Potential fungicidal and antiaflatoxigenic effects of cinnamon essential oils on Aspergillus flavus inhabiting the stored wheat grains.

Wheat is one of the essential crops for the human and animal nutrition, however, contamination with aflatoxigenic fungi, due to the improper storage conditions and high humidity, was the main global threats. So, preventing the growth of aflatoxigenic fungi in stored wheat grains, by using different essential oils was the main objective of this work. Aspergillus flavus EFBL-MU12 PP087400, EFBL-MU23 PP087401 and EFBL-MU36 PP087403 isolates were the most potent aflatoxins producers inhabiting wheat grains. The effect of storage conditions of wheat grains "humidity, temperature, incubation period, and pH" on growth of A. flavus, was assessed by the response surface methodology using Plackett-Burman design and FCCD. The highest yield of aflatoxins EFBL-MU12 B1 and B2 by A. flavus grown on wheat grains were 145.3 and 7.6 µg/kg, respectively, at incubation temperature 35°C, 16% moisture contents, initial pH 5.0, and incubated for 14 days. The tested oils had a powerful antifungal activity for the growth and aflatoxins production by A. flavus in a concentration-dependent manner. Among these oils, cinnamon oil had the highest fungicidal activity for A. flavus at 0.125%, with about 85-90 % reduction to the aflatoxins B1 and B2, conidial pigmentation and chitin contents on wheat grains. From the SEM analysis, cinnamon oils had the most deleterious effect on A. flavus with morphological aberrations to the conidial heads, vegetative mycelia, alteration in conidiophores identity, hyphae shrank, and winding. To emphasize the effect of the essential oils on the aflatoxins producing potency of A. flavus, the molecular expression of the aflatoxins biosynthetic genes was estimated by RT-qPCR. The molecular expression of nor-1, afLR, pKsA and afLJ genes was suppressed by 94-96%, due to cinnamon oil at 0.062% compared to the control. Conclusively, from the results, cinnamon oils followed by the peppermint oils displayed the most fungicidal activity for the growth and aflatoxins production by A. flavus grown on wheat grains.

Bioprocessing of Epothilone B from Aspergillus fumigatus under solid state fermentation: Antiproliferative activity, tubulin polymerization and cell cycle analysis.

Epothilone derivatives have been recognized as one of the most powerful anticancer drugs towards solid tumors, for their unique affinity to bind with ß-tubulin microtubule arrays, stabilizing their disassembly, causing cell death. Sornagium cellulosum is the main source for Epothilone, however, the fermentation bioprocessing of this myxobacteria is the main challenge for commercial production of Epothilone. The metabolic biosynthetic potency of epothilone by Aspergillus fumigatus, an endophyte of Catharanthus roseus, raises the hope for commercial epothilone production, for their fast growth rate and feasibility of manipulating their secondary metabolites. Thus, nutritional optimization of A. fumigatus for maximizing their epothilone productivity under solid state fermentation process is the objective. The highest yield of epothilone was obtained by growing A. fumigatus on orange peels under solid state fermentation (2.2 µg/g), bioprocessed by the Plackett-Burman design. The chemical structure of the extracted epothilone was resolved from the HPLC and LC-MS/MS analysis, with molecular mass 507.2 m/z and identical molecular fragmentation pattern of epothilone B of S. cellulosum. The purified A. fumigatus epothilone had a significant activity towards HepG2 (IC50 0.98 µg/ml), Pancl (IC50 1.5 µg/ml), MCF7 (IC50 3.7 µg/ml) and WI38 (IC50 4.6 µg/ml), as well as a strong anti-tubulin polymerization activity (IC50 0.52 µg/ml) compared to Paclitaxel (2.0 µg/ml). The effect of A. fumigatus epothilone on the immigration ability of HepG2 cells was assessed, as revealed from the wound closure of the monolayer cells that was estimated by ~ 63.7 and 72.5%, in response to the sample and doxorubicin, respectively, compared to negative control. From the Annexin V-PI flow cytometry results, a significant shift of the normal cells to the apoptosis was observed in response to A. fumigatus epothilone by ~ 20 folds compared to control cells, with the highest growth arrest of the HepG2 cells at the G0-G1 stage.

Current status and future trends of microbial and nematode-based biopesticides for biocontrol of crop pathogens.

The increasing public demand to avoid the use of synthetic pesticides and fertilizers in agricultural production systems, causing serious environmental damages, has challenged industry to develop new and effective solutions to manage and control phytopathogens. Biopesticides, particularly microbial-based biopesticides, are a promising new alternative with high biodegradability, specificity, suitability for incorporation into integrated pest management practices, low likelihood of resistance development, and practically no known human health risks. However: expensive production methods, narrow action spectra, susceptibility to environmental conditions, short shelf life, poor storage stability, legislation registry constraints, and general lack of knowledge are slowing down their adoption. In addition to regulatory framework revisions and improved training initiatives, improved preservation methods, thoughtfully designed formulations, and field test validations are needed to offer new microbial- and nematode-based biopesticides with improved efficacy and increased shelf-life. During the last several years, substantial advancements in biopesticide production have been developed. The novelty part of this review written in 2023 is to summarize (i) mechanisms of action of beneficial microorganisms used to increase crop performance and (ii) successful formulation including commercial products for the biological control of phytopathogens based on microorganisms, nematode and/or metabolites.

Lignocellulosic materials valorization in second generation biorefineries: an opportunity to produce fungal biopigments.

Second generation biorefineries play an important role in the production of renewable energy and fuels, utilizing forest and agro-industrial residues and by-products as raw materials. The integration of novel bioproducts, such as: xylitol, ß-carotene, xylooligosaccharides, and biopigments into the biorefinery's portfolio can offer economic benefits in the valorization of lignocellulosic materials, particularly cellulosic and hemicellulosic fractions. Fungal biopigments, known for their additional antioxidant and antimicrobial properties, are appealing to consumers and can have applications in various industrial sectors, including food and pharmaceuticals. The use of lignocellulosic materials as carbon and nutrient sources for the growth medium helps to reduce production costs, increasing the competitiveness of fungal biopigments in the market. In addition, the implementation of biopigment production in biorefineries allows the utilization of underutilized fractions, such as hemicellulose, for value-added bioproducts. This study deals with the potential of fungal biopigments production in second generation biorefineries in order to diversify the produced biomolecules together with energy generation. A comprehensive and critical review of the recent literature on this topic has been conducted, covering the major possible raw materials, general aspects of second generation biorefineries, the fungal biopigments and their potential for incorporation into biorefineries.

Aspergillus awamori MK788209 cellulase: production, statistical optimization, pea peels saccharification and textile applications.

BACKGROUND: The demand for low-cost cellulolytic enzyme synthesis is rising in the enzyme market. This work aims to produce cellulase by utilizing various agricultural wastes and investigating the use of enzyme in saccharification and textile industries. RESULTS: Solid state fermentation (SSF) was applied to produce industrial enzymes, particularly cellulase, through utilizing Molokhia (Corchorus olitorius) stems by Aspergillus awamori MK788209 isolate. Two stages of statistical factorial designs Plackett-Burman (PB) and Central Composite Design (CCD) were applied to enhance the A. awamori MK788209 cellulase production from Molokhia stems (MS). The fold increase of enzyme production by PB followed by CCD was 2.51 and 4.86, respectively. Additionally, the A. awamori MK788209 culture filtrate was highly effective in saccharifying various agricultural wastes, particularly pea peels (PP) (yielding 98.33 mg reducing sugar/ml), due to its richness in cellulase, laccase, xylanase, pectinase, and amylase. By optimizing the three main variables; pea peel weight, culture filtrate volume added, and saccharification time by CCD, the sugar recovery from PP was enhanced, leading to a 3.44-fold increase in reducing sugar recovery (338 mg reducing sugar /ml). Furthermore, the A. awamori MK788209 culture filtrate showed high efficacy in textile applications, enhancing the roughness, weight loss, white index, and printing capability of treated cotton fabrics. CONCLUSIONS: A. Awamori MK788209 produced cellulase which was effective in PP saccharification. The enzyme was also capable of enhancing cotton fabric properties.

Advanced anaerobic digestion of household food waste pretreated by in situ-produced mixed enzymes via solid-state fermentation: Feasibility and application perspectives.

Enzymatic pretreatment is an effective method which can improve the anaerobic digestion (AD) efficiency of household food waste (HFW). As an alternative to expensive commercial enzymes, mixed enzymes (MEs) produced in situ from HFW by solid-state fermentation (SSF) can greatly promote the hydrolysis rate of HFW and achieve advanced anaerobic digestion (AAD) economically sustainable. In this paper, strategies for improving the efficiency of the enzyme-production process and the abundance of MEs are briefly discussed, including SSF, fungal co-cultivation, and stepwise fermentation. The feasibility of using HFW as an applicable substrate for producing MEs (amylase, protease, and lignocellulose-degrading enzymes) and its potential advantages in HFW anaerobic digestion are comprehensively illustrated. Based on the findings, an integrated AAD process of HFW pretreated with MEs produced in situ was proposed to maximise bioenergy recovery. The mass balance results showed that the total volatile solids removal rate could reach 98.56%. Moreover, the net energy output could reach 2168.62 MJ/t HFW, which is 9.79% higher than that without in situ-produced MEs and pretreatment. Finally, perspectives for further study are presented.

Innovative sustainable bioreactor-in-a-granule formulation of Trichoderma asperelloides.

The advancement of fungal biocontrol agents depends on replacing cereal grains with low-cost agro-industrial byproducts for their economical mass production and development of stable formulations. We propose an innovative approach to develop a rice flour-based formulation of the beneficial biocontrol agent Trichoderma asperelloides CMAA1584 designed to simulate a micro-bioreactor within the concept of full biorefinery process, affording in situ conidiation, extended shelf-life, and effective control of Sclerotinia sclerotiorum, a devastating pathogen of several dicot agricultural crops worldwide. Rice flour is an inexpensive and underexplored byproduct derived from broken rice after milling, capable of sustaining high yields of conidial production through our optimized fermentation-formulation route. Conidial yield was mainly influenced by nitrogen content (0.1% w/w) added to the rice meal coupled with the fermentor type. Hydrolyzed yeast was the best nitrogen source yielding 2.6 × 109 colony-forming units (CFU)/g within 14 days. Subsequently, GControl, GLecithin, GBreak-Thru, GBentonite, and GOrganic compost+Break-Thru formulations were obtained by extrusion followed by air-drying and further assessed for their potential to induce secondary sporulation in situ, storage stability, and efficacy against Sclerotinia. GControl, GBreak-Thru, GBentonite, and GOrganic compost+Break-Thru stood out with the highest number of CFU after sporulation upon re-hydration on water-agar medium. Shelf-life of formulations GControl and GBentonite remained consistent for > 3 months at ambient temperature, while in GBentonite and GOrganic compost+Break-Thru formulations remained viable for 24 months during refrigerated storage. Formulations exhibited similar efficacy in suppressing the myceliogenic germination of Sclerotinia irrespective of their concentration tested (5 × 104 to 5 × 106 CFU/g of soil), resulting in 79.2 to 93.7% relative inhibition. Noteworthily, all 24-month-old formulations kept under cold storage successfully suppressed sclerotia. This work provides an environmentally friendly bioprocess method using rice flour as the main feedstock to develop waste-free granular formulations of Trichoderma conidia that are effective in suppressing Sclerotinia while also improving biopesticide shelf-life. KEY POINTS: • Innovative "bioreactor-in-a-granule" system for T. asperelloides is devised. • Dry granules of aerial conidia remain highly viable for 24 months at 4 °C. • Effective control of white-mold sclerotia via soil application of Trichoderma-based granules.

Extraction process, physicochemical properties, and digestive performance of red yeast rice starch.

In the present study, taking red yeast rice (RYR) as the raw material, the optimum extraction process of RYR starch was investigated through a single-factor experiment and the Box-Behnken design: The liquid-to-solid ratio was 5 mL/g, the concentration of sodium hydroxide solution was 0.075 mol/L, and the extraction time was 3.1 h. Under these extraction conditions, the extraction rate of starch reached 90.077%. To explore the influence of solid-state fermentation on RYR starch, three different fermentation stages of RYR starch, raw rice starch, semi-gelatinized rice starch, and RYR starch were used as test materials to determine the changes in the physicochemical properties and glycemic index (GI) values of RYR starch during solid-state fermentation. The results showed that with the advancement of the RYR solid-state fermentation process, the starch particle size gradually increased, the light transmittance gradually decreased, and the solubility and swelling power significantly increased. In addition, the amylose content of starch gradually increased, whereas the amylopectin content gradually decreased; the content of fast digestible starch and slow digestible starch decreased, whereas the content of resistant starch increased. In parallel, during solid-state fermentation, the hydrolysis index significantly decreased, and the GI values also decreased. In summary, solid-state fermentation reduced the digestibility of RYR starch. These results provide a theoretical basis for the structural and physicochemical properties of RYR starch and lay a foundation for its subsequent application and expansion of RYR starch.

Improving the extraction yield of essential oil from Pimenta dioica (L.) Merr. using Aspergillus niger ATCC 1004 enzyme blend.

The objective of this work was to optimize the application of an enzymatic blend produced by Aspergillus niger ATCC 1004 on the Pimenta dioica fruits for essential oil extraction. The enzyme blend was obtained from the fermentation of cocoa bean shells, an agro-industrial residue. The effects of the enzymatic pre-treatment on the extraction yield, the chemical composition of the oil through gas chromatography, and the fruit structure through scanning electron microscopy (SEM) were assessed. A Doehlert design was used to optimize the process conditions, resulting in an extraction with 117 mL of enzyme during 77 min, which increased the extraction yield by 387.5%. The chemical composition was not altered, which proves that the enzyme blend preserves the quality of the essential oil extracted. The content of eugenol (70%), the major compound in the P. dioica essential oil, had a great increase in its concentration (560%). The enzyme activity analyses showed the presence of endoglucanase (0.4 U/mL), exoglucanase (0.25 U/mL), ß-glucosidase (0.19 U/mL), and invertase (135.08 U/mL). The microscopy analyses revealed changes in the morphology of fruit surface due to the enzymatic action. These results demonstrate the great potential of using enzyme blends produced by filamentous fungi from agro-industrial residues for the essential oils extraction of interest for the pharmaceutical and food industries.

Solid-state cultivation of multiple industrial strains of koji mold on different Thai unpolished rice cultivars: biotransformation of phenolic compounds and their effects on antioxidant activity.

Colored rice is abundant in polyphenols, and koji molds have potential for biotransformation. This study aimed to produce Thai-colored rice koji to study its polyphenolic biotransformation. Four industrial koji mold strains: Aspergillus oryzae 6001, A. oryzae 6020, A. sojae 7009, and A. luchuensis 8035, were cultivated on unpolished Thai-colored rice (Riceberry and Sangyod), unpolished Thai white rice (RD43), and polished Japanese white rice (Koshihikari). We discovered that koji molds grew on all the rice varieties. Methanol extracts of all rice kojis exhibited an approximately 2-fold or greater increase in total phenolic content and DPPH antioxidant activity compared to those of steamed rice. Moreover, quercetin, quercetin-3-O-glucoside, isorhamnetin-3-O-glucoside, ferulic acid, caffeic acid, protocatechuic acid, vanillic acid, (+)-catechin, and (-)-epicatechin content increased in Riceberry and Sangyod koji samples. Consequently, Aspergillus solid-state cultivation on unpolished Thai-colored rice exhibited higher functionalization than the cultivation of unpolished Thai white rice and polished Japanese white rice.

In vitro efficacy of Rosa damascena solid state fermentation liquid and water extract on skin care.

BACKGROUND: As a medicinal and food homologous plant, Rosa damascena is not only highly ornamental, but also rich in a variety of active ingredients such as polyphenols and flavonoids. It is widely used in cosmetics, food and pharmaceutical industries. OBJECTIVE: To study the in vitro efficacy of Rosa damascena solid state fermentation liquid (RDF) and water extract (RDE). METHODS: Firstly, the effect of RDF and RDE on the proliferation rate of B16F10 cells was detected by CCK-8 method, and the melanin content was measured by sodium hydroxide lysis method to evaluate the whitening effect of them. Finally, the antioxidant, anti-wrinkling and soothing effects of RDF and RDE were evaluated by biochemical methods in vitro. RESULTS: RDF and RDE within a certain concentration range (0.05%-0.5%) had no effect on the proliferation of B16F10 cells. Compared with Rosa damascena extract (RDE), RDF showed significant effects on bleaching, antioxidant, anti-wrinkling and soothing, among which 0.5% RDF showed the best effect. CONCLUSION: Both RDF and RDE at a certain concentration have effect on skin care in vitro, but the effect of RDF is more significant than that of RDE.

Adhesive solid-state fermentation producing Aspergillus niger conidia on stainless-steel dixon ring supports.

An adhesive solid-state fermentation (adSSF) mode was developed to produce Aspergillus niger conidia, which used a stainless-steel Dixon ring as the support and water-retaining adhesive to load nutritional media on its surface. To obtain high conidia yields, the components of the water-retaining adhesive were screened, optimized by single-factor optimization and response surface methodology, and the optimal dosages of the main components were: wheat bran powder 0.023 g·cm-3bed, cassava starch 0.0022 g·cm-3bed, and xanthan gum 0.0083 g·cm-3bed. The experimentally tested conidia yield was 4.2-fold that without water-retaining adhesive but was 3.7% lower than the maximum yield predicted by the model. The observed double-side growth of A. niger on the Dixon ring supports improved space utilization of the fermentation bed, and the void fraction can increase with the shrinkage of the gel layer. In 1.6 L tray reactors with three-point online temperature monitoring, the inner-bed temperature of adSSF was at most 4 °C lower than the adsorbed carrier solid-state fermentation (ACSSF) mode, and the conidia yield was 1.68 × 108 conidia.cm-3bed, 61.5% higher than that of the ACSSF bed at the same time, but when the fermentation time was extended to 168 h, the conidia yield of the adSSF bed and ACSSF bed were close to each other. The results revealed that the high voidage of the adSSF bed was the main reason for low bed temperature, which can benefit the inner-bed natural convection and water evaporation.

Unveiling a Microexon Switch: Novel Regulation of the Activities of Sugar Assimilation and Plant-Cell-Wall-Degrading Xylanases and Cellulases by Xlr2 in Trichoderma virens.

Functional microexons have not previously been described in filamentous fungi. Here, we describe a novel mechanism of transcriptional regulation in Trichoderma requiring the inclusion of a microexon from the Xlr2 gene. In low-glucose environments, a long mRNA including the microexon encodes a protein with a GAL4-like DNA-binding domain (Xlr2-α), whereas in high-glucose environments, a short mRNA that is produced encodes a protein lacking this DNA-binding domain (Xlr2-ß). Interestingly, the protein isoforms differ in their impact on cellulase and xylanase activity. Deleting the Xlr2 gene reduced both xylanase and cellulase activity and growth on different carbon sources, such as carboxymethylcellulose, xylan, glucose, and arabinose. The overexpression of either Xlr2-α or Xlr2-ß in T. virens showed that the short isoform (Xlr2-ß) caused higher xylanase activity than the wild types or the long isoform (Xlr2-α). Conversely, cellulase activity did not increase when overexpressing Xlr2-ß but was increased with the overexpression of Xlr2-α. This is the first report of a novel transcriptional regulation mechanism of plant-cell-wall-degrading enzyme activity in T. virens. This involves the differential expression of a microexon from a gene encoding a transcriptional regulator.

Optimization and characterization of laccase (LccH) produced by Hexagonia hirta MSF2 in solid-state fermentation using coir pith wastes (CPW).

The accumulation of coir pith waste, a byproduct of coconut husk processing, poses environmental and logistical challenges. An innovative and sustainable solution involves using coir pith as a substrate for solid-state fermentation (SSF). In SSF, coir pith can be converted into valuable products, such as enzymes, organic acids, and bioactive compounds. The present study aimed to evaluate laccase production by Hexagonia hirta MSF2 through SSF using the coir pith waste as substrate. Physico-chemical parameters like moisture, pH, temperature, C source, N source, and CuSO4 concentrations were pre-optimized, and optimized through RSM. Laccase activity of 1585.24 U g-1 of dry substrate was recorded by H. hirta MSF2 on coir pith containing 1 % C source, 0.5 % N source, 0.25 mM of CuSO4 concentration, moisture content of 75 % at pH 4.6 and temperature 28 °C. Subsequently, the enzyme extraction parameters including, extraction buffer, mode of extraction, and temperature were optimized. The molecular weight of laccase was 66 kDa as observed by SDS-PAGE and native-PAGE. The optimum activity of partially purified laccase was achieved at 40 °C, and pH 4.0. Increasing salt concentration and use of different inhibitors affected the laccase activity. Organic solvents like dimethyl sulphoxide (DMSO) and methanol, and metal ions like BaCl2, CaCl2, CuSO4, and MnCl2 stimulated the laccase activity. Hence, coir pith used in SSF offers a dual benefit of waste management and enzyme synthesis through an eco-friendly and cost-effective approach.

Bioprocess optimization for food-grade cellulolytic enzyme production from sorghum waste in a novel solid-state fermentation bioreactor for enhanced apple juice clarification.

Transforming global agricultural waste into eco-friendly products like industrial enzymes through bioconversion can help address sustainability challenges aligning with the United Nations' Sustainable Development Goals. Present study explored the production of high-yield food-grade cellulolytic enzymes from Trichoderma reesei MTCC 4876, using a novel media formulation with a combination of waste sorghum grass and cottonseed oil cake (3:1). Optimization of physical and environmental parameters, along with the screening and optimization of media components, led to an upscaled process in a novel 6-L solid-state fermentation (SSF)-packed bed reactor (PBR) with a substrate loading of 200 g. Saturated forced aeration proved crucial, resulting in high fungal biomass (31.15 ± 0.63 mg glucosamine/gm dry fermented substrate) and high yield cellulase (20.64 ± 0.36 FPU/g-ds) and xylanase (16,186 ± 912 IU/g-ds) production at an optimal airflow rate of 0.75 LPM. The PBR exhibited higher productivity than shake flasks for all the enzyme systems. Microfiltration and ultrafiltration of the crude cellulolytic extract achieved 94% and 71% recovery, respectively, with 13.54 FPU/mL activity in the cellulolytic enzyme concentrate. The concentrate displayed stability across wide pH and temperature ranges, with a half-life of 24.5-h at 50 °C. The cellulase concentrate, validated for food-grade safety, complies with permissible limits for potential pathogens, heavy metals, mycotoxins, and pesticide residue. It significantly improved apple juice clarity (94.37 T%) by reducing turbidity (21%) and viscosity (99%) while increasing total reducing sugar release by 63% compared with untreated juice. The study also highlighted the potential use of lignin-rich fermented end residue for fuel pellets within permissible SOx emission limits, offering sustainable biorefinery prospects. Utilizing agro wastes in a controlled bioreactor environment underscores the potential for efficient large-scale cellulase production, enabling integration into food-grade applications and presenting economic benefits to fruit juice industries.

Purification and biochemical characterization of α- amylase from Aspergillus tamarii MTCC5152.

The purification and biochemical characterization of the extracellular alpha amylase from A.tamarii MTCC5152 were studied. The combined use of ion exchange and gel filtration chromatographic methods were used for purification studies. The specific activity was significantly increased (33 fold) and 19.41 fold purification of the enzyme α-amylase with 24% yield was achieved. The enzyme had an optimal pH of 6.5 and exhibited its highest activity at 55 °C. It is active over a wide range of pH 5-7 at room temperature. The enzyme is relatively stable in the temperature range of 25-35 °C for a period of 4 h hence, more suitable for industrial applications. Km and Vmax value of the enzyme was to be 5.882 mg/mL and 0.803 mg/mL/min respectively using starch as the substrate. The purified protein showed a single band on native and SDS PAGE and the molecular weight was found to be 31 kDa. Starch zymogram also revealed one clear zone of amylolytic activity which corresponded to the band obtained with native PAGE and SDS/PAGE. The characterization studies showed that the enzyme activity is inhibited by Ca2+, Mn2+, Hg2+, Fe2+.

Chitinase induction in Trichoderma harzianum: a solid-state fermentation approach using shrimp waste and wheat bran/commercial chitin for chitooligosaccharides synthesis.

This study innovatively employed solid-state fermentation (SSF) to evaluate chitinase induction in Trichoderma harzianum. Solid-state fermentation minimizes water usage, a crucial global resource, and was applied using shrimp waste chitin and a mixture of commercial chitin with wheat bran as substrates. Shrimp waste and wheat bran were pretreated and characterized for SSF, and the fungus's utilization of the substrates was assessed using spectrophotometric and microscopic methods. The resulting enzymes' ability to produce chitooligosaccharides (COS) mixtures was studied. Wheat bran/commercial chitin demonstrated superior performance, with a 1.8-fold increase in chitinase activity (76.3 U/mg protein) compared to shrimp waste chitin (41.8 U/mg protein). Additionally, the COS mixture obtained from wheat bran/commercial chitin showed a higher concentration of reducing sugars, reaching 87.85 mM, compared to shrimp waste chitin (14.87 mM). The COS profile from wheat bran/commercial chitin included monomers to heptamers, while the profile from shrimp waste chitin was predominantly composed of monomers. These results highlight the advantages of SSF for chitinase induction and COS production in T. harzianum, offering potential applications as dietary fiber, antioxidants, and antimicrobial agents. The findings contribute to by-product valorization, waste reduction, and the sustainable generation of valuable products through SSF-based enzyme production.

Valorization of sugarcane bagasse for high-yield production of laccase through Aspergillus terreus for effective azo dye decolourization.

Synthetic dyes such as azo dyes are significant pollutants in the wastewater released from various textile industries. The low biodegradability and production from synthetic sources with high shelf life make azo dyes a challenging material for degradation. This study used chemically mutated Aspergillus terrus in the laccase production under solid-state fermentation using sugarcane bagasse. Initially, the wild-type strain produced a laccase activity of 4.12 U/mL. Later, the alkaline pretreatment of sugarcane bagasse showed a significant increase in laccase activity by 38.9%. Further, random mutagenesis treatment with 100 mM EMS generated a hyper laccase-producing strain with a 2.3-fold increment in laccase activity compared to the wild-type strain. The enzyme displayed optimal activity at pH 6.5 and 35 °C. The metal ions such as Fe3+ (29.4 U/mL), Fe2+ (20.8 U/mL) and Cu2+ (18.05 U/mL) showed positive effects on laccase activity. The crude laccase was used to bioremediate Congo red, a prominent azo dye used in textile and pharmaceutical industries. The preliminary studies with a crude enzyme displayed 68.86% dye decolourization after 24 h of incubation. Additionally, with Taguchi orthogonal array optimization experiments, the maximal dye decolorization of 78.24% was achieved by maintaining crude enzyme concentration (20 U), dye concentration (25 mg/L) and pH 4.5.

Production of milk-coagulating protease by fungus Pleurotus djamor through solid state fermentation using wheat bran as the low-cost substrate.

Proteases are enzymes that hydrolyze peptide bonds present in proteins and peptides. They are widely used for various industrial applications, such as in the detergent, food, and dairy industries. Cheese is one of the most important products of the dairy industry, and the coagulation stage is crucial during the cheese-making process. Enzymatic coagulation is the most common technique utilized for this purpose. Microbial enzymes are frequently used for coagulation due to their advantages in terms of availability, sustainability, quality control, product variety, and compliance with dietary and cultural/religious requirements. In the present study, we identified and subsequently characterized milk coagulant activity from the fungus Pleurotus djamor PLO13, obtained during a solid-state fermentation process, using the agro-industrial residue, wheat bran, as the fermentation medium. Maximum enzyme production and caseinolytic activity occurred 120 h after cultivation. When the enzyme activity against various protease-specific synthetic substrates and inhibitors was analyzed, the enzyme was found to be a serine protease, similar to elastase 2. This elastase-2-like serine protease was able to coagulate pasteurized whole and reconstituted skim milk highly efficiently in the presence and absence of calcium, even at room temperature. The coagulation process was influenced by factors such as temperature, time, and calcium concentration. We demonstrate here, for the first time, an elastase-2-like enzyme in a microorganism and its potential application in the food industry for cheese production.

Upgrading the Bioactive Potential of Hazelnut Oil Cake by Aspergillus oryzae under Solid-State Fermentation.

Hazelnut oil cake (HOC) has the potential to be bioactive component source. Therefore, HOC was processed with a solid-state fermentation (SSF) by Aspergillus oryzae with two steps optimization: Plackett-Burman and Box-Behnken design. The variables were the initial moisture content (X1: 30-50%), incubation temperature (X2: 26-37 °C), and time (X3: 3-5 days), and the response was total peptide content (TPC). The fermented HOC (FHOC) was darker with higher protein, oil, and ash but lower carbohydrate content than HOC. The FHOC had 6.1% more essential amino acid and benzaldehyde comprised 48.8% of determined volatile compounds. Fermentation provided 14 times higher TPC (462.37 mg tryptone/g) and higher phenolic content as 3.5, 48, and 7 times in aqueous, methanolic, and 80% aqueous methanolic extract in FHOC, respectively. FHOC showed higher antioxidant as ABTS+ (75.61 µmol Trolox/g), DPPH (14.09 µmol Trolox/g), and OH (265 mg ascorbic acid/g) radical scavenging, and α-glucosidase inhibition, whereas HOC had more angiotensin converting enzyme inhibition. HOC showed better water absorption while FHOC had better oil absorption activity. Both cakes had similar foaming and emulsifying activity; however, FHOC produced more stable foams and emulsions. SSF at lab-scale yielded more bioactive component with better functionality in FHOC.