Enzymatic Liquefaction Research Articles

Ферментативное разжижение и характеристика пюре из плодов Mangifera laurina Blume

The fruit Mangifera laurina Blume lacks sufficient research attention, with no literature available on its physicochemical properties, proximate nutritional composition, carotenoid content, or enzyme liquefaction process. Therefore, we aimed to optimize the parameters for enzymatic liquefaction of M. laurina puree and comprehensively analyze its characteristics.
 Homogenized pulp of M. laurina was treated with different enzymes (Pectinex Ultra SPL, Celluclast, Fungamyl, and Termamyl). Pectinex Ultra SPL was selected as the most effective enzyme as it significantly decreased viscosity and increased juice yield. Pectinex Ultra SPL was then used to treat the homogenized pulp at different concentrations (0–4.0%), different incubation times (0–2.5 h), and different incubation temperatures (25–60°C). We considered these parameters as independent variables and studied their effects on viscosity, juice yield, total soluble solids, pH, and color to establish optimum conditions for the enzymatic liquefaction of M. laurina pulp.
 The recommended enzymatic liquefaction conditions were set as 2.0% Pectinex Ultra SPL at 45°C for 2.0 h. The optimized enzyme-liquefied mango puree showed a noteworthy decrease in total carotenoids (174.15 ± 0.04 µg/100 g), crude protein, crude fat, and crude fiber, compared to fresh mango puree. However, enzymatic liquefaction provided the mango puree with higher contents of moisture and ash, better water activity, and higher juice yield, compared to fresh mango puree.
 Enzymatic liquefaction of fruit juice provides advantages in terms of improved digestion, increased yield, and enhanced economic profit. Its ability to enhance nutrient availability, increase extraction rates, and optimize production processes makes it a valuable technique in various food industries.

Comparative study of wet and dry properties on enzymatic hydrolysis efficiency of poplar with various combined-pretreatment

In this work, the combined pretreatment of sulfuric acid and alkaline (SA), solid acid and organic solvent (SO) and phosphoric acid and peroxide (PHP) on poplar was used to thoroughly evaluate the effects of wet and dry processing on enzymatic digestibility. The finding showed a negative connection between increasing glucose yield and rising drying temperature. Moreover, research showed that wet processing is beneficial because it improve mass transfer and permeability for enzymatic liquefaction. Enzymatic hydrolysis was additionally increased by mechanical wet milling following combined pretreatment. Most importantly, SO pretreatment was superior to PHP because SO pretreatment had a stronger linear relationship between particle size and glucose yield. Wet-milled post-treatment followed by SO combined pretreatment produced an acceptable glucose yield (91.93%). In comparison to the untreated poplar, the glucose yield had an increase by 87.14%. This work offers a novel processing method that might serve as a theoretical sound foundation for the effective saccharification of poplar wood.

Amino acid profiling and structural characterization of sorghum protein concentrates using enzyme liquefaction

Amino acid profiling and structural characterization of sorghum protein concentrates using enzyme liquefaction

Effect of biomass liquefaction on glucose and xylose prices predicted by National Renewable Energy Laboratory biochemical sugar model

AbstractThe National Renewable Energy Laboratory (NREL) published a model in 2017 that enables the minimum selling price of lignocellulosic sugar to be calculated. The model can be modified to suit any biomass feedstock and operational design. In the present case, the model is used to understand the economics of a process configuration that incorporates liquefaction as a preprocessing step in corn‐stover‐fed biorefinery. This study demonstrates a quantitative approach utilizing an existing biorefinery setup to simulate the biomass liquefaction technique while estimating the price of the resulting sugar product. The objective is to understand whether the addition of liquefaction methodology – and the substitution of acid pretreatment – can reduce the cost of lignocellulosic sugars. The reason for setting up a liquefaction unit at the start is to reduce the yield stress of biomass slurry so that the flow remains unrestricted downstream. The liquefaction process is also unique because it uses no chemicals and saves the cost of pretreatment. The pretreatment step is bypassed because the output of liquefaction can be fed into enzyme hydrolysis just after simple cooking. The liquefaction process can be performed in three modes: enzyme, enzyme mimetic, and a combination of enzyme and enzyme mimetic. The results from the BC1707 model indicate the minimum cost for the enzyme liquefaction route. © 2022 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

Improved cytometric analysis of untouched lung leukocytes by enzymatic liquefaction of sputum samples

BackgroundPhenotyping sputum-resident leukocytes and evaluating their functional status are essential analyses for exploring the cellular basis of pathological processes in the lungs, and flow cytometry is widely recognized as the gold-standard technique to address them. However, sputum-resident leukocytes are found in respiratory samples which need to be liquefied prior to cytometric analysis. Traditional liquefying procedures involve the use of a reducing agent such as dithiothreitol (DTT) in temperature-controlled conditions, which does not homogenize respiratory samples efficiently and impairs cell viability and functionality.MethodsHere we propose an enzymatic method that rapidly liquefies samples by means of generating O2 bubbles with endogenous catalase. Sputum specimens from patients with suspected pulmonary infection were treated with DTT, the enzymatic method or PBS. We used turbidimetry to compare the liquefaction degree and cell counts were determined using a hemocytometer. Finally, we conducted a comparative flow cytometry study for evaluating frequencies of sputum-resident neutrophils, eosinophils and lymphocytes and their activation status after liquefaction.ResultsEnzymatically treated samples were better liquefied than those treated with DTT or PBS, which resulted in a more accurate cytometric analysis. Frequencies of all cell subsets analyzed within liquefied samples were comparable between liquefaction methods. However, the gentle cell handling rendered by the enzymatic method improves cell viability and retains in vivo functional characteristics of sputum-resident leukocytes (with regard to HLA-DR, CD63 and CD11b expression).ConclusionIn conclusion, the proposed enzymatic liquefaction method improves the cytometric analysis of respiratory samples and leaves the cells widely untouched for properly addressing functional analysis of lung leukocytes.

Conversion of corn fiber into fuel ethanol

Corn fiber due to its chemical composition (up to 20% starch, 50 - 60% non-starch polysaccharides) and availability has potential to serve as a substrate for manufacture of various products, including fuel ethanol. This paper deals with assessment of fiber-to-ethanol conversion. The water/dry fiber ratio in suspensions was 10/1. Enzyme liquefaction and saccharification of residual starch in corn fiber was carried out in two steps with thermostable α-amylase (20 min, 120°C) and mixture of pullulanase and glucomalyse (24 hours, 60°C). Procedures resulted in release of 57.7±1.6 mg of glucose per gram of dry fiber basis. It responds to the dextrose equivalent expression to 96.7±2.2%. By fermentation of the starch hydrolysates by yeasts Saccharomyces cerevisiae CCY-11-3 (5% v/v inoculum, 28°C, 72 hours) 0.48 g of ethanol per gram of glucose in hydrolysates was obtained. The solids after starch hydrolysis were separated by filtration and processed by acid pretreatment (0.1 g of conc. HCl/g of biomass/5 ml of water, 120°C, 20 min) with subsequent enzyme hydrolysis (24 hours, 60°C) by the multienzyme preparations containing cellulases and hemicellulases. Overall yield of reducing sugars after these two steps was
 740.7±3.9 mg/gram of dry corn fiber basis. Fermentation of lignocellulosic hydrolysates by yeasts Pichia stipitis CCY-39-50-1 and Candida shehatea CCY-29-68-4 (in both cases 5% v/v inoculum, 28°C, 72 hours) resulted in 0.38 and 0.12 g of ethanol per gram of reducing sugars. The results indicate that applied pretreatment methods and used microorganisms are able to produce ethanol from corn fiber.

Effects of Enzymatic Liquefaction, Drying Techniques, and Wall Materials on the Physicochemical Properties, Bioactivities, and Morphologies of Zinc-Amaranth (Amaranthus viridis L.) Powders.

The demand for vegetable powder has been escalating considerably due to its various health benefits and higher shelf life compared to fresh green leafy vegetables. Thus, much research emphasised manufacturing vegetable powder at a lower operational cost and higher efficiency while preserving the nutritive values of the vegetables. In this study, zinc- (Zn-) amaranth puree was liquefied with three types of cell wall degrading enzymes (i.e., Viscozyme L, Pectinex Ultra SP-L, and Rapidase PAC) with varying concentrations (0–3% v/w) and incubation time (0.5–24 h) at pH 5 and 45°C before the drying process. The results showed that enzymatic liquefaction using 1% (v/w) of Viscozyme L for 3 h was the optimal procedure for the reduction of the viscosity of the puree. The liquefied puree was then microencapsulated through either spray- or freeze-drying with different wall materials, e.g., 10% of maltodextrin (MD) DE 10, resistant maltodextrin (RMD), N-octenyl succinate anhydride (OSA) starches from waxy maize, HI CAP 100 (HICAP), Capsul (CAP), and gum Arabic (GA). The results showed that all freeze-dried powders generally had higher process yield (except for that encapsulated by HICAP), higher moisture content (but similar water activities), higher retention of total Zn-chlorophyll derivatives, lower hygroscopicity with slab-like particles, larger particle size, and lower bulk density than those of spray-dried powders. In contrast, the spray-dried powders exhibited irregular spherical shapes with relatively high encapsulation efficiency and antioxidant activities. Nonetheless, encapsulation using different wall materials and drying methods had no significant effect on the powder's cohesiveness and flowability.

Rheology of enzyme liquefied corn stover slurries: The effect of solids concentration on yielding and flow behavior.

The measurement of yield stress and shear thinning flow behavior of slurries formed from unpretreated corn stover at solids loadings of 100-300 g/L provides a key metric for the ability to move, pump, and mix this lignocellulosic slurry, particularly since corn stover slurries represent a major potential feedstock for biorefineries. This study compared static yield stress values and flow hysteresis of corn stover slurries of 100, 150, 200, 250, and 300 g/L, after these slurries were formed by adding pellets to a cellulase enzyme solution (Celluclast 1.5L) in a fed-batch manner. A rotational rheometer was used to quantitate relative yield stress and its dependence on processing history at insoluble solids concentrations of 4%-21% (wt/vol). Key findings confirmed previous observations that yield stress increases with solids loadings and reaches ~3000 Pa at 25% (wt/vol) solids concentration compared to ~200 Pa after enzyme liquefaction. While optimization of slurry forming (i.e., liquefaction) conditions remains to be done, metrics for quantifying liquefaction extent are needed. The method for obtaining comparative metrics is demonstrated here and shows that the yield stress, shear thinning and shear thickening flow behaviors of enzyme liquefied corn stover slurries can be analyzed using a wide-gap rheometry setup with relative measuring geometries to mimic the conditions that may exist in a mixing vessel of a bioreactor while applying controlled and precise levels of strain.

Improving the extraction efficiency and stability of β-carotene from carrot by enzyme-assisted green nanoemulsification

In this study, a green solvent (water: ethanol; 98:2) was applied to extract β-carotene (BC) from carrot pomace powder (CP). The low solubility (<5%) of BC was improved (~21%) by enzymatic hydrolysis of CP with a commercial pectinase (61 U/mL, 60 min); enzymatic liquefaction of CP improved the extraction efficiency up to 90%. Also, the nanoemulsions (NEs) based on different surfactants (Lecithin; Lec, Tween 80; T80, Tween 20; T20, and Span 20; S20) enhanced the extraction efficiency of BC. Up to >91%. HPLC data revealed that BC (60%) and α-carotene (29%) were the major carotenoids extracted into micelles of NEs, whereas lutein (9%) and lycopene (2%) as the minor ones. Finally, stability monitoring confirmed that BC in ethanolic extract from CP was completely lost, while BC in NE platform showed good stability of ~25% and 32% as exposed to UV-light and acidic conditions (pH ~ 4), respectively.

The effect of enzyme concentration on physcical characteristics of pumpkin (Cucurbita moschata) puree and its dried extract

Pumpkin (Cucurbita moschata) contain many nutritional and biologically active components such as carotenoid content, polysaccharides, sterols, vitamins and protein. Since pumpkin has perishable characteristics, pumpkin must be preserved to increase the shelf life. The present study describe the possibility of producing spraydried pumpkin extract to increase the shelf life. Since pumpkin have high viscosity, it tend to cause deposit in the wall of spray drying chamber. With the help of enzyme liquefaction technique, the viscosity of the pumpkin can be reduced. In this research, pumpkin puree were individually treated with Pectinex Ultra-SP (0-2.5% w/v). Then, concentration Pectinex Ultra SP that produce the best viscosity reduction of pumpkin puree were chosen and treated with Celluclast 1.5 L (0-2.5% w/v). The results showed that 2.5% w/v of both Pectinex and Celluclast 1.5 L produced high viscosity reduction, clarity, total soluble solid and low pH. Then this pumpkin extract are subjected to spray drying condition and physical properties are measured. The spray drying of pumpkin extract with 2.5% w/v Celluclast 1.5 L and 2.5% w/v of Pectinex Ultra SP showed the higher yield of pumpkin powder, while no differences in moisture content, water activity and colour.

Immunodetection of Lung IgG and IgM Antibodies against SARS-CoV-2 via Enzymatic Liquefaction of Respiratory Samples from COVID-19 Patients.

Lung-secreted IgG and IgM antibodies are valuable biomarkers for monitoring the local immune response against respiratory infections. These biomarkers are found in lower airway secretions that need to be liquefied prior to analysis. Traditional methods for sample liquefaction rely on reducing disulfide bonds, which may damage the structure of the biomarkers and hamper their immunodetection. Here, we propose an alternative enzymatic method that uses O2 bubbles generated by endogenous catalase enzymes in order to liquefy respiratory samples. The proposed method is more efficient for liquefying medium- and high-viscosity samples and does not fragment the antibodies. This prevents damage to antigen recognition domains and recognition sites for secondary antibodies that can decrease the signal of immunodetection techniques. The suitability of the enzymatic method for detecting antibodies in respiratory samples is demonstrated by detecting anti-SARS-CoV-2 IgG and IgM to viral N-protein with gold standard ELISA in bronchial aspirate specimens from a multicenter cohort of 44 COVID-19 patients. The enzymatic detection sharply increases the sensitivity toward IgG and IgM detection compared to the traditional approach based on liquefying samples with dithiothreitol. This improved performance could reveal new mechanisms of the early local immune response against respiratory infections that may have gone unnoticed with current sample treatment methods.

Optimized detection of lung IL-6 via enzymatic liquefaction of low respiratory tract samples: application for managing ventilated patients.

Lung IL-6 is a promising biomarker for predicting respiratory failure during pulmonary infections. This biomarker is found in respiratory samples which need to be liquefied prior to analysis. Traditional liquefying methods use reducing agents such as dithiothreitol (DTT). However, DTT impairs immunodetection and does not liquefy highly viscous samples. We propose an enzymatic method that liquefies samples by means of generating O2 bubbles with endogenous catalase. Low respiratory tract specimens from 48 mechanically ventilated patients (38 with SARS-CoV-2 infection) were treated with DTT or with the enzymatic method. We used turbidimetry to compare the liquefaction degree and IL-6 was quantified with ELISA. Finally, we used AUC-ROC, time-to-event and principal component analysis to evaluate the association between respiratory compromise or local inflammation and IL-6 determined with both methods. Enzymatically treated samples were better liquefied than those reduced by DTT, which resulted in higher ELISA signals. Lung IL-6 levels obtained with the enzymatic procedure were negatively correlated with the oxygenation index (PaO2/FiO2) and the time of mechanical ventilation. The proposed enzymatic liquefaction method improves the sensitivity for lung IL-6 detection in respiratory samples, which increases its predictive power as a biomarker for evaluating respiratory compliance.

White sorghum landrace and corn starches in glucose syrups production using enzymatic and acid amylolysis

The aim of this study was to optimize and compare the production of glucose syrups from starches isolated from Algerian white sorghum and imported corn in order to study the possibility to use sorghum starch as alternative for glucose syrups production. Two combinations (acid–enzyme and enzyme–enzyme) amylolysis of starch isolated and purified from white sorghum using alkaline method and commercial corn starch were tested. The optimal conditions of the two hydrolysis steps (liquefaction and saccharification) were determined. Concentrations of 30% and 35% (w/v) for white sorghum and corn starches, respectively, were used as substrate. Optimal saccharification process occurs at 60°C, pH of 4.5 during 72 hr, and 1% (w/v) of Rhizopus mold amyloglucosidase. Final values of DE 88.32% and 97.03% using enzymatic liquefaction and 83.81%, 94.68% using acid liquefaction were obtained for sorghum and corn starches, respectively. The results indicate that the enzyme–enzyme amylolysis is more advantageous due to a high glucose conversion yield. Practical applications The study has shown that starch of white sorghum cultivated in disadvantaged regions of Algerian Sahara can be used for glucose syrups production. Starch represents 74.82% of kernel (db) and has very interesting physicochemical properties which make it a potential source of glucose syrups industry. The enzymatic amylolysis led to get glucose syrups with DE of 88.32% and good sensory properties. This product is widely used in pharmaceutical industries and commercial food production as a sweetener, thickener, and moisture-retaining agent. Further research will be planned to carry out for its applicability.

Concentrates from citrus juice obtained by crossflow microfiltration: Guidance of the process considering carotenoid bioaccessibility

This work focused on an eco-friendly process to concentrate carotenoids from a citrus juice formulated with clementine and pink grapefruit. It is based on crossflow microfiltration associated with enzymatic liquefaction, diafiltration and pasteurization. The aim was to evaluate the impact of the main operating conditions on the process performance and on the nutritional quality of the final concentrate taking into account the bioaccessibility of β-carotene, β-cryptoxanthin and lycopene. First, the best enzyme/pressure/membrane combination was chosen in order to maximize permeate flux during microfiltration (>100 kg.h−1.m−2 at 2.6 bar with tubular inorganic membranes). Second thanks to a Plackett-Burman experimental design applied to the whole process, we showed the enzymatic dose was the most impacting parameter on carotenoid bioaccessibility and it decreased it. An optimal dose of enzyme had to be defined in order to obtain a good compromise between the process performance and the nutritional quality of the citrus concentrate.

Concentration and purification by crossflow microfiltration with diafiltration of carotenoids from a by-product of cashew apple juice processing

This work aimed to further investigate microfiltration with diafiltration to obtain a rich carotenoid extract from the solid by-product of cashew apple (Anacardium occidentale L.) juice processing. This solid residue called cashew fibers is rich in bioactive compounds, especially carotenoids. After mixing with water and pressing, an aqueous suspension was obtained and processed by crossflow microfiltration (40 °C) using tubular ceramic membrane with 0.2 μm pore diameter. Permeate flux, which increased with transmembrane pressure, could be maintained above 100 L·h−1·m−2 at high volume reduction ratio by coupling mechanical extraction with enzyme liquefaction. The concentration step led to an increase of the carotenoid content by up to 19-fold and the diafiltration step allowed the carotenoid purity to be multiplied by 5. The impact of the process on the retentate characteristics was assessed using a model based on simple assumptions. This calculation tool can easily be implemented and is helpful for choosing the operating conditions, to minimize water consumption as well as effluent production.

Enzyme-Mediated Lignocellulose Liquefaction Is Highly Substrate-Specific and Influenced by the Substrate Concentration or Rheological Regime.

The high viscosities/yield stresses of lignocellulose slurries makes their industrial processing a significant challenge. However, little is known regarding the degree to which liquefaction and its enzymatic requirements are specific to a substrate’s physicochemical and rheological properties. In the work reported here, the substrate- and rheological regime-specificities of liquefaction of various substrates were assessed using real-time in-rheometer viscometry and offline oscillatory rheometry when hydrolyzed by combinations of cellobiohydrolase (Trichoderma reesei Cel7A), endoglucanase (Humicola insolens Cel45A), glycoside hydrolase (GH) family 10 xylanase, and GH family 11 xylanase. In contrast to previous work that has suggested that endoglucanase activity dominates enzymatic liquefaction, all of the enzymes were shown to have at least some liquefaction capacity depending on the substrate and reaction conditions. The contribution of individual enzymes was found to be influenced by the rheological regime; in the concentrated regime, the cellobiohydrolase outperformed the endoglucanase, achieving 2.4-fold higher yield stress reduction over the same timeframe, whereas the endoglucanase performed best in the semi-dilute regime. It was apparent that the significant differences in rheology and liquefaction mechanisms made it difficult to predict the liquefaction capacity of an enzyme or enzyme cocktail at different substrate concentrations.

Applicability of recombinant Aspergillus sojae crude mannanase enzyme in carrot juice production

The mannanases can be used for enzymatic maceration in carrot juice in order to increase the extract yield that soluble compounds such as sugars and β-carotene can easily release. In this study, the effects of microbial β-mannanase and its combination with the most commonly used commercial type enzymes in the carrot juice production on the carrot juice yield, the amount of β-carotene, and turbidity were investigated. Enzyme concentrations on yield were optimized by the Response Surface Method. As a result of the maceration process, fruit juice yields were increased. While the highest yield (58.51%) was obtained from the combination of 0.15 g β-mannanase/kg carrot and 0.3 g Viscozyme/kg carrot, the highest β-carotene concentration was found to be 2.75 mg/100 g using an individual β-mannanase enzyme. Last, the quality of the carrot juice in turbidity was improved by individual β-mannanase enzyme or β-mannanase with combining industrial enzymes. Practical applications The yield and quality of carrot juice (total β-carotene content) can be improved by crude or industrial enzyme liquefaction treatment. The concentration of the initial enzyme concentration and combination strategy is the most important parameter to obtain well-produced carrot juice. Consequently, enzyme liquefaction (maceration) process with individual β-mannanase enzyme or β-mannanase with combining industrial enzymes can be used as an important production step which increases quality in carrot juice production.

Effect of the black chokeberry (Aronia melanocarpa (Michx.) Elliott) juice acquisition method on the content of polyphenols and antioxidant activity.

The primary objective of the study was to determine the effect of process conditions on extraction efficiency and the total amount of released polyphenols and antioxidant activity (AA) in black chokeberry juice. The study samples were fruits of black chokeberry (Aronia melanocarpa (Michx.) Elliott) cv. Galicjanka. In the study, two kinds of presses—piston press and twin gear juice extractor—were used, and two raw material pretreatment methods—freezing and thawing and enzymatic liquefaction—were applied. The study showed that pressing efficiency depends on the design of press and the nature of pretreatment. The highest pressing efficiency was obtained using the twin gear juice extractor. Enzymatic liquefaction of shredded fruits significantly increased the efficiency of pressing by the piston press. The type of press and the pretreatment method used had an effect on the quality traits of the extracted juices. The highest content of soluble solids was obtained for fruits not subjected to any pretreatment and pressed using the twin gear press. The highest total phenolic content was obtained in juice extracted using the piston press from shredded fruits subjected to enzymatic treatment at 45°C. A higher total phenolic content was also a characteristic of juice obtained from fruits not subjected to any pretreatment and extracted using the twin gear press. The capacity of the black chokeberry juices for free radical quenching oscillated around the level of approximately 90%. The study showed that the application of suitable processing methods is necessary for the acquisition of products with desirable quality traits.

Coupling of pressure-driven membrane technologies for concentrating, purifying and fractionizing betacyanins in cactus pear (Opuntia dillenii Haw.) juice

Abstract An integrated process coupling crossflow micro and ultra or nanofiltration was applied to separate the betacyanins in cactus pear juice (30 °C). Four microfiltration ceramic membranes (0.1–0.2 μm, 1.8–3.3 bar) and 4 ultra/nanofiltration organic membranes (0.2–4.0 kDa, 5–30 bar) were tested. Microfiltration was a first step to remove insoluble solids with low retention of soluble solids. By coupling with enzymatic liquefaction, permeate flux Jp was increased by 2 and the retention of betacyanins was limited. Ultra/nanofiltration was then used for solute separation. Retentions of solutes could be modulated by varying membrane/pressure combinations that favor rather the concentration of all the solutes or rather the purification of the betacyanins with respect to the total dry matter. Retention of individual betacyanins could be a little different which also made possible fractionation. Simulations using simple models allowed to evaluate the interest of the process for concentrating, purifying and fractionating betacyanins with a possible diafiltration step. Industrial relevance Betacyanins are natural colorants that can be obtained from cactus pear juice, a crop of increasing interest for its agricultural potential in Sahelian regions. The aim of this study was to evaluate a new integrated process based on membrane separation allowing to concentrate or separate betacyanins from other solutes at low temperature and with a limited environmental impact. This process associates a first step to clarify the cactus pear juice by microfiltration after enzymatic liquefaction and a second step to concentrate or purify betacyanins by ultra or nanofiltration. By choosing different membrane/transmembrane pressure combinations in the 2nd step, solute retentions could be modulated in order to favor rather the concentration of all solutes or rather the separation of betacyanins from total soluble solids or even rather the fractionation of betacyanins themselves.

Process design and optimization of bioethanol production from cassava bagasse using statistical design and genetic algorithm

Bioethanol production from agro-industrial residues is gaining attention because of the limited production of starch grains and sugarcane, and food–fuel conflict. The aim of the present study is to maximize the bioethanol production using cassava bagasse as a feedstock. Enzymatic liquefaction, by α-amylase, followed by simultaneous saccharification and fermentation (SSF), using glucoamylase and Zymomonas mobilis MTCC 2427, was investigated for bioethanol production from cassava bagasse. The factors influencing ethanol production process were identified and screened for significant factors using Plackett–Burman design. The significant factors (cassava bagasse concentration (10–50 g/L), concentration of α-amylase (5–25% (v/v), and temperature of fermentation (27–37 °C)) were optimized by employing Box–Behnken design and genetic algorithm. The maximum ethanol concentrations of 25.594 g/L and 25.910 g/L were obtained from Box–Behnken design and genetic algorithm, respectively, under optimum conditions. Thus, the study provides valuable insights in utilizing the cost-effective industrial residue, cassava bagasse, for the bioethanol production.