Concentration Of Fermentable Sugars Research Articles

Effects of carbon concentration, oxygen, and controlled pH on the engineering strain Lactiplantibacillus casei E1 in the production of bioethanol from sugarcane molasses

Sugarcane molasses are considered a potential source for bioethanol’s commercial production because of its availability and low market price. It contains high concentrations of fermentable sugars that can be directly metabolized by microbial fermentation. Heterofermentative lactic acid bacteria, especially Lactiplantibacillus casei, have a high potential to be a biocatalyst in ethanol production that they are characterized by strong abilities of carbohydrate metabolism, ethanol synthesis, and high alcohol tolerance. This study aimed to evaluate the feasibility of producing ethanol by Lactiplantibacillus casei used the ethanologen engineering strain L. casei E1 as a starter culture and cane molasses as substrate medium. The effects of environmental factors on the metabolism of L. casei E1 were analyzed by high-performance liquid chromatography (HPLC) system, and the gene expression of key enzymes in carbon source metabolism was detected using quantitative real-time PCR (RT–qPCR). Results showed that the strain could grow well, ferment sugar quickly in cane molasses. By fermenting this bacterium anaerobically at 37 °C for 36 h incubation in 5 °BX molasses when the fermenter’s pH was controlled at 6.0, ethanol yield reached 13.77 g/L, and carbohydrate utilization percentage was 78.60%. RT-qPCR results verified the strain preferentially ferment glucose and fructose of molasses to ethanol at the molecular level. In addition, the metabolism of sugars, especially fructose, would be inhibited by elevating acidity. Our findings support the theoretical basis for exploring Lactic acid bacteria as a starter culture for converting sugarcane molasses into ethanol.

Simplified methods of estimating fermentable sugar yield in sweet sorghum [Sorghum bicolor (L.) Moench] stems

Fermentable sugar is the most important component in sweet sorghum stem for its first-generation ethanol production. Estimation of fermentable sugar yield is required for sweet sorghum breeding, production, but related estimation methods available now are not so efficient. In order to establish a new method of estimating fermentable sugar yield, sweet sorghum stems were milled with a small three roll miller to recover carefully the juice and bagasse. The contents of sugars in the juice and water extraction of bagasse were analyzed with high performance liquid chromatography. Contents of soluble matter and sugars (glucose, fructose and sucrose) of the extracted juice and calculated juice of the bagasse (moisture content plus soluble matter content) were compared. The results showed that there is no significant difference in the total fermentable sugar content between squeezed juice and residue juice. So, the following four methods of analysis and estimation for sugars content of the whole stem was studied and compared: (1) analyzing juice only (but needs to determine moisture content of bagasse or stem, (2) analyzing bagasse only, (3) analyzing both juice and bagasse and (4) analyzing dried stems. The results showed that it is feasible to estimate sugars content of the whole stem by analyzing the juice or the bagasse only, and the most simplified method was that analyzing the juice and drying the bagasse. The following three formula was postulated that can be used in the estimation of sugars contents: (1) Ss=(J + B × Soj ×Wb / Wj)×Sj; (2) Ss=(1-B × Db×Ub)×Sb /(Wb + Sob); (3) Ss=J × Sj + B × Sb, where Ss is sugar content of stem (%), J is juice extraction (%), B is bagasse rate after one milling (%), Soj is content of soluble matter in extracted juice(%), Wb is water content of bagasse (%), Wj is water content of extracted juice (%); Sj is sugar content of juice(%); Db is content of dried matter in bagasse(%); Sb is sugar content of fresh bagasse; Sob is content of soluble matter in fresh bagasse. Fermentable sugar yield (FSY, MgHa−1) = Green stem yield (GSY, MgHa−1) ×Ss (%).

Bioethanol production from pretreated palm empty fruit bunch (PEFB) using sequential enzymatic hydrolysis and yeast fermentation

This study investigated the effectiveness of steam pretreatment using distilled water or waste glycerol as solvents to produce soluble sugars via enzymatic hydrolysis of palm empty fruit bunch (PEFB). Subsequently, two yeast species (S. cerevisiae and P. stipitis) were introduced to stimulate the fermentation of the soluble sugars to ethanol. The fermentable sugar (glucose plus xylose) concentration generated during hydrolysis of pretreated PEFB was found to be mainly a function of the pretreatment conditions (i.e. type of solvent, liquid-phase pH, and reaction time) as well as the hydrolysis time. Glucose was the major component of fermentable sugar in all tests; while the xylose content fluctuated from 3 to over 40% of that of glucose, with the higher percentages obtained at the shortest pretreatment time. The use of alkaline waste glycerol (pH 11) as a solvent during pretreatment resulted in optimum hydrolysis with a mean fermentable sugar concentration of 51.5 ± 4.1 g/L, while the corresponding mean value of the waste glycerol tests (pH 8.3) was 35.3 ± 4.9 g/L. Regarding fermentation, alkaline waste glycerol pretreatment enhanced ethanol production by over 50% compared to distilled water. It was also observed that fermentation using a S. cerevisiae monoculture was more effective than that of an equivalent co-culture.

Structural and composition modification of Harum Manis mango (Mangifera indica) leaves via chemical pretreatment for bioethanol production

Harum Manis mango leaves are considered lignocellulosic (LC) biomass that could contribute to the production of second generation (2G) bioethanol. However, pretreatment should be conducted to overcome the recalcitrance of LC biomass prior to bioethanol production. Hence, this study aims to elucidate the structural changes of the biomass of Harum Manis mango leaves after single-stage and two-stage chemical pretreatment. The Harum Manis mango leaves were treated with only acid, only alkaline, acid-alkaline, or alkaline-acid process. One per cent (v/v) sulphuric acid and 1% (w/v) sodium hydroxide were used as the acid and alkaline hydrolysing agent in the four approaches of pretreatment, respectively. Consequently, the pretreated biomass was enzymatically hydrolysed to produce reducing sugar followed by the conversion into bioethanol through yeast fermentation. Acid-alkaline pretreatment yielded the highest holocellulose composition of 95.26%, with the highest delignification effect of 86.97 ± 1.26%. Furthermore, Fourier transform infrared (FTIR) spectroscopy and X-ray powder diffraction (XRD) validated the acid-alkaline pretreated biomass to be the most feasible substrate for bioethanol production in this study. Finally, the maximum fermentable sugar content and bioethanol concentration of 415.02 ± 7.01 mg/g and 1.57 ± 0.06 mg/ml, respectively, were obtained.

Biotransformation of Citrus Waste-I: Production of Biofuel and Valuable Compounds by Fermentation

Citrus is the largest grown fruit crop on the globe with an annual production of ~110–124 million tons. Approximately, 45–55% of the whole fruit post-processing is generally discarded as waste by the food processing industries. The waste is a huge problem to the environment in terms of land and water pollution along with displeasure from aesthetic viewpoint and spread of diseases owing to its huge content of fermentable sugars. The waste can be utilized as a raw material feedstock for producing a number of valuable chemicals and products, such as bioethanol, biogas, bio-oil, organic acids, enzymes, and so on. The production of these chemicals from waste biomass gives an inexpensive alternative to the harsh chemicals used during industrial synthesis processes as well as the possibility of controlling pollution from the waste discarded to the environment. The derived chemicals can be further utilized in the production of industrially important chemicals, as solvents and building blocks of newer chemicals. Furthermore, organic acids, pectin, enzymes, prebiotics, etc., derived from citrus wastes have an edge over their synthetic counterparts in practical applications in the food processing and pharmaceutical industries.

Lactic acid fermentation in the development of a seaweed sauerkraut-style product: Microbiological, physicochemical, and sensory evaluation.

Consumption of nutrient-rich seaweeds and fermented nondairy foods represent fast growing trends among health-minded consumers. Assessment of lacto-fermented seaweed was performed to address these trends, and to offer shelf-life extension and product diversification for fresh kelps. The objectives were to evaluate the effects of kelp species and inclusion level on fermentation kinetics, physicochemical quality, safety, shelf-life, and consumer acceptability of a seaweed sauerkraut-style product. Six formulations with different inclusion levels (25, 50, and 75%) of shredded kelp (sugar kelp, SK or winged kelp, WK) were mixed with cabbage, 2% salt, and inoculated with Lactobacillus plantarum (approximately 106 CFU/g) and Leuconostoc mesenteroides (approximately 101 CFU/g). Products were processed in triplicate, fermented until a target pH of ≤4.6 was achieved, and sampled periodically for 60 days. Kelp species and inclusion level significantly affected most variables tested. The most rapid fermentation (3 days), as evidenced by pH decrease, lactic acid bacteria counts, and lactic acid levels, was noted in WK formulations. Some SK formulations took up to 14 days to achieve the target pH, and coliforms persisted to a greater extent in the SK formulations. Higher levels of kelp decreased the fermentation rate and concentration of fermentable sugars in the brine, but increased the total phenolic content and antioxidant activity of the sauerkrauts. Despite differences in instrumental color (L* a* b* ) and texture (shear force) among formulations, overall liking as rated by a consumer panel was not significantly affected by species or inclusion level. Results support the use of lacto-fermentation in the production of refrigeration-stable seaweed sauerkraut-style product. PRACTICAL APPLICATION: Health-conscious consumers are becoming increasingly interested in plant-based diets and fermented foods, and the development of novel seaweed sauerkraut-style products can help to meet these needs. This study demonstrated the successful production of a sauerkraut-style product formulated with up to 50% farm-raised kelp. Physical, chemical, microbiological, and consumer acceptability testing established lactic acid fermentation as a viable method for shelf life extension and value addition of fresh kelps. These results provide science-based information on an alternative processing method for cultivated seaweeds and can assist the industry in product diversification efforts.

Investigation of Fermentation Regimes for the Production of Low-alcohol and Non-alcohol Beers

The combination of modified mashing method and arrested fermentation for the production of low-alcohol and non-alcohol beers was studied. Therefore, five regimes for fermentation of wort with reduced fermentable sugar content with top-fermenting yeast strain at low temperatures and pitching rates were investigated. According to the fermentation dynamic results the decrease in the fermentation temperature from 10 °C to 5 °C at pitching rate of 109 Colony Forming Units cm−3 ( CFU cm−3 ) led to significantly reduced concentrations of ethanol and secondary metabolites in beer. The temperature decrease from 10 °C to 7 °C at pitching rate of 107 CFU cm−3 resulted in a decrease in the alcohol concentration and increase in all the secondary metabolite concentrations except for the vicinal diketones concentration. Data show that yeast biomass does not grow at 5 °C and at inoculum concentration of 107 CFU cm−3, which makes fermentation impossible. Fermentation kinetics using Monod's model supplemented with product inhibition was also investigated. Up to 1.7 % of alcohol accumulates in the beer in some of the variants within 7 days. At low fermentation temperatures, yeast biomass utilizes part of the substrate to maintain its vital activity under stress fermentation conditions, which leads to a reduction in the amount of alcohol synthesized. The synthesis and reduction of the secondary metabolites was delayed compared to conventional beer fermentation. The sensory evaluation of the beers produced showed that the most appealing beer was the one produced at 10 °C and pitching rate of 109 CFU cm−3.

The Use of Non-Saccharomyces Yeast and Enzymes in Beer Production

Abstract The objective of this paper was to test the potential of selected non-Saccharomyces strains for beer production, by using Saccharomyces cerevisiae as a control sample. For some of variants brewing enzymes were added to wort to increase the content of fermentable sugars. The non-Saccharomyces yeasts differed in the fermentation process rate. The basic beer physiochemical parameters were assessed, including: alcohol content, extract, free amino nitrogen, sugars, acidity, colour, and the profile of volatile compounds and metal ions. The use of enzymes caused an increase in alcohol and fusel alcohols concentration in beers obtained. Total acidity, free amine nitrogen content, colour and sugar content indicated that the tested non-Saccharomyces yeast allowed obtaining beers with the proper analytical parameters.

Acid pretreatment of sugarcane biomass to obtain hemicellulosic hydrolisate rich in fermentable sugar

The objective of this work was to find the ideal pretreatment conditions with high efficiency to obtain a hydrolyzate rich in fermentable sugars and low possible inhibitors levels. Thus, it was applied diluted phosphoric acid to pretreat the sugarcane biomass. Through a Central Composite Design, it was evaluated the influence of temperature, operating time and acid concentration. The pretreatment efficiency was verified by the concentration of total monosaccharides in the liquid fraction after the reaction. The phosphoric acid concentration of 4.95% at 80 °C, during 375 min, resulted in a hemicellulosic hydrolyzate with the highest concentration of fermentable sugars (saccharification greater than 99%), with the absence of HMF and furfural, and relatively low amounts of acetic acid.

Enhanced Enzymatic Hydrolysis and Structure Properties of Bamboo by Moderate Two-Step Pretreatment.

A moderate two-step pretreatment method was investigated to improve the enzymatic saccharification of bamboo residues. SEM and FTIR were employed to characterize the structure changes. Fed-batch enzymatic saccharification was performed to obtain high concentration of fermentable sugar. Bamboo was impregnated at low severity of conditions (room temperature, 2% H2SO4 or 2% NaOH, 48h) to initially alter the structure of bamboo, and then further pretreated by steam explosion at 1.0MPa for 6min. The highest delignification of 51% and the highest enzymatic hydrolysis of 47.1% were reached at 2% NaOH impregnation followed by steam explosion. The changes in the structural characteristics showed beneficial effects on the enzymatic hydrolysis. When a mixer of cellulase (30 FPU) and β-glucosidase (10 CBU) was further used, the maximum enzymatic hydrolysis of 78.9% and total glucose yield of 68.2% were obtained. The maximum sugar release from the holocellulose was 500mg/g bamboo, approximately 83.3% conversion efficiency based on monomeric sugar recovery. With fed-batch saccharification, a final substrate loading of 30% brought 107.7g/L glucose, 35.81g/L xylose, and 7.82g/L arabinose release, respectively. This study provided an effective strategy for potential utilization of bamboo residues.

Approach for modelling the extract formation in a continuous conducted “β-amylase rest” as part of the production of beer mash with targeted sugar content

Continuous mashing provides advantages compared to conventional batch-wise mashing in terms of space time yield. The majority of fermentable sugars are generated during the so-called “β-amylase rest” (62–64 °C). These low molecular sugars are fermented later in the brewing process by yeasts and therefore determine the beer attenuation degree. Biological malt variations complicate the application of a continuous system in industrial scale particularly concerning targeted quality parameters. The aim is the prediction of sugar formation from process parameters for a real time control system. Therefore, a semi-empirical model for sugar formation in a continuous stirred tank reactor (CSTR) system was developed under incorporation of the residence time distribution (RTD). The here presented model, which focuses on the “β-amylase rest”, is able to predict fermentable sugar concentrations in the continuous “β-amylase rest” with sufficient accuracy, in contrast to models that only use the flow rate and the reactor volume to determine the reaction time. However, the precision and trueness depend on the quality of the empirical data acquired previously in laboratory experiments for the selected temperature and raw material quality.

Production of fermentable sugars from Chlorella sp. by solid-acid catalyst

The hydrolysis of microalgae Chlorella sp. via a solid acid catalyst was conducted in order to obtain fermentable sugars. To optimize the hydrolysis conditions, Box-Behnken design was used to construct the experimental setup. Results show that the highest fermentable sugar yield of 50.4% (25.2 g/L) was achieved using a reaction composed of 5% biomass and 40% solid acid catalyst loading (based on biomass), at a reaction temperature of 160 °C for 45 min. Moreover, under these conditions, only 1.16 g/L of 5-HMF and 0.12 g/L of levulinic acid were formed as by-products. Furthermore, at 12.5% biomass concentration, a 56.97 g/L (45.58%) high concentration of fermentable sugars was obtained. In conclusion, the utilization of microalgae and a solid acid catalyst for fermentable sugar production has a high possibility of applicability.

Thermotolerant glycosyl hydrolases-producing Bacillus aerius CMCPS1 and its saccharification efficiency on HCR-laccase (LccH)-pretreated corncob biomass

BackgroundThe current production of bioethanol based on lignocellulosic biomass (LCB) highly depends on thermostable enzymes and extremophiles owing to less risk of contamination. Thermophilic bacterial cellulases are preferred over fungi due to their higher growth rate, presence of complex multi-enzymes, stability, and enhanced bioconversion efficiency. Corncob, underutilized biomass, ensures energy conservation due to high lignocellulosic and more fermentable sugar content. In the present study, the thermophilic bacterium Bacillus aerius CMCPS1, isolated from the thermal springs of Manikaran, Himachal Pradesh, India, was characterized in terms of its activity, stability, and hydrolytic capacity. A two-step process comprising: (i) a combined strategy of hydrodynamic cavitation reaction (HCR)-coupled enzymatic (LccH at 6.5 U) pretreatment for delignification and (ii) subsequent hydrolysis of pre-treated (HCR-LccH) corncob biomass (CCB) using a thermostable cocktail of CMCPS1 was adopted to validate the efficiency of the process. Some of the parameters studied include lignin reduction, cellulose increase, and saccharification efficiency.ResultAmong the five isolates obtained by in situ enrichment on various substrates, B. aerius CMCPS1, isolated from hot springs, exhibited the maximum hydrolytic activity of 4.11. The GH activity of the CMCPS1 strain under submerged fermentation revealed maximum filter paper activity (FPA) and endoglucanase activity of 4.36 IU mL−1 and 2.98 IU mL−1, respectively, at 44 h. Similarly, the isolate produced exoglucanase and β-glucosidase with an activity of 1.76 IU mL−1 and 1.23 IU mL−1 at 48 h, respectively. More specifically, the enzyme endo-1,4-β-d glucanase E.C.3.2.1.4 (CMCase) produced by B. aerius CMCPS1 displayed wider stability to pH (3–9) and temperature (30–90 °C) than most fungal cellulases. Similarly, the activity of CMCase increased in the presence of organic solvents (118% at 30% acetone v/v). The partially purified CMCase from the culture supernatant of CMCPS1 registered 64% yield with twofold purification. The zymogram and SDS-PAGE analyses further confirmed the CMCase activity with an apparent molecular mass of 70 kDa. The presence of genes specific to cellulases, such as cellulose-binding domain CelB, confirmed the presence of GH family 46 and β-glucosidase activity (GH3). The multifunctional cellulases of CMCPS1 were evaluated for their saccharification efficiency on laccase (LccH, a fungal laccase from Hexagonia hirta MSF2)-pretreated corncob in a HCR. The lignin and hemicelluloses removal efficiency of HCR-LccH was 54.1 and 6.57%, respectively, with an increase in cellulose fraction (42.25%). The saccharification efficiency of 55% was achieved with CMCPS1 multifunctional cellulases at 50 °C and pH 5.0.ConclusionThe multifunctional cellulase complex of B. aerius CMCPS1 is a potential biocatalyst for application in lignocellulosic biomass-based biorefineries. The saccharification ability of HCR-LccH-pretreated corncob at elevated temperatures would be an advantage for biofuel production from lignocellulosic biomass.

Application of Supercritical CO2 Treatment Enhances Enzymatic Hydrolysis of Sugarcane Bagasse

This study sought to investigate the effects caused by the application of supercritical CO2 treatment in the commercial cellulase Celluclast 1.5L. The influence of this treatment on the enzymatic hydrolysis of sugarcane bagasse (2% w v−1) and on the kinetic parameters was assessed in a central composite design (CCD). The results show that the application of supercritical treatment for 180 min at 40 °C and 300 bar causes an increase in 14.31% in total cellulase enzymatic activity (FPase). Furthermore, this treatment conditions also enhance in 73.63% (concentration of 1.176 g L−1) the concentration of fermentable sugars released during the enzymatic hydrolysis of sugarcane bagasse, with theoretical yield of cellulose hydrolysis of 17.56%. In addition, KM was reduced 3 times for the enzyme compared to the untreated enzyme. Thus, treatment with supercritical CO2 proved to be a green and attractive alternative for fermentable sugars release, since it resulted in enhancements of enzymatic activities of the cellulolytic complex and an increase in enzymatic hydrolysis degree of the sugarcane bagasse.

A Review of UAE Native Seaweed as Potential Bio-Refinery Feedstock for Jet Fuel and High Value Chemicals

The UAE government has hosted several initiatives to produce sustainable jet fuel from locally available feedstock to support its sustainable energy strategy and vision. With more than 2000 km of coastline UAE is home to a large variety of aquatic biomass, such as seaweed. The local seaweed strains can act as ultimate candidate feedstock for not only bioenergy (jet fuel) but also a source for high value chemicals. Seaweed contains high carbohydrates and rapid growth rates and low lignin content. Several seaweed biomasses strains have been identified along the shores of the Emirate of Abu Dhabi amongst which one strain Ulva Sp. was the most dominant in terms of occurrence and availability. A bio refinery utilizing the local UAE seaweed strains could provide many advantages for the commercial viability the due to the fact that seaweed has potential to other high value product such as active components for pharmaceutical products as their market value is much higher that sustainable jet fuel. The preliminary chemical characterization showed significant glucan contents which indicate fermentable sugar content in these biomass samples. This make the local aquatic biomass an interesting research project both to fulfill the sustainable jet fuel initiative and establish further knowledge in the local aquatic biomass biorefinery capabilities.

Pressurized liquid hot water pretreatment and enzymatic hydrolysis of switchgrass aiming at the enhancement of fermentable sugars

Pressurized Liquid Hot Water (PLHW) process is an essential and new method to remove lignin from biomass for biorefinery applications. In this study, a cascade method was investigated to obtain reducing sugars of switchgrass using optimization of PLHW and enzymatic hydrolysis. Optimization of pressurized liquid hot water and enzymatic hydrolyses were achieved by Box-Behnken design. First, pretreatments including PLHW were carried out step by step, with respect to the independent variables such as temperature (100, 140, 180 °C), pressure (100, 150, 200 bar) and time (20, 40, 60 min) at fixed flow rate (2 ml/min). The conditions which give the most optimized reducing sugar were 122.12 °C, 100 bar and 50.08 min and optimized fermentable sugar content was measured 107.49 g/l. Then, enzymatic hydrolysis was applied to solid phase with 4.8 pH citrate buffer at 50 °C during 24, 48 and 72 h with the help of Novozyme 188 and Celluclast enzymes. The reducing sugar amount obtained from switchgrass with enzymatic hydrolysis was measured 248.23 g/L, which means totally 355.72 g/L.

Integrating bran starch hydrolysates with alkaline pretreated soft wheat bran to boost sugar concentration

Soft wheat bran (SWB), one of the most abundant byproducts from the wheat milling industry, is a potential candidate for biofuel production. In this study, bran starch hydrolysates were separately integrated with dilute acid pretreated SWB and alkaline pretreated SWB to boost fermentable sugar concentration. Alkaline pretreatment showed higher sugar recoveries than acid pretreatment. Significant sugar degradation for acid pretreatment was observed when pretreatment temperature higher than 170 ℃. The optimal pretreatment condition was 15% solid loading with 0.08 mol/L NaOH at 150 ℃ for 20 min. The neutralization reaction between dilute alkaline and released acids reduced sugar decomposition and inhibitors formation. Integrating bran starch hydrolysates with alkaline pretreated SWB yielded the highest glucose concentration of 50.91 g/L and a total sugar concentration of 101.29 g/L.

Hydrotropic pretreatment on distillery stillage for efficient cellulosic ethanol production

Effectiveness of hydrotropic delignification using sodium cumene sulfonate for pretreatment of rye, wheat and maize stillage for further use in the production of bioethanol was evaluated. The highest stillage biomass extractives was obtained for a biomass particle size <1.0 mm, when exposed to 131 °C for 1 h at 20% v/v hydrotrope concentration. It has been shown that hydrotropic treatment causes changes in the stillage biomass structure (increase in porosity) and reduces the lignin content in biomass by 7–17%. Delignification with a hydrotrope also increased the concentration of fermentable sugars in the media prepared with stillage biomass, which led to a higher final ethanol concentration (up to ca. 3.5 g/L). Hydrotropic treatment is an effective way of pretreatment of stillage biomass. It provides a high degree of biomass bioconversion and creates the prospect of integrating the 1st and 2nd generation ethanol production process to more fully utilize the raw material.

Malt protein inhibition of β-amylase alters starch molecular structure during barley mashing

The molecular structural changes in starch in barley malts during mashing (a major step in brewing beer) with and without protein removal were investigated using size exclusion chromatography. The aim was to uncover how proteins affects barley starch degradation in brewing. It was found that for malts containing lower β-amylase activity, protein removal significantly increased fermentable sugar content, whilst no significant change was observed for malts with higher β-amylase, with or without addition of a metalloprotease (Neutrase®). However, metalloprotease addition significantly reduced both the content and molecular sizes of remaining wort-soluble starches. This suggests that the effects of malt protein removal on starch degradation, particularly on fermentable sugar production, largely depend on malt enzyme activity, especially that of β-amylase. This provides useful information for brewers: for example, the fact that soluble starch molecular structure correlates significantly with fermentation efficiency gives a new criterion for selecting barley varieties for optimal brewing performance.

Bioethanol production from Ataulfo mango supplemented with vermicompost leachate

• Vermicompost leachate was used as nutrient supplement for the ethanologenic yeast Saccharomyces cerevisiae . • Dehydration of Ataulfo mango pulp allowed to increase the concentration of fermentable sugars in the fermentation process. • All tested Ataulfo dehydrated mango pulp treatments with vermicompost leachate showed bioethanol production. • Moderate concentration of added vermicompost leachate has a positive effect on bioethanol yield. Mango fruits are easily damaged by knocking during harvest and transport, producing agro-industrial waste with high content of fermentable sugars. The aim of this work was to assess the production of bioethanol from residual Ataulfo ( Mangifera indica L .) mango pulp, using vermicompost leachate as a nutritional supplement for ethanologenic yeast Saccharomyces cerevisiae during the fermentation process. Mango pulp was subjected to a dehydration process at 60 °C in order to preserve fermentable sugars. Moisture and ash content, total soluble solids (TSS), titratable acidity (TA), pH and total reducing sugar (TRS) concentration of the Ataulfo mango pulp were determined. Five treatments with different vermicompost leachate concentration (0%, 10%, 20%, 50% and 100%) were tested. The fermentation progress was evaluated by physicochemical characterization analysis (TSS and TRS) and accumulated production of CO 2 . Initial and final concentration of bioethanol was determined by HPLC. The highest bioethanol concentration of 44.67 ± 1.6 g/L was reached for treatment with 50% of vermicompost leachate. This result represents a viable option for using mango waste and vermicompost leachate as a renewable alternative for bioethanol production.