximum EPS production. Under these optimized conditions, small-scale batch experiments yielded a biomass concentration of 10.1 g/L and an EPS yield of 520.2 mg/L. In comparison, scale-up experiments in 2L reactors resulted in a biomass concentration of 8.54 g/L (a reduction of 18%) and an EPS yield of 654.6 mg/L (an increase of 26%). The produced EPS was purified and characterised through Fourier transform infrared spectroscopy and showed characteristic peaks associated with polysaccharides. The immunomodulatory potential of the L. rhamnosus LRH30 cells and EPS was evaluated through cytokine and chemokine secretion in a J774A.1 murine macrophage, resulting in a predominantly anti-inflammatory effect of L. rhamnosus LRH30 and EPS.

Impact of Management Practices on Coffee-Pine Agroforestry: Coffee Yield and Soil Respiration

The coffee-pine agroforestry system offers a promising solution to enhance coffee yields and maintain soil health on degraded lands. This study aims to evaluate the impact of various agroforestry management practices on coffee yield and soil respiration. The experiment was conducted using a complete randomized block design across five management treatments: without management, without fertilization, organic fertilization, mixed fertilization, and recommended management by Perhutani. The observed parameters included coffee yield, soil respiration, soil moisture, soil temperature, litter biomass, canopy cover, and soil organic carbon (SOC) content. Results indicated that the recommended management (RM) plot achieved the highest coffee yield (834 kg ha⁻¹), attributed to wider planting spacing, which reduced resource competition between coffee and pine trees. The RM plot also displayed stable soil moisture and temperature, supporting coffee growth. Meanwhile, soil respiration showed no significant differences across treatments, though the mixed fertilization (MF) plot exhibited the highest respiration rate, indicating higher microbial activity due to combined fertilizer use. In conclusion, optimal management in agroforestry systems can enhance coffee productivity while preserving soil health. Keywords: Agroforestry, Coffee Yield, Soil Management, Soil Moisture, Soil Respiration.

Usage of the Fungus Mucor indicus and the Bacterium Rhodovulum adriaticum in a Biorefinery System for Biochemical Production on Grass Hydrolysates

Utilization of various biomasses as raw materials in biorefineries represents a promising alternative for the production of valuable chemicals and biofuels. This study investigates the potential of the fungus Mucor indicus DSM 2158, cultivated on media containing the liquid phase of grass hydrolysates (LGH) and various nitrogen sources (yeast extract and corn steep liquor), for the production of valuable metabolites, such as ethanol, chitin, chitosan, and fatty acids. The ethanol yield varied depending on the cultivation media and conditions. The highest substrate-into-ethanol conversion coefficients (0.14–0.2 g g−1) were achieved during M. indicus cultivation on the LGH medium containing 5 g L−1 CSL in Erlenmeyer flasks and a bubble column bioreactor. In these cultivations, the highest fungal biomass concentrations (5.61–5.91 g L−1) were also observed. In flask cultivations, the highest content of total lipids in fungal dry biomass (15.76%) was observed. The obtained fungal biomass contained up to 22 fatty acids, with oleic acid (≈50%) being the most predominant. Chitin and chitosan yields were from 0.1 g g−1 to 0.3 g g−1 of dry biomass depending on the cultivation media and conditions. The residual media from the cultivation of M. indicus were used for the growth of the non-sulfur purple bacterium Rhodovulum adriaticum DSM 2781. Cultivations of R. adriaticum DSM 2781 on the residual media, in Erlenmeyer flasks and a stirred-tank bioreactor, resulted in a biomass yield of 0.50 to 2.26 g L−1. After extraction of bacterial biomass, total pigments (expressed as bacteriochlorophyll-a) were obtained in the range from 1.8 to 48.1 mg g−1 dry biomass depending on the media and cultivation conditions. The highest titer of bacteriochlorophyll-a was achieved during cultivation on the exhausted LGH medium with 5 g L−1 yeast extract. The established biorefinery system has to be optimized in order to reach capacity for transfer to a larger scale.

Unraveling the depth-dependent causal dynamics of methanogenesis and methanotrophy in a high-latitude fen peatland

Abstract The dynamics of methane (CH4) cycling in high-latitude peatlands through different pathways of methanogenesis and methanotrophy are still poorly understood due to the spatiotemporal complexity of microbial activities and biogeochemical processes. Additionally, long-term in situ measurements within soil columns are limited and associated with large uncertainties in microbial substrates (e.g., dissolved organic carbon, acetate, hydrogen). To better understand CH4 cycling dynamics, we first applied an advanced biogeochemical model, ecosys, to explicitly simulate methanogenesis, methanotrophy, and CH4 transport in a high-latitude fen (within the Stordalen Mire, northern Sweden). Next, to explore the vertical heterogeneity in CH4 cycling, we applied the PCMCI/PCMCI+ causal detection framework with a bootstrap aggregation method to the modeling results, characterizing causal relationships among regulating factors (e.g., temperature, microbial biomass, soil substrate concentrations) through acetoclastic methanogenesis, hydrogenotrophic methanogenesis, and methanotrophy, across three depth intervals (0-10 cm, 10-20 cm, 20-30 cm). Our results indicate that temperature, microbial biomass, and methanogenesis and methanotrophy substrates exhibit significant vertical variations within the soil column. Soil temperature demonstrates strong causal relationships with both biomass and substrate concentrations at the shallower depth (0-10 cm), while these causal relationships decrease significantly at the deeper depth within the two methanogenesis pathways. In contrast, soil substrate concentrations show significantly greater causal relationships with depth, suggesting the substantial influence of substrates on CH4 cycling. CH4 production is found to peak in August, while CH4 oxidation peaks predominantly in October, showing a lag response between production and oxidation. Overall, this research provides important insights into the causal mechanisms modulating CH4 cycling across different depths, which will improve carbon cycling predictions, and guide the future field measurement strategies.

Effects of Sodium Selenate on Growth, Selenium Forms, and Nutritional Quality of Chlorella pyrenoidosa

In this study, C. pyrenoidosa were cultured with seven different concentrations of Na2SeO4 (0–10 mg/L), and the effects of Na2SeO4 on the growth, Se-forms, and nutritional quality of C. pyrenoidosa were explored. The results showed that at the concentration of 0.5 mg/L Na2SeO4, the C. pyrenoidosa were plump and healthy; the contents of biomass, soluble protein, lipids, and TPUFA reached the highest level; the total Se content in C. pyrenoidosa increased with the increasing Na2SeO4 concentrations. However, the proportion of organic Se in C. pyrenoidosa. reached the highest value of 87.58% at the concentration of 0.5 mg/L Na2SeO4. Among organic Se forms, SeMet accounted for the largest proportion, while MeSeCys accounted for a relatively smaller proportion, but SeCys2 was not detected. The addition of Na2SeO4 (except for ≤0.5 mg/L) reduced the contents of photosynthetic pigments in C. pyrenoidosa. In addition, the antioxidant capacity of C. pyrenoidosa first increased and then decreased with the increasing Na2SeO4 concentrations, but different enzymes exhibited different tolerances to Na2SeO4. Based on the above research results, 0.5 mg/L Na2SeO4 concentration is recommended for the production of Se-rich C. pyrenoidosa. Our findings will provide a theoretical basis and practical references for the development of Se-rich C. pyrenoidosa health care products.

Using morphometric characters to estimate leaf productivity of seagrass Halophila major

Abstract. Darus RF, Bengen DG, Zamani NP, Ismet MS. 2024. Using morphometric characters to estimate leaf productivity of seagrass Halophila major. Biodiversitas 25: 4994-5004. Halophila major is a seagrass species with new records in Indonesia. This species was described based on morphometric characteristics and DNA sequencing. In this study, we expand our understanding about this species by looking at its leaf productivity. This study aims to determine the productivity of H. major leaves collected across various locations of Indonesian waters and analyses its relationship with morphometric characters. Morphometric characters (Leaf Length-LL, Leaf Width-LW, and Leaf Area-LA) were used to see the correlation with leaf productivity parameters, namely Leaf Dry Weight (LDW), Specific Leaf Area (SLA), Biomass (BIO), and Carbon Concentration (CS) estimated using allometric methods. The result of this study indicates that the biomass of H. major is greater than H. ovalis, its closest relative. LL and LW were more strongly correlated with LDW compared to LA. Biomass was also greatly influenced by LL and LDW. Leaf productivity variation is affected by the leaf size, suggesting that leaf productivity can be used to distinguish seagrass species under the similar genus. This study showed that allometric equations can be used quickly to assess the biomass of small seagrasses. However, more data is needed for knowing and interpreting a character in new seagrass species. Hence, this study must be replicated for other seagrass species.

Nano-based co-valorization, detoxification, and fermentation of potato waste and black liquor for bioethanol production

Abstract Black liquor from paper and pulp mills is an underutilized waste resource. Black liquor can be valorized due to its useful chemical fractions and water component that can be employed for the pretreatment and biochemical conversion of starchy potato waste (SPW) into bioethanol. Hence, in this study, the simultaneous co-valorization, detoxification, and fermentation of SPW and black liquor (without the addition of freshwater and chemicals) were optimized for bioethanol production. The scanning electron microscopy (SEM) and the Fourier-transform infrared (FTIR) clearly confirmed the distortion of SPW inherent structure for the recovery of useful carbohydrates. A significant reduction in process inhibitors (furfural = 1.26-fold, hydroxymethylfurfural (HMF) = 5.68-fold, and phenols = 1.03-fold) was observed with CuO NP inclusion. The response surface methodology (RSM) model of the bioethanol production showed a high coefficient of determination (R 2 ) value of 0.98. The optimized process with CuO NP inclusion displayed a biomass and bioethanol concentrations of 2.12 g/L and 21.37 g/L corresponding to 1.74- and 1.68-fold improvement over the control respectively. In addition, the kinetic data showed that the incorporation of CuO nanoparticle (NP) significantly improved (1.86-fold) the potential maximum bioethanol concentration (Pm) (20.21 g/L) compared to the control experiment (10.86 g/L). The study demonstrates a 100% freshwater conservation approach for improved sugar recovery, remarkable inhibitor removal, and bioethanol production from pretreated SPW towards reduced biofuel production cost, waste management, and green environment sustainability.

Pre-Treatment and Characterization of Water Hyacinth Biomass (WHB) for Enhanced Xylose Production Using Dilute Alkali Treatment Method

Lignocellulosic biomass from water hyacinth, a readily available waste material, holds potential for producing commercial products such as xylose, which can be further converted into value-added products like xylitol. However, the complex structure of lignocellulosic biomass necessitates energy-intensive processes to release fermentable sugars. Chemical pre-treatment methods, such as alkali pre-treatment, offer a viable approach to degrade lignocellulose biomass. In this study, water hyacinth biomass (WHB) was treated with 3% potassium hydroxide and subjected to autoclaving to hydrolyse the sample. The total xylose released during the process was quantified using a UV-Vis spectrophotometer and was found to 0.253 g/g of water hyacinth biomass when the sample was treated for 20 min at 2% biomass concentration. The morphological changes in the treated biomass compared to the untreated sample were analysed using Field Emission Scanning Electron Microscopy (FE-SEM). Crystallinity alterations were evaluated through X-Ray Diffraction (XRD), while Fourier-Transform Infrared Spectroscopy (FTIR) was employed to study the changes in chemical states of the biomass. The primary objective of this study was to identify a reliable pre-treatment method for processing water hyacinth biomass, facilitating the efficient release of fermentable sugars for downstream applications.