Wheat Straw Extracts Research Articles

Exploring a facile preparation method for Co-Ni/MoS2-derived nanohybrid from wheat straw extract and its physicochemical properties.

This study presents a novel approach for the fabrication of a Co,Ni/MoS2-derived nanohybrid material using wheat straw extract. The facile synthesis method involves a sol-gel process, followed by calcination, showcasing the potential of agricultural waste as a sustainable reducing and chelating reagent. The as-prepared nanohybrid has been characterized using different techniques to analyse its physicochemical properties. X-ray diffraction analysis confirmed the successful synthesis of the nanohybrid material, identifying the presence of NiMoO4, CoSO4 and Mo17O47 as its components. Fourier-transform infrared spectroscopy differentiated the functional groups present in the wheat straw biomass and those in the nanohybrid material, highlighting the formation of metal-oxide and sulphide bonds. Scanning electron microscopy revealed a heterogeneous morphology with agglomerated structures and a grain size of around 70 nm in the nanohybrid. Energy-dispersive X-ray spectroscopy analysis shows the composition of elements with weight percentages of (Mo) 9.17%, (S) 6.21%, (Co) 12.48%, (Ni) 12.18% and (O) 50.46% contributing to its composition. Electrochemical analysis performed through cyclic voltammetry showcased the exceptional performance of the nanohybrid material as compared with MoS2, suggesting its possible applications for designing biosensors and related technologies. Thus, the research study presented herein underscores the efficient utilization of natural resources for the development of functional nanomaterials with promising applications in various fields. This study paves a way for manufacturing innovation along with advancement of novel synthesis method for sustainable nanomaterial for future technological developments.

Anaerobic Digestion of Dye Wastewater and Agricultural Waste with Bio-Energy and Biochar Recovery: A Techno-Economic and Sustainable Approach

While several researchers have investigated the anaerobic digestion (AD) of textile wastewater for dye degradation, their studies suffer from lower biogas productivity due to substrate inhibition and the occurrence of secondary pollution from digestate disposal. Hence, this study focuses on using the extract of wheat straw (WS) as a co-substrate to facilitate the dye AD process, followed by recycling the digestate sludge for biochar production. In the first study, the batch digesters were operated at different dye wastewater (DW)/WS ratios (0–50% v/v), substrate-to-inoculum ratio of 0.28–0.50 g/g, pH 7.0 ± 0.2, and 37 °C. The digester operated at a DW/WS fraction of 65/35% (v/v) showed the best chemical oxygen demand (COD) removal efficiency of 68.52 ± 3.40% with bio-CH4 of 270.52 ± 19.14 mL/g CODremoved. About 52.96 ± 3.61% of the initial COD mass was converted to CH4, avoiding inhibition caused by volatile fatty acid (VFA) accumulation. In the second experiment, the dry digestate was thermally treated at 550 °C for 2 h under an oxygen-deprived condition, yielding 0.613 ± 0.031 g biochar/g. This biochar exhibited multiple functional groups, mineral contents, and high stability (O/C = 0.193). The combined digestion/pyrolysis scenario treating 35 m3/d (106.75 kg COD/d) could maintain profits from pollution reduction, biogas, biochar, and carbon trading, obtaining a 6.5-year payback period.

Revival of wild edible-medicinal mushroom (Hericium erinaceus) based on organic agro-industrial waste- achieving a commercial protocol with the highest yield; optimum reuse of organic waste

Hericium erinaceus (Bull.: Fr.) pers mushroom is belonging to the Class Agaricomycetes and family Hericiaceae that has been used as medicinal interests in traditional Chinese and Japanese medicine in Eastern Asia for hundreds of years. It is grown on a substrate based on hardwood sawdust and agricultural or industrial wastes supplemented with various additives. In the present experiment, the mycelial growth rate of Hericium erinaceus investigated in the eight media including the malt extract agar (MEA), Quercus infectoria (Oak) sawdust extract agar (OEA), Carpinus betulus (Hornbeam) sawdust extract agar (HEA), wheat straw extract agar (WEA), buttom mushroom compost extract agar (CEA), Pterocarya fraxinifolia (Lam.) sawdust extract agar (CWEA), Ulmus americana (Elm) sawdust extract agar (EEA), bagasse extract agar (BEA). Results showed the highest rate in CWEA and CEA media cultures and the lowest growth rate in the BEA media culture with 5.13, 4.83, and 1.73 mm/day, respectively. In this present study, has been used of compounds including wheat straw, sawdust, bagasse, rice bran, wheat bran, soybean powder, and corn flour. Among the 19 substrates for the cultivation of H. erinaceus, the best substrate found composition 17 (wheat straw 30 % + sawdust 30% + wheat bran 15% + bagasse 15% + corn flour 10%) for SRP, PHFP, FHP, TCP, Y and BE with values of 25, 29, 34.33, 44 days, 244.19 g/bag and 69.77%, respectively. Also, the maximum values of protein, dietary fiber, carbohydrate, fat, and energy were recorded with values of 19.33, 30, 35.33, and 1.23 g/100 g DW and 289.6 kcal/100 g DW, respectively.

Potential Allelopathic Effect of Wheat Straw Aqueous Extract on Bermudagrass Noxious Weed

Residues of several crops, including wheat, have a promising allelopathic effect on noxious weed species and thus represent eco-friendly alternatives to harmful, widely applied herbicides. The current investigation deals with the effects of wheat straw aqueous extract on the growth and biochemical aspects of bermudagrass (Cynodon dactylon L.) as a model of harmful weeds for the wheat crop. The prepared aqueous extract from wheat straw was subjected to high-performance liquid chromatography (HPLC) analysis to identify and quantify phenolic and flavonoid components. In addition, the allelopathic effect of different concentrations of the extract on the germination, seedling growth, and biochemical aspects of bermudagrass was assessed. Our findings showed a significant decrease in bermudagrass seed germination percentage (ranging from 29.6 to 82.4%) and germination index (ranging from 10.07 to 32.43) in response to the extract treatments and a significant decline in all morphological growth parameters of the seedling. HPLC analysis of the extract showed the presence of seven phenolic acids and six flavonoids. The most prevalent phenolics included pyrogallol (13.75 µg/g), ferulic acid (9.82 µg/g), gallic acid (8.5 µg/g), and isoferulic acid (4.47 µg/g), while the predominant flavonoids included catechin (11.04 µg/g), luteolin (8.26 µg/g) and quercetin (7.74 µg/g). The highest extract concentrations (75% and 100%) showed a corresponding decline in the leaf content of chlorophylls a and b but a significant increase in the content of free amino acids, total protein and soluble carbohydrates. Superoxide dismutase (SOD) activity exposed a concentration-dependent reduction, while the activities of both catalase (CAT) and ascorbate peroxidase (APX) were reduced only with the highest extract concentration. The principal component analysis (PCA) showed a high correlation among the morphological growth parameters, indicating that these elements either have a common ground of variance or are inter-correlated. Accordingly, our findings suggest the possibility of combating bermudagrass weeds using the aqueous extract of wheat straw.

Bundling the removal of emerging contaminants with the production of ligninolytic enzymes from residual streams

Enzymes offer interesting features as biological catalysts for industry: high specificity, activity under mild conditions, accessibility, and environmental friendliness. Being able to produce enzymes in large quantities and having them available in a stable and reusable form reduces the production costs of any enzyme-based process. Agricultural residues have recently demonstrated their potential as substrates to produce ligninolytic enzymes by different white rot fungi. In this study, the biotechnological production of a manganese peroxidase (MnP) by Irpex lacteus was conducted through solid-state fermentation (SSF) with wheat straw as substrate and submerged fermentation (SmF) employing wheat straw extract (WSE). The obtained enzyme cocktail also showed manganese-independent activity (MiP), related to the presence of a short MnP and a dye-decolorizing peroxidase (DyP) which was confirmed by shotgun proteomic analyses. In view of the enhanced production of ligninolytic enzymes in SmF, different parameters such as WSE concentration and nitrogen source were evaluated. The highest enzyme titers were obtained with a medium formulated with glucose and peptone (339 U/L MnP and 15 U/L MiP). The scale-up to a 30 L reactor achieved similar activities, demonstrating the feasibility of enzyme production from the residual substrate at different production scales. Degradation of five emerging pollutants was performed to demonstrate the high oxidative capacity of the enzyme. Complete removal of hormones and bisphenol A was achieved in less than 1 h, whereas almost 30% degradation of carbamazepine was achieved in 24 h, which is a significant improvement compared to previous enzymatic treatments of this compound.Key points• Wheat straw extract is suitable for the growth of I. lacteus.• The enzyme cocktail obtained allows the degradation of emerging contaminants.• Mn-dependent and Mn-independent activities increases the catalytic potential.Graphical abstract

Isolation of Fungi from a Textile Industry Effluent and the Screening of Their Potential to Degrade Industrial Dyes.

Six fungal strains were isolated from the textile industry effluent in which they naturally occur. Subsequently, the fungal strains were identified and characterized in order to establish their potential decolorizing effect on textile industry effluents. The strains of interest were selected based on their capacity to decolorize azo, indigo, and anthraquinone dyes. Three of the strains were identified as Emmia latemarginata (MAP03, MAP04, and MAP05) and the other three as Mucor circinelloides (MAP01, MAP02, and MAP06), while the efficiency of their decolorization of the dyes was determined on agar plate and in liquid fermentation. All the strains co-metabolized the dyes of interest, generating different levels of dye decolorization. Plate screening for lignin-degrading enzymes showed that the MAP03, MAP04, and MAP05 strains were positive for laccase and the MAP01, MAP02, and MAP06 strains for tyrosinase, while all strains were positive for peroxidase. Based on its decolorization capacity, the Emmia latemarginata (MAP03) strain was selected for the further characterization of its growth kinetics and ligninolytic enzyme production in submerged fermentation under both enzyme induction conditions, involving the addition of Acetyl yellow G (AYG) dye or wheat straw extract, and no-induction condition. The induction conditions promoted a clear inductive effect in all of the ligninolytic enzymes analyzed. The highest level of induced enzyme production was observed with the AYG dye fermentation, corresponding to versatile peroxidase (VP), manganese peroxidase (MnP), and lignin peroxidase (LiP). The present study can be considered the first analysis of the ligninolytic enzyme system of Emmia latemarginata in submerged fermentation under different conditions. Depending on the results of further research, the fungal strains analyzed in the present research may be candidates for further biotechnological research on the decontamination of industrial effluents.

Effect of Different Vermiwash Sources on Germination and Seedling Growth of Fenugreek (Trigonella foenum-graecum L.)

Physiological process of germination depends on several factors such as temperature, water potential, light and nutrients. A laboratory study was carried out to asses, the effect of different Vermiwash sources on germination and seedling growth of fenugreek. A factorial design was used with four replications. Treatments were factorial of different Vermiwash (water as a control=W0, Vermicompost extract of wheat straw=W1, horse manure=W2, sheep manure=W3, 25% straw + 75% horse manure =W4, 25% straw + 75% sheep manure =W5, 50% straw + 50% horse manure =W6, 50% straw + 50% sheep manure =W7, 25% alfalfa residue + 75% sheep manure =W8, 50% alfalfa residue + 50% sheep manure =W9, 25% chicken manure + 75% straw manure =W10) and two levels of Vermiwash concentration (20% and 40%). Results showed that germination rate was significantly affected by all treatments. The maximum germination rate was observed at concentration of 40 percent of vermiwash with 25% alfalfa residue + 75% sheep manure. The maximum percentage of germination was obtained in 20 percent of vermiwash with sheep manure treatment and concentration of 40% in wheat straw. A significant difference was observed through treatments at 1% level in root length. In addition, root dry weight differed significantly among treatments at the 5% level. Also, a significant increasing was considered in root length by increasing the concentration of vermiwash.

Phenolic Compounds and Allelopathic Potential of Fermented and Unfermented Wheat and Corn Straw Extracts.

Total phenolic (TPC) and flavonoid (TFC) content, individual phenolic compounds and antioxidant activities of methanol extracts of wheat and corn straw were determined. Germination bioassay was conducted with Abutilon theophrasti Medik., Asclepias syriaca L., and Chenopodium album L. seed. Samples were fermented by Lactobacillus plantarum and changes in TPC, TFC, antioxidant, and biological activity were investigated. TPC and TFC were significant in both samples and after fermentation their recovery was improved. All samples contain mainly quercetin, cinnamic acid, p-coumaric acid, and ferulic acid. Fermentation changed the content of phenolic and flavonoid compounds, differently in each case. All tested extracts showed high DPPH activity with IC50 being significantly lower for fermented samples. FRAP activity was also high. Crude straw extracts were overall more effective than fermented ones concerning inhibition of germination and seedlings growth, mainly without statistically significant differences between wheat and corn. Compared with mesotrione, extracts were more effective in germination and seedling growth inhibition of C. album and in seedling growth inhibition of A. theophrasti.

Trichoderma species associated with green mould disease of Pleurotus ostreatus and their sensitivity to prochloraz

Green mould disease causes serious economic losses in Pleurotus ostreatus crops worldwide, including in Italy, where prochloraz is the only chemical fungicide allowed to control the disease. The effectiveness of the doses 0.01, 0.05, 0.25 and 1.25 μL L−1 (field dose) of prochloraz (Sponix Flow, 450 g L−1), against colony growth rate and spore germination of Trichoderma pleuroti, T. pleuroticola and T. guizhouense strains on wheat straw extract agar plates were evaluated. Complete inhibition of Trichoderma pleuroti and T. pleuroticola growth was shown by the field dose of prochloraz, and also by the 0.25 μL L−1 dose for T. pleuroti. Complete inhibition of spore germination occurred for all Trichoderma strains at field dose, and at 0.25 μL L−1 for T. pleuroti strains. In in vivo assays, the effect of prochloraz doses 0.05, 0.25 and 1.25 μL L−1 on colonization of straw substrate by T. pleuroti, T. pleuroticola and T. guizhouense inoculated at two spore densities (102 and 105 spores mL−1) immediately after P. ostreatus spawn was studied. Trichoderma pleuroti and T. pleuroticola were both responsible for green mould disease, whereas T. guizhouense was not pathogenic. Trichoderma pleuroti was more aggressive than T. pleuroticola. Prochloraz was effective against T. pleuroti at the field dose, and against T. pleuroticola at 0.25 and 1.25 μL L−1. The study on Trichoderma × Pleurotus interaction type showed that Trichoderma species were active against the mycelial growth of P. ostreatus by competition for space and nutrients, and neither hyphal interaction nor effect by volatile or nonvolatile metabolites occurred.

Mycelial Growth and Fruit Body Nutritional Composition of Pleurotus Species Grown on Different Lignocellulosic Waste-based Media

Pleurotus species are edible mushrooms that possess the ability to degrade lignocellulose and are cultivated on lignocellulosic substrates to produce fruiting bodies that are appreciated for their nutritional and culinary values. Radial growth rate (ur), mycelial biomass, and intracellular glycogen and protein contents were evaluated in the colonies of two strains of P. ostreatus (strains 26 and 50) and one strain of P. pulmonarius (strain 35) grown on barley straw extract agar, corn stover extract agar (CSEA), wheat straw extract agar, and glucose-yeast extract agar (GYEA). The nutritional composition of the Pleurotus fruit bodies cultivated on barley straw, corn stover, and wheat straw were also determined. Of all of the strains, P. ostreatus 50 showed the highest ur on the CSEA and GYEA, and P. ostreatus 26 showed the greatest mycelial biomass production on the lignocellulosic waste-based agar media (LWAM). All of the Pleurotus strains showed the greatest and lowest glycogen contents on the CSEA and GYEA, respectively. These results showed that the LWAM are more suitable for mycelial growth than a glucose-based agar medium, and that Pleurotus fruit bodies cultivated on corn stover had the highest nutritional value compared with fruit bodies grown on the wheat and barley substrates.

Inducing sporulation of Drechslera graminea

Barley stripe, caused by the fungus Pyrenophora graminea, is a single-cycle, seedborne disease. P. graminea is rarely observed in the nature, but its imperfect state, Drechslera graminea, occurs in all infected barley leaves. D. graminea produces conidia, which are in clusters of three to five. The fungus can also produce pycnidia, but it is rare in nature. Although barley stripe is effectively managed by seed-treatment with fungicides, losses to this disease still incurs wherever proper seed treatment is not practiced. D. graminea does not sporulate on commonly used artificial culture media. Therefore, production of spores to be used for screening accessions and breeding lines of barley for resistance to barley strip was not possible. A simple method was developed to induce sporulation in D. graminea. Thirty-six isolates of D. graminea, gathered from Canada, Germany, Montana and Syria, were cultured, developed vigorous colonies and produced abundant conidia. Sporulation of the fungus was induced using straw extract from the barley cultivars arta, bowman, bracken, clark, gallatin, and salmas. There were significant differences in sporulation among isolates from different areas as well as among isolates originating from the same barley field. Incubating the culture plates at 160C under fluorescent light (12 h light/12 h dark) for 5 d following incubation under near ultraviolet (NUV) light for 7 d resulted in 40% higher conidia production. Extract of seed, green straw or green leaves of barley as well as extract of mature wheat straw did not induce sporulation in D. graminea in culture. Twenty-one of the 36 isolates produced pycnidia following the 7-day incubation under NUV light. Five of 25 isolates grown on V8juice agar failed to sporulate. Germination of conidia of 12 isolates ranged from 72 to 99%.

Evaluation of Selected White-Rot Fungal Isolates for Improving the Sugar Yield from Wheat Straw

Biological pretreatment of lignocellulosic biomass by fungi can represent a low-cost and eco-friendly alternative to physicochemical methods to facilitate enzymatic hydrolysis. However, fungal metabolism can cause cellulose loss and it is therefore necessary to use the appropriate fungal strain-biomass type combination. In this work, the effects of biological pretreatments carried out by five different fungi on enzymatic hydrolysis of wheat straw were investigated. The best results were obtained with a Ceriporiopsis subvermispora strain, which minimized weight and cellulose losses and gave the highest net sugar yield (calculated with respect to the holocellulose content of the untreated straw), up to 44 % after a 10-week pretreatment, more than doubling the yields obtained with the other isolates. Moreover, prolonging the pretreatment from 4 up to 10 weeks produced a 2-fold increase, up to 60 %, in digestibility (sugar yield, calculated considering the holocellulose content of the pretreated material). The hemicellulose content of the pretreated material resulted inversely correlated with digestibility, and it could thus be utilized as an index of the pretreatment efficacy. Finally, a correlation was also found between digestibility and the difference between the absorbance values at 290 and 320 nm of pretreated wheat straw extracts.

Persistent and Transient Inhibition of Seed Germination by Fractions of Methanol-Water Extract of Wheat Straw

The objectives of this work were to investigate the effects of wheat straw constituents on total seed germination and on time needed for seed germination to start and to assess the usefulness of evaluating the recovery of germination to help guide the screening for a sequential search of bio active natural phytochemicals. Dose -response bioassays of lettuce seed germination to increasing concentrations of six fractions of methanol -water extract were conducted and whenever inhibition of germination exceeded 90% non

Induction of laccase activity in the white rot fungus Pleurotus ostreatus using water polluted with wheat straw extracts

The purpose of this work was to explore the use of polluted water effluents from wheat straw using industries as inducers of lignocellulolytic enzymatic activities in cultures of white rot basidiomycetes. For this purpose, we studied the effect of a wheat straw water extract on the evolution of the laccase activity recovered from submerged cultures of Pleurotus ostreatus made in different media and under various culture conditions. Our results demonstrated an accumulative induction effect in all the cultures and conditions tested. This induction is parallel to changes in the laccase electrophoretic profiles recovered from the culture supernatants. The isoenzyme that appeared to be mainly responsible for the laccase activity under these conditions was laccase 10, as confirmed by sequencing the induced protein. These results support the idea of using wheat straw effluents as inducers in liquid cultures of P. ostreatus mycelia for the production of ligninolytic enzymatic cocktails.

Wheat straw ethanolysis under subcritical and supercritical conditions

The composition of ethanol extract of wheat straw obtained under subcritical and supercritical conditions has been studied. It was found out that treatment with increased temperature, pressure and prolonged time of extraction leads to increased yield of ethanol soluble products, because of destruction of pentosan, lignin and, partially, cellulose. Delignification and hydrolysis product condensation processes prevailed under treatment with temperatures higher than 200°C.

Toxic action of aqueous wheat straw extract on horse e purslane

The toxic action of aqueous wheat (Triticum aestivum) straw extracts was investigated on germination, early seedling growth, some biochemical attributes and the antioxidant enzymes of horse purslane (Trianthemaportulacastrum). Aqueous extracts of wheat straw were prepared by soaking the wheat straw in distilled water in 1:10 w/v ratio and diluted to obtain the concentrations of 0, 25, 50, 75 and 100%. These were used as pre and post emergence in laboratory and screen house trials. Wheat aqueous extracts exhibited phytotoxicity to horse purslane by inhibiting and delaying its germination and suppressing seedling growth. Wheat phytotoxins in its aqueous extracts suppressed the chlorophyll content and soluble protein, and enhanced soluble phenolics and the activity of antioxidant enzymes as catalase, peroxidase and superoxide dismutase in the seedlings of horse purslane compared with the control. Such inhibitory activity is believed to originate from exposure to wheat phytotoxins that are present in its aqueous straw extract. The suppressive effects of wheat straw need to be investigated further under field conditions.

Transcriptional and Enzymatic Profiling of Pleurotus ostreatus Laccase Genes in Submerged and Solid-State Fermentation Cultures

The genome of the white rot basidiomycete Pleurotus ostreatus includes 12 phenol oxidase (laccase) genes. In this study, we examined their expression profiles in different fungal strains under different culture conditions (submerged and solid cultures) and in the presence of a wheat straw extract, which was used as an inducer of the laccase gene family. We used a reverse transcription-quantitative PCR (RT-qPCR)-based approach and focused on determining the reaction parameters (in particular, the reference gene set for the normalization and reaction efficiency determinations) used to achieve an accurate estimation of the relative gene expression values. The results suggested that (i) laccase gene transcription is upregulated in the induced submerged fermentation (iSmF) cultures but downregulated in the solid fermentation (SSF) cultures, (ii) the Lacc2 and Lacc10 genes are the main sources of laccase activity in the iSmF cultures upon induction with water-soluble wheat straw extracts, and (iii) an additional, as-yet-uncharacterized activity (Unk1) is specifically induced in SSF cultures that complements the activity of Lacc2 and Lacc10. Moreover, both the enzymatic laccase activities and the Lacc gene family transcription profiles greatly differ between closely related strains. These differences can be targeted for biotechnological breeding programs for enzyme production in submerged fermentation reactors.

The effect of spraying of wheat straw extracts on controlling some weed species.

This experiment was designed to compare the effect of spraying wheat straw aqueous extracts to control broad and narrow leaf weed plants in wheat fields with some common used herbicides in the region. The study consisted of five treatments; wheat straw aqueous extract; grass weeds herbicide clodinafop-propargyl (Topik); broad leaf herbicide tribenuron-methyl (Granstar); zero control (no weed control) and zero or no- weed treatments , chlorophyll a, b and total chlorophyll were indicated for all treatments after 48 hours from herbicide application. Results illustrated significant differences between all treatments, minimum wheat yield was recorded in zero control plots then plots that was treated with wheat straw aqueous extracts, Broad leaf weed herbicide (Granstar), narrow leaf weeds herbicide (Topic) and maximum yield was recorded with zero weed treatments, results of this study elucidate the potentiality of using wheat aqueous extracts for controlling some weed plants due to its obvious effect on reducing the weed plants height and the levels of chlorophyll a, b and total chlorophyll in treated wheat plants. Keywords - Allelopathy, Dicot, Monocot, weed plants.

English

  Allelopathy is a process in which secondary metabolites produced by plants, micro-organisms, viruses and fungi control growth and development of other biological systems. Some plants may beneficially or antagonistically affect other plants through allelochemical compounds which may be released directly or indirectly from live or dead parts and cause allelopathic and phytotoxic effects. In Kerman province of Iran, cultivating corn after winter wheat usually causes less growth and yield, hence, this study was conducted to estimate the effects of different concentrations of two native Iranian wheat (Alvand and Falat) straw extracts on germination, radicle growth, coleoptile length, plant height, leaf area (LA), wet weight (WW) and dry weight (DW) of two hybrid corn varieties (single cross 704 and 647). Results showed that the straw extracts had significant negative allelopathic effects on both corn varieties' growth. Furthermore, based on the study results, we suggest that before corn cultivation, wheat straw and residues should be eliminated from the field by leaving no-till fields fallow to avoid negative allelopathic effects of wheat straw on corn growth.   Key words: Allelopathic, corn, wheat straw. &nbsp

Bioprocess strategies for enhanced production of xylanase by Melanocarpus albomyces IITD3A on agro-residual extract

The production of high titer xylanase without cellulase is required for prebleaching of pulps in pulp and paper industry. The mutant IITD3A of Melanocarpus albomyces developed from the spores of the wild type organism was used in this study. The statistical optimization of the process parameters by response surface methodology revealed that the production of xylanase was most affected by changes in the pH of the production medium which contained a soluble extract of wheat straw as the sole carbon source. When the pH of the production medium in a 14 L bioreactor was controlled on-line at 7.8, xylanase activity of 415 IU mL⁻¹ was obtained after 36 h fermentation. On cycling the pH between 7.8 and 8.2, the same activity could be attained in 24 h with an overall productivity of 16,670 IU L⁻¹ h⁻¹. The production of xylanase was also influenced by the fungus morphology; the activity being maximum when it exhibited pellet form at an agitation speed of 600 rpm. On optimization of aeration rate to 0.25 vvm, the xylanase activity further increased to 550 IU mL⁻¹ with a very high overall volumetric productivity of 22,000 IU L⁻¹ h⁻¹. Thus, a 5.2-fold enhancement in overall volumetric productivity of xylanase could be obtained by the mutant in comparison to that obtained on insoluble wheat straw.