Hydrolysis Of Bagasse Research Articles

Sorbitol production from a mixture of sugarcane bagasse and cassava pulp hydrolysates using thermotolerant Zymomonas mobilis TISTR548

The sorbitol production capability of different thermotolerant strains of Zymomonas mobilis and the optimization conditions for sorbitol production using sugarcane bagasse hydrolysate (SBH) and cassava pulp hydrolysate (CPH) as feedstocks were investigated. Among the different bacterial strains and combinations of SBH and CPH, the thermotolerant Z. mobilis TISTR548 and a mixture of SBH and CPH at a ratio of 0.50:0.50 provided the highest sorbitol concentration at 37 °C. A screening of the environmental factors influencing sorbitol production by Z. mobilis TISTR548 using the Plackett-Burman design (PBD) revealed three significant independent variables, i.e., CaCl 2 , NaCl, and pH, which positively affected sorbitol production using a mixture of SBH and CPH as substrate. The response surface methodology (RSM) based on the central composite design (CCD) resulted in the optimum CaCl 2 concentration of 2.47 g/L, a NaCl concentration of 0.08 g/L, and a pH of 6.49, yielding the maximum sorbitol concentration of 5.89 g/L, which was approximately 2.0-fold higher than that of the non-optimal conditions. This finding suggested that the bioconversion of lignocellulosic biomasses into sorbitol through microbial fermentation is another platform for sustainable industrial high-value bioproducts . • Sorbitol production from a mixture of sugarcane bagasse and cassava pulp hydrolysates. • High-temperature sorbitol fermentation using thermotolerant Zymomonas mobilis. • Optimization conditions for sorbitol production using a statistical experimental model.

Continuous long-term glucose biosensor in agitation condition for bioconversion processes

The use of a glucose biosensor in the bioconversion processes is challenging due to a long period of intensive stirring that is required to mix the heterogenous substants together. In this work, a glucose biosensor was developed to be accurate and robust for an extended period of measuring time in agitated conditions. The sensor probe was fabricated by electro-polymerization of polyaniline (PANI) nanostructures on a gold wire before putting in gold nanoparticles (AuNPs) and carrageenan (carr) solution to make an PANI-carr-AuNPs layer. Then the probe was soaked in PQQ-Glucose dehydrogenase (GDH) solution before coating with polyurethane (PU) to prevent the enzymes from leaching away from the sensor. The sensor probe showed a sensitivity of 0.85 μA/mg/ml of glucose with R2 of 0.9973. The storage stability of the probe was up to 4 days with stable signal. In agitated condition of 150 rpm, steady signals from the sensor were continuously obtained for 72 h. In sugarcane bagasse hydrolysis with speed at 150 rpm for 72 h, the biosensor continuously displayed signals which were not significantly different in glucose concentration to the results from the HPLC method. This biosensor displayed promising applications in bioconversion processes.

An Approach for Incorporating Glycerol as a Co-Substrate into Unconcentrated Sugarcane Bagasse Hydrolysate for Improved Lipid Production in Rhodotorula glutinis

Sugarcane bagasse is a potential raw material for microbial lipid production by oleaginous yeasts. Due to the limited sugar concentrations in bagasse hydrolysate, increasing carbon the concentration is necessary in order to improve lipid production. We aimed to increase carbon concentration by incorporating glycerol as a co-substrate into unconcentrated bagasse hydrolysate in the cultivation of Rhodotorula glutinis TISTR 5159. Cultivation in hydrolysate without nitrogen supplementation (C/N = 42) resulted in 60.31% lipid accumulation with 11.45 ± 0.75 g/L biomass. Nitrogen source supplementation increased biomass to 26.29 ± 2.05 g/L without losing lipid accumulation at a C/N of 25. Yeast extract improved lipid production in the hydrolysate due to high growth without altering the lipid content of the cells. Mixing glycerol up to 10% v/v into the unconcentrated hydrolysate improved biomass and lipid production. A further increase in glycerol concentrations drastically decreased growth and lipid accumulation by the yeast. By maintaining C/N at 27 using yeast extract as the sole nitrogen source, hydrolysate mixed with 10% v/v glycerol resulted in the highest lipid yield, at 19.57 ± 0.53 g/L with 50.55% lipid content, which was a 2.8-fold increase compared to using the hydrolysate alone. In addition, yeast extracts were superior for promoting growth and lipid production compared to inorganic nitrogen sources.

Economic and Environmental Sustainability of Vegetative Oil Extraction Strategies at Integrated Oilcane and Oil-Sorghum Biorefineries

The production of biodiesel from conventional oilseed crops (e.g., soybean) is limited by the low productivity of oil per hectare. Oilcane (derived from sugarcane) holds the potential to improve vegetable oil production in agriculture to help meet projected demand for oil-based biofuels. However, the financial viability of oilcane-derived biofuels remains uncertain, with key questions centered on the technical feasibility of vegetative oil recovery and the economic/environmental implications of designing integrated biorefineries to process multiple oil-rich feedstocks. To address these questions, two biorefinery configurations producing biodiesel and ethanol were evaluated: (i) direct cogeneration of heat and power from bagasse (lower oil recovery) and (ii) an integrated, single-step co-fermentation of both extruded juice and bagasse hydrolysate (higher oil recovery). Sensitivity and uncertainty analyses demonstrated the sustainability gains of improved oil recovery, higher feedstock oil content, and the integration of oil-sorghum processing when oilcane is not in season. For the direct cogeneration and co-fermentation configurations, Monte Carlo simulations resulted in maximum feedstock purchase prices of 34.7 [22.4, 48.4] (median; 5th and 95th percentiles in brackets) and 40.0 [19.3, 63.7] USD·MT–1 and life cycle global warming potentials of 0.313 [0.285, 0.345] and 0.320 [0.294, 0.351] kg CO2-eq·L–1 of ethanol (under economic allocation), respectively.

The fermentation efficiency exhibited by Saccharomyces cerevisiae on Sugarcane bagasse hydrolysate, by analyzing the effects of pre-treatment and detoxification

In this study, the possibility of increasing fermentation efficiency of Saccharomyces cerevisiae on sugarcane bagasse (a type of lignocellulosic waste) was analyzed. Sugarcane bagasse was subjected to hydrothermal and acidic pre-treatment. Next, the enzymatic hydrolysis of raw biomass and each pre-treated biomass was performed using CellicCtec® enzymatic complex to obtain sugarcane hydrolysate, hydrothermal hydrolysate and acidic hydrolysate. Next, these were fermented by S. cerevisiae to check if the by-products of enzymatic hydrolysis, furfural and acetic acid had an inhibitory effect on fermentation efficiency. Next, each pre-treated biomass was subjected to detoxification involving activated charcoal. Each detoxified biomass was tested for fermentation efficiency. The lignocellulosic composition for sugarcane hydrolysate, hydrothermal hydrolysate and acidic hydrolysate, varied significantly, and were found to be, for cellulose 36.7%, 27.7% and 63.7% respectively; for hemicellulose 22.2%, 4.4% and 12% respectively; and for lignin 21.2%, 27.7% and 28.7% respectively. The presence of furfural and acetic acid had a strong influence on the fermentation efficiency of S. cerevisiae, and affected the consumption of sugars in each biomass by more than 90%. Further, we found that the detoxification process increased fermentation efficiency by 12.7% for the hydrothermal hydrolysate while for the acidic hydrolysate no significant difference was observed. This study showed that fermentation with greater efficiency is viable through the combined use of hydrothermal pre-treatment and detoxification. This combination of methods also causes less pollution as compared with the method involving acid pre-treatment due to the reduced number of effluents produced.

Simultaneous production of cellobiose and xylobiose from alkali-treated bagasse using cellulase secreted by Fe-ion-irradiated Trichoderma reesei mutant

Cellobiose and xylobiose are disaccharides composed of two glucose or xylose units with β-1,4 linkages. This study aimed to isolate a Trichoderma reesei mutant that lacks β-glucosidase and β-xylosidase activities for the simultaneous production of these disaccharides. Mutagenesis using Fe-ion beam resulted in a mutant strain, T.reesei T1640; the cellulase production in this strain was as high as that in the parent strain. Genomic analysis revealed that T1640 lost both the β-glucosidase and β-xylosidase activities owing to the translocation of the responsible genes. Hydrolysis of alkali-treated bagasse using the enzymes from T1640 leads to high yields (365 mg/g-biomass) and ratios (72.7% of the total sugars) of cellobiose and xylobiose.

Production of Enzymatic Extract with High Cellulolytic and Oxidative Activities by Co-Culture of Trichoderma reesei and Panus lecomtei

This work aimed to produce enzymatic fungi extracts with hydrolytic and oxidative activities to hydrolyze lignocellulosic biomasses efficiently. For this, the fungi Trichoderma reesei and Panus lecomtei were co-cultured using the vegetable biomasses oil palm decanter cake, wheat bran, and cottonseed cake as substrates in submerged fermentation. T. reesei and P. lecomtei showed partially compatible positive interaction on plates. The co-cultures respond positively to variations of temperature and inoculum interval, generating extracts responsible for higher hydrolysis yield when grown at 25 °C, and P. lecomtei is inoculated 24 h after T. reesei. The enzymatic extract production of co-cultures was also improved by modifying the components of the initial media and evaluating enzymatic activities, hydrolysis of sugarcane bagasse pretreated by autohydrolysis and ethanol production as a response. Five culture media were evaluated with variations in the composition of nutritional elements, minerals and substrates. The best extract showed a maximum cellulose hydrolysis efficiency of 68.7% compared with 44.8% of the initial medium. The ethanolic fermentation of hydrolysates obtained by co-culture extracts showed higher ethanol yields than monocultures. This work demonstrates the use of fungi co-cultures to produce enzymatic extracts composed of cellulolytic, hemicellulolytic, and ligninolytic enzymes complexes, which allow hydrolyzing pretreated lignocellulosic biomass with high efficiency, generating hydrolysates that are easier fermented by yeast.

Lychee-Derived, Thermotolerant Yeasts for Second-Generation Bioethanol Production

Thermotolerant yeasts are widely considered to be alternative strains to traditional yeasts for bioethanol production at high temperatures. In this study, thirty-two yeasts isolated from lychees were screened for thermotolerance, and seven selected isolates were identified as Candida tropicalis (isolates H8, H19, and H23), Meyerozyma guilliermondii (isolates H1 and H12) and Saccharomyces cerevisiae (isolates H10 and H18). They tolerated up to 45 °C, 12% (v/v) ethanol concentration, 10 g/L acetic acid, and 5 g/L furfural, respectively, and produced 47.96 to 70.18 g/L of ethanol from 160 g/L glucose at 40 °C during 48 h of fermentation. Among the evaluated yeasts, M. guilliermondii H1 showed great potential for second-generation bioethanol fermentation with its ability to ferment xylose and arabinose. Under the optimal conditions resulting from a Plackett Burman design and a Box Behnken design, the highest ethanol concentration of 11.12 g/L was produced from 40 g/L substrate-based sugarcane bagasse hydrolysate (non-detoxified hydrolysate) at 40 °C by M. guilliermondii H1. These findings suggested that the newly isolated thermotolerant yeast M. guilliermondii H1 is a good candidate for ethanol production from agricultural wastes.

Evaluation of Enzymatic Hydrolysis of Sugarcane Bagasse Using Combination of Enzymes or Co-Substrate to Boost Lytic Polysaccharide Monooxygenases Action

This study evaluated innovative approaches for the enzymatic hydrolysis of lignocellulosic biomass. More specifically, assays were performed to evaluate the supplementation of the commercial cellulolytic cocktail Cellic® CTec2 (CC2) with LPMO (GcLPMO9B), H2O2, or cello-oligosaccharide dehydrogenase (CelDH) FgCelDH7C in order to boost the LPMO action and improve the saccharification efficiency of biomass into monosaccharides. The enzymatic hydrolysis was carried out using sugarcane bagasse pretreated by hydrodynamic cavitation-assisted oxidative process, 10% (w/w) solid loading, and 30 FPU CC2/g dry biomass. The results were compared in terms of sugars release and revealed an important influence of the supplementations at the initial 6 h of hydrolysis. While the addition of CelDH led to a steady increase in glucose production to reach 101.1 mg of glucose/g DM, accounting for the highest value achieved after 72 h of hydrolysis, boosting the LPMOs activity by the supplementation of pure LPMOs or the LPMO co-substrate H2O2 were also effective to improve the cellulose conversion, increasing the initial reaction rate of the hydrolysis. These results revealed that LPMOs play an important role on enzymatic hydrolysis of cellulose and boosting their action can help to improve the reaction rate and increase the hydrolysis yield. LPMOs-CelDH oxidative pairs represent a novel potent combination for use in the enzymatic hydrolysis of lignocellulose biomass. Finally, the strategies presented in this study are promising approaches for application in lignocellulosic biorefineries, especially using sugarcane bagasse as a feedstock.

Morphological Characterization Of Rumen Protozoa Isolated From Sweet Sorghum Hydrolysis Using Carabao (Bubalus bubalis Linn) Rumen Fluid

This study was conducted to characterize the morphology of rumen protozoa isolated in the batch type hydrolysis of sweet sorghum using 1% fresh carabao rumen fluid with duration of 0, 3, 6, 9, 12 and 15 days of the novel process hydrolysis. Hydrolysis was conducted using 5% chopped sweet sorghum bagasse. Nitrogen content was augmented with 0.35 g urea per 750 ml effective volume with low speed agitation of fermentation bottle at least 20 minutes twice daily and incubated at room temperature. Characterization was limited to microscopic evaluation of the morphological features of protozoa that was stained with methylene blue formalin saline solution. Protozoon population of 2.61 x 10 4 cfu/ml at initial period had significantly lowered down at the 15 days hydrolysis to 0.62 x 104 cfu/ml. Evaluation of morphology for the types of protozoa at different durations showed the predominance of species types with different orientations of caudal spines, shapes of the macromolecules, size of the body, and presence of adoral ciliary zones were features of species types from genus Eodinium Entodinium of the family Ophryoscolecidae. Evaluation of the hydrolysis condition showed that duration had significant effect on the pH (P>0.05). Sweet sorghum hydrolysis has initial pH 7 that significantly declined to pH 5 at 15 days duration. The population of the protozoa in the rumen fluid hydrolysis was significantly affected by duration of the hydrolysis (P>0.05). Entodinium were isolated at all durations of the acidic hydrolysis of sweet sorghum bagasse using carabao rumen fluid. In conclusion, morphological characteristics of the rumen protozoan shows how diverse are the composition of rumen protozoa in the carabao rumen fluid hydrolysis. The presence of the rumen protozoa is a justification of the novel carabao rumen fluid hydrolysis conversion of lignocelluloses in sweet sorghum bagasse into soluble carbohydrates for bioethanol production. The information is vital for animal feed utilization and bioethanol production optimization.

Wastes recycling of non-sterile cellulosic ethanol production from low-temperature pilot-scale enzymatic saccharification of alkali-treated sugarcane bagasse

High energy consumption has been one of bottlenecks for bioconversion of lignocellulose into biofuels and biochemicals. A self-designed pilot-scale device with recycling of black liquor (BL) and waste washing water (WWW) was constructed to conduct low-temperature pretreatment and high-solid enzymatic hydrolysis of sugarcane bagasse (SCB) at ordinary atmospheric pressure. Results showed that enzymatic hydrolysis of WWW-washed BL-WWW-NaOH-treated SCB at 30% solid concentration for 72 h achieved 91.59 g/L glucose with glucan conversion of 70.94%. The pretreatment unit shared only 19.68%–22.43% of total energy consumption and 8.32%–8.81% of total cost. The non-sterile enzymatic hydrolysate could be directly fermented by BL-adapted yeasts to maximally produce 44.82 g/L ethanol at 48 h, while the sterile hydrolysate could not be fermented. 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, furancarboxaldehyde and 5-hydroxymethylfurfural might be the dominant inhibitors in the sterile enzymatic hydrolysate for ethanol production. Finally, a low-emission strategy for cellulosic ethanol production with low energy consumption was proposed.

Producción de azúcares por hidrólisis ácida diluida del bagazo de avena con tres ácidos diferentes: cinética y termodinámica

Acid hydrolysis is used as a treatment method to hydrolyse the polysaccharides present in biomass to fermentable sugar. In this research the hydrolysis of oat bagasse was studied employing different inorganic acids (HCl, H2SO4 and H3PO4) at low temperatures (90 – 110 °C) in a long-term process. Sulphuric acid showed a high potential to produce reducing sugars reaching the maximum production yields at 110°C, while hydrochloric acid at 110°C was the most catabolic acid promoting sugars transformation into furfural. FTIR and relative transmittance analyses suggested that major impact on lignin polymer was made by phosphoric acid hydrolysis at Combined Severity Factors (CSF) higher than 1.5. Kinetic constants calculated from conventional Saeman model allowed to determine thermodynamic parameters for each inorganic acid. Decomposition of sugars occurred most frequently when the Activation Energies (Ae) were low than calculated for sugar production, being aldehydes, the most stable products obtained during hydrolysis. Thermodynamic parameters show and endothermic and non-spontaneous oat bagasse hydrolysis reaction for different inorganic acids.

Hydrolysis of Mixed Sugarcane Bagasse and Rice Husk Using Cellulase Enzyme for Reducing Sugar Production

Reducing sugar can be produced from lignocellulosic raw materials. The content of polysaccharides such as cellulose, hemicellulose, and starch will be broken down into simpler carbohydrates. This study used a mixture of sugarcane bagasse and rice husks as lignocellulosic raw materials. The lignin content in the raw material must be removed through delignification or pretreatment so that enzymes can access cellulose and hemicellulose. This study used a physics-chemical pretreatment method, in which lignocellulosic material soak in 3% NaOH then heated with microwave and boiling water. The next process is enzymatic hydrolysis with variations of cellulase enzymes activity 0.434, 0.871, 2.61, and 3.49 FPU/g mixture of bagasse and rice husks. The cellulase enzyme used in this study was also derived from the fungus Trichoderma viride. Analysis of the sugar concentration resulting from hydrolysis used the DNS method with the 3.5-dinitrosalicylic acid reagent. The concentration of sugar from hydrolysis using a variety of enzymes with microwave heating pretreatment and boiling water pretreatment obtained the highest results which were the same at the addition of enzyme activity 3.49 FPU/g substrate at 24 hours, namely 4.077 g/L and 15.18 g/L. The optimum time for enzymatic hydrolysis is 12 hours and optimum enzyme activity is the addition of enzyme activity 2.61 FPU/g. The average concentration of sugar hydrolyzed by the addition of Trichoderma viride solution in pretreatment using microwave heating was 0.7611 g/L with a yield of 21.01 mg sugar/g substrate and with pretreatment in boiling water obtained 0.8679 g/L with a yield of 23.95 mg sugar/g substrate.

Single cell protein production by Candida robusta isolated from sugar cane (Saccharum sp.) for animal feed

The protein obtained from the microorganisms is not only cheap but can be used as additive to provide a balanced nutrition for many animals feeding. The aim of this work was the single cell protein (SCP) production by Candida robusta URM5293 using sugarcane bagasse as substrate. The yeast C. robusta URM5293 was isolated from root sugarcane and was identified based on morphological and biochemical characteristics. Biomass production was done into Erlenmayers flasks (250 mL) containing culture medium supplemented of sugarcane bagasse hydrolyzate. Fermentations were carried varying culture conditions through the study of four different variables: temperature (25, 30, and 35°C), agitation intensity (110, 140 or 170 rpm), pH (6.0, 7.0, and 8.0) and production time (72, 96, and 120h), according to a 24-1 fractional factorial design. Results demonstrated that this yeast was able to ensure the highest level of biomass (141 g/L) when cultivated at 25°C, pH 6.0, 170 rpm of agitation intensity after 72h of cultivation using sugarcane bagasse. The present results demonstrate the potential of sugarcane bagasse hemicellulosic hydrolyzate as a substrate for the production of microbial protein by C. robusta URM5293.

Efficient production of ε-poly-L-lysine from cassava bagasse hydrolysate used as carbon source by Streptomyces albulus US3-18.

The production of ε-poly-L-lysine (ε-PL) from cassava bagasse hydrolysate (CBH) by Streptomyces albulus US3-18 was investigated in this study. With 30g/L glucose from CBH, 1.30g/L ε-PL and 10.68g/L biomass were obtained in shake flask fermentation. Interestingly, the two values were increased by 14.0% and 21.5%, respectively, compared to the control (1.14g/L and 8.79g/L). Simultaneously, the activities of four key enzymes of ε-PL synthesis during CBH fermentation were enhanced to varying degrees. In batch fermentation of 5-L bioreactor, 3.39g/L ε-PL and 10.17g/L DCW were harvested with 40g/L glucose from CBH. The combination of fed-batch fermentation with two-stage pH strategy significantly increased ε-PL titer and biomass to 37.41g/L and 41.0g/L, respectively. Moreover, eleven volatile components were detected in CBH by GC-MS, and 6-pentyl-α-pyrone (6PP) was first identified as the most abundant volatile ingredient. The results in CBH fermentation demonstrated that S. albulus US3-18 exhibited high tolerance to these volatile byproducts. Using ICP-MS, the calcium concentration in CBH was determined as 195.0mg/(kghydrolyzate), and cobalt, copper, lead, chromium, mercury and arsenic were not detected. By adding 0.05g/L CaCl2 to M3G medium, ε-PL yield was improved by 28.0%, indicating calcium was one of the factors for the enhanced ε-PL production. The study provides a reference for the efficient production of ε-PL from low-cost agricultural residues.

Sugarcane Bagasse-Based Ethanol Production and Utilization of Its Vinasse for Xylitol Production as an Approach in Integrated Biorefinery

Biorefinery of sugarcane bagasse into ethanol and xylitol was investigated in this study. Ethanol fermentation of sugarcane bagasse hydrolysate was carried out by Saccharomyces cerevisiae. After ethanol distillation, the vinasse containing xylose was used to produce xylitol through fermentation by Candida guilliermondii TISTR 5068. During the ethanol fermentation, it was not necessary to supplement a nitrogen source to the hydrolysate. Approximately 50 g/L of bioethanol was produced after 36 h of fermentation. The vinasse was successfully used to produce xylitol. Supplementing the vinasse with 1 g/L of yeast extract improved xylitol production 1.4-fold. Cultivating the yeast with 10% controlled dissolved oxygen resulted in the best xylitol production and yields of 10.2 ± 1.12 g/L and 0.74 ± 0.04 g/g after 60 h fermentation. Supplementing the vinasse with low fraction of molasses to improve xylitol production did not yield a positive result. The supplementation caused decreases of up to 34% in xylitol production rate, 24% in concentration, and 24% in yield.

Single cell protein production by Candida robusta isolated from sugar cane (Saccharum sp.) for animal feed / Produção de Biomassa por Candida robusta isolada da Cana-de-açúcar (Saccharum sp.) para alimentação animal

The protein obtained from the microorganisms is not only cheap but can be used as additive to provide a balanced nutrition for many animals feeding. The aim of this work was the single cell protein (SCP) production by Candida robusta URM5293 using sugarcane bagasse as substrate. The yeast C. robusta URM5293 was isolated from root sugarcane and was identified based on morphological and biochemical characteristics. Biomass production was done into Erlenmayers flasks (250 mL) containing culture medium supplemented of sugarcane bagasse hydrolyzate. Fermentations were carried varying culture conditions through the study of four different variables: temperature (25, 30, and 35°C), agitation intensity (110, 140 or 170 rpm), pH (6.0, 7.0, and 8.0) and production time (72, 96, and 120h), according to a 24-1 fractional factorial design. Results demonstrated that this yeast was able to ensure the highest level of biomass (141 g/L) when cultivated at 25°C, pH 6.0, 170 rpm of agitation intensity after 72h of cultivation using sugarcane bagasse. The present results demonstrate the potential of sugarcane bagasse hemicellulosic hydrolyzate as a substrate for the production of microbial protein by C. robusta URM5293.

Low-cost homemade cocktails for enzymatic conversion of sugarcane and cassava bagasses

ABSTRACT The agricultural industries generate lignocellulosic wastes that can be modified by fungi to generate high value-added products. This work aimed to analyze the efficiency and the cost-effectiveness of the bioconversion of sugarcane and cassava bagasses using low-cost homemade enzymatic cocktails from Aspergillus niger LBM 134. Both bagasses were pretreated with a soft alkaline solution without any loss of polysaccharides. After the hydrolysis, a 28% of conversion to glucose and 42% to xylose were reached in the hydrolysis of sugarcane bagasse while an 80% of saccharification yield, in the hydrolysis of cassava bagasse using the homemade enzymes. Furthermore, a more disorganised surface and no starch granules were observed in the sugarcane and cassava bagasses, respectively. The bioethanol yield from sugarcane and casava bagasses was predicted to be 4.16 mg mL−1 and 2.57 mg mL−1, respectively. A comparison of the cost of the homemade and the commercial enzymes was carried out. Similar hydrolysis percentages were achieved employing any enzyme; however, it was 1000–2000 times less expensive using the homemade cocktails than using the commercial enzymes. Therefore, the cost of obtaining glucose from bagasses was most expensive when applying the commercial enzymes. Moreover, the hydrolysis of the cassava bagasse was most efficient with the homemade cocktails. The importance and novelty of this work lie in the similar performance and the lower cost of the homemade cocktails from the fungus A. niger LBM 134 compared with the commercial enzymes on the hydrolysis of the sugarcane and cassava bagasses.

Biodiesel quality assessment of microalgae cultivated mixotrophically on sugarcane bagasse

In the present study FAMEs were analyzed qualitatively while growing microalgae mixotrophically in sugarcane bagasse hydrolysate under two concentrations and compared with biodiesel international standards. Biodiesel produced from microalgal feedstocks has gained attraction these days and for its commercial acceptance it must have to comply with the international biodiesel standards. Scenedesmus dimorphus and Nannochloropsis sp. showed high FAMEs contents of 138.7 and 170.5 µg mg−1 when cultivated mixotrophically. Nannochloropsis sp. and S. dimorphus showed high quantity of saturated fatty acids as 72 and 40%, respectively during mixotrophic cultivations. Mixotrophy enhanced the biodiesel quality in Chlorella sp. BR2 but decreased its FAMEs contents. Cetane number increased to 50, 57 and 47 in S. dimorphus, Chlorella sp. BR2 and Nannochloropsis sp., respectively, while iodine value decreased in all the three strains during mixotrophic cultivations and values found in accordance with the standards.

Economic Evaluation for Bioproducts Production from Carbohydrates Obtained from Hydrolysis of Sugarcane Bagasse

Economic Evaluation for Bioproducts Production from Carbohydrates Obtained from Hydrolysis of Sugarcane Bagasse