Biomass Derived Biofluorescent Carbon Dots for Energy Applications: Current Progress and Prospects.

Biomass resources are often disposed of inefficiently and it causes environmental degradation. These wastes can be turned into bio-products using effective conversion techniques. The synthesis of high-value bio-products from biomass adheres to the principles of a sustainable circular economy in a variety of industries, including agriculture. Recently, fluorescent carbon dots (C-dots) derived from biowastes have emerged as a breakthrough in the field, showcasing outstanding fluorescence properties and biocompatibility. The C-dots exhibit unique quantum confinement properties due to their small size, contributing to their exceptional fluorescence. The significance of their fluorescent properties lies in their versatile applications, particularly in bio-imaging and energy devices. Their rapid and straight-forward production using green/chemical precursors has further accelerated their adoption in diverse applications. The use of green precursors for C-dot not only addresses the biomass disposal issue through a scientific approach, but also establishes a path for a circular economy. This approach not only minimizes biowaste, which also harnesses the potential of fluorescent C-dots to contribute to sustainable practices in agriculture. This review explores recent developments and challenges in synthesizing high-quality C-dots from agro-residues, shedding light on their crucial role in advancing technologies for a cleaner and more sustainable future.

Valorization of Eichhornia crassipes for the production of cellulose nanocrystals further investigation of plethoric biobased resource.

Chemical processing is among the significant keys to tackle agro-residues utilization field, aiming to obtain value-added materials. Extraction of cellulose nanocrystals (CNCs) is an emerging route to valorize lignocellulosic wastes into high value particles. In this investigation, effect of acidic hydrolysis duration was monitored on size and morphology of obtained crystals; namely: CNCs from Nile roses fibers (NRFs) (Eichhornia crassipes). Different acidic hydrolysis duration range or different characterization techniques set this article apart from relevant literature, including our group research articles. The grinded NRFs were firstly subjected to alkaline and bleaching pretreatments, then acid hydrolysis process was carried out with varied durations ranging from 5 to 30 min. Microcrystalline cellulose (MCC) was used as reference for comparison with NRFs based samples. The extracted CNCs samples were investigated using various techniques such as scanning electron microscopy (SEM), Atomic force microscopy (AFM), Raman spectroscopy, and thermogravimetric (TGA) analysis. The figures gotten from SEM and AFM depicted that NRFs based CNCs appeared as fibril-like shapes, with reduced average size when the NRFs underwent pulping and bleaching processes. This was indicated that the elimination of hemicellulose and lignin components got achieved successfully. This outcome was proven by chemical composition measurements and TGA/DTG curves. On the other hand, AFM-3D images indicated that CNCs topology and surface roughness were mostly affected by increasing hydrolysis durations, besides smooth and homogeneous surfaces were noticed. Moreover, Raman spectra demonstrated that the particle size and crystallinity degree of NRFs based CNCs can be affected by acidic hydrolysis durations and optimum extraction time was found to be 10 min. Thermal stability of extracted CNCs-NRFs and CNCs-MCC was measured by TGA/DTG and the kinetic models were suggested to identify the kinetic parameters of the thermal decomposition of CNCs for each acid hydrolysis duration. Increasing hydrolysis duration promoted thermal stability, particularly for NRFs based CNCs. Results showcased in this article add new perspective to Nile rose nanocellulose and pave down the way to fabricate NRFs based humidity nano-sensors.

Employing soil isolated fungi for production of bioactive phenolic compounds: a fermentative approach.

An efficient method of solid-state fermentation (SSF) is reported for producing bioactive phenolic compounds using soil-isolated fungi. Antioxidant activity using a rapid DPPH (1,1-diphenyl-2-picryl hydrazyl), was employed to screen the 120 fungal isolates from soil. Aspergillus terreus 1, Aspergillus fumigatus, Aspergillus terreus 2, Penicillium citrinum, Aspergillus wentii1, Aspergillus wentii 2, Penicillium expansum and Penicillium granulatum were chosen, concerning their antioxidant activity and total phenolic content. These fungal strains were applied on agro residues viz. sugarcane bagasse, corn cob, rice straw, pea pod and wheat straw, to evaluate the release of phenolic compounds. The fermented extracts from various agro-residues showed good antioxidant activity against DPPH, ferric ion, and nitric oxide radicals. The highest antioxidant activity was observed in fermented extracts of sugarcane bagasse, followed by pea pod. Additionally, the total phenolic content in the fermented extracts positively correlated with antioxidant potential. This study highlights the significant potential of solid substrate fermentation using soil-isolated fungi and agro-residues to produce bioactive phenolic compounds with potent antioxidant properties. The utilization of SSF for the extraction of bioactive compounds from natural sources not only offers a clean and sustainable approach but also contributes to the valorization of agro-industrial residues.

Emerging trends in the appliance of ultrasonic technology for valorization of agricultural residue into versatile products.

The utilization of agricultural residues to obtain biocompounds of high-added value has significantly increased in the past decades. The conversion of agro-based residues into valuable products appears to be an economically efficient, environment-friendly, and protracted waste management practice. The implementation of ultrasonic technologies in the conversion of value-added goods from agricultural waste materials through pre-treatment and valorization processes has imparted many advantageous effects including rapid processing, effective process performance, minimization of processing steps, minimal dependency on harmful chemicals, and an increased yield and properties of bio-products. To further enliven the literature and inspire new research investigations, this review covers the comprehensive work including theoretical principles, processes, and potential benefits of ultrasonic treatment technologies to assist the production of bio-products which emphasize the extraction yield and the characteristic of the end-product extracted from agriculture residues. A detailed evaluation of these methods and key aspects impacting their performance as well as the features and shortcomings of each ultrasound-assisted approach is also discussed. This review also addressed some of the challenges associated with using ultrasonic irradiation and proposed several potential techniques to maximize productivity. Understanding the concept of ultrasonication technique allow the academician and industrial practitioners to explore the possibility of applying a greener and sustainable approach of biomass extraction to be translated into higher scale production of commercial products.

Valorization of millet agro-residues for bioenergy production through pyrolysis: Recent inroads, technological bottlenecks, possible remedies, and future directions.

Millets are receiving increasing attention, lately, in view of their preeminent agronomic traits, nutritional significance, and renewed emphasis on highlighting their health benefits through national and international programs. As a consequence, a variety of millets are being cultivated in different parts of the world resulting in significant amount of millet agro-residues. Present study comprehends critical analysis of reported investigations on pyrolysis of different millet agro-residues encompassing (i) physico-chemical characterization (ii) kinetics and thermodynamic parameters (iii) reactors employed and (iv) relationship between the reaction conditions and characteristics of millets-derived biochar and its prospective applications. Based on the analysis of reported investigations, specific research gaps have been figured out. Finally, future directions for leveraging the energy potential of millet agro-residues are also discussed. The analysis elucidated is expected to be useful for the researchers for making further inroads pertaining to sustainable utilization of millet agro-residues in tandem with other commonly employed agro-residues.

The screening of various biochars for Cd2+ removal at relevant soil pH.

Fourteen biochars from seven biomass sources were investigated on their long-term Cd2+ removal. The experiments consisted of a ten-day batch Cd2+ adsorption in a pH-buffered solution (pH = 6) to minimise pH effects. Insect frass, spent peat and chicken manure-derived biochars are promising Cd2+ adsorbents. Pyrolysis temperature was crucial for optimising Cd2+ removal by insect frass and spent peat-derived biochars. For these biochars, a pyrolysis temperature of 450 °C was optimal. In contrast, the Cd2+ removal by chicken manure biochars was independent of pyrolysis temperature. The Cd2+ removal by insect-frass and spent peat-derived biochars was associated with chemisorption on surface functionalities, while using chicken manure biochars was more associated with Cd2+ precipitation. The kinetics of Cd2+ removal over the course of ten days showed that insect frass biochar (450 °C) showed a gradual increase from 36 to 75 % Cd2+ removal, while chicken manure and spent peat-derived biochar (450 °C) already showed a higher Cd2+ removal (72 - 89 %) after day 1. This evidences that a long-term Cd2+ removal effect can be expected for some biochars. This should certainly be taken into consideration in future soil-based experiments.

Agricultural waste biomass for sustainable bioenergy production: Feedstock, characterization and pre-treatment methodologies.

The worldwide trend in energy production is moving toward circular economy systems and sustainable availability of sources. Some advanced methods support the economic development of energy production by the utilization of waste biomass, while limiting ecological effects. The use of agro waste biomass is viewed as a major alternative energy source that expressively lowers greenhouse gas emissions. Agricultural residues produced as wastes after each step of agricultural production are used as sustainable biomass assets for bioenergy production. Nevertheless, agro waste biomass needs to go through a few cyclic changes, among which biomass pre-treatment contributes to the removal of lignin and has a significant role in the efficiency and yield of bioenergy production. As a result of rapid innovation in the utilization of agro waste for biomass-derived bioenergy, a comprehensive overview of the thrilling highlights and necessary advancements, in addition to a detailed analysis of feedstock, characterization, bioconversion, and contemporary pre-treatment procedures, appear to be vital. To this end, the current status in the generation of bioenergy from agro biomass through various pre-treatment procedures was examined in this study, along with presenting relevant challenges and a perspective for future investigations.

Novel naringin tablet formulations of agro-resides based nano/micro crystalline cellulose with neuroprotective and Alzheimer ameliorative potentials.

This study aimed to prepare micro/nanocrystalline cellulose-loaded naringin (NAR) tablets and evaluate their neuro-protective/therapeutic potentials in Alzheimer's disease (AD) model. Micro/nanocellulose was prepared from different agro-wastes, and the different cellulose preparations were then used to formulate eight oral tablets of naringin micro/nanoparticles by direct compression. AD-like symptoms were induced in adult male Sprague Dawley rats by co-administration of 150 mg/kg AlCl3 and 300 mg/kg D-galactose (oral administration/one week), and NAR tablets were assessed for neuroprotective/therapeutic potentials in terms of behavioral changes, levels of neurodegenerative and inflammatory markers, brain redox status, neurotransmitter tones, and cortex/hippocampus histopathological alterations. NAR treatments have significantly reversed the neurotoxic effect of AlCl3 as demonstrated by improved spatial and cognitive memory functions and promoted antioxidant defense mechanisms in treated AD animals. Also, the neurodegeneration was markedly restrained as reflected by marked histopathological enhancement, and prevention/amelioration of neuropsychiatric disorders, besides the restorative effect on dysregulated neurotransmitters tone. Both NAR tablet forms showed an overall higher ameliorative effect compared to the DPZ reference drug. The formulated tablets represent promising neuroprotective/therapeutic agents for Alzheimer's disease.

Conversion of quinoa and lupin agro-residues into biochar in the Andes: An experimental study in a pilot-scale auger-type reactor.

In the last decades, the cultivation of quinoa and lupin became an important source of income for Andean farmers due to the demand for high nutrient-density foods from the Global North. The increase in the cultivation intensity caused by this exogenous demand led to the overexploitation of local ecosystems and a decrease in soil fertility. As an alternative to recover and improve soil quality, this work uses a pilot-scale auger pyrolysis reactor, implemented in the Andes, to assess the conversion of the agro residues generated in the post-harvesting processes of quinoa and lupin into biochar for soil amendment. Following the European Biochar Certificate guidelines, the pyrolyzed quinoa stems can be classified as biochar while the pyrolyzed quinoa husks can be classified as pyrogenic carbonaceous material. Both can be used for soil amendment considering their molar ratios (H/Corg, O/Corg) and carbon content. It was not possible to carbonize lupin stems and seedcases. Despite the altitude (2,632 m.a.s.l), the CO concentration during the carbonization of quinoa stems and husks were 1,024.4 and 559 mg/Nm3, this last, near the European eco-design standard of 500 mg/Nm3. A subsequent SWOT analysis showed the need to explore low-cost and low-complexity pyrolysis reactors that allow the decentralized conversion of agro residues at the farm-scale. The development of local standards to regulate the production and use of biochar is also essential to grant the safety of the processes, the quality of the products, and mobilize funds that allow implementation at relevant scales.

A critical review on exploitation of agro-industrial biomass as substrates for the therapeutic microbial enzymes production and implemented protein purification techniques.

Annually, a huge amount of waste is generated by the industries that use agricultural biomass. Researchers have looked into employing this cheap and renewable agro-biomass as a substrate for enzyme production via fermentation processes to meet the ever-increasing worldwide need. Although there are a number of sources for enzyme extraction, microbial sources have dominated industrial sectors due to their easy availability and rapid growth. Microbial enzymes are currently used in a variety of industries, including pharmaceuticals, food, biofuels, textiles, paper, detergents, and so on, and using these nutritious feedstocks not only reduces production costs but also helps to reduce environmental concerns. The present review focuses on the therapeutic microbial enzymes produced using different agro-industrial biomass as raw materials, with down-streaming techniques for obtaining a final pure product. Additionally, the article also discussed biomass pretreatment processes, including physical, chemical and biological. The type of pretreatment method to be used is mostly governed by the intended use of the major molecular components of biomass (cellulose, hemicelluloses and lignin). Finally, purification challenges are included. All of this information will be useful in the industrial synthesis of high-purity targeted enzymes if the crucial aspects that have been discussed are taken into account.

A comprehensive review on tannase: Microbes associated production of tannase exploiting tannin rich agro-industrial wastes with special reference to its potential environmental and industrial applications.

Microorganisms have been used for the production of various enzymes, including inducible tannase for various industrial and environmental applications. Tannases have lot of potential to convert hydrolysable tannins to gallic acid, which is one of the important industrial and therapeutic significant molecules whose demand is over 10000 tons per year. Tannins invariably occur in angiosperms, gymnosperms and pteridophytes, and predominantly present in various parts of plants such as, leaves, roots, bark and fruit. Furthermore, tannery effluents are frequently loaded with significant levels of tannic acid. Tannase can be effectively used to decrease tannin load in the toxic tannery effluent thus providing the opportunity to minimize the operational cost. Over the past three decades, tannase from microbial sources has been proposed for the degradation of natural tannins. The availability of various agro-industrial residues paves a way for maximum utilization of tannase production for the degradation of tannin and eventually the production of gallic acid. In this review, an illustrative and comprehensive account on tannase from microbial source for current day applications is presented. The present review emphasises on up-to-date microbial sources of tannases, biochemical properties, optimization of tannase production in solid state and submerged fermentation and its industrial and environmental applications.

Hydrothermal Conversion of Spent Sugar Beets into High-Value Platform Molecules.

The growing importance of bio-based products, combined with the desire to decrease the production of wastes, boosts the necessity to use wastes as raw materials for bio-based products. A waste material with a large potential is spent sugar beets, which are mainly used as animal feeds or fertilizers. After hydrothermal treatment, the produced chars exhibited an H/C ratio of 1.2 and a higher heating value of 22.7 MJ/kg, which were similar to that of subbituminous coal and higher than that of lignite. Moreover, the treatment of 25 g/L of glucose and 22 g/L of fructose by heating up to 160 °C led to a possible application of spent sugar beets for the production of 5-hydroxymethylfurfural. In the present study, the maximum concentration of 5-hydroxymethylfurfural was 3.4 g/L after heating up to 200 °C.

Comparative assessment of solvents and lignocellulolytic enzymes affiliated extraction of polyphenols from the various lignocellulosic agro-residues: identification and their antioxidant properties.

The present investigation was aimed to utilize lignocellulosic agro-residues and compare the extraction of polyphenols utilizing lignocellulolytic enzymes secreted by Sphingobacterium sp. ksn and with that of the solvents (ethanol, methanol) affiliated methods. The maximum amount of polyphenols, flavonoids and tannins were 94.29, 11.36, and 79.21 g 100 g-1 respectively, found in the extracts obtained by enzymes affiliated extraction of coffee cherry husk (CCH). The phenolics namely, gallic acid, caffeic acid, coumaric acid, 1-hydroxybenzoic acid, 2,5-dihydroxybenzoic acid, p-hydroxybenzaldehyde were commonly found whereas syringic acid, quercetin, kaempferol, and epicatechin were hardly found in the extracts of agro-residues. The extracts of CCH shown maximum antioxidant properties for DPPH, ABTS, and FRAP. The present study reports that the affiliation of enzymes for the extraction of polyphenols from agro-residues is more efficient than that of the solvents affiliation and CCH as the good source of polyphenols.

Effect of alkaline pretreatments on the enzymatic hydrolysis of wheat straw.

Lignocellulosic materials are mainly consisted of lignin, cellulose, and hemicellulose. Lignin is recognized as the main obstacle for the enzymatic saccharification of cellulose towards the fermentable sugars' production. Hence, the removal of lignin from the lignocellulosic feedstock is beneficial for reducing the recalcitrance of lignocellulose for enzymatic attack. For this purpose, various different alkaline pretreatments were examined in order to study their effect on the enzymatic saccharification of wheat straw, as a typical lignocellulosic material. Results revealed that the alkaline pretreatments promoted delignification reactions. Regarding the removal of lignin, the most efficient pretreatments were alkaline treatment with hydrogen peroxide 10% and NaOH 2% autoclave with delignification efficiencies of 89.60% and 84.86% respectively. X-ray diffraction analysis was performed to enlighten the structural changes of raw and pretreated materials. The higher the delignification of the raw material, the higher the conversion of cellulose during enzymatic saccharification. In all cases after enzymatic saccharification, the cellulosic conversion was much higher (32-77%) than the untreated wheat straw (8.6%). After undergoing alkaline peroxide 10% pretreatment and cellulase treatment, 99% of the initial raw straw was eventually solubilized. Thus, wheat straw could be considered as an ideal material for the production of glucose with proper pretreatments and effective enzymatic hydrolysis.

Agro-industrial residues as a unique support in a sand filter to enhance the bioactivity to remove microcystin-Leucine aRginine and organics.

In the past, the versatility of a biosand filter has been successfully checked to counter suspended solids, metals, dissolved organic carbon (DOC), coliforms and other water quality parameters (WQPs) from the drinking water sources. In this study, cyanotoxin in the form of microcystin-LR (MC-LR) along with above-mentioned WQPs including nitrate, nitrite, and ammonia are analyzed for their removal using agro-residue based biosand filters (ARSFs) for 49 days (7 cycles). Three different agro-residue materials (ARMs) viz. deinking sludge (DSF), hemp fiber (HFF) and paper-pulp dry sludge (PPF) were used as the support material (top 5 cm) along with sand (49 cm) as the primary filter media to enhance the overall bioactivity. This enhancement in bioactivity is hypothesized to remove more MC-LR, DOC, coliform along with efficient nitrification/denitrification. Native bacterial community isolated from the filtration unit of a drinking water treatment plant (Chryseobacterium sp. and Pseudomonas fragi = X) along with the MC-LR-degrader: Arthrobacter ramosus (which was screened as the best biofilm-former among two other MC-LR-degraders tested) were used to inoculate the filters (all three ARSFs). Overall, DSF performed the best among all the ARSFs when compared to the sand filter (SFI) inoculated with the same bacterial strains (A + X). An increase in the bioactivity for ARSFs, particularly DSF was evident from the DOC removal (44 ±â€¯11%, 15% more than SFI), coliform removal (92.7 ±â€¯12.8%, 24% more than SFI), MC-LR removal (87 ±â€¯14%, 13% more than SFI) and an effective nitrification/denitrification, reducing ammonia, nitrate and nitrite level to below guideline values. Toxic assessment using bioindicator (Rhizobium meliloti) revealed safe filter water only in case of DSF.

Efficient and economic process for the production of bacterial cellulose from isolated strain of Acetobacter pasteurianus of RSV-4 bacterium.

In the present investigation, several residues from agro-forestry industries such as rice straw acid hydrolysate, corn cob acid hydrolysate, tomato juice, cane molasses and orange pulp were evaluated as the economical source for the production of bacterial cellulose. The bacterial cellulose attained the significant yield of 7.8 g/L using tomato juice, followed by 3.6 g/L using cane molasses and 2.8 g/L using orange pulp after 7 days of incubation. Furthermore, the optimum pH and temperature of fermentation for maximum production of bacterial cellulose was 4.5 and 30 ±â€¯1 °C. The identified bacterium Acetobacter pasteurianus RSV-4 has been deposited at repository under the accession number MTCC 25117. The produced bacterial cellulose was characterized through FTIR, SEM, TGA and DSC and found to be of very good quality. The bacterial cellulose produced by identified strain on these various agro-waste residues could be a cost effective technology for commercial its production.

One-step process for producing prebiotic arabino-xylooligosaccharides from brewer's spent grain employing Trichoderma species.

Xylooligosaccharides (XOS) are prebiotic nutraceuticals that can be sourced from lignocellulosic biomass, such as agro-residues. This study reports for the first time an optimization study of XOS production from agro-residues by direct fermentation using two Trichoderma species. A total of 13 residues were evaluated as potential substrates for single-step production. The best results were found for Trichoderma reesei using brewers' spent grain (BSG) as substrate. Under optimal conditions (3 days, pH 7.0, 30 °C and 20 g/L of BSG), a production yield of 38.3 ±â€¯1.8 mg/g (xylose equivalents/g of BSG) was achieved. The obtained oligosaccharides were identified as arabino-xylooligosacharides (AXOS) with degree of polymerization from 2 to 5. One-step fermentation proved to be a promising strategy for AXOS production from BSG, presenting a performance comparable with the use of commercial enzymes. This study provides new insights towards the bioprocess integration, enabling further developments of low-cost bioprocesses for the production of these valuable compounds.

Biosynthesis, molecular modeling and statistical optimization of xylanase from a mangrove associated actinobacterium Streptomyces variabilis (MAB3) using Box-Behnken design with its bioconversion efficacy.

The present study was undertaken to evaluate the biosynthesis, molecular modeling and statistical optimization of xylanase production through Box-Behnken design by a mangrove associated actinobacterium Streptomyces variabilis (MAB3). Initially, the production of xylanase by the selected strain was carried through submerged fermentation using birchwood xylan as substrate. Further the xylanase production was statistically optimized through Box-Behnken design. It showed 5.30 fold increase of xylanase production by the isolate compared to 'one factor at a time approach' in the presence of the basal medium containing birchwood xylan (2.0% w/v) at pH 8.2, temperature 46.5 °C, inoculum size of 2% for 68 h. The analysis of variance (ANOVA) revealed high coefficient of determination (R2 = 0.9490) for the respective responses at significant level (P < 0.0001). The xylanase was purified by different purification steps and it resulted 5.30 fold increase with the yield of 21.27% at the final step using sephadex G-75 chromatography. The molecular weight of the purified xylanase was observed as 50 kDa on 10% SDS-PAGE. The homology 3D structure of the purified xylanase protein was predicted and this protein encodes with 420 amino acid residues. The maximum activity of purified xylanase was observed at pH 8, temperature 40 °C and the production medium supplemented with 1 mM Ca2+ metal ion, 2.0% xylan and 1.5% NaCl. The kinetic parameters of the purified xylanase expressed the Km and Vmax values of 5.23 mg/ml and 152.07 µg/min/mg, respectively. Finally, the xylanolytic hydrolysis of pretreated agro-residues, especially the rice straw substituted medium yielded maximum (46.28 mg/g) level of reducing sugar and saccharification (63.18%), followed by bioethanol production (3.92 g/l) at 72 h of incubation. Based on the results, it could be confirmed that the selected isolate is a potent strain for xylanase production and also it can able to convert the pretreated agro-residues into economically important byproduct like bioethanol.

Decolorization of complex dyes and textile effluent by extracellular enzymes of Cyathus bulleri cultivated on agro-residues/domestic wastes and proposed pathway of degradation of Kiton blue A and reactive orange 16.

In this study, the white-rot fungus Cyathus bulleri was cultivated on low-cost agro-residues, namely wheat bran (WB), wheat straw (WS), and domestic waste orange peel (OP) for production of ligninolytic enzymes. Of the three substrates, WB and OP served as good materials for the production of laccase with no requirement of additional carbon or nitrogen source. Specific laccase activity of 94.4 U mg-1 extracellular protein and 21.01 U mg-1 protein was obtained on WB and OP, respectively. Maximum decolorization rate of 13.6 µmol h-1 U-1 laccase for reactive black 5 and 22.68 µmol h-1 U-1 laccase for reactive orange 16 (RO) was obtained with the WB culture filtrate, and 11.7 µmol h-1 U-1 laccase for reactive violet 5 was observed with OP culture filtrate. Importantly, Kiton blue A (KB), reported not to be amenable to enzymatic degradation, was degraded by culture filtrate borne activities. Products of degradation of KB and RO were identified by mass spectrometry, and a pathway of degradation proposed. WB-grown culture filtrate decolorized and detoxified real and simulated textile effluents by about 40%. The study highlights the use of inexpensive materials for the production of enzymes effective on dyes and effluents.

Screening of filamentous fungi to produce xylanase and xylooligosaccharides in submerged and solid-state cultivations on rice husk, soybean hull, and spent malt as substrates.

We investigated the enzymatic complex produced by selected fungi strains isolated from the environment using the agro-industrial residues rice husk, soybean hull, and spent malt as substrates. Microbial growth was carried out in solid-state cultivation (SSC) and in submerged cultivations (SC) and the enzymatic activities of xylanase, cellulase, ß-xylosidase, and ß-glucosidase were determined. All substrates were effective in inducing enzymatic activities, with one strain of Aspergillus brasiliensis BLf1 showing maximum activities for all enzymes, except for cellulases. Using this fungus, the enzymatic activities of xylanase, cellulase, and ß-glucosidase were generally higher in SSC compared to SC, producing maxima activities of 120.5, 25.3 and 47.4 U g-1 of dry substrate, respectively. ß-xylosidase activity of 28.1 U g-1 of dry substrate was highest in SC. Experimental design was carried out to optimize xylanase activity by A. brasiliensis BLf1 in SSC using rice husk as substrate, producing maximum xylanase activity 183.5 U g-1 dry substrate, and xylooligosaccharides were produced and characterized. These results suggest A. brasiliensis BLf1 can be used to produce important lytic enzymes to be applied in the preparation of xylooligosaccharides.