High Ethanol Concentrations Research Articles

Unveiling genetic anchors in saccharomyces cerevisiae: QTL mapping identifies IRA2 as a key player in ethanol tolerance and beyond.

Ethanol stress in Saccharomyces cerevisiae is a well-studied phenomenon, but pinpointing specific genes or polymorphisms governing ethanol tolerance remains a subject of ongoing debate. Naturally found in sugar-rich environments, this yeast has evolved to withstand high ethanol concentrations, primarily produced during fermentation in the presence of suitable oxygen or sugar levels. Originally a defense mechanism against competing microorganisms, yeast-produced ethanol is now a cornerstone of brewing and bioethanol industries, where customized yeasts require high ethanol resistance for economic viability. However, yeast strains exhibit varying degrees of ethanol tolerance, ranging from 8 to 20%, making the genetic architecture of this trait complex and challenging to decipher. In this study, we introduce a novel QTL mapping pipeline to investigate the genetic markers underlying ethanol tolerance in an industrial bioethanol S. cerevisiae strain. By calculating missense mutation frequency in an allele located in a prominent QTL region within a population of 1011 S. cerevisiae strains, we uncovered rare occurrences in gene IRA2. Following molecular validation, we confirmed the significant contribution of this gene to ethanol tolerance, particularly in concentrations exceeding 12% of ethanol. IRA2 pivotal role in stress tolerance due to its participation in the Ras-cAMP pathway was further supported by its involvement in other tolerance responses, including thermotolerance, low pH tolerance, and resistance to acetic acid. Understanding the genetic basis of ethanol stress in S. cerevisiae holds promise for developing robust yeast strains tailored for industrial applications.

Tolerance and efficient metabolization of extremely high ethanol concentrations by a social wasp

Ethanol, a natural by-product of sugar fermentation, can be found in various fruits and nectar. Although many animals routinely consume ethanol in low concentrations as part of their natural diets, its inherent toxicity can cause severe damage. Even species particularly well adapted to ethanol consumption face detrimental effects when exposed to concentrations above 4%. Here, we investigated the metabolism of ethanol and its impact on survival and behavior in the Oriental hornet (Vespa orientalis), a social wasp that naturally consumes ethanol. We show that chronic ethanol consumption, even at concentrations as high as 80%, had no impact on hornet mortality, construction behavior, or agonistic behavior. Using 13C1 labeled ethanol, we show that hornets efficiently metabolized ingested ethanol and at a much higher rate than honey bees. The presence of multiple copies of the alcohol dehydrogenase (NADP+) gene in the Vespa genera suggests a potential mechanism for ethanol tolerance. These findings support the hypothesis that the mutualistic relationship between ethanol-producing organisms and vespid hosts may be at the origin of their remarkable capacity to utilize and metabolize ethanol.

Development of an Effective Sterilization Protocol for Plant Tissue Culture Studies in Superfruit Aronia [Aronia melanocarpa (Michaux) Elliot

Effective sterilization protocols are crucial for a successful tissue culture study in Aronia. These protocols directly influence contamination rates, shoot health, and root development. In this context, the aim of the study is to develop an effective sterilization protocol for plant tissue culture studies in Aronia [Aronia melanocarpa (Michaux) Elliot], commonly known as the "superfruit." In study, shoot tips of the Nero Aronia variety were used as material. The sterilized shoot tips were transferred to the respective plant tissue culture media in a randomized parcels trial pattern with three replicates, each containing three explants per replicate. Various concentrations and combinations of sterilizing agents, such as sodium hypochlorite (NaOCl), hydrogen peroxide (H2O2), mercuric chloride (HgCl2), and ethanol (C2H5OH), were evaluated to determine their effectiveness in maintaining tissue health and reducing contamination. A total of twelve protocols were developed, incorporating different concentrations of these chemicals. The results showed that the combination of 5% NaOCl and 3% H2O2 provided the lowest average contamination rate (5%) and the highest average number of healthy (uncontaminated) explants (9.00 piece), demonstrating the sterilization efficiency of this combination. On the other hand, protocols containing HgCl2, especially at higher concentrations, resulted in impaired root development. High ethanol concentrations also contributed to effective sterilization, with the combination of 7% NaOCl and 80% ethanol yielding a low contamination rate (8%) and preserving tissue health. This study emphasizes the need to balance sterilization protocols between effective contamination control and tissue viability. The findings are expected to benefit the improvement and development of tissue culture techniques for Aronia and similar species, providing a basis for further research on effective sterilization practices, which are currently limited in Aronia tissue culture.

Enhanced bioethanol production from cassava waste: optimization of thermochemical pretreatment for maximum sugar recovery and characterisation of potential fractions

ABSTRACT Thermochemical pretreatment is an interesting approach for the effective separation of lignocellulosic biomass before fermentation for bioethanol production. This research focused on optimising the thermochemical pretreatment conditions of cassava waste using response surface methodology to predict the glucose yields under the optimal condition. The optimised conditions of 0.045 M of NaOH concentration at 153.59 °C for 48.03 min resulted in the maximum glucose yield of 93.87%. In addition, fermentation process can generate ethanol within a range of solid loading from 10% to 20%. The highest concentration of ethanol was 34.53 ± 0.56 g/L after 72 h, equivalent to ethanol yield of 0.46 g/g. The co-products were also characterised for further utilisation in biorefinery concept. The results of this study confirmed that the thermochemical pretreatment process using the NaOH catalyst could provide high glucose yields, which can be easily converted into bio-based fuels and further valorised of co-products to value-added chemicals.

Physicochemical properties, moisture retention, and biological activities of polysaccharides from Panax notoginseng separated by fractional precipitation.

The dried root of Panax notoginseng is a medicinal and food ingredient. Panax notoginseng polysaccharides (PNPs) have physicochemical properties, which have not been fully elucidated. This study aimed to identify a method to separate the PNP fractions and investigate their activities. PNPs were prepared from roots by hot water extraction, deproteinization, and decolorization. PNP20, PNP40, and PNP60 fractions were isolated through stepwise ethanol precipitation at 20%, 40%, and 60% concentrations, respectively. The three polysaccharide fractions were characterized using chromatography, spectroscopy, and thermogravimetric analysis, and their moisture retention, antioxidant, and tyrosinase-inhibition properties were evaluated. Monosaccharide composition analysis showed that the three PNPs contained mannose (Man), galacturonic acid (GalA), glucose (Glc), galactose (Gal), and arabinose (Ara) in different molar ratios. HPGPC analysis demonstrated that the polysaccharides precipitated with higher ethanol concentrations had lower molecular weights (Mw). Furthermore, it was observed that all PNPs have certain moisturizing and hygroscopic properties and antioxidant activities, with PNP60 showing better antioxidant properties and a competitive mixture of hygroscopic properties and tyrosinase inhibition. The chemical composition and structural characteristics of PNPs could affect their functional attributes. PNP60 has the potential to be a moisturizer and antioxidant and could be used in the development of cosmetic ingredients.

Dynamic changes in microbial communities and volatile compounds in kombucha fermentation using Flos sophorae and Elm fruits, compared to Black and Green Tea

The dynamic changes in physicochemical properties, microbial communities, and volatile compounds in kombucha made from Flos sophorae (FLSK) and Elm fruit (EFK) were compared to those of black tea (BTK) and green tea (GTK) over a 12-day fermentation period. The results revealed that overall flavonoid and polyphenol content, as well as antioxidant activity, increased initially and then decreased, accompanied by a steady reduction in pH within the fermentation broths investigated. Notably, the GTK exhibited stronger antioxidant activity than the other fermentation broths. Furthermore, 16S rRNA gene sequencing revealed that Komagataeibacter rhaeticus, Komagataeibacter saccharivorans, and Acidovorax wautersii were the dominating microbial species in the fermentation broths under this study. Komagataeibacter rhaeticus initially reduced and then increased throughout the FLSK fermentation, whereas Komagataeibacter saccharivorans increased from day 0 to day 6, and remain stable by day 12 during the EFK fermentation. Comparative analysis revealed that Komagataeibacter rhaeticus was more abundant in the FLSK and GTK than in the EFK and BTK, whereas Komagataeibacter saccharivorans showed a higher abundance in the EFK relative to the other fermentation broths. Gas chromatography-mass spectrometry identified acetic acid, linalool, ethanol, and ethyl acetate as the major volatile chemicals that rose significantly in fermentation mixtures of the examined substrates. The FLSK had a much higher linalool concentration than the other fermentation broths, although the EFK and GTK had higher ethanol content. Correlation study found that Komagataeibacter rhaeticus was negatively related with alcohol compounds, but Komagataeibacter saccharivorans was positively associated with a diverse spectrum of acids, alcohols, and esters. The study found changes in bioactive chemicals as well as interactions between bacterial populations and volatile compounds throughout fermentation in the substrates investigated.

Ethosomes-mediated tryptanthrin delivery as efficient anti-psoriatic nanotherapy by enhancing topical drug absorption and lipid homeostasis

Psoriasis is a chronic, relapsing, and refractory immune-mediated skin disease with the etiology and pharmaceutical targets remaining unsatisfactorily addressed. Topical herbal-derived compounds, such as tryptanthrin (Tryp), have been considered as an alternative therapy for psoriasis due to their lower costs and fewer side effects compared to other therapies. However, the effectiveness of topically administered drugs is substantially limited by the thickened pathological skin barrier and the low bioavailability of drugs in the deeper layers of the lesion. Ethosomes, being a novel phospholipid-based vesicle system with high content of ethanol, have been implicated in enhancing topical drug absorption and restoring psoriatic lesions. In this study, taking advantages of ethosomes as a soft and malleable drug carrier, we constructed the Tryp-loaded ethosome (Tryp-ES) through a one-step microfluidics-based technique. The optimal formulation of Tryp-ES was achieved by adding amino-acid-derived surfactant sodium lauroyl glutamate, and Tryp-ES exhibited homogeneous particle size and favorable stability at room temperature. In vitro evaluations showed that Tryp of Tryp-ES could be easily internalized into cells and accumulated in cell nuclei, hence inhibited the abnormally proliferated keratinocytes by inducing apoptosis. In vivo and in vitro assessment using psoritic skin of mice revealed that Tryp-ES had preferred skin retention and permeation of loaded drugs within the initial 1 h of topical administration, which could be attributed to transient disintegrations of cell membranes by ethosomes, thus improved cellular fluidity and permeability. Notably, a synergistic effect of ethosomes and Tryp was found in psoriatic mice. Tryp-ES-treated mice showed substantially ameliorated symptoms of psoriasis and reduced pathological alterations due to hyperplasia, inflammation and angiogenesis, without detectable local or systemic toxicities. Interestingly, lipidomics analysis confirmed that the supplementation of phospholipids, as in the form of ethosome vehicles, was an alterantive strategy to relieve psoriatic pathologies. Taken together, this study provides a novel impact for ethosomal topical delivery of Tryp and underlines their potential as an effective therapy for the management of psoriasis.

Saccharomyces cerevisiae for lignocellulosic ethanol production: a look at key attributes and genome shuffling.

These days, bioethanol research is looking at using non-edible plant materials, called lignocellulosic feedstocks, because they are cheap, plentiful, and renewable. However, these materials are complex and require pretreatment to release fermentable sugars. Saccharomyces cerevisiae, the industrial workhorse for bioethanol production, thrives in sugary environments and can handle high levels of ethanol. However, during lignocellulose fermentation, S. cerevisiae faces challenges like high sugar and ethanol concentrations, elevated temperatures, and even some toxic substances present in the pretreated feedstocks. Also, S. cerevisiae struggles to efficiently convert all the sugars (hexose and pentose) present in lignocellulosic hydrolysates. That's why scientists are exploring the natural variations within Saccharomyces strains and even figuring out ways to improve them. This review highlights why Saccharomyces cerevisiae remains a crucial player for large-scale bioethanol production from lignocellulose and discusses the potential of genome shuffling to create even more efficient yeast strains.

Conversion of glycerol into value-added products

Biomass residues and industrial waste are of great interest for their potential to produce a wide range of bioenergy and value-added products. Crude glycerol can be valorized into value added products by several microorganisms through microbial fermentation. Thus, Significant efforts have been made to develop biological methods to convert crude glycerol into various valuable chemicals and fuels, including 1, 3-propanediol, hydrogen and ethanol.In this context, our work have use glycerol medium as source of carbon for investigate bioethanol and 1, 3-propandiol production, using a microbial consortium. All experiments was carried out in sealed bottles, the reaction medium is placed in the shaker incubator at 37°C with stirring at 130 rpm. . Nitrogen gas was injected to create anaerobic conditions. The highest concentration of ethanol and 1,3 – propanediol obtained were 3.47 (g/l) and 4.8 mg/l respectively . These results highlight promising avenues for the valorization of biomass residues and industrial wastes in sustainable bioenergy production.

Emerging Nanotechnology Involved in Skin Cancer: Pathogenesis, Biomarkers, Ethosomal Formulation and Future Perspective.

Skin cancer, which comprises both melanoma and non-melanoma forms, is frequently diagnosed as the predominant malignancy among today's population. Existing treatments are often prolonged and complex, have a low rate of success, and have side effects. This complexity leads to poor patient adherence and increases the risk of disease recurrence. Ethosomes, extensively studied for their applications in topical and transdermal therapies, are distinguished by their high ethanol content, which facilitates enhanced skin penetration and efficient drug delivery. Compared to traditional liposomes, ethosomes offer notable advantages due to their unique composition, demonstrating potential efficacy in treating various skin conditions, including basal cell carcinoma, squamous cell carcinoma, and melanoma. The present review provides a brief introduction to skin melanoma and its pathogenesis, signalling pathways, biomarkers, the need for ethogel-based drug delivery, applications of ethosomes against skin cancer, and clinical trials.

Exploring lipids: A comprehensive review on their utilization in the formulation of liposomes, phytosomes, and ethosomes for advanced drug delivery systems"

This comprehensive review explores the diverse applications of lipids in the formulation of advanced drug delivery systems, specifically focusing on liposomes, phytosomes, and ethosomes. Lipids, crucial components in these formulations, play a pivotal role in enhancing drug solubility, stability, and bioavailability. The review systematically examines the latest advancements in lipid-based delivery systems, shedding light on their unique characteristics and applications. In the realm of liposomes, the study delves into various lipid compositions, highlighting their influence on liposomal structure and function. Additionally, the review explores the integration of phytosomes, which involve the complexation of drugs with plant-derived phospholipids, showcasing their potential to improve therapeutic efficacy. Ethosomes, lipid vesicles containing high concentrations of ethanol, are also extensively discussed, emphasizing their ability to enhance transdermal drug delivery. Critical analyses of recent research findings, including the impact of lipid selection on vesicle stability, drug release kinetics, and pharmacokinetics, are presented. The review further examines the challenges associated with lipid-based formulations, providing insights into potential avenues for future research and development. By synthesizing current knowledge, this review serves as a valuable resource for researchers, clinicians, and pharmaceutical scientists seeking a comprehensive understanding of the role of lipids in optimizing liposomal, phytosomal, and ethosomal drug delivery systems.

Simultaneous improvement of fructophilicity and ethanol tolerance of Saccharomyces cerevisiae strains through a single Adaptive Laboratory Evolution Strategy

Saccharomyces cerevisiae is the main yeast used in the winemaking industry. Its innate glucophilicity provokes a discrepancy in glucose and fructose consumption during alcoholic fermentation of grape must, which, combined with the inhibitory effect of ethanol accumulated in the fermentation broth, might lead to stuck or sluggish fermentations. In the present study, we realized an Adaptive Laboratory Evolution strategy, where an alcoholic fermentation of a 20 g/L fructose broth was followed by cell selection in a high ethanol concentration environment, employed in two different S. cerevisiae strains named CFB and BLR. The evolved populations originated from each strain after 100 generations of evolution exhibited diverse fermentative abilities. One evolved population, originated from CFB strain, fermented a synthetic broth of 100 g/L glucose and 100 g/L fructose to dryness in 170 h, whereas the parental strain did not complete the fermentation even after 1000 h of incubation. The parameters of growth of the parental and evolved populations of the present study, as well as of the ethanol tolerant populations acquired in a previous study, when grown in a synthetic broth of 100 g/L glucose and 100 g/L fructose, were calculated through a kinetic model, and were compared to each other in order to identify the effect of evolution on the biochemical behavior of the strains. Finally, in a 200 g/L fructose synthetic broth fermentation, only the evolved population derived from CFB strain showed improved fermentative behavior than its parental strain.

From tyrosine to hydroxytyrosol: a pathway involving biologically active compounds and their determination in wines by ultra performance liquid chromatography with mass spectrometry.

Hydroxytyrosol (HT) is a bioactive compound present in a limited number of foods such as wines, olives, and olive oils. During alcoholic fermentation, yeast converts aromatic amino acids into higher alcohols such as tyrosol, which can undergo hydroxylation into HT. The aim of this study was to validate an analytical method using ultra performance liquid chromatography coupled with mass spectrometry (UPLC/MS-MS) to quantify HT and its precursors (tyrosine, hydroxyphenylpyruvic acid, hydroxyphenylacetaldehyde, 4-hydroxyphenylacetic acid, and tyrosol) in wines. Their occurrence was evaluated in a total of 108 commercial Spanish wine samples. The validated method simultaneously determined both HT and its precursors, with adequatelimits of detection between 0.065 and 21.86 ng mL-1 and quantification limits between 0.199 and 66.27 ng mL-1 in a 5 min run. The concentration of HT in red wines was significantly higher (0.12-2.24 mg L-1) than in white wines (0.01-1.27 mg L-1). The higher the alcoholic degree, the higher was the content of HT. The bioactive 4-hydroxyphenylacetic acid was identified in Spanish wines for the first time at 3.90-127.47 mg L-1, being present in all the samples. The highest HT concentrations were found in red wines and in wines with higher ethanol content. These data are useful for a further estimation of the intake of these bioactive compounds and to enlarge knowledge on chemical composition of wines. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Conversion of wine lees and waste activated sludge into caproate and heptanoate: Thermodynamic and microbiological insights

In this study, wine lees and waste activated sludge (WAS) were co-fermented for the first time in a 4:1 ratio (COD basis) at 20, 40, 70 and 100 gCOD/L, in batch at 37 °C and pH 7.0. The substrates were successfully converted to caproate (C6) and heptanoate (C7) with a high selectivity (40.2 % at 40 gCOD/L). The rapidly-growing chain-elongating microbiome was enriched inClostridiaceaeandOscillospiraceae, representing together 3.4–8.8 % of the community. Substrate concentrations higher than 40 gCOD/L negatively affected C6 and C7 selectivities and yields, probably due to microbial inhibition by high ethanol concentrations (15.82–22.93 g/L). At 70 and 100 gCOD/L, chain elongation shifted from ethanol-based to lactate-based, with a microbiome enriched in the lactic acid bacteriaRoseburia intestinalis(27.3 %) andEnterococcus hirae(13.8 %). The partial pressure of H2(pH2) was identified by thermodynamic analysis as a fundamental parameter for controlling ethanol oxidation and improving C6 and C7 selectivities.

Biochemical and Biorefinery Platform for Second-Generation Bioethanol: Fermentative Strategies and Microorganisms

Bioethanol is the most commonly used biofuel. It is an alternative to replace fossil fuels in renewable energy; it can be produced from lignocellulosic feedstock using a biotechnological process. Their participation of microorganisms is crucial in the bioconversion process of fermentation for ethanol production and can involve bacteria, fungi, and yeasts. However, when working within bioethanol processes from lignocellulose feedstock, microorganisms face some challenges, such as high temperature, high solids content, and the ability to ferment sugars for high ethanol concentration. Such challenges will depend on operative strategies, such as simultaneous saccharification and fermentation, separate hydrolysis and fermentation, semi-simultaneous saccharification and fermentation, and consolidated bioprocessing; these are the most common configurations. This review presents different trends of the microbial role, biochemical application, and fermentation operative strategies for bioethanol production of the second generation.

Silica Wort Supplementation as an Alternative for Yeast Stress Relief on Corn Ethanol Production with Cell Recycling

In very high gravity (VHG) fermentation, yeast cells are subjected to a multitude of challenging conditions, including the osmotic pressure exerted by the high sugar content of the wort and the stress factors associated with the high ethanol concentrations present at the end of the fermentation cycle. The response of this biological system to abiotic stresses may be enhanced through biochemical and physiological routes. Silica may play a significant role in regulating the cellular homeostasis of yeast. Alternatively, it is expected that this outcome may be achieved through biochemical responses from the effects of vitamins on yeast cells and the physiological yeast route changing by the culture medium aeration. The objective of this study was to investigate the effects of adding 500 mg L−1 of silica on corn ethanol wort medium and the possibility of supplementing the same wort with vitamins alongside aeration (0.2 v v−1 min−1) as an alternative resource to sustain the fermentation yield rather than adding silica in a fed-batch fermentation cycle with yeast recycling. Upon completion of the five fermentation cycles, yeast samples subjected to the treatment with the addition of silica exhibited a 3.1% higher fermentation yield in comparison to the results observed in the vitamins plus aeration medium bath. Even though greater biomass production (19.1 g L−1) was observed through aerobic yeast behavior in vitaminized supplemented corn medium, the provided silica had a more beneficial effect on yeast stress relief for very high gravity fermentation in a corn hydrolyzed wort with cell recycling.

Pyrolysis and oxidation mechanisms of ethylene and ethanol blended fuel based on ReaxFF molecular dynamics simulation

To gain detailed atomic-level insights into the reaction mechanisms associated with the oxy-fuel combustion of ethylene and ethanol, ReaxFF reactive force field molecular dynamics simulations were performed to analyze the behavior of their high-temperature pyrolysis and oxidation. Results showed that the main reaction of pure ethylene involves the formation of long carbon chains by C–C polymerization in an oxygen-free environment. The polycondensation-cyclization of long carbon chains significantly contributes to the formation of polycyclic aromatic hydrocarbons (PAHs). The addition of ethanol enriches the initial reaction pathways of ethylene. For instance, ethanol participates in the following reactions: C2H4 + C2H6O → C4H10O, C2H6O + C2H4 → C2H5 + C2H5O, and C2H6O + C2H4 → C2H5 + H2O + C2H3. Ethanol inhibits the growth of long carbon chains, with a more pronounced effect at higher ethanol concentrations. In an oxygen atmosphere, the decay rate of ethylene decreases significantly, and its main reaction pathway involves dehydrogenation and oxidation with the assistance of OH, HO2, H, and O2. The final products are released in the form of CO, CO2, and H2O. In addition, the formation of soot particles is mainly divided into three steps: (i) ethylene aggregates to form long carbon chains, (ii) rearrangement and cyclization of long carbon chains, and (iii) growth of PAHs.

Intensification of high-gravity brewer’s wort fermentation process with the use of microelements

In high-gravity brewing, conditions arise that adversely affect the yeast. These are high osmotic pressure, high fermentation temperature, high ethanol content. As a result of these unfavorable factors, the intensity of yeast reproduction and the rate of fermentation decrease, the duration of the process increases, the degree of fermentation decreases, which leads to a change in the taste and aroma profile of the drink. Cofactors of important enzymes and stress modulators are microelement ions, the optimal content of which can be provided by adding appropriate salts to the wort. In this work, the influence of calcium and zinc on the fermentation of high-gravity beer wort with the participation of Saccharomyces cerevisiae yeast strain Saflager W-34/70 was investigated. The optimal dosage of CaCl2 and ZnSO4 salts was determined, which is 5.0 and 0.1 mg/dm3, respectively. It was established that adding CaCl2 to the wort leads to an increase in the rate of fermentation by 21.9 %, the apparent and actual degree of fermentation by 17.8 and 17.0 %, respectively. At the same time, the ethanol content in young beer increases by 19.1 %, the content of visible and actual extract decreases by 28.8 and 17.5 %, respectively, and the biomass of yeast accumulated during fermentation increases by 14.0 %. When using ZnSO4, the changes in the values of all these indicators are significantly smaller and lie in the range of 3.2‒5.8 %. Other physical-chemical parameters of the studied samples of young beer, namely acidity, pH value, content of vicinal diketones, do not undergo significant changes. To enhance the growth and metabolism of yeast under adverse conditions that occur during high-gravity brewing, it is recommended to add CaCl2 to beer wort in the amount of 5.0 mg/dm3. This will make it possible to reduce the duration of fermentation of wort with a dry matter content of 18 % at a temperature of 15 ℃ by 1.5 days (21 %)

Exploiting the Thermotolerance of Clostridium Strain M1NH for Efficient Caproic Acid Fermentation from Ethanol and Acetic Acid.

A novel thermotolerant caproic acid-producing bacterial strain, Clostridium M1NH, was successfully isolated from sewage sludge. Ethanol and acetic acid at a molar ratio of 4:1 proved to be the optimal substrates, yielding a maximum caproic acid production of 3.5g/L. Clostridium M1NH exhibited remarkable tolerance to high concentrations of ethanol (up to 5% v/v), acetic acid (up to 5% w/v), and caproic acid (up to 2% w/v). The strain also demonstrated a wide pH tolerance range (pH 5.5-7.5) and an elevated temperature optimum between 35 and 40°C. Phylogenetic analysis based on 16S rRNA gene sequences revealed that Clostridium M1NH shares a 98% similarity with Clostridium luticellarii DSM 29923T. The robustness of strain M1NH and its efficient caproic acid production from low-cost substrates highlight its potential for sustainable bio-based chemical production. The maximum caproic acid yield achieved by Clostridium M1NH was 1.6-fold higher than that reported for C. kluyveri under similar fermentation conditions. This study opens new avenues for valorizing waste streams and advancing a circular economy model in the chemical industry.

Vinasse treated with charcoal as a molasses diluent for ethanol fermentation.

The demand for new products derived from agro-industrial residues has increased recently. Furthermore, vinasse, a wastewater from ethanol production, needs treatment to be reused in the sugarcane industry, reducing industrial water consumption. This study performed vinasse filtration with charcoal from industrial sugarcane residues and used filtered molasses dilution in ethanolic fermentation. There were five treatments in randomized blocks with three repetitions. The treatments included deionized water and natural vinasse as positive and negative controls, respectively, and filtered vinasse from charcoal made from bamboo, sugarcane bagasse, and straw. Hence, fermentation for ethanol production was performed. Compared with natural vinasse, filtered vinasse with all types of charcoal showed lower soluble solids, total residual reducing sugars, higher ethanol concentrations, and greater fermentative efficiency. Filtered vinasse from bagasse and straw charcoals had efficiencies of 81.14% and 77.98%, respectively, in terms of ethanol production, which are close to those of deionized water (81.49%). In a hypothetical industry, vinasse charcoal filtration and charcoal regeneration should prevent 84.12% of water consumption from environmental resources. This process is feasible because it uses a product of sugarcane residue to treat wastewater and reduce industrial water consumption and vinasse disposal.