Sugarcane Vinasse Research Articles

Novel insights on the versatility of biohydrogen production from sugarcane vinasse via thermophilic dark fermentation: Impacts of pH-driven operating strategies on acidogenesis metabolite profiles

An innovative application of the anaerobic structured-bed reactor (AnSTBR) in thermophilic dark fermentation of sugarcane vinasse targeting biohydrogen (bioH2) production was assessed. A detailed metabolite monitoring program identified the major substrates and primary metabolic pathways within the system. Increasing the applied organic loading rate positively affected bioH2 production, reaching 2074 N mL-H2 L−1 d−1 and indicating an optimal load of approximately 70 kg-COD m−3 d−1. Controlling the fermentation pH (5.0–5.5) was the primary strategy to maintain bioH2-producing conditions, offsetting negative impacts associated with the compositional variability of vinasse. Metabolic correlations pointed out lactate as the primary substrate for bioH2 production, indicating its accumulation as evidence of impaired reactors. The versatility of the acidogenic system was confirmed by identifying three major metabolic pathways according to the pH, i.e., lactate-producing (pH <5.0), bioH2-/butyrate-producing (pH = 5.0–5.5) and bioH2-producing/sulfate-reducing (pH >6.0) systems, which enables managing the operation of the reactors for diversified purposes in practical aspects.

Treatment of sugarcane vinasse from cachaça production for the obtainment of Candida utilis CCT 3469 biomass

Ethanol and “Cachaça” production processes generate considerable amounts of residues known as vinasse. The indiscriminate disposal of this waste represents a potential risk to both surface water and groundwater, soil, animals, and ultimately the entire environment. This work describes an alternative to reduce the environmental impact through cachaça vinasse management practices by using it as a culture medium for the growth of Candida utilis CCT 3469 to produce biomass, replacing the conventional production from cane molasses. For that both, the raw and vacuum evaporated, vinasses from cachaça were treated by using different pH adjustments and activated charcoal adsorption (2.5%). The vinasses treated at pH 6.0 were selected to produce Candida utilis CCT 3469 biomass (2.25 g L−1). In this case, higher values of volumetric biomass productivity (0.08 gL−1 h−1) and biomass yield (0.13 gg−1) were obtained, as also for the higher specific rates for glucose consumption (1.354 gglucose gcell−1 h−1), fructose consumption (0.811 gfructose gcell−1 h−1) and biomass (0.616 h−1). The ratio values for BOD/COD (0.02) characterized the vinasse as an effluent of difficult degradation and biological treatability. Probably this fact favored the obtainment of yeast biomass in the treated vinasse at the lowest concentration factor.

Operating control for enrichment of hydrogen-producing bacteria from anaerobic sludge and kinetic analysis for vinasse inhibition

This study was aimed to evaluate bio-hydrogen production from sugarcane vinasse by the mixed culture enriched through controlling operational parameters in an Anaerobic Sequencing Batch Reactor (AnSBR), as well as determining the effect of the sugarcane vinasse concentration on hydrogen production and the critical kinetic analysis. The Volumetric Hydrogen Production Rate (VHPR) of 28.1 mL H2/L h at the substrate concentration of 10 g COD/L was obtained in biomass enriching step. In batch tests, the increase in substrate concentration ranging from 1.70 to 11.60 g COD/L caused an increase in Hydrogen Yield (HY); however, it had a negative effect on HY at the substrate concentrations of higher than 11.60 g COD/L. The maximum HY in terms of initial Chemical Oxygen Demand (CODi) of 58.41 mL H2/g CODi was obtained at the substrate concentration of 11.60 g COD/L. Additionally, Andrew and Han-Levenspiel models were employed to model the hydrogen production rate (R) in case of different chemical oxygen demand (COD) concentrations of vinasse. According to the comparison made between the correlation coefficient values of the fittings using the aforementioned models, the Han-Levenspiel model could be considered as a better model to describe the substrate inhibition effect. The carbohydrate removal efficiency was superior to 90% at substrate concentrations less than 16.80 g COD/L.

Integration of microbial biodiesel and bioethanol industries through utilization of vinasse as substrate for oleaginous fungi

The main aim of this work was to assess a conceptual strategy of submerged pelletized growth of Mucor circinelloides in sugarcane vinasse under different conditions aiming at the production of lipids prone to be used in biodiesel syntheses. Industrial vinasse was characterized and then tested in its raw form as culture medium. Relatively high concentrations of lipids were observed (approximately 23%), and biomass accumulation can be enhanced by the addition of corn steep liquor (approximately 5-fold increase when compared to control). Phenolic compounds present in vinasse pose inhibitory effects in biomass and lipid accumulation. The pelletized hyphae then proceeded to a simple sieve separation, on which lipids were extracted in a microwave extraction system, with a resulting fatty acid profile that indicate a potential suitable feedstock for biodiesel production due to the balance of saturated and unsaturated fatty acids.

Changes in the Microbial Metabolism of Agricultural Tropical Soils Amended with Sugarcane Vinasses

Sugarcane vinasse is a liquid waste derived from ethanol production. In Brazil, large amounts of this waste are applied to soil as fertigation. In general, this management seems to be beneficial for soil fertility and for some biological parameters, though the published information about the effects of sugarcane vinasse on the soil biota is controversial and the results may vary according to the vinasses’ composition. In this study, we assessed the effects of different sugarcane vinasses on microbial growth and activity indicators to verify their influence on soil microbial metabolism. For this purpose, we used two vinasses from different distillery plants (VA and VB) and a vinasse from a laboratory production (VC). Increasing concentrations of these vinasses were amended on two tropical Oxisols, with 33.6% (RL) and 17.6% (RYL) of clay, in a microcosm experiment with sugarcane plants. Ten, 30 and 60 days after application, we assessed the effects of the vinasses on soil microbial biomass carbon (MBC), basal soil respiration (C–CO2), the metabolic quotient (qCO2) and dehydrogenase activity of the soils. We found an increase in MBC, C–CO2, qCO2, as well as in dehydrogenase activity with increasing vinasse concentrations in both soils, when compared to the control. These changes were attributed mainly to the addition of carbon sources (C) of the vinasses to the soils, which improves the general biological activity.

Effects of recirculation in anaerobic baffled reactors

Recirculation of treated effluent is usually used to prevent organic overloading events in anaerobic digestion of high concentrated wastewater. The aim of this study was to determine the influence of effluent recirculation in anaerobic baffled reactors (ABR) treating high concentrated wastewater as the literature is not conclusive about its effects. To achieve this, an innovative experimental and mathematical modeling dual approach was used. A bench-scale ABR was fed with sugarcane vinasse (COD = 18.0 g L−1) and monitored for 273 days. Real kinetic and mass transfer parameters were obtained and used to create a mathematical model for the organic matter conversion. Operating data and the kinetic parameters showed that at high COD concentrations the ABR does not behave as a two-stage system as expected. Both results, i.e. the mathematical model and the operational data, showed that in terms of conversion capacity using high recirculation ratios is not necessary for suitable ABR performances, only increasing operational costs due to pumping.

Utilization of a new approach for the potassium concentration of sugarcane vinasse by reverse osmosis: case study

Ethanol is an alternative fuel produced from sugarcane and economically very important for Sao Paulo state and Brazil. Vinasse, which has been traditionally distributed on the agricultural soil as an organic fertilizer, is the main residue of the ethanol production. Its dosage has been annually rationed in function of the potassium balance for reuse in agriculture. The vinasse potassium for ferti-irrigation can fully substitute potassium from mineral sources, but its transport is economically unviable from a determined distance. In this context, the paper presents the dehydration of sugarcane vinasse using a reverse osmosis technology to reduce the cost of transport until the sugarcane tillage. The main contributions are the reduction in the water content (concentration) and increase in the solid and the potassium content (13.8%). The study showed a payback value of 5.49 years.

Population Changes of Eubacteria, Sulfate-Reducing Bacteria and Methanogenic Archaea in an Anaerobic Reactor Processing Ethanol Distillery Vinasse

Abstract The microbiological characterization by molecular techniques (DGGE and quantitative PCR) of Archaea, Bacteria domain and sulfate-reducing bacteria (SRB) from a laboratory scale Up-flow Anaerobic Sludge Blanket (UASB) processing sugar cane vinasse was performed during the operational phase with increasing organic loads. The organic load removal efficiency was between 97% and 75% for volumetric organic loads (VOL) in the range of 0.6 to 15.4 kgCOD.m-3.d−1 and for higher VOL (until 27.0 kgCOD.m-3 .d−1) the removal efficiency decreased to 48%. Archaea represented the majority of the estimated population (107 copies of 16S RNA ribosomal gene. mL-1) followed by bacteria (106 copies of 16S RNA ribosomal gene. mL-1) and sulfate-reducing bacteria (SRB) (105 copies of dsrB gene. mL-1). There was a significant difference between the populations of Archaea and SRB with increasing VOL. DGGE profiles show differences among populations with increasing VOL, especially with respect to sulfate-reducing bacteria. The presence of SRB together with a high sulfate removal percentage (97%) of about 15 kgCOD.m-3d-1h, indicates the establishment of a sulfidogenic process.

Genome sequence of the H2-producing Clostridium beijerinckii strain Br21 isolated from a sugarcane vinasse treatment plant.

We report on the nearly complete genome sequence of Clostridium beijerinckii strain Br21, formerly isolated from a sugarcarne vinasse wastewater treatment plant. The resulting genome is ca. 5.9 Mbp in length and resembles the size of previously published C. beijerinckii genomes. We annotated the genome sequence and predicted a total of 5323 genes. Strain Br21 has a genetic toolkit that allows it to exploit diverse sugars that are often found after lignocellulosic biomass pretreatment to yield products of commercial interest. Besides the whole set of genes encoding for enzymes underlying hydrogen production, the genome of the new strain includes genes that enable carbon sources conversion into butanol, ethanol, acetic acid, butyric acid, and the chemical block 1,3-propanediol, which is used to obtain polymers. Moreover, the genome of strain Br21 has a higher number of ORFs with predicted beta-glucosidase activity as compared to other C. beijerinckii strains described in the KEGG database. These characteristics make C. beijerinckii strain Br21 a remarkable candidate for direct use in biotechnological processes and attest that it is a potential biocatalyst supplier.

Fast Pyrolysis of Dried Sugar Cane Vinasse at 400 and 500 °C: Product Distribution and Yield

Fast pyrolysis of sugar cane vinasse, a byproduct from the integrated sugar–ethanol process, has not been investigated so far. In this work, fast pyrolysis of dried sugar cane vinasse was carried out at 400 and 500 °C in a drop-tube type N2-purged reactor, and the yields and compositions of the oil, char, and gas were determined. The results show that the water-free bio-oil yield was low and independent of the pyrolysis temperature. This is probably due to the high potassium content of the vinasse. For other biomass fuels, it is well established that alkali metals catalyze secondary reactions in the vapor-phase of the pyrolysis product, thereby reducing the organic liquid yield and increasing the gas and water yields. The char yield decreased, and the gas yield increased with temperature. 45% to 55% of the carbon in the vinasse was retained in the chars. Thus, approximately half of the carbon in the vinasse could be sequestered if the chars are returned to the soil. Moreover, since over 85% of the potassium in the vinasse was also retained in the chars, pyrolysis may be an interesting option for the production of biochar with a high potassium content for fertilizer. The recovery of most of the potassium with the chars indicates that the liquid and gaseous pyrolysis products could be burned in a boiler with lower ash-related problems than the original vinasse.

Tailor-made 3D-nanoelectrode ensembles modified with molecularly imprinted poly(o-phenylenediamine) for the sensitive detection of L-arabitol

A highly selective and sensitive sensor for L-arabitol is developed combining the advantages of three-dimensional nanostructrured electrodes, namely, 3D-ensembles of gold nanowires (3DNEE), with the recognition capability of molecularly imprinted polymer (MIP). The MIP/3DNEE is prepared by controlled etching of polycarbonate templated nanoelectrode ensembles, followed by electropolymerization of o-phenylenediamine on the gold nanowires in the presence of L-arabitol as molecular imprinting template. For activating the sensor, L-arabitol is removed from the MIP with an ethanol/water mixture. The sensor is characterized by scanning electron microscopy and dispersive energy X-ray spectroscopy while its electrochemical properties are examined by cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. Analytically usefull signals are obtained using the ferrocenylmethytrimethylammonium cation as an electroactive probe which can access the MIP cavities, furnishing voltammetric signals which scale inversely with the L-arabitol concentration. The sensor is characterized by a low detection limit (7.5 × 10−10 mol L-1), satisfactory quantification range, selectivity, reproducibility and repeatability. The applicability of the MIP/3DNEE in real samples is demonstrated by successfully quantifying L-arabitol concentration in sugarcane vinasse.

Hybrid treatment system for remediation of sugarcane vinasse

The sugar and alcohol industries provide promising alternative energy sources to replace the use of petroleum derivatives. Vinasse is a byproduct of the alcoholic fermentation of various raw materials, and is used in the fertirrigation of sugarcane plantations. However, its excessive use leads to many soil and groundwater related problems, including toxicity to living organisms, acidification of soil and water, accumulation of heavy metals, and contamination of groundwater. The use of integrated systems, such as stabilization, filtration, and phytoremediation, have attracted interest in the treatment of wastewater from various sources, as these highly effective biogeochemical systems can reduce the pollutant concentrations in wastewater, thereby reducing its adverse effects. The aim of this work was to develop a hybrid treatment system to optimize the physical and chemical characteristics of vinasse so that it can be used as fertilizer for crops with a lower pollution impact. The results of this study validated the effectiveness of the proposed system and demonstrated positive modifications of vinasse.

The potential application of an autochthonous fungus from the northwest of Argentina for treatment of sugarcane vinasse.

Vinasse is a waste material from distillery industries, which causes major environmental problems around the world. Argentina alone produces about 4 billion liters of vinasse annually; consequently, diverse biological eco-friendly treatments are evaluated for their ability to reduce the detrimental effects. The present study reports on the degradation of a 50% (v/v) local vinasse sample by an autochthonous fungus identified as Aspergillus sp. V1. The Bioprocess was conducted for 15 d at 30 °C after inoculation of spores at an end concentration of 1 × 106 CFU/mL. Effluent neutralization was detected after 6 d of treatment, with maximum COD and BOD removal after 12 d (49% and 59%, respectively). Effects of vinasse before and after treatment were predicted using Caco-2 cells and Triticum aestivum L. (wheat) seeds as toxicological indicators. Only 13% viability was observed for Caco-2 cells exposed to untreated vinasse, but this percentage increased more than 3-fold for cells exposed to the treated effluent. While vinasse without treatment completely inhibited germination of seeds, exposure to treated effluent demonstrated a germination percentage of 60%. The present study highlights the use of a dual-purpose biotechnological process that aimed at reducing the detrimental effects of vinasse, enhancing its quality for agricultural practices.

Calibration of ADM1 using the Monte Carlo Markov Chain for modeling of anaerobic biodigestion of sugarcane vinasse in an AnSBBR

The Anaerobic Digestion Model No. 1 (ADM1) was applied in this study to simulate the processing of sugarcane vinasse in an Anaerobic Sequencing Batch Biofilm Reactor (AnSBBR). In the model calibration, the values of the free parameters, concentration of anaerobic biomass for specific species (Xsu, Xc4, Xpro, Xac, Xh2)11Xsu: Sugar degraders, Xc4: Butyric and valeric acids degraders, Xpro: Propionic acid degraders, Xac: Acetic acid degraders, Xh2: Hydrogen degraders, were obtained by minimizing the objective function expressed by the determinant of the Box-Draper Matrix. Afterwards, these parameters were optimized with the Monte Carlo Markov Chain Method, using the Delayed Rejection Adaptive Metropolis Algorithm. The Geweke statistic test evaluated the convergence of the method. All results passed for direct and cross validation to elucidate the methane production, production and consumption of the organic acids and organic matter removal. The ADM1 was able to show the syntrophism between the species and to describe the experimental data, thus making it possible to be applied in others scenarios. However, it was not so adequate for all conditions in cross validation due to a lack of experimental data and the need to include other metabolic pathways in the model. The chosen concentration of anaerobic biomass for specific species were shown as an important step in this work, because these parameters are difficult to be determined in practice.

Enriched microbial consortia for dark fermentation of sugarcane vinasse towards value-added short-chain organic acids and alcohol production

The role of sugarcane vinasse as a nutrient source and the impacts of different inoculum pretreatment methods (acid-thermal and thermal treatment) were assessed in acidogenic systems aiming to produce value-added short-chain organic acids (SCOA) and alcohols. In-depth microbiome characterization was also conducted by high-throughput sequencing of the 16S rRNA gene using the Miseq Illumina platform. SCOA production was 47.3 % higher in vinasse-fed reactors, with isobutyric (up to 10.3gL-1) and butyric (up to 10.6gL-1) acids as the primary metabolites most likely resulting from lactate conversion. Ethanol comprised the main product from solventogenic pathways in all conditions, with values ranging between 2.7 and 5.2gL-1, whereas no butanol was detected. Microbial analyses revealed high relative abundance values for the Clostridium, Lactobacillus, Bacillus and Ruminococcus genera, with the predominance of the Clostridium genus (17%) in acid-thermal treatment reactors and the Lactobacillus genus (37%) in thermal treatment reactors. Overall, vinasse proved to be a suitable substrate for value-added SCOA production, which characterizes a potential management approach to this wastewater stream. In this sense, the biochemical production of butyrate from vinasse could diversify the product portfolio of sugarcane biorefineries, also minimizing bioenergy losses by converting residual carbon fractions.

Arthrospira maxima OF15 biomass cultivation at laboratory and pilot scale from sugarcane vinasse for potential biological new peptides production

An environmental friendly process was developed to produce Arthrospira maxima's biomass from sugarcane vinasse, which was generated in a bioethanol production chain, at laboratory and pilot scale. Peptides fractions were than obtained from enzymatically hydrolyzed biomass. High microalgae biomass productivities were reached (0.150 g L−1 day−1) coupled with a significant reduction of BOD and COD (89.2 and 81%, respectively). Three peptide fractions were obtained from microalgae biomass through single or sequential enzymatic hydrolysis. Antioxidant, antimicrobial, anti-inflammatory, and/or anti-collagenase activities of biopetides’ fractions were observed. The PHS showed multi-biological activities. The three peptides fractions could be potential candidates for different applications in pharmaceutical, cosmetic and food industry.

Hydraulic and organic rates applied to pilot scale UASB reactor for sugar cane vinasse degradation and biogas generation

A pilot-scale upflow anaerobic sludge blanket (UASB) reactor (120 L) was operated for biogas production by vinasse degradation. The reactor was operated for 700 days using a recirculation rate of 1:3 with organic loading rates (OLR) ranging from 0.5 to 32.4 kgCOD.m−3.d−1, upflow velocities ranged from 0.008 to 0.292 m h−1(feed added with recirculation) and the hydraulic retention time ranged from 33.33 to 0.86 days. The reactor demonstrated a stable performance at OLR at all applied loads. The COD removal efficiencies throughout the experiment were 87.5 ± 5.3 and 90.5 ± 3.6% for raw and soluble COD, respectively. Total volatile acids ranged from 59 mg L−1 to 585 mg L−1. The concentration of acetic and propionic acids at the reactor effluent reached 28 mg L−1 on OLR 20 kgCOD.m−3.d−1. The methane content in the biogas was 68.8 ± 7.14%.The methane yield of 0.299 ± 0.066 LCH4.g−1COD corresponds to about 76.4% of the theoretical methane yield. The methane productivity reached the highest value of 8.059 LCH4.L−1.d−1 at 32.27 kgCOD.m−3.d−1., corresponding to 83.9% of the theoretical value (9.611 LCH4.L−1.d−1). This result is very promising for power generation in the sugar and ethanol industry, complementing the energy balance of sugarcane, as shown by an energy balance evaluation.

Metallic-aromatic compounds synergistically induce Lentinus crinitus laccase production

Abstract Lentinus crinitus is a basidiomycete with the ability to produce laccase and other enzymes of biotechnological interest. Laccase production depends on cultivation conditions and can be induced by metallic, phenolic or aromatic compounds. This study aimed to evaluate the laccase production of L. crinitus cultivated in sugarcane vinasse and urea with addition of laccase inducers. L. crinitus was cultivated in sugarcane vinasse with urea and supplemented with copper sulfate (0, 50, 150, 250, 350 and 450 μM) and aromatic compounds (guaiacol, veratryl alcohol, or 2,5-xylidine) added alone or combined to the cultivation medium. Cooper (150 or 250 μM) increased laccase activity in 14.5 (49,000 U/L) and 28.5% (55,000 U/L), respectively. Guaiacol had no significant effect, but veratryl alcohol (~46000 U/L) and xylidine (~75000 U/L) increased laccase activity. Copper with other inducers had the most relevant effects on laccase production. Simultaneous guaiacol addition with 150 or 250 μM copper increased 108% and 151% laccase activity, respectively, when compared with only copper addition to vinasse-urea medium. Veratryl alcohol and 150 or 250 μM copper addition increased 100% and 138% laccase activity, respectively, when compared to only copper addition. Interaction analysis of the variables guaiacol or veratryl alcohol and copper (250 µM) added to cultivation medium demonstrated synergistic effects resulting in laccase activity increase. These results highlight the importance of L. crinitus as a laccase producer and emphasize the relevance of studies using a combination of inducers to increase laccase production.

Sugarcane vinasse and microalgal biomass in the production of pectin particles as an alternative soil fertilizer

High methoxyl pectin was used as biopolymeric matrix to produce a novel slow release soil fertilizer added with sugarcane vinasse and lipid extracted microalgal (Desmodesmus subspicatus) biomass residue (LMBR). Vinasse acted as the biopolymer solvent, providing greater stability to pectin gel, and as a source of nitrogen (N), potassium (K), calcium (Ca) and magnesium (Mg). LMBR (0.5%) was considered a complementary source of N and micronutrients, copper (Cu), iron (Fe) and zinc (Zn). Compared to blank pectin particles, the particles with vinasse and LMBR showed homogeneous polymer matrix, spherical shapes, higher soluble matter release and enhanced mechanical properties. Scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analysis indicated the incorporation of microalgal biomass and nutrients from vinasse. Higher rates of biodegradation as well as larger degree of mineralization were found over a period of 36 days for vinasse and LMBR particles. These particles exhibit good perspectives as an alternative fertilizer for agriculture applications and represent an innovative solution for vinasse and LMBR final disposal.

Toxicity evaluation of leached of sugarcane vinasse: Histopathology and immunostaining of cellular stress protein

Sugarcane vinasse is a residue generated at a rate fifteen times greater than the ethanol production. Because of its high organic and micronutrient content, this residue is used as a fertilizer on sugarcane crops. However, when used in large quantities, vinasse can saturate the soil and contaminate nearby water resources by percolation and leaching. Given the proven toxic potential of in natura vinasse, the present study aimed to evaluate the toxic potential of leached sugarcane vinasse using Nile tilapia (Oreochromis niloticus) as a test organism. A bioassay was performed after vinasse percolation in laboratory soil columns. The bioassay included one control group containing fresh water and two treatment groups, the first exposed to a 2,5% dilution of leached of vinasse and the second to a 2,5% dilution of in natura vinasse. After exposure, histopathological analysis was performed in gills and livers, and the latter were labelled for HSP70 proteins. No significant changes were detected in the gills of the exposed fish. However, in the liver, both in natura and leached vinasse induced statistically significant histopathological changes. These changes include hydropic degeneration, cell boundary losses, pyknotic nuclei and cellular disorganization. HSP70 expression significant increase in liver of both treatment groups were observed, being higher for the in natura vinasse exposed group. Results suggested that both leached vinasse and in natura vinasse were toxic, its still able to provoke histological changes and induce the cytoprotective response in exposed fish liver, evidenced by a immunostaining of cellular stress proteins. Thus, in order to reduce its environmental impact, appropriated effluent disposal is essential.