Solid state production of polygalacturonase and xylanase by Trichoderma species using cantaloupe and watermelon rinds

Investigating process parameters to enhance (hemi)cellulolytic enzymes activity produced by Trichoderma reesei RUT-C30 using deoiled oil palm mesocarp fiber in solid-state fermentation

This study investigates the synthesis of (hemi)cellulolytic enzymes, including endoglucanase (CMCase), xylanase, and β-glucosidase, employing Trichoderma reesei RUT-C30 and deoiled oil palm mesocarp fiber (OPMF) through solid-state fermentation (SSF). The objective was to determine the optimal process conditions for achieving high enzyme activities through a one-factor-at-a-time approach. The study primarily focused on the impact of the solid-to-liquid ratio, incubation period, initial pH, and temperature on enzyme activity. The effects of OPMF pretreatment, particularly deoiling and fortification, were explored. This approach significantly improved enzyme activity levels compared to the initial conditions, with CMCase increasing by 111.6 %, xylanase by 665.2 %, and β-Glucosidase by 1678.1 %. Xylanase and β-glucosidase activities, peaking at 1346.75 and 9.89 IU per gram dry substrate (GDS), respectively, under optimized conditions (1:4 ratio, pH 7.5, 20 °C, 9-day incubation). With lower moisture levels, CMCase reached its maximum activity of 227.84 IU/GDS. The study highlights how important it is for agro-industrial byproducts to support environmentally sustainable practices in the palm oil industry. It also emphasizes how differently each enzyme reacts to changes in process parameters.

Exploration of the Potential Application of Banana Peel for Its Effective Valorization: A Review

The production of banana peel by the food-processing industry is substantial and the disposal of this waste material has become a matter of concern. However, recent studies have demonstrated that banana peel is a rich source of biologically active compounds that can be transformed into valuable products. This review aims to explore the potential of converting banana peel into valuable products and provides a comprehensive analysis of the physical and chemical composition of banana peel. Additionally, the utilization of banana peel as a substrate to produce animal feed, bio fertilizer, dietary fibers, renewable energy, industrial enzymes, and nanomaterials has been extensively studied. According to the researches that has been done so far, it is clear that banana peel has a broad range of applications and its effective utilization through biorefinery strategies can maximize its economic benefits. Based on previous studies, A plan for feasibility of a banana peel biorefinery has been put up which suggest its potential as a valuable source of renewable energy and high-value products. The utilization of banana peel through biorefinery strategies can provide a sustainable solution for waste management and contribute to the development of a circular economy.

Release characteristic of bound polyphenols from tea residues insoluble dietary fiber by mixed solid-state fermentation with cellulose degrading strains CZ-6 and CZ-7

The purpose of this work was to investigate the release characteristic of bound polyphenols (BP) from tea residues insoluble dietary fiber (IDF) by mixed solid-state fermentation (SSF) with cellulose degrading strains CZ-6 and CZ-7. The results implied that cellulase, β-glucosidase and filter paper lyase activities were strongly correlated with the BP content. The scanning electron microscop and fourier transform infrared spectroscopy manifested that the cellulose network of the IDF was decomposed and dissolve, forming more loose fibrous structure. Additionally, 28 polyphenols components were detected and their biotransformation pathways were preliminary speculated. Moreover, the BP obtained by mixed SSF produced prominent inhibitory activities against α-glucosidase and α-amylase, as well as exhibited significant scavenging effects on DPPH•, ABTS+• free radicals and ferric reducing antioxidant power. These findings could further promote the utilization of BP from agricultural by-products in a more natural and economical method, CZ-6 and CZ-7 strains provide a new approach to expound the release and conversion of BP.

Detergent-stable amylase production by Paenibacillus lactis strain OPSA3 isolated from soil; optimization by response surface methodology

This study aimed to isolate thermostable, alkaliphilic, and detergent-tolerant amylase-producing bacteria. Pure isolates from environmental samples were screened on a starch-based medium (pH 11), and selected isolates were identified using cultural and molecular techniques. Product optimization studies were conducted, and secreted amylase was partially purified using 40% (w/v) saturation ammonium sulfate at 4 °C. The wash performance of concentrated amylase was analyzed. A novel isolate, Paenibacillus lactis OPSA3, was selected for further studies. The isolate produced amylase optimally when grown on banana peels and soybean extracts, which are agro-wastes. Optimization by Response surface Methodology resulted in a 2.1-fold increase in alkaliphilic amylase production. A 2.46-fold purification was achieved, with an enzyme activity yield of 79.53% and specific activity of 26.19 Umg^-1. Wash performance analysis using the amylase supplemented with boiled commercial detergent (kiln®) showed good cleaning efficiency. The amylase has the potential for application as a component of green detergent.

Antioxidant-polyphenols of saw palmetto seeds: statistical optimized production and improved functional properties under solid-state fermentation by Trichoderma reesei

Saw palmetto seeds (SPS) contain essential phenolic compounds that provide antioxidant, antimicrobial, anti-inflammatory, and anti-diabetic benefits when added to food. Maximized/improved production of these valuable phenolic compounds is the main purpose of this study. Solid-state fermentation (SSF) is a promising processing technique that positively alters the levels of health-promoting compounds in plants and plant residues. Here, a central composite design matrix (16 runs) and response surface methodology were experimentally applied to investigate the best SSF conditions and their interactions for maximum production of phenolic compounds from SPS. A good correlation between actual and expected results was observed with higher multiple coefficients (R2 ~ 0.93–0.97) and strongly significant P values (< 0.0001) proving the accuracy of the statistical model/design. Under optimized SSF conditions, temperature 30 °C, moisture 10%, pH 7.0, and fermentation time 6 days, the total phenolic content and total antioxidant activity of SPS were maximized by 11-fold and 46–49 folds, respectively. According to HPLC analysis, the contents of all identifying polyphenols were 3.3–30.0 times greater in fermented SPS extract (FSPS) than in the unfermented SPS extract (UFSPS). The FSPS extract also contained four new/additional polyphenols (vanillic, p-coumaric, cinnamic, and quercetin). FSPS extract demonstrated much greater antibacterial and antifungal activities than UFSPS extract against various human pathogenic bacteria and fungi. Consequently, the FSPS-phenolic compounds can be exploited as a food supplement and an antimicrobial remedy.

Exploitation of cantaloupe peels for bacterial cellulose production and functionalization with green synthesized Copper oxide nanoparticles for diverse biological applications

The promising features of most bacterial celluloses (BC) promote the continuous mining for a cost-effective production approach toward wide and sustainable applications. Herein, cantaloupe peels (CP) were successfully implemented for sustainable BC production. Results indicated that the enzymatically hydrolyzed CP supported the maximum BC production of approximately 3.49 g/L when used as a sole fermentation media. The produced BC was fabricated with polyvinyl alcohol (PVA) and chitosan (Ch), and loaded with green synthesized copper oxide nanoparticles (CuO-NPs) to improve its biological activity. The novel composite showed an antimicrobial activity against several human pathogens such as Staphylococcus aureus, Streptococcus mutans, Salmonella typhimurium, Escherichia coli, and Pseudomonas fluorescens. Furthermore, the new composite revealed a significant in vitro anticancer activity against colon (Caco-2), hepatocellular (HepG-2), and breast (MDA) cancer cells, with low IC50 of 0.48, 0.27, and 0.33 mg/mL for the three cell lines, respectively. On the other hand, the new composite was remarkably safe for human skin fibroblast (HSF) with IC50 of 1.08 mg/mL. Interestingly, the composite membranes exhibited lethal effects against all stages of larval instar and pupal stage compared with the control. In this study, we first report the diverse potential applications of BC/PVA/Ch/CuO-NPs composites based on green synthesized CuO-NPs and sustainably produced BC membrane.

Improved production of antioxidant-phenolic compounds and certain fungal phenolic-associated enzymes under solid-state fermentation of chia seeds with Trichoderma reesei: response surface methodology-based optimization

Chia seeds (CS) are becoming increasingly consumed due to their great nutritional and therapeutic properties. In this study, solid-state fermentation (SSF) of CS by Trichoderma reesei was employed to maximize the production of the antioxidant-phenolic compounds and some fungal phenolic-associated enzymes (α-amylase, xylanase, β-glucosidase, polygalacturonase, and phenylalanine ammonia-lyase). The SSF-conditions were statistically optimized using response surface methodology (RSM). In the statistical model, four variables were analyzed at two levels. According to RSM, the adjusted R2 (< 0.9) is reasonably consistent with the predicted R2 (< 0.9), indicating that the statistical model is valid. The optimal conditions for maximum production of both phenolic compounds and fungal phenolic-associated enzymes were found to be 28 °C, pH 7.0, 20% moisture, and 7-day fermentation. The total phenolic content of fermented CS (FCS) increased 23 folds and total antioxidant activity was enhanced by 113- and 150-fold using DPPH and ABTS methods, respectively. Three new phenolics (kaempferol, apigenin, and p-coumaric) were recognized in FCS using HPLC analysis. The activities of all the extracted phenolic-associated enzymes showed strong correlations with the phenolic content of FCS. Against some human-pathogenic bacteria, FCS extract displayed considerably better antibacterial activity than UFCS extract. Finally, the phenolic-rich-FCS can be employed as a dietary supplement as well as an antibacterial agent. Furthermore, T. reesei has produced considerable quantities of industrially valuable enzymes.

Biotechnology approach using watermelon rind for optimization of α-amylase enzyme production from Trichoderma virens using response surface methodology under solid-state fermentation

Production of amylases by fungi under solid-state fermentation is considered the best methodology for commercial scaling that addresses the ever-escalating needs of the worldwide enzyme market. Here response surface methodology (RSM) was used for the optimization of process variables for α-amylase enzyme production from Trichoderma virens using watermelon rinds (WMR) under solid-state fermentation (SSF). The statistical model included four variables, each detected at two levels, followed by model development with partial purification and characterization of α-amylase. The partially purified α-amylase was characterized with regard to optimum pH, temperature, kinetic constant, and substrate specificity. The results indicated that both pH and moisture content had a significant effect (P < 0.05) on α-amylase production (880 U/g) under optimized process conditions at a 3-day incubation time, moisture content of 50%, 30 °C, and pH 6.98. Statistical optimization using RSM showed R² values of 0.9934, demonstrating the validity of the model. Five α-amylases were separated by using DEAE-Sepharose and characterized with a wide range of optimized pH values (pH 4.5-9.0), temperature optima (40-60 °C), low Km values (2.27-3.3 mg/mL), and high substrate specificity toward large substrates. In conclusion, this study presents an efficient and green approach for utilization of agro-waste for production of the valuable α-amylase enzyme using RSM under SSF. RSM was particularly beneficial for the optimization and analysis of the effective process parameters.

Biochemical properties of cellulolytic and xylanolytic enzymes from Sporotrichum thermophile and their utility in bioethanol production using rice straw

Production of cellulolytic and xylanolytic enzymes by Sporotrichum thermophile was enhanced using response surface methodology in solid-state fermentation (SSF) using wheat straw and cotton oil cake. Cellulolytic and xylanolytic enzymes were partially purified by ammonium sulfate precipitation followed by ion exchange and gel filtration chromatographic techniques. Xylanase of S. thermophile is neutral xylanase displaying optimal activity at 60 °C with K_m and V_max values of 0.2 mg/mL and 238.05 µmole/min, respectively. All cellulases produced by the thermophilic mold showed optimal activity at pH 5.0 and 60 °C with K_m values of 0.312 mg/mL, 0.113 mg/mL, and 0.285 mM for carboxymethyl cellulase (CMCase), filter paper cellulase (FPase), and β-glucosidase, respectively and while V_max values were 181.81, 138.88, and 66.67 µmole/min, respectively. The presence of various metal ions (Ca²⁺ and Co²⁺), chemical reagent (glutaraldehyde), and surfactants (Tween 80 and Triton X-100) significantly improved the activities of all enzymes. All the enzymes showed high storage stability under low temperature (-20 and 4 °C) conditions. Cellulolytic and xylanolytic enzymes resulted in enhanced liberation of reducing sugars (356.34 mg/g) by hydrolyzing both cellulosic and hemicellulosic fractions of ammonia-pretreated rice straw as compared to other pretreatment methods used in the study. Fermentation of enzymatic hydrolysate resulted in the formation of 28.88 and 27.18 g/L of bioethanol in separate hydrolysis and fermentation (SHF) process by Saccharomyces cerevisiae and Pichia stipitis, respectively. Therefore, cellulolytic and xylanolytic enzymes of S. thermophile exhibited ideal properties of biocatalysts useful in the saccharification of cellulosic and hemicellulosic fractions of rice straw for the production of bioethanol.

Phenolic Content and Antioxidant Activity of Extracts of 12 Melon (Cucumis melo) Peel Powders Prepared from Commercial Melons

Melons are a diverse group of fresh, dessert fruits that includes orange flesh cantaloupe, green flesh honeydew, and mixed hybrid melons. As part of an effort to discover potential health benefits of fruit and vegetable peels that are considered to be byproducts of food processing, we determined the total phenolic content and antioxidative activities of methanolic extracts of the powdered peels of the following commercial melon (Cucumis melo) varieties sold at retail markets in California that were imported from Mexico and Honduras: nonorganic Canary, Charentias, Hani Gold, Vine ripened, and Santa Claus; and organic Ambrosia, Cantaloupe, Galia, Goddess, Ham, Honeydew, and Tuscan. The total phenolic content (in mg gallic acid equivalents/g extract) ranged from 0.69 (Tuscan) to 2.96 (Galia) or 4.3-fold variation from lowest to highest value. The antioxidative activity (in mg ascorbic acid equivalents/mL extract) ranged from 0.13 (organic Tuscan) to 0.26 (organic Galia). Similar results were observed using the ABTS antioxidative assay. The content of the phenolic and flavonoid compounds 3-hydroxybenzoic acid, chlorogenic acid, neochlorogenic acid, isovanillic acid, apigenin-7-α-glucoside, luteolin-7-o-glucoside, and quercetin-3-galactoside in three melon flesh samples (nonorganic and organic Galia from Honduras and organic Galia from Mexico and two peel samples (Mexican organic peel and flesh) were analyzed using HPLC. The results suggest that the peel from the Honduran Galia melon with the highest antioxidative activity merits further study to investigate potential health properties. Potential nutritional and health benefits of melon peels, Seeds, and their bioactive compounds are discussed. PRACTICAL APPLICATION: The peel from the Honduran Galia melon variety merits further study for potential health benefits, including antioxidative, anticholesterol, and antidiabetic activities, and stimulation of thyroid function, as reported for peels from other melon varieties, as well as antibiotic activities against pathogenic bacteria, protozoa, and viruses.

Effect of stirring on growth and cellulolytic enzymes production by Trichoderma harzianum in a novel bench-scale solid-state fermentation bioreactor

A novel bench-scale stirred bioreactor for solid-state fermentation was used to determine the effect of the stirring rate on growth and enzymes production by Trichoderma harzianum PBLA. Lab-scale static tubular bioreactors were first used to assess the effect of bioreactor diameter on heat accumulation, growth, and production of cellulases and xylanases. The increased diameters (1.8-4.2 cm) led to increases in temperature up to 36 °C (at a rate of 1.08 °C/cm), which negatively affected the growth and enzyme production. Afterward, in the bench-scale bioreactor operated at rates up to 3.0 rpm, maximum xylanases production (107 ± 0.3 U/g dm) was attained at rates of 0.5 and 1.0 rpm, reaching a maximum of 34 ± 0.3 °C. Cellulases production was reduced (up to 79%) due to stirring. Therefore, the production of xylanases by T. harzianum can be performed in this cross-flow stirred SSF bioreactor at rates up to 1.0 rpm, avoiding heat accumulation and damage on metabolic activity.

Fruit and Vegetable Waste: Bioactive Compounds, Their Extraction, and Possible Utilization

Fruits and vegetables are the most utilized commodities among all horticultural crops. They are consumed raw, minimally processed, as well as processed, due to their nutrients and health-promoting compounds. With the growing population and changing diet habits, the production and processing of horticultural crops, especially fruits and vegetables, have increased very significantly to fulfill the increasing demands. Significant losses and waste in the fresh and processing industries are becoming a serious nutritional, economical, and environmental problem. For example, the United Nations Food and Agriculture Organization (FAO) has estimated that losses and waste in fruits and vegetables are the highest among all types of foods, and may reach up to 60%. The processing operations of fruits and vegetables produce significant wastes of by-products, which constitute about 25% to 30% of a whole commodity group. The waste is composed mainly of seed, skin, rind, and pomace, containing good sources of potentially valuable bioactive compounds, such as carotenoids, polyphenols, dietary fibers, vitamins, enzymes, and oils, among others. These phytochemicals can be utilized in different industries including the food industry, for the development of functional or enriched foods, the health industry for medicines and pharmaceuticals, and the textile industry, among others. The use of waste for the production of various crucial bioactive components is an important step toward sustainable development. This review describes the types and nature of the waste that originates from fruits and vegetables, the bioactive components in the waste, their extraction techniques, and the potential utilization of the obtained bioactive compounds.

The effect of lyophilization and storage time on the survival rate and hydrolytic activity of Trichoderma strains

The study evaluates the survivability and storage stability of seven Trichoderma strains belonging to the species: T. harzianum (1), T. atroviride (4), and T. virens (2) after the lyophilization of their solid state cultures on wheat straw. Biomass of Trichoderma strains was freeze-dried with and without the addition of maltodextrin. Furthermore, in order to determine the ability of tested Trichoderma strains to preserve selected technological features, the biosynthesis of extracellular hydrolases (cellulases, xylanases, and polygalacturonases) after a 3-month storage of lyophilizates was investigated. Strains of T. atroviride (except TRS40) and T. harzianum TRS85 showed the highest viability after lyophilization process (up to 100%). After 3 months of storage, T. atroviride TRS14 exhibited the highest stability (95.23%); however, the number of active conidia remained at high level of 10⁶–10⁷ cfu/g for all tested T. atroviride strains and T. harzianum TRS85. Interestingly, after a 3-month storage of lyophilized formulations, most of the tested Trichoderma strains exhibited higher cellulolytic and xylanolytic activities compared to the control, i.e., before freeze-drying process. The highest activities of these enzymes exhibited the following: T. atroviride TRS14–2.37 U/g and T. atroviride TRS25–21.47 U/g, respectively, whereas pectinolytic activity was weak for all tested strains, with the highest value of 0.64 U/g registered for T. virens TRS109.

A Novel Non-Cumbersome Approach Towards Biosynthesis of Pectic-Oligosaccharides by Non-Aflatoxigenic Aspergillus sp. Section Flavi Strain EGY1 DSM 101520 through Citrus Pectin Fermentation

Pectic-Oligosaccharides (POS) have a growing potential in food and feed industries. To satisfy the demand of worldwide markets from POS and avoid the shortcomings of currently applied methodologies encountered in their preparation, the present study highlights a novel robust approach for POS biosynthesis. In the current approach, Aspergillus sp.section Flavi strain EGY1 DSM 101520 was grown on citrus pectin-based medium as a core POS production medium. POS' levels accumulated in the fungal fermentation broth were optimized through a three step sequential statistical mathematical methodology; Plackett-Burman design (PBD), Box-Behnken design (BBD) and canonical analysis. Three key determinants namely citrus pectin, peptone and NaH2PO4 were pointed out by PBD to impose significant consequences (P<0.05) on the process outcome (POS' levels). Optimal levels of these key determinants along with maximal of POS' levels were set by BBD and canonical analysis to be 2.28% (w/v) citrus pectin, 0.026% (w/v) peptone and 0.28% (w/v) NaH2PO4 to achieve a net amount of 1.3 g POS /2.28 g citrus pectin. Through this approach, a yield of 57% (w/w) POS of the total citrus pectin was obtained after 24 h of fungal growth on optimized citrus pectin-based medium. A fold enhancement of 13 times in POS' levels released in the fermentation fungal broth was realized by the end of the optimization strategy. This novel robust approach is considered a new insight towards POS biosynthesis via efficient, rapid and non-cumbersome procedure. To the best of authors' knowledge, the present work is the first article underlining detailed POS production from the fermentation broth of a fungus growing on citrus pectin-based medium.

Far infrared radiated energy-proficient rapid one-pot green hydrolysis of waste watermelon peel: optimization and heterogeneous kinetics of glucose synthesis

Energy-efficient far-infrared radiation rendered significant intensification of one-pot heterogeneous catalytic hydrolysis of waste watermelon peel for green synthesis of glucose.

Valorization of banana peel: a biorefinery approach

Banana peel (BP) is an agrowaste produced in large volumes annually, especially by food-processing industries; however, its disposal is of significant concern. However, recent research suggests that BP is a valuable source of bioactive compounds, which can be converted into value-added products. This article reviews the conversion process of value-added products from BP and provides an outline on the chemical composition of BP and its possible applications. In addition, we also discuss the utilization of BP as a substrate to produce animal feed, biofertilizer, dietary fibers, clean energy, industrial enzymes, as well as its use in the synthesis of nanomaterials. Based on the research conducted so far, it is obvious that BP has a wide variety of applications, and thus, developing a biorefinery approach to adequately utilize BP will help realize its economic benefits to the fullest. Based on the valorization of BP, a scheme for BP biorefinery has been proposed. A material balance for BP biorefinery for 1-ton bone-dry BP is presented and our results show that 432 kg of protein or 170 kg of citric acid, 170 kg of pectin, 325 m

Saccharification and hydrolytic enzyme production of alkali pre-treated wheat bran by Trichoderma virens under solid state fermentation

Background

In continuation of our previously interest in the saccharification of agriculture wastes by Bacillus megatherium in solid state fermentation (SSF), we wish to report an investigation and comparative evaluation among Trichoderma sp. for the saccharification of four alkali-pretreated agricultural residues and production of hydrolytic enzymes, carboxymethyl cellulase (CMCase), filter paperase (FPase), pectinase (PGase) and xylanase (Xylase) in SSF. The optimization of the physiological conditions of production of hydrolytic enzymes and saccharification content from Trichoderma virens using alkali-pretreated wheat bran was the last goal.

Methods

The physico-chemical parameters of SSF include incubation time, incubation temperature, moisture content of the substrate, incubation pH, supplementation with carbon and nitrogen sources were optimized.

Results

Saccharification of different solid state fermentation sources wheat bran, date's seeds, grass and palm leaves, were tested for the production of fermentable sugar by Trichoderma sp. The maximum production of hydrolytic enzymes CMCase, FPase, PGase and Xylase and saccharification content were obtained on wheat bran. Time course, moisture content, optimum temperature, optimum pH, supplementation with carbon and nitrogen sources were optimized to achieve the maximum production of the hydrolytic enzymes, protein and total carbohydrate of T. virens using alkali pre-treated wheat bran. The maximum production of CMCase, FPase, PGase, Xylase, protein and carbohydrate content was recorded at 72 h of incubation, 50-70 % moisture, temperature 25-35 °C and pH 5. The influence of supplementary carbon and nitrogen sources was studied. While lactose and sucrose enhanced the activity of PGase from 79.2 to 582.9 and 632.6 U/g, starch inhibited all other enzymes. This was confirmed by maximum saccharification content. Among the nitrogen sources, yeast extract and urea enhanced the saccharification content and CMCase, PGase and Xylase.

Conclusions

The results of this study indicated that alkali pre-treated wheat bran was a better substrate for saccharification and production of hydrolytic enzymes CMCase, FPase, PGase and xylase by T. virens compared to other alkali-pretreated agricultural residues tested.

Multivariate optimization and supplementation strategies for the simultaneous production of amylases, cellulases, xylanases, and proteases by Aspergillus awamori under solid-state fermentation conditions

The production of extracts containing a pool of enzymes for extensive biomass deconstruction can lead to significant advantages in biorefinery applications. In this work, a strain of Aspergillus awamori IOC-3914 was used for the simultaneous production of five groups of hydrolases by solid-state fermentation of babassu cake. Sequential experimental design strategies and multivariate optimization using the desirability function were first used to study temperature, moisture content, and granulometry. After that, further improvements in product yields were achieved by supplementation with other agro-industrial materials. At the end of the study, the production of enzymes was up to 3.3-fold increased, and brewer's spent grains and babassu flour showed to be the best supplements. Maximum activities for endoamylases, exoamylases, cellulases (CMCases), xylanases, and proteases achieved were 197, 106, 20, 835, and 57 U g(-1), respectively. The strain was also able to produce β-glucosidases and debranching amylases (up to 35 and 43 U g(-1), respectively), indicating the potential of its enzyme pool for cellulose and starch degradation.

Solid fermentation of wheat bran for hydrolytic enzymes production and saccharification content by a local isolate Bacillus megatherium

BACK GROUND

For enzyme production, the costs of solid state fermentation (SSF) techniques were lower and the production higher than submerged cultures. A large number of fungal species was known to grow well on moist substrates, whereas many bacteria were unable to grow under this condition. Therefore, the aim of this study was to isolate a highly efficient strain of Bacillus sp utilizing wheat bran in SSF and optimizing the enzyme production and soluble carbohydrates.

RESULTS

A local strain Bacillus megatherium was isolated from dung sheep. The maximum production of pectinase, xylanase and α-amylase, and saccharification content (total soluble carbohydrates and reducing sugars) were obtained by application of the B. megatherium in SSF using wheat bran as compared to grasses, palm leaves and date seeds. All enzymes and saccharification content exhibited their maximum production during 12-24 h, at the range of 40-80% moisture content of wheat bran, temperature 37-45°C and pH 5-8. An ascending repression of pectinase production was observed by carbon supplements of lactose, glucose, maltose, sucrose and starch, respectively. All carbon supplements improved the production of xylanase and α-amylase, except of lactose decreased α-amylase production. A little increase in the yield of total reducing sugars was detected for all carbon supplements. Among the nitrogen sources, yeast extract induced a significant repression to all enzyme productivity. Sodium nitrate, urea and ammonium chloride enhanced the production of xylanase, α-amylase and pectinase, respectively. Yeast extract, urea, ammonium sulphate and ammonium chloride enhanced the productivity of reducing sugars.

CONCLUSIONS

The optimization of enzyme production and sccharification content by B. megatherium in SSF required only adjustment of incubation period and temperature, moisture content and initial pH. Wheat bran supplied enough nutrients without any need for addition of supplements of carbon and nitrogen sources.