Hydrolysis Of Sugarcane Bagasse Research Articles

Exploring the potential of novel thermophilic bacterial strain for the production of bioemulsifiers using the hydrolysate of sugarcane bagasse

Exploring the potential of novel thermophilic bacterial strain for the production of bioemulsifiers using the hydrolysate of sugarcane bagasse

Investigating the concomitant production of carotenoids and lipids by the yeast Rhodosporidium babjevae using sugarcane bagasse hydrolysate or corn steep liquor

The yeast Rhodosporidium babjevae was used to produce carotenoids, lipids, and fatty acids using sugarcane bagasse hydrolysates or glucose. Investigating the impact of glucose concentrations (10-150 g/L), the yeast showed the capability to yield 16.9 g/L biomass and 10.5 g/L lipids at 60 g glucose/L, while the highest pigments concentration (312 μg/g) was observed at 10 g glucose/L. Pre-treatment methods, including organosolv (ethanol 60 %(w/w)), alkali (NaOH 2 %(w/v)) and alkaline-organosolv (ethanol 60 %(w/w) and NaOH 2 %(w/v)) were used on the sugarcane bagasse following enzymatic hydrolysis. Among these, alkaline organosolv pre-treatment exhibited the most effective lignin removal of 81.9 %, releasing 46.7 g/L sugars by hydrolysis. Yeast cultivation on the enzymatic hydrolysates of alkaline organosolv pre-treatment resulted in the highest biomass (9.6 g/L) and lipids (5.0 g/L) yields. However, the highest content of pigments (280 μg/g) was achieved when the yeast was cultivated on the enzymatic hydrolysates of organosolv pre-treatment. Production of 11.3 g/L biomass, 204 μg/g pigments, and 6.7 g/L lipids established that corn steep liquor holds potential as a cheap and viable alternative to yeast extract as nitrogen source. The analysis of fatty acid composition revealed the prevalence of oleic acid and linoleic acid as dominant components.

Fed-batch fermentation of sugarcane biomass applied for biomolecules production in fluidized bed reactor

A production of xylitol and ethanol from a mixture of sugarcane straw and bagasse (biomass composed of 50 % m/m of both) hydrolysates was evaluated in a batch-fed column reactor. The biomass underwent acid hydrolysis, and the xylitol production process from hemicellulosic hydrolysate was assessed to determine the feasibility of operating four batches, showing conversions (YP/S of 0.28, 0.46, 0.57 and 0.47 g/g). Afterwards, alkaline pretreatment was performed, followed by enzymatic saccharification of the remaining biomass to obtain fermentable sugars for ethanol production. This involved operating five cycles, showing YP/S values of 0.14, 0.18, 0.24, 0.38 and 0.37 g/g, respectively. Additionally, the utilization of the black liquor generated from alkaline pretreatment was studied for reuse in subsequent pretreatments, demonstrating the feasibility of 4 cycles and thus, reducing the need for chemical preparation. The potential for maximizing the use of the main fractions of sugarcane biomass was confirmed.

Enhancing fermentable sugar production from sugarcane bagasse through surfactant-assisted ethylene glycol pretreatment and enzymatic hydrolysis: Reduced temperature and enzyme loading

In this study, an efficient coupling surfactant to ethylene glycol pretreatment (EG) and enzymatic hydrolysis of sugarcane bagasse (SCB) was proposed to enhance fermentable sugar production with lower pretreatment energy consumption and reduced enzyme loading. Under optimized conditions, 5 % Tween 80-assisted EG pretreatment of SCB achieved 80.5 % delignification while retaining cellulose (91.6 %) and hemicellulose (81.6 %) content. This led to an enhanced glucose yield of 81.3 %, compared to 65.1 % without Tween 80. The addition of Tween 80 to pretreatment modified residual lignin through etherification, reduced phenolic hydroxyl groups and enhanced hydrophilicity by 23.7 % and 9.4 %, respectively, compared to the lignin sample without Tween 80. Consequently, this modification alleviated non-productive adsorption between lignin and enzymes, improving substrate hydrolyzability. Moreover, when 4.5 % Triton-X 100 was introduced during the hydrolysis of Tween 80-assisted EG-pretreated substrates, a maximum glucose yield of 91.8 % and xylose yield of 92.6 % were achieved. Energy and enzyme cost analyses revealed a reduction of 35 % in pretreatment energy consumption and a 58.8 % decrease in enzyme costs, thanks to the synergistic action of surfactants in EG pretreatment and enzymatic hydrolysis. Overall, integrating surfactants into pretreatment and enzymatic hydrolysis holds promise for highly efficient conversion of SCB into fermentable sugars in enzyme-mediated lignocellulosic biorefineries.

Sugarcane bagasse valorization through integrated process for single cell oil, sulfonated carbon-based catalyst and biodiesel co-production

This study demonstrates the conversion of sugarcane bagasse (SB) into single cell oil (SCO), sulfonated carbon-based catalyst and biodiesel; this process aligns with waste-to-energy and circular bioeconomy concepts. SB was treated with dilute sulfuric acid to achieve SB hydrolysate (SBH) and SB solid residue (SBS). Candida tropicalis KKU-NP1, a newly isolated yeast, accumulated SCO content of 26.5 % from undetoxified SBH medium. A novel sulfonated carbon-based catalyst (SBS@SC) was generated from SBS by a one-step hydrothermal sulfonation process. It showed significant catalytic activity for the conversion of SCO-rich KKU-NP1 wet cell into biodiesel (FAME) under direct transesterification optimal conditions, with a FAME conversion yield of 90.1 %. Based on FAME profile, most of the estimated physicochemical and fuel properties of FAME were within the limits of ASTMD6751 and EN 14214 for biodiesel standards. For integrated process the final production of about 12.0 g SCO, 606.3 g SBS@SC catalyst and 10.8 g biodiesel from 1000 g raw SB were achieved.This study highlights the utilization of SB as a low-cost feedstock for producing multiple value-added products, emphasizing the advantages of waste utilization by integrated biorefinery concept, yielding practically no waste by-products over the whole production process.

Development of a co-culture system for green production of caffeic acid from sugarcane bagasse hydrolysate.

Caffeic acid (CA) is a phenolic acid compound widely used in pharmaceutical and food applications. However, the efficient synthesis of CA is usually limited by the resources of individual microbial platforms. Here, a cross-kingdom microbial consortium was developed to synthesize CA from sugarcane bagasse hydrolysate using Escherichia coli and Candida glycerinogenes as chassis. In the upstream E. coli module, shikimate accumulation was improved by intensifying the shikimate synthesis pathway and blocking shikimate metabolism to provide precursors for the downstream CA synthesis module. In the downstream C. glycerinogenes module, conversion of p-coumaric acid to CA was improved by increasing the supply of the cytoplasmic cofactor FAD(H2). Further, overexpression of ABC transporter-related genes promoted efflux of CA and enhanced strain resistance to CA, significantly increasing CA titer from 103.8 mg/L to 346.5 mg/L. Subsequently, optimization of the inoculation ratio of strains SA-Ec4 and CA-Cg27 in this cross-kingdom microbial consortium resulted in an increase in CA titer to 871.9 mg/L, which was 151.6% higher compared to the monoculture strain CA-Cg27. Ultimately, 2311.6 and 1943.2 mg/L of CA were obtained by optimization of the co-culture system in a 5 L bioreactor using mixed sugar and sugarcane bagasse hydrolysate, respectively, with 17.2-fold and 14.6-fold enhancement compared to the starting strain. The cross-kingdom microbial consortium developed in this study provides a reference for the production of other aromatic compounds from inexpensive raw materials.

Sorbitol production from mixtures of molasses and sugarcane bagasse hydrolysate using the thermally adapted Zymomonas mobilis ZM AD41

Byproducts from the sugarcane manufacturing process, specifically sugarcane molasses (SM) and sugarcane bagasse (SB), can be used as alternative raw materials for sorbitol production via the biological fermentation process. This study investigated the production of sorbitol from SM and sugarcane bagasse hydrolysate (SBH) using a thermally adapted Zymomonas mobilis ZM AD41. Various combinations of SM and SBH on sorbitol production using batch fermentation process were tested. The results revealed that SM alone (FM1) or a mixture of SM and SBH at a ratio of 3:1 (FM2) based on the sugar mass in the raw material proved to be the best condition for sorbitol production by ZM AD41 at 37 °C. Further optimization conditions for sorbitol production revealed that a sugar concentration of 200 g/L and a CaCl2 concentration of 5.0 g/L yielded the highest sorbitol content. The maximum sorbitol concentrations produced by ZM AD41 in the fermentation medium containing SM (FM1) or a mixture of SM and SBH (FM2) were 31.23 and 30.45 g/L, respectively, comparable to those reported in the literature using sucrose or a mixture of sucrose and maltose as feedstock. These results suggested that SBH could be used as an alternative feedstock to supplement or blend with SM for sustainable sorbitol production. In addition, the fermentation conditions established in this study could also be applied to large-scale sorbitol production. Moreover, the thermally adapted Z. mobilis ZM AD41 is also a promising sorbitol-producing bacterium for large-scale production at a relatively high fermentation temperature using agricultural byproducts, specifically SM and SB, as feedstock, which could reduce the operating cost due to minimizing the energy required for the cooling system.

Fabrication of carbon black nanoparticles from green algae and sugarcane bagasse

There are several industrial uses for carbon black (CB), an extremely fine powdered form of elemental carbon that is made up of coalesced particle aggregates and almost spherical colloidal particles. Most carbon black is produced from petroleum-derived feedstock, so there is a need to find an alternative method to produce CB, which relies on renewable resources such as algae and agricultural waste. A process involving hydrolysis, carbonization, and pyrolysis of green algae and sugarcane bagasse was developed, as the optimal hydrolysis conditions (16N sulfuric acid, 70 °C, 1 h, 1:30 g/ml GA or SC to sulfuric acid ratio), a hydrolysis ratio of 62% for SC and 85% for GA were achieved. The acidic solution was carbonized using a water bath, and the solid carbon was then further pyrolyzed at 900 °C. The obtained carbon black has a high carbon content of about 90% which is confirmed by EDX, XRD, and XPS analysis. By comparison carbon black from sugar cane bagasse (CBB) and carbon black from green algae Ulva lactuca (CBG) with commercial carbon black (CCB) it showed the same morphology which was confirmed by SEM analysis. The BET data, showed the high specific surface area of prepared CB, which was 605 (m2/g) for CBB and 424 (m2/g) for CBG compared with commercial carbon black (CBB) was 50 (m2/g), also the mean pore diameter of CBB, CBG and CCB indicated that CBB and CBG were rich in micropores, but CCB was rich in mesoporous according to IUPAC classification. This study might have created a technique that can be used to make carbon black from different kinds of biomass.

Quantitative correlation analysis between particle liquefaction and saccharification through dynamic changes of slurry rheological behavior and particle characteristics during high-solid enzymatic hydrolysis of sugarcane bagasse

This study identified the intrinsic relationships among slurry rheology, particle characteristics, and lignocellulosic liquefaction/saccharification based on correlation analysis and principal component analysis during the hydrolysis of sugarcane bagasse pretreated by deep eutectic solvents (DES) and mechanical milling (MM). The DES-MM pretreated lignocellulosic slurry (20% solids) exhibited high apparent viscosity of 1.4 × 104 Pa·s and shear stress of 929.0 Pa under steady state. Glucose production had a negative linear correlation with slurry viscosity (R2, 0.69–0.97), whereas its correlation with yield stress (R2, 0.85–0.98) depended on the particle liquefaction rate. The availability of free water provided a major contribution to improving slurry rheology. However, the size reduction of submillimeter particles and the changes in particle hydrophilicity during liquefaction were not significantly correlated with rheological changes. Various interrelated particle characteristics and rheological changes were integrated into two simple principal variables to predict glucose production with a high R2 of 0.96.

Enhancing Enzymatic Hydrolysis and Delignification of Sugarcane Bagasse Using Different Concentrations of Sodium Alkaline Pretreatment

Lignin, being highly resistant, needs to be eliminated in the process of extraction of soluble reducing sugar and bioethanol production from lignocellulosic biomass. In the present work, pretreatment of sugarcane bagasse (SCB) was performed using NaOH of various concentrations (1-5%) to facilitate delignification. The hydrolysis efficiency of pretreated SCB was evaluated at different reaction times by the production of reducing sugar using the Cellic CTec2 enzyme. The maximum cellulose content of 57.6% and lignin removal of 62.04% were observed with 2% sodium hydroxide at 121°C autoclaved for 60 min. The hemicellulose content decreased with increasing NaOH concentration with the maximum decrease of 13.6% from native bagasse having 26.5% xylan content. The microstructure, morphology, and chemical composition of SCB were analyzed using Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform InfraRed (FTIR), and XRD. The hydrolysis with 10 FPU.g-1 of enzyme at 48 h of reaction time shows a maximum yield of 12.34 g.L-1 corresponding to 55.53 ± 0.45% at 2% NaOH pretreated SCB. This study claims that lignin components exhibited the highest susceptibility to NaOH pretreatment, which directly affects enzymatic hydrolysis.

Hydrolysate derived from sugarcane bagasse by hydrothermal and enzymatic treatment as an external carbon source for wastewater nitrogen removal

Research on the preparation of denitrifying carbon sources from agricultural wastes persists with problems of environmentally unfriendly pretreatment methods and unstable carbon release. In this study, a hydrolysis method without secondary waste liquid generation was used and the obtained hydrolysate was applied as a denitrifying carbon source. Firstly, the optimum hydrothermal condition of sugarcane bagasse (SCB) was explored, which showed a higher reducing sugar concentration (13.68 g/L) and COD concentration (20,691.67 mg/L) at 200 °C, 40 min with relatively low energy consumption (EC) requirement (1.81 kW·h). Afterward, all three bio-additives (tea saponins, rhamnolipids, and whey proteins) were found to enhance enzymatic hydrolysis, with whey proteins being the most effective, increasing the reducing sugar and COD concentrations by 29.40 % and 17.51 %, respectively. The enzymatic reaction was optimized using the following conditions: whey protein concentration of 0.2 %, pH 5.0, temperature 50 °C, cellulase to the β-glucosidase ratio of 4:1, and total enzyme amount of 30 mg. Moreover, the nitrogen removal effect of SCB hydrolysate as a carbon source was determined, and the average TN removal was 98.23 % at C/N of 5 and HRT of 8. Finally, the microbial community was analyzed, and the dominant phylum was denitrifying bacteria (Proteobacteria), and organic matter utilizing bacteria (Bacteroidetes, Acidobacteriota, and Patescibacteria), and the relative abundance of the latter both improved with increasing C/N, which further demonstrated the feasibility of SCB hydrolysate as a carbon source. This research provides a reference for the application of agricultural waste hydrolysate in wastewater nitrogen removal.

Use of an inexpensive carbon source for the production of a cellulase enzyme complex from Penicillium ucsense S1M29 and enzymatic hydrolysis optimization

AbstractThe high cost of cellulolytic enzyme complexes (CECs) has been a significant impediment to the commercial production of bioproducts from lignocellulose biomass. This study aimed to develop a cost‐effective CEC derived from Penicillium ucsense (former Penicillium echinulatum), utilizing diverse forms of pretreated sugarcane bagasse as the primary carbon/inductor source. Among the different pretreatments used, the hydrothermal pretreatment followed by NaOH delignification (BHD) produced higher FPase and xylanase activities (4.5 FPU mL–1 and 120 IU mL–1) in bioreactor experiments at 20 g BHD L–1 initial concentration. A batch‐mode assay conducted across a range of initial carbon source (5 to 60 g L–1) confirmed the highest FPase activity (4.0 to 5.0 FPU mL–1 at 120 h), in the range of 20–40 g BHD L–1. During these assays the agitation rate, controlled by dissolved O2, tended to stabilize at lower levels, indicating substrate limitation. Conversely, higher initial carbon source concentrations led to an excess of glucose, likely triggering carbon catabolite repression and inhibiting cellulase production. This insight prompted the development of a controlled pulsed fed‐batch strategy, resulting in FPase activity of 11 FPU mL–1 at 220 h using 90 g L–1 BHD controlled fed into the bioreactor. An enzymatic hydrolysis procedure using the generated CEC was also optimized using a central composite rotational design (CCRD). The optimized enzyme hydrolysis conditions achieved a reducing sugar concentration of 80.9 g L–1 in 48 h using 170 g L–1 of BHD as the substrate at a ratio of 15 FPU of enzyme substrate per g of BHD. A preliminary economic assessment demonstrated that, for a first‐ and second‐generation (1G + 2G) ethanol biorefinery, the cost contribution of enzymes would be about US$0.2/L of biofuel. In conclusion, an efficient and highly productive procedure was developed successfully for the production of a CEC. It was particularly effective for the enzymatic hydrolysis of pretreated sugarcane bagasse.

Comparative study for enzymatic hydrolysis of sugarcane bagasse using free and nanoparticle immobilized holocellulolytic enzyme cocktail

This study aimed at a comparative analysis of enzymatic hydrolysis of sugarcane bagasse biomass by using a free holocellulase cocktail of an enzyme (Cellic CTec2) and immobilized enzyme system on IOMNP@SiO2-NH2 support to make the process cost-effective. The immobilization was substantiated by examining the nano biocatalysts using FTIR, TEM, and DLS analysis. IOMNP@SiO2 –NH2 and immobilized enzyme system have average particle sizes of 81.1, and 455.9 nm confirmed by DLS. Response surface methodology (RSM) based on the Box Behnken design was employed to optimize the saccharification process conditions. The free cellulase cocktail showed a maximum hydrolysis yield of 70.71 % at 12.5FPU/gm enzyme dose, while the immobilized enzyme at a dose of 20 FPU/gm achieved a conversion rate of 74.19 % under optimized parameters likes hydrolysis time, surfactant and substrate concentration. Pretreated sugarcane bagasse substrate was used to evaluate the reusability potential of magnetically immobilized cellulase enzyme compared to recovered free enzyme up to 5 cycles. In the second and third cycles, the conversion rates of cellulose to glucose were determined to be 68.21 %, and 52.6 %, respectively. The findings of this study demonstrate that the immobilized Cellic CTec2 enzyme cocktail on functionalized IOMNP is effective for hydrolyzing sugarcane bagasse which also provides the advantages of easy recovery and reusability of enzyme for multiple hydrolysis cycles.

Glycerol Production from Undetoxified Lignocellulose Hydrolysate by a Multiresistant Engineered Candida glycerinogenes.

Glycerol is an important platform compound with multidisciplinary applications, and glycerol production using low-cost sugar cane bagasse hydrolysate is promising. Candida glycerinogenes, an industrial yeast strain known for its high glycerol production capability, has been found to thrive in bagasse hydrolysate obtained through a simple treatment without detoxification. The engineered C. glycerinogenes exhibited significant resistance to furfural, acetic acid, and 3,4-dimethylbenzaldehyde within undetoxified hydrolysates. To further enhance glycerol production, genetic modifications were made to Candida glycerinogenes to enhance the utilization of xylose. Fermentation of undetoxified bagasse hydrolysate by CgS45 resulted in a glycerol titer of 40.3 g/L and a yield of 40.4%. This process required only 1 kg of bagasse to produce 93.5 g of glycerol. This is the first report of glycerol production using lignocellulose, which presents a new way for environmentally friendly industrial production of glycerol.

OPTIMIZATION AND QUALITY ANALYSIS OF BIO-BUTANOL PRODUCTION FROM SUGARCANE (Saccharum officinarum) BAGASSE HYDROLYSATE

Several companies are currently investigating in development for the production of Biobutanol. This research was concerned with Biobutanol production from ABE (Acetone, Butanol, and Ethanol) fermentation of sugarcane bagasse hydrolysate by Clostridium Perfringens. The sample was hydrolyzed with concentrated H2SO4 solution for 1 hour at 121oC. Response surface designed by optimizing the fermentation parameters (Time, Temperature, and pH) by the used media (C. Perfringens) showed the highest Biobutanol yield at temperature (350C), Time 48 (Hhs), and pH 6.0 with 163 cm3 which is exactly around 0.543(g/L) by converted to a gram per liter as mostly represented by many researchers. The produced Biobutanol from the sugarcane bagasse hydrolysate was characterized using FT-IR and GC-MS analysis. Conclusively this work revealed the importance of sugarcane bagasse as a good potential feedstock of Biobutanol.

Recycling enzymatic hydrolysis lignin residues saved cellulase in enzymatic hydrolysis of lignocellulose: An insight from cellulase adsorption mechanism

Enzymatic hydrolysis lignin residues (EHLRs) of lignocellulose usually adsorbs cellulase, which can be recycled and used to replace parts of cellulase in the hydrolysis process. To understand this phenomenon during enzymatic hydrolysis (EH) of sugarcane bagasse (SCB) treated with sulfite (SPORL) and dilute acid (DA), the adsorption characteristics between lignin and cellulase in EHLRs were investigated, focusing on interaction force at molecular level and enzymatic activity. The results revealed that SPORL-EHLR adsorbed more β-glucosidases (β-GLs) through the stronger electrostatic attraction and hydrogen bond force, causing higher cellulase adsorption amount compared to DA-EHLR. Further exploration demonstrated that the cellobiose’s catalytic and binding sites on β-GLs were separated from the binding site of SPORL-EHLR on β-GLs, resulting in minimal inhibition of β-GLs activity when bound to SPORL-EHLR. Furthermore, adding SPORL-EHLR in SCB hydrolysis saved 40% cellulase. This study deepens the understanding of the adsorption behavior between lignin and cellulase.

Adaptive laboratory evolution under acetic acid stress enhances the multistress tolerance and ethanol production efficiency of Pichia kudriavzevii from lignocellulosic biomass

Second-generation bioethanol production using lignocellulosic biomass as feedstock requires a highly efficient multistress-tolerant yeast. This study aimed to develop a robust yeast strain of P. kudriavzevii via the adaptive laboratory evolution (ALE) technique. The parental strain of P. kudriavzevii was subjected to repetitive long-term cultivation in medium supplemented with a gradually increasing concentration of acetic acid, the major weak acid liberated during the lignocellulosic pretreatment process. Three evolved P. kudriavzevii strains, namely, PkAC-7, PkAC-8, and PkAC-9, obtained in this study exhibited significantly higher resistance toward multiple stressors, including heat, ethanol, osmotic stress, acetic acid, formic acid, furfural, 5-(hydroxymethyl) furfural (5-HMF), and vanillin. The fermentation efficiency of the evolved strains was also improved, yielding a higher ethanol concentration, productivity, and yield than the parental strain, using undetoxified sugarcane bagasse hydrolysate as feedstock. These findings provide evidence that ALE is a practical approach for increasing the multistress tolerance of P. kudriavzevii for stable and efficient second-generation bioethanol production from lignocellulosic biomass.

Sugar cane bagasse hydrolysate (SBH) as a lucrative carbon supplement to upgrade the lipid and fatty acid production in Chlorococcum sp. for biodiesel through an optimized binary solvent system

Cost is the crucial impediment in commercializing microalgal biodiesel. Therefore, cultivating microalgae in cost-effective nutrients reduces the upstream process cost remarkably. Thus, in this study, sugar cane bagasse hydrolysate (SBH) as a lucrative carbon supplement for Chlorococcum sp. and subsequent lipid extraction via an optimized solvent system for biodiesel production was investigated. Characterization of SBH revealed the presence of various monosaccharides and other sugar derivatives such as glucose, fructose, xylose, arabinose, etc. The maximum dry cell weight of 1.7 g/L was estimated in cultures grown in 10 mL SBH. Different solvents such as diethyl ether (DEE), chloroform (CHL), ethyl acetate (ETA), hexane (HEX), methanol (MET), ethanol (ETOH), acetone (ACE) and also combination of solvents (2:1 ratio) such as DEE: MET, CHL: MET, HEX: MET, HEX: ETOH was tested for lipid extraction efficacy. Among solvents used, 12.3% and 18.4% of lipids were extracted using CHL and CHL: MET, respectively, from 10 mL SBH amended cultures. However, the biodiesel yield was found to be similar at about 70.16 % in both SBH and no SBH-added cultures. The fatty acid profile of the biodiesel shows palmitic, oleic, linoleic, linolenic, and arachidonic acid as principal fatty acids. Further, the levels of SFAs, MUFAs, and PUFAs in 10 mL SBH-added cells were 24.67, 12.89, and 34.24%, respectively. Eventually, the fuel properties of Chlorococcum sp. biodiesel, satisfying international biodiesel standards, make the biodiesel a viable diesel substitute in the future.

Calcium alginate-immobilized β-glucosidase from Moniliophthora perniciosa: characterization and sugarcane bagasse hydrolysis

The utilization of lignocellulosic materials for second-generation ethanol production via enzymatic catalysts is primarily hindered by enzyme cost. Enzymatic immobilization emerges as a viable solution, enabling enzyme reuse. This study investigated the immobilization of an enzymatic extract obtained from Moniliophthora perniciosa fermentation in calcium alginate spheres using the direct trapping method. Initial tests assessed β-glucosidase activity, showing that a higher concentration of calcium chloride (1 M) alongside larger diameter spheres yielded improved results. The immobilized enzyme was reused for up to 17 cycles without significant loss of activity. The percentage of reducing sugars after 48-h hydrolysis with the supplemented enzymatic extract was 226%, doubling the value achieved with only the free enzymatic extract. The immobilized enzyme retained 50% of its initial activity after 1 h at 80 °C, demonstrating higher activity at pH 6 and 60 °C. These findings suggest that this immobilization technique is simple, economically viable, and effective for the hydrolysis of pretreated sugarcane bagasse.

Fermentative Production of β-Carotene from Sugarcane Bagasse Hydrolysate by Rhodotorula glutinis CCT-2186.

Β-Carotene is a red-orange pigment that serves as a precursor to important pharmaceutical molecules like vitamin A and retinol, making it highly significant in the industrial sector. Consequently, there is an ongoing quest for more sustainable production methods. In this study, glucose and xylose, two primary sugars derived from sugarcane bagasse (SCB), were utilized as substrates for β-carotene production by Rhodotorula glutinis CCT-2186. To achieve this, SCB underwent pretreatment using NaOH, involved different concentrations of total solids (TS) (10%, 15%, and 20%) to remove lignin. Each sample was enzymatically hydrolyzed using two substrate loadings (5% and 10%). The pretreated SCB with 10%, 15%, and 20% TS exhibited glucose hydrolysis yields (%wt) of 93.10%, 91.88%, and 90.77%, respectively. The resulting hydrolysate was employed for β-carotene production under batch fermentation. After 72h of fermentation, the SCB hydrolysate yielded a β-carotene concentration of 118.56 ± 3.01mg/L. These findings showcase the robustness of R. glutinis as a biocatalyst for converting SCB into β-carotene.