Search Results (23)

The sugarcane industry plays a crucial economic role worldwide, with sucrose and ethanol as its main products. However, its processing generates large volumes of by-products—such as bagasse, molasses, vinasse, and straw—that contain valuable components for biotechnological valorization. This review integrates approximately 100 original research articles published in JCR-indexed journals between 2015 and 2025, of which over 50% focus specifically on sugarcane-derived agroindustrial residues. The biotechnological approaches discussed include submerged fermentation, solid-state fermentation, enzymatic biocatalysis, and anaerobic digestion, highlighting their potential for the production of biofuels, enzymes, and high-value bioproducts. In addition to identifying current advances, this review addresses key technical challenges such as (i) the need for efficient pretreatment to release fermentable sugars from lignocellulosic biomass; (ii) the compositional variability of by-products like vinasse and molasses; (iii) the generation of metabolic inhibitors—such as furfural and hydroxymethylfurfural—during thermochemical processes; and (iv) the high costs related to inputs like hydrolytic enzymes. Special attention is given to detoxification strategies for inhibitory compounds and to the integration of multifunctional processes to improve overall system efficiency. The final section outlines emerging trends (2024–2025) such as the use of CRISPR-engineered microbial consortia, advanced pretreatments, and immobilization systems to enhance the productivity and sustainability of bioprocesses. In conclusion, the valorization of sugarcane by-products through biotechnology not only contributes to waste reduction but also supports circular economy principles and the development of sustainable production models. Full article

The vinasse from Agave americana L. (blue cabuya) liquor has a high concentration of organic matter, nutrients with high chemical oxygen demand (COD), and low pH, properties that give it the potential to generate adverse impact on the environment if improperly disposed of. In other countries, studies have been conducted on yeast strain combinations in vinasses to produce biomass and reduce organic load, but there are no studies of the aforementioned yeast consortium in blue cabuya liqueur vinasses to produce biomass and reduce COD. Given this problem, the objective of the research was to reduce this adverse environmental impact through aerobic fermentation of this vinasse with the yeast consortium Candida utilis, Kluyveromyces marxianus and Saccharomyces cerevisiae (D 47-Lalvin). As a result, biomass production and COD reduction were achieved. The study evaluated temperature variables of 28 °C, 30 °C, and 32 °C, and pH values of 3, 4, and 5 under conditions of consortium and nutrient diammonium phosphate (DAP) concentrations of 1.32 g/L and 1.5 g/L, respectively, in a bioreactor with automatic control of temperature, time, stirring speed of 100 RPM, and air flow of 1 VVM. The result was a biomass yield of 93.4% and a COD reduction of 33.3%. It is concluded that the aerobic fermentation process of blue cabuya liquor vinasse with the yeast consortium employed produces a high biomass yield, which can be used for its protein value as an animal feed supplement and, due to its low COD value, as an agricultural fertilizer. Full article

The production of biodiesel from single-cell oils (SCOs) utilizing industrial wastes as feedstock presents an economically viable approach. To date, studies have rarely reported the utilization of vinasse combined with industrial glycerol for the production of SCO. This study aimed to assess the performance of a Rhodotorula toruloides strain in vinasse from ethanol distilleries supplemented with pure/raw glycerol as an affordable carbon feedstock for SCO production. Several critical factors, including the C/N ratio, the impact of impurities in the crude glycerol, the proper nitrogen source, and the effects of the vinasse compositions, were evaluated. The results showed that the incorporation of urea and raw glycerol increased the lipid content to 51.8 ± 1.6% and the lipid productivity to 0.034 ± 0.001 g L⁻¹h⁻¹. Elevated biomass (42.5 g L⁻¹) and lipid (11.0 g L⁻¹) concentrations indicated that impurities in the raw glycerol positively affected the growth and lipid accumulation of this strain. Notably, supplementing raw glycerol to the vinasse led to a 16.1% increase in biomass concentration and a 25.7% rise in lipid content, significantly enhancing lipid productivity by 59.6%. The fatty acid profile predominantly featured unsaturated fatty acids (96.8%), including high percentages of stearic acid (41.8 ± 2.6%), palmitic acid (21.8 ± 1.5%), and oleic acid (18.3 ± 1.4%), aligning with the standards for vegetable-oil-based biodiesel manufacture. Fed-batch strategies using pulse-feeding turned out to be less effective than the constant-flow feeding strategy with vinasse supplemented with raw glycerol, which achieved a higher lipid productivity of 0.30 g L⁻¹h⁻¹. Full article

Conventional ethanol production has limitations, including substrate and product inhibitions, which increase both energy requirements for ethanol recovery and vinasse generation. Extractive fermentation, which removes ethanol as it is produced within the fermentation vat, offers an effective alternative to reducing the inhibitory effects in conventional processes. However, an efficient method for recovering the extracted ethanol is also crucial. Thus, this study investigated an alternative ethanol production process using extractive ethanol fermentation integrated with ethanol recovery by absorption in both open and closed systems, specifically, comparing scenarios with and without CO₂ recirculation produced during fermentation. The recovery system used two absorbers connected in series using monoethylene glycol (MEG) as an absorbent. Under extractive fermentation conditions without CO₂ recirculation, the conversion of 300.0 g L⁻¹ of substrate resulted in a total ethanol concentration of 135.2 g L⁻¹, which is 68% higher than that achieved in conventional fermentation (80.4 g L⁻¹). The absorption recovery efficiency reached 91.6%. In the closed system, with CO₂ recirculation produced by fermentation, 280.0 g L⁻¹ of substrate was consumed, achieving ethanol production of 126.0 g L⁻¹, with an absorption recovery percentage of 98.3%, similar to that of industrial facilities that use a gas scrubber tower. Additionally, the overall process efficiency was close to that of conventional fermentation (0.448 g_ethanol g_substrate⁻¹). These results highlight the potential of this alternative process to reduce vinasse volume and energy consumption for ethanol recovery, lowering total costs and making it a viable option for integrated distilleries that combines ethanol production with other related processing operations. Full article

Tequila vinasses are organic wastes generated during ethanol fermentation at elevated temperatures (≥90 °C) and pH ≤ 4.0, making them hazardous to the environment. This paper describes a new, simplified UV–vis spectroscopy-based procedure for monitoring the adsorption of color compounds in tequila vinasses onto silica-based adsorbents, along with an optimized synthesis method to produce the most efficient sol–gel synthesized thiol-functionalized adsorbent. Under optimized conditions, the uptake capacity of this adsorbent reaches 0.8 g g⁻¹ in 90 min. Experimental results demonstrate that the adsorbent has a specific affinity for melanoidin-type molecules. The adsorbent demonstrates excellent thermal stability (~316 °C). The results of this work indicate that the adsorbent possesses potential in the treatment of tequila vinasses from wastewater discharges. Full article

This study compared the behavior of the biomass in two fixed-film anaerobic reactors operated under equivalent organic loading rates but at different temperatures, i.e., 30 °C (RMM) and 55 °C (RMT). The reactors were fed with sugarcane vinasse and molasses (both fermented) in a simulation of sequential periods of season and off-season. The dynamics of biomass growth and retention, as well as the microbial composition, were assessed throughout 171 days of continuous operation, coupled with an additional 10-day test assessing the microbial activity in the bed region. Despite the different inoculum sources used (mesophilic granular vs. thermophilic flocculent sludge types), the biomass growth yield was identical (0.036–0.038 g VSS g⁻¹COD) in both systems. The retention rates (higher in RMT) were regulated according to the initial amount of biomass provided in the inoculation, resulting in similar amounts of total retained biomass (46.8 vs. 43.3 g VSS in RMT and RMM) and biomass distribution patterns (30–35% in the feeding zone) at the end of the operation. Meanwhile, hydrogenotrophic methanogenesis mediated by Methanothermobacter coupled to syntrophic acetate oxidation prevailed in RMT, while the Methanosaeta-mediated acetoclastic pathway occurred in RMM. The results show that different anaerobic consortia can behave similarly in quantitative terms when subjected to equivalent organic loads, regardless of the prevailing methane-producing pathway. The community grows and reaches a balance (or a given cell activity level) defined by the amount of substrate available for conversion. In other words, while the metabolic pathway may differ, the endpoint (the amount of biomass) remains the same if operational stability is maintained. Full article

Melanoidins are heterogeneous polymers with a high molecular weight and brown color formed during the Maillard reaction by the combination of sugars and amino acids at high temperatures with the potential to inhibit the microbial activity in bioprocesses. This study assessed the impacts of melanoidins on the kinetic of substrate conversion and production of organic acids via dark fermentation using microbial consortia as inoculum. The investigations were carried out in fed-batch reactors using synthetic melanoidins following glucose-to-melanoidin ratios (G/M; g-glucose g⁻¹ melanoidins) of 0.50, 1.50, 1.62, 1.67, and 5.00, also considering a melanoidin-free control reactor. The results showed that melanoidins negatively impacted the kinetics of glucose fermentation by decreasing the first-order decay constant (k₁): when dosing equivalent initial concentrations of glucose (ca. 3 g L⁻¹), the absence of melanoidins led to a k₁ of 0.62 d⁻¹, whilst dosing 2 g L⁻¹ (G/M = 1.5) and 6.0 g L⁻¹ (G/M = 0.5) of melanoidins produced k₁ values of 0.37 d⁻¹ and 0.27 d⁻¹, respectively. The production of butyric and acetic acids was also negatively impacted by melanoidins, whilst the lactic activity was not impaired by the presence of these compounds. Lactate production reached ca. 1000 mg L⁻¹ in G/M = 1.67, whilst no lactate was detected in the control reactor. The presence of melanoidins was demonstrated to be a selective metabolic driver, decreasing the microbial diversity compared to the control reactor and favoring the growth of Lactobacillus. These results highlight the importance of further understanding the impacts of melanoidins on melanoidin-rich organic wastewater bioconversion, such as sugarcane vinasse, which are abundantly available in biorefineries. Full article

Mezcal is a drink made in Mexico, the production of which generates vinasses with a high content of organic matter (OM) that is not utilized. However, these residues have the potential to be drawn upon in dark fermentation (DF) processes to obtain biogas rich in biohydrogen, biomethane, and volatile fatty acids (VFAs) with the potential to become biofuels. In the present work, the effect of reaction time (RT) and organic load (OL) was assessed based on the efficiency of removing OM, the production of VFAs, and the generation and composition of biogas in a process of DF fed with mezcal vinasses. The results show that increasing the RT and decreasing the OL increases COD removal but decreases biohydrogen production. The maximum production of H₂ (64 ± 21 NmL H₂/L_reactor) was obtained with the lowest RT (1 d) and the highest OL (13.5 gCODm³d⁻¹), while the highest accumulation of VFAs (2007 ± 327 mg VFA/L) was obtained with an RT of 3 d. It was determined that RT and OL are key parameters in DF processes for biohydrogen and VFA production. Full article

In this work, hydrogen production from the co-digestion of sugarcane straw and sugarcane vinasse in the dark fermentation (DF) process was monitored using a cost-effective hydrogen detection system. This system included a sensor of the MQ-8 series, an Arduino Leonardo board, and a computer. For the DF, different concentrations of sugarcane vinasse and volumetric ratios of vinasse/hemicellulose hydrolysate were used together with a thermally pretreated inoculum, while the hydrogen detection system stored the hydrogen concentration data during the fermentation time. The results showed that a higher concentration of vinasse led to higher inhibitors for the DF, resulting in a longer lag phase. Additionally, the hydrogen detection system proved to be a useful tool in monitoring the DF, showcasing a rapid response time, and providing reliable information about the period of adaptation of the inoculum to the substrate. The measurement system was assessed using the error metrics SE, RMSE, and MBE, whose values ranged 0.6 and 5.0% as minimum and maximum values. The CV (1.0–8.0%) and SD (0.79–5.62 ppm) confirmed the sensor’s robustness, while the ANOVA at the 5% significance level affirmed the repeatability of measurements with this instrument. The RMSE values supported the accuracy of the sensor for online measurements (6.08–14.78 ppm). The adoption of this straightforward and affordable method sped up the analysis of hydrogen in secluded regions without incurring the expenses associated with traditional measuring instruments while offering a promising solution for biomass valorization, contributing to the advancement of rural green energy initiatives in remote areas. Full article

The aim of the study was to evaluate the impact of probiotics obtained from an agroindustrial waste substrate fermented with lactic acid bacteria and/or yeasts on the health and changes in the microbiota of the digestive tract of guinea pigs. Eighty male guinea pigs, Kuri breed, 30 days old and 250 g live weight, were randomly selected and divided into four groups of 20 animals each: T0, control; T1, Lactobacillus acidophilus and L. bulgaricus; T2, Saccharomyces cerevisiae and Kluyveromyces fragilis; and T3. L. acidophilus, L. bulgariccus, S. cerevisiae and K. fragilis. T1, T2 and T3 contained molasses-vinasse substrate in their base, the dose administered was 1.00 mL/animal orally every 3 days. The indicators evaluated were weight gain, occurrence of diarrhea and mortality, macroscopic lesions in the digestive tract organs and changes in the microbiota of the stomach, caecum, small and large intestine. Treatments T1, T2 and T3 improved weight gain (p < 0.05) and reduced the presence of guinea pigs with diarrhea (p < 0.05) and there was no mortality; animals in the control group presented a greater amount (p < 0.05) of macroscopic lesions in the digestive tract organs; in the T1, T2 and T3 groups there was an improvement in the natural microbiota. It is concluded that the inclusion of a microbial additive in young guinea pigs improves intestinal health and consequently improves weight gain, reduces diarrhea and deaths and normalizes the natural microbiota of the gastrointestinal tract. Full article

This review provides a comprehensive analysis of the production, classification, and quality control of cachaça, a traditional Brazilian sugarcane spirit with significant cultural importance. It explores the fermentation and distillation of sugarcane juice, the ageing process in wooden containers, and the regulatory aspects of cachaça labelling. It emphasises the role of quality control in maintaining the spirit’s integrity, focusing on monitoring copper levels in distillation stills. Ethyl carbamate (EC), a potential carcinogen found in cachaça, is investigated, with the study illuminating factors influencing its formation and prevalence and the importance of its vigilant monitoring for ensuring safety and quality. It also underscores the control of multiple parameters in producing high-quality cachaça, including raw material selection, yeast strains, acidity, and contaminants. Further, the impact of ageing, wood cask type, and yeast strains on cachaça quality is examined, along with potential uses of vinasse, a cachaça by-product, in yeast cell biomass production and fertigation. A deeper understanding of the (bio)chemical and microbiological reactions involved in cachaça production is essential to facilitate quality control and standardisation of sensory descriptors, promoting global acceptance of cachaça. Continued research will address safety concerns, improve quality, and support the long-term sustainability and success of the cachaça industry. Full article

This study aimed at investigating the feasibility of using a highly specialized bacterial inoculum harboring lactic acid bacteria (LAB) and lactate-oxidizing, hydrogen-producing bacteria (LO-HPB) to produce either lactate or biohydrogen and butyrate from several agro-industrial resources via dual-phase dark fermentation. The feedstocks were fruit–vegetable waste, cheese whey, coffee wastewater, tequila vinasse, and maize processing wastewater, and were tested in both mono- and co-fermentation. The results obtained indicated that the biocatalyst used was able to perform a dual-phase lactate fermentation, producing high lactate (13.1–36.4 g/L), biohydrogen (0.2–7.5 NL H₂/L_feedstock, equivalent to 0.3–1.7 mol H₂/mol hexose), and butyrate (3.3–13.9 g/L) with all the tested feedstocks. A series of self-fermentation tests were also performed with crude cheese whey and fruit–vegetable waste for comparison purposes. Compared to inoculum-aided fermentations, the self-fermentation exhibited a reduced bioconversion efficiency. Short-length 16S rRNA gene sequencing analysis showed that LO-HPB was the dominant microbial group (86.0%) in the biocatalyst, followed by acetic acid bacteria (5.8%) and LAB (5.7%). As expected, the molecular analysis also showed significant differences in the microbial community structure of the biocatalyst and those that evolved from self-fermentation. Besides lactate fermentation and oxidation, the biocatalyst also assisted the bi-phasic lactate fermentation via oxygen consumption, and apparently, via substrate hydrolysis. Overall, this study can lay the foundation for robust inoculum development, which is of special significance in the field of dark fermentation, and proposes an innovative bioprocess for agro-industrial valorization through a trade-off approach, tailoring the metabolic pathway to the target product(s). Full article

The production of fuels and other industrial products from renewable sources has intensified the search for new substrates or for the expansion of the use of substrates already in use, as well as the search for microorganisms with different metabolic capacities. In the present work, we isolated and tested a yeast from the soil of sugarcane irrigated with vinasse, that is, with high mineral content and acidic pH. The strain of Meyerozyma caribbica URM 8365 was able to ferment glucose, but the use of xylose occurred when some oxygenation was provided. However, some fermentation of xylose to ethanol in oxygen limitation also occurs if glucose was present. This strain was able to produce ethanol from molasses substrate with 76% efficiency, showing its tolerance to possible inhibitors. High ethanol production efficiencies were also observed in acidic hydrolysates of each bagasse, sorghum, and cactus pear biomass. Mixtures of these substrates were tested and the best composition was found for the use of excess plant biomass in supplementation of primary substrates. It was also possible to verify the production of xylitol from xylose when the acetic acid concentration is reduced. Finally, the proposed metabolic model allowed calculating how much of the xylose carbon can be directed to the production of ethanol and/or xylitol in the presence of glucose. With this, it is possible to design an industrial plant that combines the production of ethanol and/or xylitol using combinations of primary substrates with hydrolysates of their biomass. Full article

As we address important societal needs, the circular economy equips us with the means to jointly combat climate change and biodiversity loss, including the revaluation of waste. The wine-making process is a huge generator of waste, creating problems for manufacturers every year; therefore, an appropriate management and valorisation of winery wastes are crucial, even if it is difficult. This results from the hardship of disposing of grape marc, which is considered a pollutant for the environment. In the past, the simplest option for this waste disposal was the payment of a fee around EUR 3000, which recently increased up to EUR 30,000–40,000. Several environmentally friendly technologies have been proposed for the recovery of cellar waste. Fermentation of grape residue, pruning, or wine-making lees have been reported to yield lactic acid, surfactants, xylitol, ethanol, and other compounds. In addition, grape pulp and seeds are rich in phenolic compounds, which have antioxidant properties, and tartaric acid from vinasse can be extracted and marketed. Additionally, complex phenol mixtures, such as those found in wine residues (seeds, bark, stems, or leaves), are effective as chemotherapeutic agents and can be used in medicine. In this review, the potential of using wine-making by-products, extracts, and their constituent parts as raw materials for adsorbents, biopolymers, natural reinforcing fillers, and sustainable energy production will be a key point of discussion. An overview on how wine producers, based on wine and wastes chemistry, can implement the circular economy as an alternative to the conventional linear economy (make, use, dispose) will be provided. Full article

Fermented foods may confer several benefits to human health and play an important role in a healthy and balanced diet. Vinasse hairtail is a farmhouse-fermented food product with cultural and economic significance to locals in Zhoushan China. It is traditionally produced and subjected to 0–8 days of fermentation. In this study, we aimed to characterize the microbiota and physicochemical profiles of vinasse hairtail across different stages of fermentation. With the increase of fermentation time, pH, total sugar content, reducing sugar content, fat content, salt content, total protein content, myofibrillar protein content, TVB-N, and TBARS index increased, while the peroxide value decreased. The addition of vinasse significantly intensified the lipid and protein oxidation and protein degradation of hairtail, thereby increasing the flavor of its products. The microbial diversity and succession characterization during the fermentation of vinasse hairtail by high-throughput sequencing was measured. Results showed that Firmicutes was the predominant phylum and Lactobacillus was the main genera of bacterial diversity. Ascomycota was the main phylum of fungi and the main fungal genera detected in the samples were Saccharomyces. Additionally, the correlation between microbial community and physicochemical properties was found. Our study revealed that Lactobacillus was the major lactic acid bacteria present throughout the fermentation process. The results may provide a theoretical basis for improving the overall quality of vinasse hairtail. Full article